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Elevated Lactate Dehydrogenase Values in Patients with Pneumocystis carinii Pneumonia
Elevated Lactate Dehyd~enase Values in Patients with Pneumocyst,s carinii Pneumonia* Robert L. Smith, M.D., F.C.C.P.;t Carolyn S. Ripps, M.D.;* and Milena L. Lewis, M.D.§
We investigated the source of elevated serum lactate dehydrogenase (LDH) levels in seven patients with PneumocystiB carinii pneumonia (PCP) by analyzing blood and bronchoalveolar lavage (BAL) albumin (ALB) and LDH, with isoenzyme fractionation. Four patients with non-PCP lung disease served as control subjects. In PCP patients, BAL LDH was sixfold higher, and BAL ALB, fourfold higher than in the non-PCP patients. The increased LDBI ALB in BAL as compared to serum, in addition to a BAL isoenzyme pattern characteristic of lung, suggest that BAL
LDH arises from a pulmoDary source. We postulate that the high correlation obsened between BAL and serum LDH (r=O.93, p
Elevated serum lactate dehydrogenase (LDH) levels have been observed in association with Pneumocystis carinii pneumonia (PCP). The LDH levels have also been noted to rise and fall in parallel with disease activity 1-3 In patients with acquired immunodeficiency syndrome (AIDS), fractionation of elevated serum LDH level has revealed the isomorphic pattern: the relative amounts and distribution of the five isoenzymes are essentially the same as those found in normal serum.v' Elevated serum LDH in an isomorphic pattern has also been noted in a variety of lymphoproliferative disorders," By analogy previous investigators have speculated that elevated serum LDH levels in patients with P carinii pneumonia may be related to lymphocytic infiltration of the pulmonary interstitium. 1 We investigated the elevated serum LDH levels in patients with PCP by measuring enzyme activities in bronchoalveolar lavage (BAL) flUid. The objectives of the study were to ascertain whether elevated serum LDH levels associated with P carinl' infection arises from a pulmonary source; relate lavage fluid LDH to BAL cell populations; and analyze and relate LDH isoenzyme patterns in serum and BAL, respectively
PATIENTS AND METHODS
-From the D~ent of Medicine, Pulmonary Diseue Section. and_Department of PatholoD NewYork Veterans Administration Medical Cente!; NewYork. tInstructor In Medicine. *ClinIcal Associate Profelsor of Patholol)C IClinical Auiltant Profeuor of MedicJne. ThiJ stud}' wu IUpported In part by a grant &om the Stony \\bIdHerbert Fund. ManUlCript receivedJuly 21; revfafon accepted October 19
a.pnrat f"IquatI: Dr: SWI"" NIM Yori Vl AlItlIcal CIftMr, 408 F'm
Awn.", NIW YOti 10010
The study group included seven male patients at risk for AIDS, who presented with dyspnea, fever, and bilateral interstitial in81trates on chest x-ray 81m. Mean room air PaO I was 56.3 mm Hg (± 2.24 SEM); no patient was receiving more than 50 percent 0 1 at the time of stud~ and none was endotracheally intubated. Allhad a history of intravenous drug abuse. Their mean age was 40 years (range 28 to 54);four of seven were smokers. All patients underwent 8beroptic bronchoscopy within three days of admission and were found to have P carinU as a sole pulmonary pathogen in either lavage fluid or transbronchial biopsy The control group included four patients. Three were patients at risk for AIDS, who similarly presented with dyspnea, fever, and pulmonary infiltrates, and were suspected of having PeE All were intravenous drug abusers. None of these three had opportunistic organisms demonstrated at bronchoscopy; mild interstitial fibrosis was present in all threebiopsy specimens. The fourth control patient had previously documented sarcoidosis. Mean PaO I fOr the control group was 78 mm Hg (±6.8 SEM), not significantly different from that in the pcp group. Mean age was 42 years (range 36 to 48} Three of fourwere smokers. After obtaining infOrmed consent, BAL wasperformedthrough a fiberoptic bronchoscope gentlywedged in either a lingular or right
middle lobe subsegmental bronchus. Normal saline solution was instilled, in 30 ml aliquots. to a total of 120 ml, and Immediately upfrated manually with a syringe; in all casea. 50 to 70 ml of fluid were recovered. The collectedlavale material was pooled, strained through a singlela)'er of IUJ1lcal gauze, then centrifuged at 500 g fOr ten minutes. The resultant cell pellet wu washed and resuspended in Hanb balanced salt solution. 1bta1 ce1lJ werecountedin a hemocytomete!; and ddFerential countl peri»rmed on Wrilhtstained, cytocentl'lfuled preparatfODL No Iavap apecimen bad more than ICIIlt red cellspresenton eellcount. The SAL IUpernatant, and a apecimen of serum obtained at the time of bronch~ were stored at 4OC. The activity of LDH fa known to remain stable fOr at leut ten dayl when stored in thia wa,' Auaya were peri»rmed between flw and ten days after bronchoacop)t After WU'IIlfDI to room temperature, the SAL supernatant was concentrated 25-fold throup an Amfcon YM CHEST I IS I S I MAV. 1..
117
Table I-BAL Cell Counta, LDH and Albumin; Serom LDH and Albumin BAL
BAL Case No.
Total Cells
x lOS
pcp cases 1 2 3 4 5 6
7
Mean SEM Non-PCP cases 1 2 3 4 Mean SEM p.
Macs
Lyms
Neuts
Eos
%
%
%
%
LDH mIU/ml
29 24 91 88 65 53.6 11.7
38 31 65 24 0 7 29 27.7 8.0
44 7 0 52 9 5 5 17.4 8.0
2 2 6 0 0 0 1 1.6 0.8
161.3 26.6 84.0 122.2 114.6 48.4 45.2 86.0 18.5
97 100 95 89 95.3 2.3 <0.05
3 0 5 7 3.8 1.5 <0.05
0 0 0 4 1.0 1.0 NS
0 0 0 0 0 0 NS
9.8 10.2 23.0 15.4 14.6 3.1 <0.01
16
12 84 29 4 6.3 15 15.6 23.7 10.5
60
18 24 53 6.3 25.3 9.9 NS
ALB mg/ml 0.44 0.24 0.40 0.25 0.13 0.13 0.27 0.266 0.045 0.04 0.04 0.06 0.10 0.06 0.01 <0.01
SERUM LDH/ALB mIU/mg
LDH mIU/ml
366.5 110.7 210.0 489.0 881.2 372.0 167.6 371.0 98.7
899 475 413 789 853 504 475 630 78
245.0 255.0 383.3 154.4 259.4 47.1 NS
217 178 334 265 249 34 <0.01
ALB mg/ml
LDH/ALB mIU/mg
2.2
39.1 17.0 10.6 27.2 38.8 14.8 17.0 23.5 4.4
35 39 32 35 35.3 1.4 NS
6.2 4.6 10.4 7.6 7.2 1.2 <0.02
23 28
39 29 22 34
28 29
·Comparing mean values for PCP and non-PCP cases. membrane. Albumin was measured in a centrifugal analyzer using bromcresol green binding. Total LDR was also determined in the centrifugal analyzer, using \\brthington LDU (lactate-pyruvate) reagent The LDU isoenzymes were separated on agarose gel; quantitation was performed by scanning at 600 nm, in a densitometer. The concentration of BAL proteins was expressed as the concentration in the original lavage fluid. A sample of venous blood, drawn at the time of bronchosco~ was also assayed for albumin, total LOR activi~ and isoenzyme fractionation. All data are expressed as mean ± SEM. Group means were compared by the unpaired Students t-test. Linear regressions were calculated by the method of least squares. RESULTS
Mean BAL LDH level was sixfoldhigher, and mean BAL albumin was fourfold higher in the PCP patients, as compared to control subjects (p<0.01 for both comparisons, Table 1; Fig. 1). Mean serum LDH levels were twofold to threefold higher in patients with PCP than in control subjects (p<0.01, Table 1). None of 0.6
200
..-
E <, :::>
120
:I:
9
80
~
40
],
•
160
••
..
,... -J\r non-PCP (n-4)
•
+ PCP (n-7)
-
~-Ir
ao~
0
0
••
0
-db non-PCP (n-4)
FIGURE 1. Comparisons for non-PCP cases (open
+ PCP
0.5 0.4
~ ~c
0.3
I:
0.2
3' to
0.1
Z
<,
!
0.0
(n-7)
circles) and PCP
cases (cloaed circla) of BAL LDR on the left, and BAL albumin on the right Bothcomparisons are significantly different at p
level.
118
the PCP patients had significant nonpulmonary pathologic findings, (ie, evidence of hepatic or muscle disease, hemolysis, or lymphoma) to account for elevations of serum LDH values. The BAL total and differential cell counts are shown in Table 1. Total BAL cell counts were similar in patients and control subjects, with a wide range found in both groups. However, patients with PCP demonstrated a Significantly increased mean percentage of lymphocytes, and a correspondingly decreased proportion of macrophages compared to control subjects. Although BAL neutrophil counts tended to be higher in the PCP patients, the mean values did not differ significantly between the groups. A significant linear regression was calculated between BAL albumin and percent lymphocytes in BAL (r=O.909, p
1200
60 o
"E 1000
<, ::)
!
:I:
9 :2
::)
0::: 1£.1
(I)
non PCP n-4 n-7
• + pcp
•
800
~I~ ~
::)
0::: lIJ
600
(I)
8
200
o
r-0.93
p (0.001
40
80
120
160
200
SAL LDH (mIU/ml)
2. Relation between serum total LOR and SAL total LOR
vascular compartment Rathel; the elevated serum LDH level observed in patients with P carinii infection may result from bacldlow of pulmonary-derived LDH. Fractionation of the BAL LDH revealed increases in LDH isoenzyme fractions 3, 4, and 5, with relatively low levels of LDH 2 (Fig 3). This pattern was seen in all cases, both PCP and non PCP subjects, and was independent of BAL cell populations. The pattern of the LDH isoenzymes in BAL most closely corresponds to that previously described for pulmonary tissue." On the other hand, fractionation of serum LDH in both the PCP and control groups revealed the isomorphic, ie, normal, serum pattern in all cases (Fig 3), showing LDH 2 level greater than LD H 1 level, with relatively lower levels ofLDU 3,4, and 5. To clarify the discrepancy between these isoenzyme patterns, we compared the ratio of each isoenzyme/ albumin in BAL to the corresponding ratio in serum. As can be seen in Figure 4 for the seven patients with PC~ the BAL to serum LDU/albumin ratio was significantly greater for isoenzymes 3, 4, and 5, than the corresponding ratio for isoenzymes 1 and 2 (p<0.01). At pH 7.4, LDH 1 is the most anionic of 50
. - . +PCP (!SEU) 0 - ·0 non-PCP
M 40 .....,
~
e
30
~
9
<,
0
20
!!! :I:
9
10
\\
\~ 0 .....
1
0----------------, " "' IV V !I III IV V SERUM LDH ISOENzntES
BAL. LDH ISOENlYMES
3. The LOR isoenzyme patterns for serum and BAL. Each isoenzyme is expressed as a percent of the total LOR. The serum pattern isomorphic in both pcp and non-PCP subjects; the BAL is that of lung in both PCP and non-PCP subjects. FICURE
30
91~
20
-c m
10
-J
O----~--....a..---......L...----L..----'
FIGURE
H
40
<,
400
values.
.
50
0
111
IV
V INCRfASINC POSITNE CHARGE
NECAlNE CHARGE
FICURE 4. The ratio ofBAL LOHlalbumin to serum LOHlalbumin for each isoenzyme. This ratio increases with increasing positive charge of the isoenzymes, showing greater retention of cationic isoenzymes in the airspaces. A6teri8b indicate that the ratios for LOR isoenzymes 3, 4 and 5 are significantly greater than the ratio for isoenzymes 1 and 2 (p
the isoenzymes, while LDH 5 is the most cationic. 8 The BAL LDU/albumin to serum LDU/albumin ratio was significantly higher for isoenzymes 4 and 5, than for isoenzyme 3 (P<0.021 indicating increasing retention in the air spaces with increasing positive charge. DISCUSSION
This study was designed to investigate the source of the elevated serum LDU levels reported in patients with P carinii infection. l -3 We demonstrated a sixfold increase in the BAL LDH levels of patients with PCP compared to that in our non-PCP control subjects. Begin et al9 have reported BAL LD H levels in normal subjects ranging from 6 to 10 mIU/ml; BAL LDH levels in PCP patients averaged ten times that reported for normal subjects. In our control subjects, BAL LDU levels ranged from 10 to 23 mIU/ml. None of these control subjects proved to have P carinii or other pulmonary infections, but the presence of pulmonary disease was suggested by history blood gas abnormalities, and transbronchial biopsy specimens showing mildly increased interstitial cellularity and fibrosis. These findings may account for the increased BAL LDH levels in our non-PCP patients, as compared to normal subjects. Elevated BAL LDH levels are usually considered to reflect cell damage, although it is not clear which particular cell in pulmonary tissue is the source. 1G-13 When homogenates of human pulmonary tissue are assayed for LDH, a particular and identifying isoenzyme pattern is found. The lung pattern is characterized by proportional increases in isoenzymes 3, 4, and 5, compared to the isoenzyme pattern in normal human serum." In the present stud~ isoenzyme fractionation ofBAL LDH in PCP patients, with markedly increased total BAL LDU levels, as well as in our CHEST I 93 I 5 I MAY. 1888
..
control subjects, revealed a pattern that closely matched the isoenzyme pattern described for human lung tissue. This pattern was noted to be independent of BAL cell populations. In particular, no relation was seen between the degree of BAL lymphocytosis and either the total BAL LDH levels or the LDH isoenzyme pattern. Patients with Pneumocqstis in the present study also demonstrated increased BAL albumin. In normal subjects, the range of BAL albumin has been reported as 0.04 to 0.06 mglm1.9•14 Lavage fluid albumin was found to be fourfold higher in patients with P carinii infection, whereas BAL albumin in our non-PCP patients was in the normal range. Increased levels of BAL albumin indicate increased permeability of the ACM, and have been reported in patients with AIDS and Pneumocystis infection. 15 ,16 However, increased ACM permeability does not necessarily imply detectable cellular damage. For example, in a study of oxygen toxicity by Griffith and co-workers, 14 increased BAL albumin was detected without measurable BAL LDH. In the experimental rat model of steroidinduced pneumocystosis, increased permeability of the ACM, evidenced by leakage of horseradish peroxidase, is an early pathologic finding, and precedes cellular degeneration of type 1 pneumocytes.Fr'" In our studg the presence of both elevated BAL albumin and BAL LDH levels in the Pneumocystis patients suggests increased ACM permeability and cellular damage, respectively In the present study in both PCP patients and nonPCP control subjects, the BAL LDH/albumin ratio was significantly higher than the same ratio in serum. This observation suggests that the lavage fluid LDH originates in pulmonary tissue, rather than reflecting transudation from blood to alveoli. Since LDH (MW 140,000 daltons) is a larger molecule than albumin (MW 69,000 daltons) an increased BAL LDH/albumin ratio, as compared to serum, cannot be explained by leakage of LDH from blood to airspaces, unless an alveolar concentrating mechanism for LDH is postulated. On the basis of molecular size, one would predict a BAL LDH/albumin ratio lower than that in serum if leakage from the blood compartment was the sole source of airspace LDH. On the other hand, the elevated serum LDH level previously reported in pcp patients, and observed in the present group, could arise from bacldlow of pulmonary-derived LDH into the circulation. Presumabl~ a more permeable alveolocapillary membrane (ACM1 evidenced by increased BAL albumin, would permit leakage of abnormally high LDH present in the airspaces. The increased BAL LDHlalbumin ratio, taken together with the strongcorrelation observed in the PCP patients between BAL and serum LDH level, leads us to postulate that increased LDH in the ainpaces 110
flows back across a more permeable ACM and gives rise to the elevations of serum LDH level seen in Pneumocystis pneumonia. An analogous situation is seen in sarcoidosis, where increased amounts of IgG produced at pulmonary sites of disease are considered responsible for the observed serum hypergammaglobulinemia." A correlation between BAL and serum LDH level does not exclude the possibility that both the airspaces and blood are functioning as two independent compartments, each compartment responding to diverse insults secondary to the infection. This situation could give rise to independent but proportional elevations of BAL and serum LDH level, respectively We think this possibility is unlikely since the organism is primarily a pulmonary pathogen; in the vast majority of cases, the infection does not directly involve organs other than lung. 20.21 In the present study no patient had obvious extrapulmonary organ pathologic conditions to account for an independent elevation of serum LDH level. Alternatively the elevation of serum LDH level could be due to an indirect effect of P carinii infection, such as hypoxemia. A significant inverse correlation was found between °a02 and serum LDH levels, however, both may reflect severity of the infection and are not necessarily causally related. Although increased serum LDH is found in alveolar proteinosis and some cases of desquamative interstitial pneumonitis, both associated with varying degrees of hypoxemia, it is not usually seen in cases of adult respiratory distress syndrome. 22,23 In the present study multivariate analysis including Pa02 , did not significantly improve the correlation between serum and BAL LDH. We reason, therefore, that elevated serum LDH level in P carinii-infected patients probably arises from elevated LD H level in the airspaces. If the elevated serum LDH in patients with PCP originates in lung, then the isoenzyme patterns of BAL and serum might be expected to be similar, as has been reported in pulmonary infarction. 7 In models ofprotein flux across the pulmonary capillary endothelium, the membrane is seen as having equivalent pores that sieve proteins by molecular size.i4-27 H sieving by molecular size pertained to the complete alveolocapillary membrane, we should have observed similar LDH isoenzyme patterns-in both BAL and serum, since the five isoenzymes of LDH are approximately equal in size and molecular weight Instead, in the present stud~ the BAL LDH isoenzyme pattern closely matched that of human lung tissue, with elevations of cationic isoenzymes 3, 4, and 5 relative to isoenzyme 2, whereas that in the serum was the usual isomorphic pattern found in normal individuals, with an elevation of isoenzyme 2 relative to 3, 4, and 5. If the postulated bacldlow of LDH from airspaces EI..-d LOH Valu.. In pcp (smith, Rip!», LewI.)
to blood accounts for the elevated serum LOB level in PCP patients, then the discrepancy between the LOB isoenzyme pattern in BAL and serum of such patients needs to be clarified. Figure 4 presents the ratio of each LDU isoenzyme/ albumin in BAL related to that in serum for our patients with P carinii infection. From this comparison, it appears that the more positively charged isoenzymes are preferentially retained in the lung. The degree of backHow is apparently least for the cationic isoenzymes, LDU 3, 4 and 5, and greater for LDH 1 and 2, the anionic isoenzymes. These findings suggest that the alveolocapillary membrane sieves molecules on the basis of electrical charge, showing less permeability to the cationic LOH isoenzymes. A number of animal studies have explored the effects of charge on solute movement across the pulmonary microvascular barrier, as well as through the alveolar epithelium. 8 •24.28-30 In a rat model of permeability pulmonary edema, Brody et al3I have demonstrated that cationic ferritin, unlike anionic ferritin, does not penetrate the ACM. Two of three membrane components were shown to be negatively charged and to bind cationic molecules. In our study while increased BAL albumin reflects increased ACM permeability in P carinii infection, the finding of relative increases of LOU/albumin ratios for the cationic isoenzymes indicates that sieving on the basis of charge is maintained. This preferential retention of cationic isoenzymes could account for the isomorphic LOU pattern observed in serum. In summary P carinii infection is associated with increased levels of total BAL LOH, as well as increased BAL albumin. The higher LDU/albumin ratio in BAL as compared to serum, in addition to a BAL isoenzyme pattern of LDU characteristic of lung tissue, suggest that BAL LOU derives from a pulmonary source. BackHow of elevated BAL LDU through a more permeable alveolocapillary membrane may account for the elevated serum LOU level observed in Pneumocystis patients. Analysis of the relative ratios of LDU isoenzymes in BAL and serum indicates that cationic isoenzymes 3, 4, and 5, are preferentially retained in the air spaces. Thus, despite increased permeability the ACM continues to function as a sieving membrane, discriminating between proteins of equal molecular weight on the basis of electrical charge. Selective backHow of elevated BAL LOH, in particular isoenzyme 2, may be responsible for the isomorphic LD H pattern seen in the serum of patients with PCE REFERENCES 1 Silverman BA, Rubinstein A. Serum lactate dehydrogenase levels in adults and children with acquired immune deficiency syndrome (AIDS) and AIDS-related complex: possible indicator
2
3
4 5
of B cell lymphoproliferation and disease activi~ Am J Med 1985; 78:728-36 Garay SM, Greene J. Diagnostic and prognostic implications of elevated serum lactate dehydrogenase (LDH) in AIDS-related PneumocyBtiB carin" pneumonia (PCP) [abstract]. Am Rev Respir Dis 1987; 135 (suppl):172 Smith RL, EISadr ~ Lewis ML. Correlation ofbronchoalveolar lavage oell populations with clinical severity of P carin" pneumonia. Chest (in press) Jacobs DS, Robinson RA, Clark GM, Thcker JM. Clinical signi&cance of the isomorphic pattern of the isoenzymes of serum lactate dehydrogenase. Ann Clin Lab Sci 1977; 7:411-21 Ferrais AM, Guintini ~ Gaetani Glf: Serum lactate dehydrogenase as a prognostic tool for non-Hodgkins lymphomas. Blood
1979;54:928-32
6 Wacker WEC, Ulmer DD, Vallee BL. Metalloenzymes and myocardial infarction. N Engl J Med 1~; 255:449-56 7 Papadopoulos NM. Clinical applications of lactate dehydrogenase isoenzymes. Ann Clio Lab Sci 1977; 7:506-10 8 Parker JC, Gilchrist S, Cartledge J[ Plasma-lymph exchange and interstitial distribution volumes of charged macromolecules in the lung. J Appl Physiol 1985; 59:1128-36 9 ~gin R, Cantin A, Berthiaume t Boileau R, Bisson G, Lamoureaux G, et al. Clinical features to stage alveolitis in asbestos workers. Am J Indust Med 1985; 8:521-36 10 Henderson RF, Rebar AH, DeNicola DB, Henderson TR, Damon EG. The use of pulmonary washingsas a probe to detect lung injul")t Chest 1981; 80 (suppl):12-14S 11 Block ER, Jawaharlal M~ Sheridan NE Effect of oxygen and endotoxin on lactate dehydrogenase release, 5-hydroxytryptamine uptake and antioxidant enzyme activities in endothelial cells. J Cell Physioll985; 122:240-48 12 Ody C, Junod AF. Direct toxic effects of paraquat and oxygen on cultured endothelial cells. Lab Invest 1985; 52:77-84 13 Nelson S, Laughon BE, Summer WR, Eckhaus MA, Bartlett JG, Jakab GJ. Characterization of the pulmonary inBammatory response to an anaerobic bacterial challenge. Am Rev Respir Dis 1986; 133:212-17 14 Griffith DE, Holden WE, Morris JF, Kim LK, Krishnamurthy Gl: Effects of common therapeutic concentrations of oxygen on lung clearance of 99mTc DTPA and bronchoalveolar lavage albumin concentration. Am Rev Respir Dis 1986; 134:233-37 15 Young KR, Rankin )A, Naegel G~ Paul ES, Reynolds H~ Bronchoalveolar lavage cells and proteins in patients with the acquired immunodeficiency syndrome. Ann Intern Med 1985; 103:522-33 16 Spragg RG, Smith RM, Harrell JH. Evidence of lung inflammation in patients with AIDS and E carinii pneumonia [abstract]. Am Rev Respir Dis 1987; 135 (suppl):I69 17 Yoneda K, Walzer PD. Mechanism of pulmonary alveolar injury in experimental Pneumocystis carinii pneumonia in the rat. Br J Exp Patholl981; 62:339-46 18 Walzer PD, Powell RD, Yoneda K, Rutledge ME, Milder JE. Growth characteristics and pathogenesis of experimental Pneumocystis carinii pneumonia. Infect Immun 1980; 27:928-37 19 Rankin)A, Naegel G~ Shrader CE, Matthay RA, Reynolds flY: Airspace immunoglobulin production and levels in bronchoalveolar lavage fluid of normal subjects and patients with sarcoidosis. Am Rev Respir Dis 1983; 127:442-48 20 Coulman CU, Greene I, Archibald RWR. Cutaneous pneumacystosis. Ann Intern Med 1987; 106:396-98 21 Murray JIt: Felton C~ Garay SM, Gottlieb MS, Hopewell PC, Stover DE, et al. Pulmonary complications of the acquired immunodeficiency syndrome.• N Engl J Med 1984; 310:1682-88 22 Faling LJ, Mark EJ. A sixty-year-old man with rapidly progressive dyspnea (CPC~ N Engl J Med 1983; 308:511-19 23 Martin RJ, Rogers RM, Myers NM. Pulmonary alveolar proteinCHEST I 93 I 5 I MAY. 1988
811
osis. Am Rev Respir Dis 1978; 117:1059-62 24 Brigham KL, Parker RE, Roselli RJ, Hobson J, Harris TR. Exchange of macromolecules in the pulmonary microcirculation. Ann NY Acad Sci 1982; 384:246-64 25 Gorin AB, Hsagawa G, Hollinger M, Sperry J, Zuckerman J. Release of angiotensin converting enzyme by the lung after Pseudomonas bacteremia in sheep. J Clio Invest 1981; 68:16370 26 Gorin AB, Stewart PA. Differential permeability of endothelial and epithelial barriers to albumin flux. J Appl Physiol 1979; 47:1315-24 27 Crandall ED, Staub NC, Goldberg HS, EfIros RM. Recent developments in pulmonary edema. Ann Intern Med 1983;
99:808-22
28 Pietra GG, Sampson ~ Lanken PN, Hansen-Flaschen J, Fishman AE Thmscapillary movement of cationized ferritin in the isolated perfused rat lung. Lab Invest 1983; 49:54-61 29 Fairman R~ Miller JE, Glauser FL. The role of electrical charge interaction on normal pulmonary microvascular permeability [abstract]. Fed Proc 1982; 41:1247 30 Weaver LJ, Gleisner J, Winn R, Mansfield E, Stothert J, Hildebrandt J. Electrical potential and differences in lymphplasma ratios of molecules of similar size but differing charge [abstract]. Fed Proc 1982; 41:1246 31 Brody JS, Vaccaro CA, Hill NS, Rounds S. Binding of charged ferritin to alveolar wall components and charge selectivity of macromolecular transport in permeability pulmonary edema in rats. Cire Res 1984; 55:155-67
second Annual Symposium on Magnetic Resonance Imaging This symposium will be presented at the Ritz-Carleton Resort Hotel, Laguna Niguel, California, July 28-31. For information, contact Ms. Dawne Ryals, PO Box 920113, Norcross, GA 30092-0113 (404:641-9773).
892
Elevated LDH values In pcp (smith, RJpps, Lewis)
We investigated the source of elevated serum lactate dehydrogenase (LDH) levels in seven patients with PneumocystiB carinii pneumonia (PCP) by analyzing blood and bronchoalveolar lavage (BAL) albumin (ALB) and LDH, with isoenzyme fractionation. Four patients with non-PCP lung disease served as control subjects. In PCP patients, BAL LDH was sixfold higher, and BAL ALB, fourfold higher than in the non-PCP patients. The increased LDBI ALB in BAL as compared to serum, in addition to a BAL isoenzyme pattern characteristic of lung, suggest that BAL
LDH arises from a pulmoDary source. We postulate that the high correlation obsened between BAL and serum LDH (r=O.93, p
Elevated serum lactate dehydrogenase (LDH) levels have been observed in association with Pneumocystis carinii pneumonia (PCP). The LDH levels have also been noted to rise and fall in parallel with disease activity 1-3 In patients with acquired immunodeficiency syndrome (AIDS), fractionation of elevated serum LDH level has revealed the isomorphic pattern: the relative amounts and distribution of the five isoenzymes are essentially the same as those found in normal serum.v' Elevated serum LDH in an isomorphic pattern has also been noted in a variety of lymphoproliferative disorders," By analogy previous investigators have speculated that elevated serum LDH levels in patients with P carinii pneumonia may be related to lymphocytic infiltration of the pulmonary interstitium. 1 We investigated the elevated serum LDH levels in patients with PCP by measuring enzyme activities in bronchoalveolar lavage (BAL) flUid. The objectives of the study were to ascertain whether elevated serum LDH levels associated with P carinl' infection arises from a pulmonary source; relate lavage fluid LDH to BAL cell populations; and analyze and relate LDH isoenzyme patterns in serum and BAL, respectively
PATIENTS AND METHODS
-From the D~ent of Medicine, Pulmonary Diseue Section. and_Department of PatholoD NewYork Veterans Administration Medical Cente!; NewYork. tInstructor In Medicine. *ClinIcal Associate Profelsor of Patholol)C IClinical Auiltant Profeuor of MedicJne. ThiJ stud}' wu IUpported In part by a grant &om the Stony \\bIdHerbert Fund. ManUlCript receivedJuly 21; revfafon accepted October 19
a.pnrat f"IquatI: Dr: SWI"" NIM Yori Vl AlItlIcal CIftMr, 408 F'm
Awn.", NIW YOti 10010
The study group included seven male patients at risk for AIDS, who presented with dyspnea, fever, and bilateral interstitial in81trates on chest x-ray 81m. Mean room air PaO I was 56.3 mm Hg (± 2.24 SEM); no patient was receiving more than 50 percent 0 1 at the time of stud~ and none was endotracheally intubated. Allhad a history of intravenous drug abuse. Their mean age was 40 years (range 28 to 54);four of seven were smokers. All patients underwent 8beroptic bronchoscopy within three days of admission and were found to have P carinU as a sole pulmonary pathogen in either lavage fluid or transbronchial biopsy The control group included four patients. Three were patients at risk for AIDS, who similarly presented with dyspnea, fever, and pulmonary infiltrates, and were suspected of having PeE All were intravenous drug abusers. None of these three had opportunistic organisms demonstrated at bronchoscopy; mild interstitial fibrosis was present in all threebiopsy specimens. The fourth control patient had previously documented sarcoidosis. Mean PaO I fOr the control group was 78 mm Hg (±6.8 SEM), not significantly different from that in the pcp group. Mean age was 42 years (range 36 to 48} Three of fourwere smokers. After obtaining infOrmed consent, BAL wasperformedthrough a fiberoptic bronchoscope gentlywedged in either a lingular or right
middle lobe subsegmental bronchus. Normal saline solution was instilled, in 30 ml aliquots. to a total of 120 ml, and Immediately upfrated manually with a syringe; in all casea. 50 to 70 ml of fluid were recovered. The collectedlavale material was pooled, strained through a singlela)'er of IUJ1lcal gauze, then centrifuged at 500 g fOr ten minutes. The resultant cell pellet wu washed and resuspended in Hanb balanced salt solution. 1bta1 ce1lJ werecountedin a hemocytomete!; and ddFerential countl peri»rmed on Wrilhtstained, cytocentl'lfuled preparatfODL No Iavap apecimen bad more than ICIIlt red cellspresenton eellcount. The SAL IUpernatant, and a apecimen of serum obtained at the time of bronch~ were stored at 4OC. The activity of LDH fa known to remain stable fOr at leut ten dayl when stored in thia wa,' Auaya were peri»rmed between flw and ten days after bronchoacop)t After WU'IIlfDI to room temperature, the SAL supernatant was concentrated 25-fold throup an Amfcon YM CHEST I IS I S I MAV. 1..
117
Table I-BAL Cell Counta, LDH and Albumin; Serom LDH and Albumin BAL
BAL Case No.
Total Cells
x lOS
pcp cases 1 2 3 4 5 6
7
Mean SEM Non-PCP cases 1 2 3 4 Mean SEM p.
Macs
Lyms
Neuts
Eos
%
%
%
%
LDH mIU/ml
29 24 91 88 65 53.6 11.7
38 31 65 24 0 7 29 27.7 8.0
44 7 0 52 9 5 5 17.4 8.0
2 2 6 0 0 0 1 1.6 0.8
161.3 26.6 84.0 122.2 114.6 48.4 45.2 86.0 18.5
97 100 95 89 95.3 2.3 <0.05
3 0 5 7 3.8 1.5 <0.05
0 0 0 4 1.0 1.0 NS
0 0 0 0 0 0 NS
9.8 10.2 23.0 15.4 14.6 3.1 <0.01
16
12 84 29 4 6.3 15 15.6 23.7 10.5
60
18 24 53 6.3 25.3 9.9 NS
ALB mg/ml 0.44 0.24 0.40 0.25 0.13 0.13 0.27 0.266 0.045 0.04 0.04 0.06 0.10 0.06 0.01 <0.01
SERUM LDH/ALB mIU/mg
LDH mIU/ml
366.5 110.7 210.0 489.0 881.2 372.0 167.6 371.0 98.7
899 475 413 789 853 504 475 630 78
245.0 255.0 383.3 154.4 259.4 47.1 NS
217 178 334 265 249 34 <0.01
ALB mg/ml
LDH/ALB mIU/mg
2.2
39.1 17.0 10.6 27.2 38.8 14.8 17.0 23.5 4.4
35 39 32 35 35.3 1.4 NS
6.2 4.6 10.4 7.6 7.2 1.2 <0.02
23 28
39 29 22 34
28 29
·Comparing mean values for PCP and non-PCP cases. membrane. Albumin was measured in a centrifugal analyzer using bromcresol green binding. Total LDR was also determined in the centrifugal analyzer, using \\brthington LDU (lactate-pyruvate) reagent The LDU isoenzymes were separated on agarose gel; quantitation was performed by scanning at 600 nm, in a densitometer. The concentration of BAL proteins was expressed as the concentration in the original lavage fluid. A sample of venous blood, drawn at the time of bronchosco~ was also assayed for albumin, total LOR activi~ and isoenzyme fractionation. All data are expressed as mean ± SEM. Group means were compared by the unpaired Students t-test. Linear regressions were calculated by the method of least squares. RESULTS
Mean BAL LDH level was sixfoldhigher, and mean BAL albumin was fourfold higher in the PCP patients, as compared to control subjects (p<0.01 for both comparisons, Table 1; Fig. 1). Mean serum LDH levels were twofold to threefold higher in patients with PCP than in control subjects (p<0.01, Table 1). None of 0.6
200
..-
E <, :::>
120
:I:
9
80
~
40
],
•
160
••
..
,... -J\r non-PCP (n-4)
•
+ PCP (n-7)
-
~-Ir
ao~
0
0
••
0
-db non-PCP (n-4)
FIGURE 1. Comparisons for non-PCP cases (open
+ PCP
0.5 0.4
~ ~c
0.3
I:
0.2
3' to
0.1
Z
<,
!
0.0
(n-7)
circles) and PCP
cases (cloaed circla) of BAL LDR on the left, and BAL albumin on the right Bothcomparisons are significantly different at p
level.
118
the PCP patients had significant nonpulmonary pathologic findings, (ie, evidence of hepatic or muscle disease, hemolysis, or lymphoma) to account for elevations of serum LDH values. The BAL total and differential cell counts are shown in Table 1. Total BAL cell counts were similar in patients and control subjects, with a wide range found in both groups. However, patients with PCP demonstrated a Significantly increased mean percentage of lymphocytes, and a correspondingly decreased proportion of macrophages compared to control subjects. Although BAL neutrophil counts tended to be higher in the PCP patients, the mean values did not differ significantly between the groups. A significant linear regression was calculated between BAL albumin and percent lymphocytes in BAL (r=O.909, p
1200
60 o
"E 1000
<, ::)
!
:I:
9 :2
::)
0::: 1£.1
(I)
non PCP n-4 n-7
• + pcp
•
800
~I~ ~
::)
0::: lIJ
600
(I)
8
200
o
r-0.93
p (0.001
40
80
120
160
200
SAL LDH (mIU/ml)
2. Relation between serum total LOR and SAL total LOR
vascular compartment Rathel; the elevated serum LDH level observed in patients with P carinii infection may result from bacldlow of pulmonary-derived LDH. Fractionation of the BAL LDH revealed increases in LDH isoenzyme fractions 3, 4, and 5, with relatively low levels of LDH 2 (Fig 3). This pattern was seen in all cases, both PCP and non PCP subjects, and was independent of BAL cell populations. The pattern of the LDH isoenzymes in BAL most closely corresponds to that previously described for pulmonary tissue." On the other hand, fractionation of serum LDH in both the PCP and control groups revealed the isomorphic, ie, normal, serum pattern in all cases (Fig 3), showing LDH 2 level greater than LD H 1 level, with relatively lower levels ofLDU 3,4, and 5. To clarify the discrepancy between these isoenzyme patterns, we compared the ratio of each isoenzyme/ albumin in BAL to the corresponding ratio in serum. As can be seen in Figure 4 for the seven patients with PC~ the BAL to serum LDU/albumin ratio was significantly greater for isoenzymes 3, 4, and 5, than the corresponding ratio for isoenzymes 1 and 2 (p<0.01). At pH 7.4, LDH 1 is the most anionic of 50
. - . +PCP (!SEU) 0 - ·0 non-PCP
M 40 .....,
~
e
30
~
9
<,
0
20
!!! :I:
9
10
\\
\~ 0 .....
1
0----------------, " "' IV V !I III IV V SERUM LDH ISOENzntES
BAL. LDH ISOENlYMES
3. The LOR isoenzyme patterns for serum and BAL. Each isoenzyme is expressed as a percent of the total LOR. The serum pattern isomorphic in both pcp and non-PCP subjects; the BAL is that of lung in both PCP and non-PCP subjects. FICURE
30
91~
20
-c m
10
-J
O----~--....a..---......L...----L..----'
FIGURE
H
40
<,
400
values.
.
50
0
111
IV
V INCRfASINC POSITNE CHARGE
NECAlNE CHARGE
FICURE 4. The ratio ofBAL LOHlalbumin to serum LOHlalbumin for each isoenzyme. This ratio increases with increasing positive charge of the isoenzymes, showing greater retention of cationic isoenzymes in the airspaces. A6teri8b indicate that the ratios for LOR isoenzymes 3, 4 and 5 are significantly greater than the ratio for isoenzymes 1 and 2 (p
the isoenzymes, while LDH 5 is the most cationic. 8 The BAL LDU/albumin to serum LDU/albumin ratio was significantly higher for isoenzymes 4 and 5, than for isoenzyme 3 (P<0.021 indicating increasing retention in the air spaces with increasing positive charge. DISCUSSION
This study was designed to investigate the source of the elevated serum LDU levels reported in patients with P carinii infection. l -3 We demonstrated a sixfold increase in the BAL LDH levels of patients with PCP compared to that in our non-PCP control subjects. Begin et al9 have reported BAL LD H levels in normal subjects ranging from 6 to 10 mIU/ml; BAL LDH levels in PCP patients averaged ten times that reported for normal subjects. In our control subjects, BAL LDU levels ranged from 10 to 23 mIU/ml. None of these control subjects proved to have P carinii or other pulmonary infections, but the presence of pulmonary disease was suggested by history blood gas abnormalities, and transbronchial biopsy specimens showing mildly increased interstitial cellularity and fibrosis. These findings may account for the increased BAL LDH levels in our non-PCP patients, as compared to normal subjects. Elevated BAL LDH levels are usually considered to reflect cell damage, although it is not clear which particular cell in pulmonary tissue is the source. 1G-13 When homogenates of human pulmonary tissue are assayed for LDH, a particular and identifying isoenzyme pattern is found. The lung pattern is characterized by proportional increases in isoenzymes 3, 4, and 5, compared to the isoenzyme pattern in normal human serum." In the present stud~ isoenzyme fractionation ofBAL LDH in PCP patients, with markedly increased total BAL LDU levels, as well as in our CHEST I 93 I 5 I MAY. 1888
..
control subjects, revealed a pattern that closely matched the isoenzyme pattern described for human lung tissue. This pattern was noted to be independent of BAL cell populations. In particular, no relation was seen between the degree of BAL lymphocytosis and either the total BAL LDH levels or the LDH isoenzyme pattern. Patients with Pneumocqstis in the present study also demonstrated increased BAL albumin. In normal subjects, the range of BAL albumin has been reported as 0.04 to 0.06 mglm1.9•14 Lavage fluid albumin was found to be fourfold higher in patients with P carinii infection, whereas BAL albumin in our non-PCP patients was in the normal range. Increased levels of BAL albumin indicate increased permeability of the ACM, and have been reported in patients with AIDS and Pneumocystis infection. 15 ,16 However, increased ACM permeability does not necessarily imply detectable cellular damage. For example, in a study of oxygen toxicity by Griffith and co-workers, 14 increased BAL albumin was detected without measurable BAL LDH. In the experimental rat model of steroidinduced pneumocystosis, increased permeability of the ACM, evidenced by leakage of horseradish peroxidase, is an early pathologic finding, and precedes cellular degeneration of type 1 pneumocytes.Fr'" In our studg the presence of both elevated BAL albumin and BAL LDH levels in the Pneumocystis patients suggests increased ACM permeability and cellular damage, respectively In the present study in both PCP patients and nonPCP control subjects, the BAL LDH/albumin ratio was significantly higher than the same ratio in serum. This observation suggests that the lavage fluid LDH originates in pulmonary tissue, rather than reflecting transudation from blood to alveoli. Since LDH (MW 140,000 daltons) is a larger molecule than albumin (MW 69,000 daltons) an increased BAL LDH/albumin ratio, as compared to serum, cannot be explained by leakage of LDH from blood to airspaces, unless an alveolar concentrating mechanism for LDH is postulated. On the basis of molecular size, one would predict a BAL LDH/albumin ratio lower than that in serum if leakage from the blood compartment was the sole source of airspace LDH. On the other hand, the elevated serum LDH level previously reported in pcp patients, and observed in the present group, could arise from bacldlow of pulmonary-derived LDH into the circulation. Presumabl~ a more permeable alveolocapillary membrane (ACM1 evidenced by increased BAL albumin, would permit leakage of abnormally high LDH present in the airspaces. The increased BAL LDHlalbumin ratio, taken together with the strongcorrelation observed in the PCP patients between BAL and serum LDH level, leads us to postulate that increased LDH in the ainpaces 110
flows back across a more permeable ACM and gives rise to the elevations of serum LDH level seen in Pneumocystis pneumonia. An analogous situation is seen in sarcoidosis, where increased amounts of IgG produced at pulmonary sites of disease are considered responsible for the observed serum hypergammaglobulinemia." A correlation between BAL and serum LDH level does not exclude the possibility that both the airspaces and blood are functioning as two independent compartments, each compartment responding to diverse insults secondary to the infection. This situation could give rise to independent but proportional elevations of BAL and serum LDH level, respectively We think this possibility is unlikely since the organism is primarily a pulmonary pathogen; in the vast majority of cases, the infection does not directly involve organs other than lung. 20.21 In the present study no patient had obvious extrapulmonary organ pathologic conditions to account for an independent elevation of serum LDH level. Alternatively the elevation of serum LDH level could be due to an indirect effect of P carinii infection, such as hypoxemia. A significant inverse correlation was found between °a02 and serum LDH levels, however, both may reflect severity of the infection and are not necessarily causally related. Although increased serum LDH is found in alveolar proteinosis and some cases of desquamative interstitial pneumonitis, both associated with varying degrees of hypoxemia, it is not usually seen in cases of adult respiratory distress syndrome. 22,23 In the present study multivariate analysis including Pa02 , did not significantly improve the correlation between serum and BAL LDH. We reason, therefore, that elevated serum LDH level in P carinii-infected patients probably arises from elevated LD H level in the airspaces. If the elevated serum LDH in patients with PCP originates in lung, then the isoenzyme patterns of BAL and serum might be expected to be similar, as has been reported in pulmonary infarction. 7 In models ofprotein flux across the pulmonary capillary endothelium, the membrane is seen as having equivalent pores that sieve proteins by molecular size.i4-27 H sieving by molecular size pertained to the complete alveolocapillary membrane, we should have observed similar LDH isoenzyme patterns-in both BAL and serum, since the five isoenzymes of LDH are approximately equal in size and molecular weight Instead, in the present stud~ the BAL LDH isoenzyme pattern closely matched that of human lung tissue, with elevations of cationic isoenzymes 3, 4, and 5 relative to isoenzyme 2, whereas that in the serum was the usual isomorphic pattern found in normal individuals, with an elevation of isoenzyme 2 relative to 3, 4, and 5. If the postulated bacldlow of LDH from airspaces EI..-d LOH Valu.. In pcp (smith, Rip!», LewI.)
to blood accounts for the elevated serum LOB level in PCP patients, then the discrepancy between the LOB isoenzyme pattern in BAL and serum of such patients needs to be clarified. Figure 4 presents the ratio of each LDU isoenzyme/ albumin in BAL related to that in serum for our patients with P carinii infection. From this comparison, it appears that the more positively charged isoenzymes are preferentially retained in the lung. The degree of backHow is apparently least for the cationic isoenzymes, LDU 3, 4 and 5, and greater for LDH 1 and 2, the anionic isoenzymes. These findings suggest that the alveolocapillary membrane sieves molecules on the basis of electrical charge, showing less permeability to the cationic LOH isoenzymes. A number of animal studies have explored the effects of charge on solute movement across the pulmonary microvascular barrier, as well as through the alveolar epithelium. 8 •24.28-30 In a rat model of permeability pulmonary edema, Brody et al3I have demonstrated that cationic ferritin, unlike anionic ferritin, does not penetrate the ACM. Two of three membrane components were shown to be negatively charged and to bind cationic molecules. In our study while increased BAL albumin reflects increased ACM permeability in P carinii infection, the finding of relative increases of LOU/albumin ratios for the cationic isoenzymes indicates that sieving on the basis of charge is maintained. This preferential retention of cationic isoenzymes could account for the isomorphic LOU pattern observed in serum. In summary P carinii infection is associated with increased levels of total BAL LOH, as well as increased BAL albumin. The higher LDU/albumin ratio in BAL as compared to serum, in addition to a BAL isoenzyme pattern of LDU characteristic of lung tissue, suggest that BAL LOU derives from a pulmonary source. BackHow of elevated BAL LDU through a more permeable alveolocapillary membrane may account for the elevated serum LOU level observed in Pneumocystis patients. Analysis of the relative ratios of LDU isoenzymes in BAL and serum indicates that cationic isoenzymes 3, 4, and 5, are preferentially retained in the air spaces. Thus, despite increased permeability the ACM continues to function as a sieving membrane, discriminating between proteins of equal molecular weight on the basis of electrical charge. Selective backHow of elevated BAL LOH, in particular isoenzyme 2, may be responsible for the isomorphic LD H pattern seen in the serum of patients with PCE REFERENCES 1 Silverman BA, Rubinstein A. Serum lactate dehydrogenase levels in adults and children with acquired immune deficiency syndrome (AIDS) and AIDS-related complex: possible indicator
2
3
4 5
of B cell lymphoproliferation and disease activi~ Am J Med 1985; 78:728-36 Garay SM, Greene J. Diagnostic and prognostic implications of elevated serum lactate dehydrogenase (LDH) in AIDS-related PneumocyBtiB carin" pneumonia (PCP) [abstract]. Am Rev Respir Dis 1987; 135 (suppl):172 Smith RL, EISadr ~ Lewis ML. Correlation ofbronchoalveolar lavage oell populations with clinical severity of P carin" pneumonia. Chest (in press) Jacobs DS, Robinson RA, Clark GM, Thcker JM. Clinical signi&cance of the isomorphic pattern of the isoenzymes of serum lactate dehydrogenase. Ann Clin Lab Sci 1977; 7:411-21 Ferrais AM, Guintini ~ Gaetani Glf: Serum lactate dehydrogenase as a prognostic tool for non-Hodgkins lymphomas. Blood
1979;54:928-32
6 Wacker WEC, Ulmer DD, Vallee BL. Metalloenzymes and myocardial infarction. N Engl J Med 1~; 255:449-56 7 Papadopoulos NM. Clinical applications of lactate dehydrogenase isoenzymes. Ann Clio Lab Sci 1977; 7:506-10 8 Parker JC, Gilchrist S, Cartledge J[ Plasma-lymph exchange and interstitial distribution volumes of charged macromolecules in the lung. J Appl Physiol 1985; 59:1128-36 9 ~gin R, Cantin A, Berthiaume t Boileau R, Bisson G, Lamoureaux G, et al. Clinical features to stage alveolitis in asbestos workers. Am J Indust Med 1985; 8:521-36 10 Henderson RF, Rebar AH, DeNicola DB, Henderson TR, Damon EG. The use of pulmonary washingsas a probe to detect lung injul")t Chest 1981; 80 (suppl):12-14S 11 Block ER, Jawaharlal M~ Sheridan NE Effect of oxygen and endotoxin on lactate dehydrogenase release, 5-hydroxytryptamine uptake and antioxidant enzyme activities in endothelial cells. J Cell Physioll985; 122:240-48 12 Ody C, Junod AF. Direct toxic effects of paraquat and oxygen on cultured endothelial cells. Lab Invest 1985; 52:77-84 13 Nelson S, Laughon BE, Summer WR, Eckhaus MA, Bartlett JG, Jakab GJ. Characterization of the pulmonary inBammatory response to an anaerobic bacterial challenge. Am Rev Respir Dis 1986; 133:212-17 14 Griffith DE, Holden WE, Morris JF, Kim LK, Krishnamurthy Gl: Effects of common therapeutic concentrations of oxygen on lung clearance of 99mTc DTPA and bronchoalveolar lavage albumin concentration. Am Rev Respir Dis 1986; 134:233-37 15 Young KR, Rankin )A, Naegel G~ Paul ES, Reynolds H~ Bronchoalveolar lavage cells and proteins in patients with the acquired immunodeficiency syndrome. Ann Intern Med 1985; 103:522-33 16 Spragg RG, Smith RM, Harrell JH. Evidence of lung inflammation in patients with AIDS and E carinii pneumonia [abstract]. Am Rev Respir Dis 1987; 135 (suppl):I69 17 Yoneda K, Walzer PD. Mechanism of pulmonary alveolar injury in experimental Pneumocystis carinii pneumonia in the rat. Br J Exp Patholl981; 62:339-46 18 Walzer PD, Powell RD, Yoneda K, Rutledge ME, Milder JE. Growth characteristics and pathogenesis of experimental Pneumocystis carinii pneumonia. Infect Immun 1980; 27:928-37 19 Rankin)A, Naegel G~ Shrader CE, Matthay RA, Reynolds flY: Airspace immunoglobulin production and levels in bronchoalveolar lavage fluid of normal subjects and patients with sarcoidosis. Am Rev Respir Dis 1983; 127:442-48 20 Coulman CU, Greene I, Archibald RWR. Cutaneous pneumacystosis. Ann Intern Med 1987; 106:396-98 21 Murray JIt: Felton C~ Garay SM, Gottlieb MS, Hopewell PC, Stover DE, et al. Pulmonary complications of the acquired immunodeficiency syndrome.• N Engl J Med 1984; 310:1682-88 22 Faling LJ, Mark EJ. A sixty-year-old man with rapidly progressive dyspnea (CPC~ N Engl J Med 1983; 308:511-19 23 Martin RJ, Rogers RM, Myers NM. Pulmonary alveolar proteinCHEST I 93 I 5 I MAY. 1988
811
osis. Am Rev Respir Dis 1978; 117:1059-62 24 Brigham KL, Parker RE, Roselli RJ, Hobson J, Harris TR. Exchange of macromolecules in the pulmonary microcirculation. Ann NY Acad Sci 1982; 384:246-64 25 Gorin AB, Hsagawa G, Hollinger M, Sperry J, Zuckerman J. Release of angiotensin converting enzyme by the lung after Pseudomonas bacteremia in sheep. J Clio Invest 1981; 68:16370 26 Gorin AB, Stewart PA. Differential permeability of endothelial and epithelial barriers to albumin flux. J Appl Physiol 1979; 47:1315-24 27 Crandall ED, Staub NC, Goldberg HS, EfIros RM. Recent developments in pulmonary edema. Ann Intern Med 1983;
99:808-22
28 Pietra GG, Sampson ~ Lanken PN, Hansen-Flaschen J, Fishman AE Thmscapillary movement of cationized ferritin in the isolated perfused rat lung. Lab Invest 1983; 49:54-61 29 Fairman R~ Miller JE, Glauser FL. The role of electrical charge interaction on normal pulmonary microvascular permeability [abstract]. Fed Proc 1982; 41:1247 30 Weaver LJ, Gleisner J, Winn R, Mansfield E, Stothert J, Hildebrandt J. Electrical potential and differences in lymphplasma ratios of molecules of similar size but differing charge [abstract]. Fed Proc 1982; 41:1246 31 Brody JS, Vaccaro CA, Hill NS, Rounds S. Binding of charged ferritin to alveolar wall components and charge selectivity of macromolecular transport in permeability pulmonary edema in rats. Cire Res 1984; 55:155-67
second Annual Symposium on Magnetic Resonance Imaging This symposium will be presented at the Ritz-Carleton Resort Hotel, Laguna Niguel, California, July 28-31. For information, contact Ms. Dawne Ryals, PO Box 920113, Norcross, GA 30092-0113 (404:641-9773).
892
Elevated LDH values In pcp (smith, RJpps, Lewis)