PLASMA-TRIGLYCERIDES DO NOT REGULATE HIGH-DENSITY LIPOPROTEIN CONCENTRATIONS

1368 PLASMA-TRIGLYCERIDES DO NOT REGULATE HIGH-DENSITY LIPOPROTEIN CONCENTRATIONS PETER N. HERBERT

LLOYD O. HENDERSON

unrestricted diets before initiation of protocols. All type-5 patients were studied while consuming high-carbohydiets for 5-10 days drate (80% of calories) low-fat (<5g/day) and during maintenance on hypocaloric (<1200 kcal) diets for 7-10 days. These diets induced changes of 50% or greater in while

on

Molecular Disease Branch, National Heart, Lung, and Blood Institute; and Miriam Hospital, Providence, Rhode Island, U.S.A.

Diets high in carbohydrate and diets restricted in fat and calories were used to induce large fluctuations in plasma-triglycerides in patients with severe familial hypertriglyceridæmia. Highdensity-lipoprotein (HDL) concentrations were estimated by radioimmunoassay of the major HDL apoprotein, apo A-I, and were correlated with plasma cholesterol and triglyceride concentrations. Patients with type-1 hyperlipoproteinæmia had apo A-I concentrations about 50% of normal, and no increase in apo A-I concentrations was observed even when plasmatriglycerides were reduced to the normal range. Apo A-I concentrations in type-5 hyperlipoproteinæmia were not consistently low and did not correlate with plasma-lipid concentrations. It does not seem that hypertriglyceridæmia reduces HDL in either disorder.

Summary

Introduction REDISCOVERY of the inverse relation between

plasma-triglyceride concentrations. Triglyceride reductions in type-1 patients were accomplished by restriction of dietary fat (<25 g/day). Blood anticoagulated with edetic acid (1 mg/ml) was drawn after a 12-14 h fast and plasma was used for lipid and lipoproteinS measurements and quantification of the major HDL apolipoprotein, apo A-1, by radioimmunoassay.9 Linear correlation coefficients and their statistical significance were computed by standard techniques. 10 Results Mean

(±1 SD) apo A-I concentrations in normal men in our laboratory are 100±12 mg/dl and 108±18 mg/dl, respectively.9 Apo A-I concentrations ranged from 37 to 62 mg/dl in patients with type-1 hyperlipoproteinaemia. Over a wide range of plasmalipid concentrations (fig. 1) the plasma apo A-1 concenand

women

plasma-

high-density-lipoprotein (HDL) concentrations and atherosclerosis 1-4 has prompted investigation of the interrelatedness of the concentrations of HDL and other plasma lipoproteins. Schaefer et al. reported that all the major forms of familial hypertriglyceridaemia seemed to be associated with reduced HDL-cholesterol concentrations and they agreed with the view that lipid-lowering diets usually increase HDL-cholesterol concentrations. The usefulness of HDL-cholesterol measurement to estimate HDL mass in hypertriglyceridsmia is uncertain because hypertriglyceridaemia changes the chemical composition of HDL, producing cholesterol depletion and triglyceride enrichment. 6, Consequently it has remained unclear whether control of hypertriglyceridaemia actually increases the mass of circulating HDL. The findings reported here indicate that there is no simple relation between plasma triglyceride and HDL concentrations in the more severe forms of familial hypertriglyceridaemia. Patients and Methods Four subjects with type-1 hyperlipoproteinxmia and ten with type-5 hyperlipoproteinxmia were admitted to hospital at the NIH Clinical Center. Subjects were sampled at least once

4. Smith RE, Wolnisty C. Allergic reactions to tetanus, diphtheria, influenza, and poliomyelitis immunization. Ann Allergy 1962; 20: 809-813. 5. Edsall G. Specific prophylaxis of tetanus. JAMA 1959; 171:417-427. 6. Stavitsky AB. Micromethods for the study of proteins and antibodies. J Im-

munol 1954; 72: 360-367. 7. European Pharmacopoeia Vol 2 Paris: Maisonneuve, 1971:274. 8. Griffith AH. In: Eckmann L, ed. Principles on tetanus. Berne: Hans Huber, 1967. 9. Bainton D, Freeman M, Magrath DI et al. Immunity of children to diphtheria, tetanus, and poliomyelitis. Brit Med J 1979; i: 854-857.

1-Relation of plasma cholesterol (A) and triglyceride (B) concentrations to concentration of major H.D.L. apoprotein,

Fig.

apo A-1, in type-1 hyperlipoproteinaemia.

1369 A-1 concentrations were not noted even in the tients with massive hypeitriglyceridsemia.

type-5

pa-

Discussion

Among subjects with familial hyperlipoproteinaemia, those with type-1 disease have the lowest plasma HDL concentrations whether HDL mass is measured by analytic ultracentrifugation" or estimated as HDL-cholesterol concentration.5 The severe hypertriglyceridsemia in these patients, presumed to be secondary to lipoproteinlipase deficiency,12 responds to drastic limitation of dietary fat. We succeeded in lowering triglycerides from more than 1000 mg/dl to less than 250 mg/dl in two of the four type-1 subjects studied, but no increase in the plasma apo A-1 concentration accompanied this change. It appears, therefore, that neither dietary fat consumption nor the attendant hyperchylomicronasmia is the cause of the HDL deficiency in this disorder. The strikingly low HDL concentrations in type-1 hyperlipoproteinsemia, as in analphalipoproteinæmia (Tangier disease), are not associated with premature atherosclerosis.12.13 This may be because reduced quantities of plasma low-density lipoproteins are typical of both disorders. The correlation between HDL cholesterol and apo A-1 concentrations in type-5 hyperlipoproteinaemia, while statistically highly significant, is much less strong than would be expected if the proportions of constituents of HDL remained constant. Strisower et al. 14 reported that triglyceride may account for 18% of HDL lipid in hypertriglyceridxmic states, and we have found triglyceride comprising more than 25% of HDL mass in type-5 plasma (unpublished). This triglyceride enrichment is accompanied by cholesteryl-ester depletion and limits the usefulness of HDL-cholesterol measurements as estimates of HDL mass in such plasma. Furthermore, the absence of a correlation between apo A-I concentrations and plasma triglyceride does not accord with the suggestion that dietary control of hypertriglyceridmmia will necessarily have a beneficial effect on the HDL concentration.5 Other workers successfully treating hypertriglyceridzemic outpatients have reached similar conclusions.15 Requests for reprints should be addressed to P. N. H., Miriam Hos164 Summit Hospital, Providence, Rhode Island 02906, U.S.A.

pital,

REFERENCES

2-Relation of plasma cholesterol (A), triglyceride (B), and H.D.L.-cholesterol (C) concentrations to concentration of apo

Fig.

A-1 in type-5 hyperlipoproteinaemia.

tration showed

cholesterol (r

=

no

significant

—0-24, p>0-1)

correlation with or

plasma triglyceride (r = —0-24,

p>0.1). Plasma apo A-I concentrations in the ten subjects with type-5 hyperlipoproteinasmia were measured on 106 occasions and were correlated with HDL cholesterol concentrations at 44 time points. Apo A-1 concentrations were unrelated (fig. 2) to both cholesterol (r —0-11, P>0.1) and triglyceride (r —0-13, p>0.1) concentrations but did correlate with the HDL-cholesterol concentration (r In contrast to type-1 +0.53, p<0.001). hyperlipoproteinaemia, pronounced reductions of apo =

=

=

1. Barr DP, Russ EM, Eder HA. Protein-lipid relationships in human plasma. II. In atherosclerosis and related conditions Am J Med 1951; 11: 480-493. 2. Miller GJ, Miller NE. Plasma-high-density-lipoprotein concentration and development of ischæmic heart-disease. Lancet 1975; i: 16-19. 3. Castelli WP, Doyle JT, Gordon T, et al. HDL cholesterol and other lipids in coronary heart disease. The cooperative lipoprotein phenotyping study. Circulation 1977: 55:767-772. 4. Williams P, Robinson D, Bailey A. High-density lipoprotein and coronary risk factors in normal men. Lancet 1979; i. 72-75. 5. Schaefer EJ, Levy RI, Anderson DW, Danner RN, Brewer HB Jr, Blackwelder WC. Plasma-triglycerides in regulation of H.D.L.-cholesterol levels. Lancet 1978; ii: 391-392. 6. Barter PJ, Connor WE. The transport of triglyceride in the high-density lipoproteins of human plasma. J Lab Clin Med 1975; 85: 260-272. 7. Carlson LA. Serum lipoprotein composition in different types of hyperlipo-

8.

proteinemia. Adv Exp Med Biol 1975; 63: 185-199. Lipid and lipoprotein analysis 1974. Manual of Laboratory Operations, Lipid Research Clinics Program, Vol. 1 (D.H.E.W. publication No. [N.I.H.] 75-628).

9. Henderson LO, Herbert PN, Fredrickson DS, Heinen RJ, Easterling JF. Abnormal concentration and anomalous distribution of apolipoprotein A-I in Tangier disease. Metabolism 1978; 27:165-174.

.

1370 KARYOTYPIC CONVERSION IN Ph1-POSITIVE CHRONIC MYELOID LEUKÆMIA WITH COMBINATION CHEMOTHERAPY

J. C. SHARP

A. W. WAYNE

M. CROFTS G. MCARTHUR H. STERNDALE

TABLE I-PRESENTING FEATURES

M. V.

JOYNER J. KEMP A. D. J. BIRCH S. LAI Y. WILLIAMS

Department of Hæmatology, King’s College Hospital, London SE5; and Department of Hæmatology, Isle of Thanet Hospital, Canterbury Twelve previously untreated patients with Ph1-positive chronic myeloid leukæmia received combination chemotherapy soon after diagnosis. There was karyotypic conversion in five: in four, the percentage of Ph1-positive cells fell to 10 or less. In two other patients, who had mosaic karyotypes at presentation, the percentage fell to 5% and zero.

Summary

.

* Enlarged radiographically metaphases were examined in (40)

25

all

patients except no. 7 (30)

and 11

Patient 6, whose bone-marrow contained 30% myeloconsidered to have accelerated disease from the blasts,

table

L

was

Introduction

THE appearance of karyotypic mosaicism in Ph’-positive chronic myeloid leukaemia (C.M.L.)-i.e., karyotypically normal cells combined with Ph’+ cells-at presentation or during disease has been considered to improve prognosis.1-5 Karyotypic mosaicism during the disease has been associated with busulphan therapy and, in some patients, with a period of bone-marrow hypoplasia. In these few patients, particularly long survival has been recorded. In an effort to bring about karyotypic conversion with greater consistency, and thereby improve survival, we selected, on the basis of cytotoxic effect and our experience, a combination of drugs. Because the role of splenectomy in C.M.L. remains at best equivocal,6 we first planned not to do routine splenectomy. However, in the light of early experience in the trial this policy was amended and splenectomy was considered during the intensive phase of treatment if there was persistent spleno-

megaly. Patients and Methods

Only fit patients under the age of 60 years were considered for entry to the trial. Patient 10 was made an exception because he was fit when seen and had no past medical history. All patients were untreated before the trial. The presenting features of the twelve patients are shown in

GW, Cochran WG. Statistical methods. 6th ed. Ames: Iowa State University Press, 1967. 11. Fredrickson DS, Levy RI, Lindgren FT. A comparison of heritable abnormal lipoprotein patterns as defined by two different techniques. J Clin Invest

10. Snedecor

1968; 47:2446-2457. 12. Fredrickson DS, Goldstein JL, Brown MS. The familial hyperlipoproteinemias. In: Stanbury JB, Wyngaarden JB, Fredrickson DS, eds. The metabolic basis of inherited disease. 4th ed. New York: McGraw-Hill, 1978: 604-655. 13. Herbert PN, Gotto AM, Fredrickson DS. Familial lipoprotein deficiency (abetalipoproteinemia, hypobetalipoproteinemia, and Tangier disease). In: Stanbury JB, Wyngaarden JB, Fredrickson DS, eds. The metabolic basis of inherited disease. 4th ed. New York: McGraw-Hill, 1978: 544-588. 14. Strisower EH, Nichols AV, Lindgren FT, Smith L. The effect of Sf 20-105 concentration changes induced by ethyl chlorphenoxyisobutyrate on highdensity lipoprotein lipid composition. J Lab Clin Med 1965; 65: 748-755. 15. Witztum J, Dillingham M, Giese W, Schonfeld G, Weidman S. Triglyceride lowering fails to correct low high density lipoprotein cholesterol in primary hypertriglyceridemia (type IV). Circulation 1978; 58:II-38.

beginning. At first we planned to give six courses of chemotherapy at 2-3 week intervals: day 1 : doxorubicin (patients 1 and 2 had 30 mg/m2 but thereafter it was increased to 60 mg/m2 intravenously) ; day 1: vincristine 1.5 mg/m2, maximum 2 mg intravenously ; days 1-7: Ara-C (cytosine arabinoside) (patients 1 and 2 had 30 mg/m2 as a 12-hourly infusion but thereafter it was increased to 50 mg/m2 and in patients 11 and 12 to 100 mg/m2); days 1-7: 6-thioguanine, 80 mg/m2 orally at first but in patients 11 and 12, 80 mg/m2 orally twice daily. Patient 7, whose twin brother had presented a year earlier with chronic lymphatic leukaemia, and patient 8 received, in addition, on day 7, daunorubicin 60 mg/m2 intravenously and vincristine 1.5mg/m2 intravenously in the first course. Patient 7 received no further anthracycline. Patient 8 completed five further courses of the standard induction therapy. Patient 7 had splenectomy after five intensive courses because of persist-

ing splenomegaly. Patient 5 defaulted after one course but returned after 4 months via one of H.M. prisons. He had two further courses before defaulting again. He has been seen subsequently in another hospital, 14 months after presentation, and is reported to have had a normal blood-count and no splenomegaly. After six courses the patients received more conventional drugs in a 3-month cycle; day 1: vincristine 1.5 mg/m2 intravenously ; days 1-21: busulphan 4 mg; days 28-48: hydroxyurea 1 g and 6-mercaptopurine 50 mg; days 55-75: dibromannitol 250 mg. Reinduction therapy was given to patient 3, who had had no therapy for the previous 11 months, in month 24 and to patient 4 in month 7: day 1 : vincristine; days 1-5: Ara- C intravenous bolus, and 6-thioguanine twice daily. Bone-marrow examination and chromosome analysis were done before each intensive block and at the beginning of the 3-monthly maintenance cycle. Chromosome preparations were obtained by a direct harvesting technique. At least 25 metaphases were examined. Chromosome banding was done by modifications of the quinacrine fluorescence method’ and Sea-

bright’s trypsinisation technique.8 Results Banding showed that the Ph’ in all patients was the result of a 9:22 translocation. The percentage Ph’ positivity fell in seven of the twelve patients during the intensive treatment phase (table II). In the first two patients with fairly massive disease, Phi status was not influenced although reasonable clinical and hsematological control of the disease was achieved. After this, doses of