1887

Abstract

Current serological tests do not discriminate between asymptomatic latent infection and reactivating toxoplasmosis, but timely therapeutic intervention before the development of symptoms would lead to major reductions in morbidity and permanent disability. This study developed a new enzyme-linked immunosorbent assay (ELISA) for antibody to tissue cyst antigens and screened tissue cyst antigens by Western blot analysis to test the hypothesis that antibody recognition of tissue cyst-derived antigen is a good indicator of reactivation disease. A total of 187 sera was tested by Sabin-Feldman dye test and tissue cyst ELISA. AIDS patients and patients with ocular disease were considered separately, as the exposure to parasite antigens may be different in these two groups. The dye test did not discriminate between immunocompetent and immunocompromised seropositive patients or between active and quiescent toxoplasmosis. Tissue cyst ELISA demonstrated a raised specific antibody response in immunocompetent seropositive patients and in quiescent HIV positive sera. These data support the view that the tissue cyst population is in a state of dynamic equilibrium. It is proposed that, in the immunocompetent host, tissue cyst development and rupture are under some degree of immune control, but that in the immunocompromised host this equilibrium is disturbed and reactivation disease results. Data from patients with reactivating ocular toxoplasmosis demonstrate that tissue cyst-specific antibody levels are not different in active and quiescent disease and indeed they are not significantly different from immunocompetent seronegative sera. In the Western blot analysis of 57 HIV positive patient sera, eight antigens (65, 57, 49, 47, 36, 28, 26 and 18 kDa) were consistently recognised by one third or more of the sera tested, but no single antigen was diagnostic of quiescent or active toxoplasmosis. It is concluded that tissue cyst-derived antigens are not a reliable serological marker of reactivating toxoplasmosis.

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1997-07-01
2022-01-19
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References

  1. Luff B. J., Remington J. S. Toxoplasmic encephalitis in AIDS. Clin Infect Dis 1992; 15:211–222
    [Google Scholar]
  2. Holliman R. E., Stevens P. J., Duffy K. T., Johnson J. D. Serological investigation of ocular toxoplasmosis. Br J Ophthalmol 1991; 75:353–355
    [Google Scholar]
  3. Suzuki Y., Remington J. S. Importance of membrane-bound antigens of Toxoplasma gondii and their fixation for serodiagnosis of toxoplasmic encephalitis in patients with Acquired Immunodeficiency Syndrome. J Clin Microbiol 1990; 28:2354–2356
    [Google Scholar]
  4. Kasper L. H. Identification of stage-specific antigens of Toxoplasma gondii. Infect Immun 1989; 57:668–672
    [Google Scholar]
  5. Darcy F., Charif H., Caron H. Identification and biochemical characterization of antigens of tachyzoites and bradyzoites of Toxoplasma gondii with cross-reactive epitopes. Parasitol Res 1990; 76:473–478
    [Google Scholar]
  6. Soete M., Fortier B., Camus D., Dubremetz J. F. Toxoplasma gondii: kinetics of bradyzoite-tachyzoite interconversion in vitro. Exp Parasitol 1993; 76:259–264
    [Google Scholar]
  7. McHugh T. D., Gbewonyo A., Johnson J. D., Holliman R. E., Butcher P. D. Development of an in vitro model of Toxoplasma gondii cyst formation. FEMS Microbiol Lett 1993; 114:325–332
    [Google Scholar]
  8. Roberts C. W., Alexander J. Studies on a murine model of congenital toxoplasmosis: vertical disease transmission only occurs in BALB/c mice infected for the first time during pregnancy. Parasitology 1992; 104:19–23
    [Google Scholar]
  9. Comelissen A. W. C. A., Overdulve J. P., Hoenderboom J. M. Separation of Isospora (Toxoplasma) gondii cysts and cystozoites from mouse brain tissue by continuous density-gradient centrifugation. Parasitology 1981; 83:103–108
    [Google Scholar]
  10. Savva D., Morris J. C., Johnson J. D., Holliman R. E. Polymerase chain reaction for detection of Toxoplasma gondii. J Med Microbiol 1990; 32:25–31
    [Google Scholar]
  11. Sabin A. B., Feldman H. A. Dyes as microchemical indicators of a new immunity phenomenon affecting a protozoon parasite (Toxoplasma). Science 1948; 108:660–663
    [Google Scholar]
  12. Duffy K. T., Wharton P. J., Johnson J. D., New L., Holliman R. E. Assessment of immunoglobulin-M immunosorbent agglutination assay (ISAGA) for the detection of Toxoplasma specific IgM. J Clin Pathol 1989; 42:1291–1295
    [Google Scholar]
  13. Balfour A. H., Harford J. P. Quality control and standardisation. In Wreghitt T. G., Morgan-Capner P. (eds) ELISA in the clinical microbiology laboratory London: Public Health Laboratory Service; 199036–47
    [Google Scholar]
  14. Laemmli U. K. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature 1970; 111:680–685
    [Google Scholar]
  15. Holliman R. E. Toxoplasmosis and the acquired immunedeficiency syndrome. J Infection 1988; 16:121–128
    [Google Scholar]
  16. Suzuki Y., Thulliez P., Remington J. S. Use of acute-stage-specific antigens of Toxoplasma gondii for serodiagnosis of acute toxoplasmosis. J Clin Microbiol 1990; 28:1734–1738
    [Google Scholar]
  17. Frenkel J. K., Escajadillo A. Cyst rupture as a pathogenic mechanism of toxoplasmic encephalitis. Am J Trop Med Hyg 1987; 36:517–522
    [Google Scholar]
  18. McHugh T. D., Holliman R. E., Butcher P. D. The in vitro model of tissue cyst formation in Toxoplasma gondii. Parasitol Today 1994; 10:281–285
    [Google Scholar]
  19. Filice G. A., Hitt J. A., Mitchell C. D., Blackstad M., Sorensen S. W. Diagnosis of Toxoplasma parasitemia in patients with AIDS by gene detection after amplification with polymerase chain reaction. J Clin Microbiol 1993; 31:2327–2331
    [Google Scholar]
  20. Liesenfeld O., Roth A., Weinke T., Foss H.-D., Hahn H. A case of disseminated toxoplasmosis - value of PCR for the diagnosis. J Infection 1994; 29:133–138
    [Google Scholar]
  21. Zhang Y. W., Fraser A., Balfour A. H., Wreghitt T. G., Gray J. J., Smith J. E. Serological reactivity against cyst and tachyzoite antigens of Toxoplasma gondii determined by FAST-ELISA. J Clin Pathol 1995; 48:908–911
    [Google Scholar]
  22. Woodison G., Smith J. E. Identification of the dominant cyst antigens of Toxoplasma gondii. Parasitology 1990; 100:389–392
    [Google Scholar]
  23. Woodison G., Balfour A. H., Smith J. E. Sequential reactivity of serum against cyst antigens in Toxoplamsa infection. J Clin Pathol 1993; 46:548–550
    [Google Scholar]
  24. Ware P. L., Kasper L. H. Strain-specific antigens of Toxoplasma gondii. Infect Immun 1987; 55:778–783
    [Google Scholar]
  25. Tomavo S., Fortier B., Soete M., Ansel C., Camus D., Dubremetz J. F. Characterization of bradyzoite-specific antigens of Toxoplasma gondii. Infect Immun 1991; 59:3750–3753
    [Google Scholar]
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