Trichomoniasis is a common sexually transmitted disease with an estimated incidence of 4 million to 8 million cases a year in the United States. The most commonly used method of diagnosis is a direct microscopic observation (wet mount) of vaginal secretions and, although both rapid and inexpensive, the sensitivity of this technique is generally 50 to 70%. We developed an indirect enzyme-linked immunosorbent assay (ELISA) for the detection of Trichomonas vaginalis which is both rapid and sensitive (detection limit of approximately 100 trichomonads per ml). This assay, which employs affinity-purified rabbit anti-T. vaginalis antibodies in a "sandwich" configuration, is simple to perform and is neither interfered with nor appears to cross-react with other microorganisms which are common inhabitants of the urogenital tract. One hundred and seventy-seven consecutive unselected patients attending a clinic for sexually transmitted diseases were evaluated for trichomoniasis by a broth culture technique monitored for up to 7 days (and considered here to be the standard for positivity), the conventional wet mount method, a solid culture procedure, and the ELISA. Of these, 84 were positive by culture; 33 were positive by the wet mount; and despite the fact that the vaginal specimens were diluted 20-fold during the culture procedures prior to testing in the ELISA, 65 were positive by ELISA. In addition to exhibiting a sensitivity of 77%, the specificity of the ELISA was 100%. These results demonstrate that the ELISA is a significant improvement over the wet mount method for the diagnosis of trichomoniasis.

Mucoid fluid accumulating within syphilitic lesions has been considered to be of Treponema pallidum origin. To test this assumption, we examined testicular exudative fluids from T. pallidum-infected rabbits for the presence of T. pallidum antigens by various sensitive immunochemical methods, including Western blot analysis. Antigenic analysis of these fluids revealed host components but not treponemal antigens. Prolonged immunization of rabbits, guinea pigs, and a goat with this material in complete Freund adjuvant elicited low titers (fluorescent-treponemal-antibody test titer, .10) of antitreponemal antibodies in the rabbits and guinea pigs but not in the goat. The data suggest that these mucoid fluids are of host origin. The presence of mucopolysaccharides in these fluids may be related to the infective process. The possible mechanism by which mucopolysaccharides protect T. pallidum from immune mechanisms and its potential relationship to the pathogenesis of the disease are discussed. 228on July 16, 2020 by guest

Xenograft transplantation is perhaps the most immunologically difficult problem in transplantation today. An overwhelming hyperacute rejection reaction (HAR) occurs within minutes of organ implantation. Preformed antibodies are thought to initiate this process. We used a pig-to-dog renal xenograft transplant model and investigated methods of decreasing the severity of hyperacute rejection. Female pigs weighing 15-20 kg were used as donors. Recipients were mongrel dogs weighing 15-25 kg. Experimental dogs were all given a number of treatments of IgG depletion using an antibody removal system (Dupont-Excorim). This machine immunoadsorbs plasma against a column containing immobilized staphylococcal protein A, which is known to bind the IgG Fc receptor. An 84% reduction in the IgG levels and a 71% reduction in IgM levels was achieved. Postoperative assessment was made of urine output, time to onset of HAR, and histopathological examination of the rejected kidneys. Although cross-matches between donor lymphocytes and recipient sera remained strongly positive in the treated dogs, there was a two-to fourfold reduction in the titers. The time to onset of HAR was prolonged in the experimental group, and the urine output was increased slightly. The histopathologic changes in the experimental group generally showed signs of HAR, but of less intensity than in the nonimmunodepleted control group. KeywordsImmunoadsorption; xenotransplantation; immunodepletion; hyper-acute rejection Currently, one of the major limitations in renal transplantation involves the large number of sensitized dialysis patients. Blood transfusions, prior transplants, or multiple pregnancies can all play an etiologic role, but result in an identical situation. These highly sensitized patients, who have antibodies to most or all HLA antigens, are rendered immunologically untransplantable. At present there is no effective means of dealing with this problem, and these patients can spend years on transplant waiting lists. Materials and Methods ImmunodepletionMale or female mongrel dogs weighing between 15 and 25 kg were anesthetized with pentothal, intubated, and maintained on a ventilator with 40% oxygen, ketamine 1.5 mg/kg every 1-2 h intravenously, and pancuronium 0.05-0.1 mg/kg every 1-2 h intravenously. Cutdowns in the neck on both the carotid artery and the external jugular vein were made and the vessels cannulated with 13-gauge Quinton-Scribner shunt cannulas. Arterial blood was fed into a Haemonetics V-50 plasmapheresis unit, which separates the red blood cells from the plasma. Citrate was used as an anticoagulant. The plasma was then fed into the immunoadsorption system which contains two columns of protein A attached to Sepharose CL-4B (Immunosorba A) in parallel (Figs 3 and 4). The CITEM 10 (Excorim KG, Lund, Sweden/Dupont) is a computer-controlled device which controls the flow of plasma and various regeneration solutions over the two columns. While plasma was run across one column, the adsorbed IgG and IgM were eluted from the other c...

Studies of anti-Trichomonas vaginalis antibodies in patients with vaginal trichomoniasis were undertaken in attempts to identify the predominant antibody isotype produced and to delineate clinically significant antigens. The total antibody content of serum samples from 23 patients was determined by an enzyme-linked immunosorbent assay (ELISA) that employed anti-human immunoglobulin and isotype-specific antisera. The immunochemical reactivity of these antibodies was examined by Western blot analysis. The anti-T. vaginalis titer of all but two of these serum samples was greater than 200 (range, greater than 200 to 12,800). By using an ELISA titer of at least 200 as a criterion, 21 of the serum samples contained antibodies of the immunoglobulin G (IgG) isotype, 17 contained IgM antibodies, and 6 contained IgA antibodies directed to the protozoan. Western blot analyses of these serum samples revealed approximately 29 antigenic trichomonad polypeptides, with apparent molecular sizes ranging from 14 to greater than 100 kilodaltons and with individual serum samples possessing different patterns of reactivity. These results add to the current understanding of the serological and secretory immune responses to T. vaginalis, as well as define potential antigens for use in immunodiagnostics.

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