- Email: [email protected]
STAPHYLOCOCCAL TEICHOIC-ACID ANTIBODIES
731 but the visual hallucinations together with several paranoid ideas and some auditory hallucinations of mechanical sounds have persisted for the past 17 years. Despite her many disabilities she has continued to live alone and has shown no evidence either of personality defect or of affective illness. In this patient, as in the elderly, blindness did not protect against the development of schizophrenia. Institute of Psychiatry, London SE5
S. A. CHECKLEY
The London London El
A. P. SLADE
Hospital,
superficial infection resolved promptly, antistaphylococcal therapy was given for only 2 weeks, with no relapse or metastatic staphylococcal infection detected on follow-up. The measurement of teichoic-acid antibody levels has limiBecause the
tations similar to those associated with any serological test. Further prospective evaluation is required in patients with staphylococcal bacterxmia before the role of this test in guiding the duration of therapy is established. Infectious Disease Section,
Department of Medicine, Baylor College of Medicine, Houston, Texas 77030, U.S.A.
SALICYLATES AND SURVIVAL OF HEART ALLOGRAFTS IN RATS
STAPHYLOCOCCAL TEICHOIC-ACID ANTIBODIES
SIR,-Your editorial on teichoic-acid antibodies in staphylococcal infection (Jan. 27, p. 196) correctly stresses the limitations of this serological assay in identification of patients with many forms of staphylococcal disease. Less than half of patients with bone, soft tissue, or other deep staphylococcal infections without an intravascular focus will have raised teichoic-acid antibody levels, even when measurements are done one month or more after the onset of infection. When positive, the gel-diffusion test continues to be reasonably specific for staphylococcal infection; however, we have found a positive precipitin reaction in serum from an intravenous heroin abuser with endocarditis caused by Bacillus cereus, which confirms that occasional cross-reactions can occur. Several investigators have noted that the staphylococcal teichoic-acid antibody test may be helpful as an adjunct to the diagnosis of endocarditis and other intravascular infections. 2-5 The usefulness of this serological test in endocarditis is the result of prompt secondary antibody responses, since sensitive techniques demonstrate that most normal adults have low levels of teichoic-acid antibodies in the absence of recent infection.’ The passive immunodiffusion-in-agar test is simple and is sufficiently insensitive so that normal antibody levels do not result in formation of a precipitin line. Where available, coun-
terimmunoelectrophoresis (C.LE.) gives
a more
rapid result,
but antibody in uninfected individuals may be detected and titration may be required to determine the diagnostic antibody increases.5 Consequently, we continue to prefer the passive immunodiffusion assay for routine use. Attempts to use the teichoic-acid antibody test as a guide to therapy results in some uncertainty. This antibody test could play a role in the diagnosis of staphylococcal endocarditis or other deep infection when anti-staphylococcal therapy may have been initiated before blood cultures. The positive antibody test could confirm the necessity to treat the patients for endocarditis, even when blood cultures are negative. The possibility that a positive teichoic-acid-antibody test may identify patients who are at risk of metastatic foci of infection after bacterxmia (presumably requiring longer therapy) has been discussed.5 Bernhardt et al.6 have described a limitation of this antibody test to determine those patients with staphylococcal bactera:mia who can be treated for a shorter duration. Their report emphasises that hospital-acquired staphylococcal bacterxmia may result in deep infection, leading to raised antibody levels only when careful serial tests are done. On the other hand, we have followed up several patients who have converted from negative to a positive serological test after transient bacterxmia from infected intravenous catheters. 1. Martin, R.
R., Daugharty, H., White, A. Antimicrob. Ag. Chemother. 1965, p. 91. 2. Crowder, J. G., White, A. Ann. intern. Med. 1972, 77, 87. 3. Nagel, J. B., Tuazon, C. U., Cardella, T. A., Sheagren, J. N. ibid. 1975, 82, 13. 4. Tuazon, C. U., Sheagren, J. N. ibid. 1976, 84, 543. 5. Tuazon, C. U., Sheagren, J. N., Choa, M. S., Marais, D., Curtin, infect. Dis 1978, 137, 57 6. Bernhardt, L. L., Autopol, S. C., Simberkoff, M. S., Rahal, J. J.,
J Med. 1979, 66, 355.
J. A. J. Jr. Am.
R. RUSSELL MARTIN STEPHEN B. GREENBERG RICHARD J. WALLACE
SIR,-Mr Jamieson and his colleagues (Jan. 20, p. 130) reported that sodium salicylate (200 mg/kg body-weight subcutaneously once daily) prolonged the survival time of heart allografts in rats and they ascribed this to inhibition of endothelial damage secondary to the reaction of antigen-antibody complexes with platelets. We studied’ the effect of daily intraperitoneal injection of 400 mg/kg b.w. of lysine-acetylsalicylate on heart allografts in outbred C.D. male rats (Charles River, Italy). The median time of rejection was 11 days in 18 control and 9 days in 22 treated rats-i.e., not a statistically significant difference.- Salicylate is about 100 times less active than acetylsalicylate in inhibiting platelet function in vitro. Moreover salicylate failed to inhibit generation of thromboxane Az activity in platelets after in vivo administration to rats (200 mg/kg b.w. subcutaneously).3 It therefore seems unlikely that inhibition of platelet function plays a major role in the protective effect of sodium salicylate against transplant rejection, and the effect must therefore be ascribed
to
other mechanisms. Enhancement of blood
fibrinolysis could be important in the prevention of transplant rejection4 and sodium salicylate increases blood fibrinolyfic activity to a much greater extent than acetylsalicylic acid.5 Istituto di Ricerche Farmacologiche "Mario Negri",
20157 Milan, Italy
ERYTHROCYTE
GIOVANNI DI MINNO INE REYERS MARIA BENEDETTA DONATI GIOVANNI DE GAETANO
SODIUM/POTASSIUM FLUXES IN HYPERTENSION
SiR,—Dr Garay and Professor Meyer demonstrate (Feb. 17,
349) that the ratio of Na+/K+ net fluxes is decreased in erythrocytes of patients with essential hypertension. They suggest that this defect in transmembrane permeability, if present p.
in vascular smooth-muscle cells, could lead to an increase in intracellular Na+ and thus play a major role in the pathogenesis of hypertension through enhancement of vascular smooth-muscle contractility. The association of vascular smooth-muscle constriction with ionic transfers in the vascular wall has been well documented.6 In most of the studies, however, acute vessel changes were induced by drug administration or electrical stimulation. More interesting, in relation to Garay and Meyer’s hypothesis, is the fact that a direct correlation exists between sustained vascular tension and transmembrane concentration gradients.’ Using Reyers, I., Di Minno, G., Donati, M. B., de Gaetano, G. Experientia, 1979, 35, 117. 2. Smith, J. B., Willis, A. L. Br. J. Pharmac. 1970, 40, 545P. 3. Vargaftig, B. B. J. Pharmac. Pharmacol. 1978, 30, 101. 4. Baille, Y., Blanc, M. Th., Monties, J. R., Goudard, A., Henry, E. Presse méd. 1969, 77, 1459. 5. Moroz, L. A. New Engl. J. Med. 1977, 296, 525. 6. Friedman, S. M., Friedman, C. L. in Pulmonary Circulation and Interstitial Space (edited by A. P. Fishman and H. H. Hecht); p. 173. Chicago, 1969. 7. Guignard, J. P., Friedman, S. M. Circulat. Res. 1970, 27, 505. 1.
S. A. CHECKLEY
The London London El
A. P. SLADE
Hospital,
superficial infection resolved promptly, antistaphylococcal therapy was given for only 2 weeks, with no relapse or metastatic staphylococcal infection detected on follow-up. The measurement of teichoic-acid antibody levels has limiBecause the
tations similar to those associated with any serological test. Further prospective evaluation is required in patients with staphylococcal bacterxmia before the role of this test in guiding the duration of therapy is established. Infectious Disease Section,
Department of Medicine, Baylor College of Medicine, Houston, Texas 77030, U.S.A.
SALICYLATES AND SURVIVAL OF HEART ALLOGRAFTS IN RATS
STAPHYLOCOCCAL TEICHOIC-ACID ANTIBODIES
SIR,-Your editorial on teichoic-acid antibodies in staphylococcal infection (Jan. 27, p. 196) correctly stresses the limitations of this serological assay in identification of patients with many forms of staphylococcal disease. Less than half of patients with bone, soft tissue, or other deep staphylococcal infections without an intravascular focus will have raised teichoic-acid antibody levels, even when measurements are done one month or more after the onset of infection. When positive, the gel-diffusion test continues to be reasonably specific for staphylococcal infection; however, we have found a positive precipitin reaction in serum from an intravenous heroin abuser with endocarditis caused by Bacillus cereus, which confirms that occasional cross-reactions can occur. Several investigators have noted that the staphylococcal teichoic-acid antibody test may be helpful as an adjunct to the diagnosis of endocarditis and other intravascular infections. 2-5 The usefulness of this serological test in endocarditis is the result of prompt secondary antibody responses, since sensitive techniques demonstrate that most normal adults have low levels of teichoic-acid antibodies in the absence of recent infection.’ The passive immunodiffusion-in-agar test is simple and is sufficiently insensitive so that normal antibody levels do not result in formation of a precipitin line. Where available, coun-
terimmunoelectrophoresis (C.LE.) gives
a more
rapid result,
but antibody in uninfected individuals may be detected and titration may be required to determine the diagnostic antibody increases.5 Consequently, we continue to prefer the passive immunodiffusion assay for routine use. Attempts to use the teichoic-acid antibody test as a guide to therapy results in some uncertainty. This antibody test could play a role in the diagnosis of staphylococcal endocarditis or other deep infection when anti-staphylococcal therapy may have been initiated before blood cultures. The positive antibody test could confirm the necessity to treat the patients for endocarditis, even when blood cultures are negative. The possibility that a positive teichoic-acid-antibody test may identify patients who are at risk of metastatic foci of infection after bacterxmia (presumably requiring longer therapy) has been discussed.5 Bernhardt et al.6 have described a limitation of this antibody test to determine those patients with staphylococcal bactera:mia who can be treated for a shorter duration. Their report emphasises that hospital-acquired staphylococcal bacterxmia may result in deep infection, leading to raised antibody levels only when careful serial tests are done. On the other hand, we have followed up several patients who have converted from negative to a positive serological test after transient bacterxmia from infected intravenous catheters. 1. Martin, R.
R., Daugharty, H., White, A. Antimicrob. Ag. Chemother. 1965, p. 91. 2. Crowder, J. G., White, A. Ann. intern. Med. 1972, 77, 87. 3. Nagel, J. B., Tuazon, C. U., Cardella, T. A., Sheagren, J. N. ibid. 1975, 82, 13. 4. Tuazon, C. U., Sheagren, J. N. ibid. 1976, 84, 543. 5. Tuazon, C. U., Sheagren, J. N., Choa, M. S., Marais, D., Curtin, infect. Dis 1978, 137, 57 6. Bernhardt, L. L., Autopol, S. C., Simberkoff, M. S., Rahal, J. J.,
J Med. 1979, 66, 355.
J. A. J. Jr. Am.
R. RUSSELL MARTIN STEPHEN B. GREENBERG RICHARD J. WALLACE
SIR,-Mr Jamieson and his colleagues (Jan. 20, p. 130) reported that sodium salicylate (200 mg/kg body-weight subcutaneously once daily) prolonged the survival time of heart allografts in rats and they ascribed this to inhibition of endothelial damage secondary to the reaction of antigen-antibody complexes with platelets. We studied’ the effect of daily intraperitoneal injection of 400 mg/kg b.w. of lysine-acetylsalicylate on heart allografts in outbred C.D. male rats (Charles River, Italy). The median time of rejection was 11 days in 18 control and 9 days in 22 treated rats-i.e., not a statistically significant difference.- Salicylate is about 100 times less active than acetylsalicylate in inhibiting platelet function in vitro. Moreover salicylate failed to inhibit generation of thromboxane Az activity in platelets after in vivo administration to rats (200 mg/kg b.w. subcutaneously).3 It therefore seems unlikely that inhibition of platelet function plays a major role in the protective effect of sodium salicylate against transplant rejection, and the effect must therefore be ascribed
to
other mechanisms. Enhancement of blood
fibrinolysis could be important in the prevention of transplant rejection4 and sodium salicylate increases blood fibrinolyfic activity to a much greater extent than acetylsalicylic acid.5 Istituto di Ricerche Farmacologiche "Mario Negri",
20157 Milan, Italy
ERYTHROCYTE
GIOVANNI DI MINNO INE REYERS MARIA BENEDETTA DONATI GIOVANNI DE GAETANO
SODIUM/POTASSIUM FLUXES IN HYPERTENSION
SiR,—Dr Garay and Professor Meyer demonstrate (Feb. 17,
349) that the ratio of Na+/K+ net fluxes is decreased in erythrocytes of patients with essential hypertension. They suggest that this defect in transmembrane permeability, if present p.
in vascular smooth-muscle cells, could lead to an increase in intracellular Na+ and thus play a major role in the pathogenesis of hypertension through enhancement of vascular smooth-muscle contractility. The association of vascular smooth-muscle constriction with ionic transfers in the vascular wall has been well documented.6 In most of the studies, however, acute vessel changes were induced by drug administration or electrical stimulation. More interesting, in relation to Garay and Meyer’s hypothesis, is the fact that a direct correlation exists between sustained vascular tension and transmembrane concentration gradients.’ Using Reyers, I., Di Minno, G., Donati, M. B., de Gaetano, G. Experientia, 1979, 35, 117. 2. Smith, J. B., Willis, A. L. Br. J. Pharmac. 1970, 40, 545P. 3. Vargaftig, B. B. J. Pharmac. Pharmacol. 1978, 30, 101. 4. Baille, Y., Blanc, M. Th., Monties, J. R., Goudard, A., Henry, E. Presse méd. 1969, 77, 1459. 5. Moroz, L. A. New Engl. J. Med. 1977, 296, 525. 6. Friedman, S. M., Friedman, C. L. in Pulmonary Circulation and Interstitial Space (edited by A. P. Fishman and H. H. Hecht); p. 173. Chicago, 1969. 7. Guignard, J. P., Friedman, S. M. Circulat. Res. 1970, 27, 505. 1.