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To test the possibility that autoimmunity could be related to increased levels of anti-bovine antibodies and/or circulating immune complexes in selective IgA deficiency, we studied the sera of 30 consecutive patients for the quantitative level of antibody to bovine milk, the presence of antigen--antibody complexes and 10 selected autoantibodies. Higher titres of anti-milk antibody and circulating immune complexes were to be correlated with positive serological tests of autoimmunity in these patients, and rheumatoid arthritis (three cases) and neurological disease (four cases) were found in individuals who had both milk precipitins and circulating immune complexes. We suggest that the chronic excessive permeability of the gastrointestinal tract in selective IgA deficiency may permit the excessive absorption of many food proteins, leading to the formation of antigen--antibody complexes and autoimmunity.

The presence of Fc receptors, but not C3 receptors, on human and bovine spermatozoa was shown by sperm-induced rosette formation of antibody-treated ox erythrocytes and by immunofluorescence of aggregated human gammaglobulin (AHG) treated spermatozoa. Human and bovine spermatozoa bound AHG as well as circulating immune complexes (CIC) from human sera; monomeric IgG bound to these cells to a much lesser extent. Binding of AHG to the sperm surface also occurred when the AHG was suspended in either buffer or in serum that had been heated at 56 degrees C for 30 min. A bovine spermatozoa radioimmunoassay for the detection of immune complexes in human sera was developed and was shown to be comparable to the Raji cell radioimmunoassay (r = 0 . 81, P < 0 . 01) in the quantitation of soluble immune complexes from a variety of human sera. An enzyme-linked immunoassay was then developed, using bovine spermatozoa fixed to wells of microtitre plates, to simplify the immune complex detection assay. The technique provides an analysis that is rapid, does not require radioactive chemicals, expensive equipment, or cultured cells and yields values for immune complex determination both comparable and complementary to the Raji cell radioimmunoassay (r = 0 . 70, P < 0 . 01). The sperm assays detected soluble immune complexes in sera of vasectomized males, cancer patients and patients with autoimmune or dermatological diseases.

Spontaneous sperm agglutination was observed in the ejaculate of a 39-year-old male (patient Z). Using an enzyme-linked immunosorbent assay (ELISA) with spermatozoa fixed to wells of a microtitre plate it was determined that IgA was associated with patient Z's spermatozoa but not with a pooled sample of spermatozoa from fertile men Z's seminal fluid agglutinated human spermatozoa (titre 1:16). In contrast, no sperm-agglutinating or immobilizing activity was present in the patient's serum. Agglutination was prevented by preincubation of the seminal fluid with anti-IgA antibody but not with anti-IgA antibody. IgG from Z's seminal fluid readily bound to human spermatozoa, as determined by the ELISA assay. IgA from a pool of seminal fluids from fertile men or from 18 human sera bound to spermatozoa to a much lesser extent. By sucrose-gradient velocity centrifugation it was demonstrated that the anti-sperm IgA in patient Z's seminal fluid was 11S. Finally, antibody to secretory component removed the anti-sperm IgA from Z's seminal fluid. These data provide evidence that secretory IgA with anti-sperm activity is produced in the male genital tract. Furthermore, a new methodology is presented for the determination of antibodies to spermatozoa.

Unmeasurable total haemolytic complement (C) was observed in serum of a patient with untreated chronic lymphocytic leukaemia and recurrent non-hereditary angioedema. Analysis of C components immunochemically demonstrated a marked reduction of C1q and C1s inhibitor, undetectable C1r, C1s and an elevated B. Haemolytic C1, C4 and C2 were less than 5 percent of normal, functional C1s inhibitor was absent. Cryoglobulin and C1q precipitins were present in the serum. Of special interest was the presence of high levels of cold-reactive antilymphocyte antibody, determined by both C-dependent cytotoxicity and indirect immunofluorescence. The antibody exhibited specificities for both autologous lymphocytes and lymphocytes from normal donors; cytotoxic activity for autologous leukaemia cells was removed by absorption with normal isologous tonsil lymphocytes. Specific enrichment of this antibody relative to the serum level was demonstrated in the cryoglobulin and its isolated 19S fractions. Free lymphocyte surface antigen was also demonstrated by gel diffusion using specific rabbit antilymphocyte antiserum. These data strongly suggest the presence of pathogenetically significant circulating complexes of lymphocyte surface antigen and specific antibody in certain patients with CLL.

The effect of ultraviolet-inactivated feline leukaemia virus (UV-FeLV) on the development of feline immunoglobulin-secreting cells (ISC) was investigated using a reverse haemolytic plaque assay. Low concentrations of UV-FeLV at 2 X 10(-4) to 2.0 micrograms/ml stimulated the production of ISC. By contrast, the same concentration of UV-FeLV suppressed the development of pokeweed mitogen (PWM)-driven ISC. Maximum suppression of ISC occurred at 50 micrograms/ml of UV-FeLV. The generation of an interferon resistant to acid, heat and sodium dodecyl sulphate (SDS) in the media of lymphocyte cultures incubated with PWM was also significantly suppressed in the presence of 0.2 microgram/ml of UV-FeLV. These findings suggest that non-infectious viral particles appear to modify feline immunoglobulin and interferon-secreting systems.

An enzyme-linked immunosorbent assay (ELISA) for the quantitation of immune complexes in sera has been developed using Raji cells. In this assay the Raji cell-adherent complexes are detected by an alkaline phosphatase-conjugated rabbit anti-human IgG and the results are obtained by spectrophotometric measurements of the concentration of yellow colour produced after the enzyme's substrate, p-nitrophenyl phosphate, is added. This assay is as sensitive and reproducible as the Raji cell radioimmune assay using 125I, as it can detect as little as 16 micrograms of immune complex equivalent to heat-aggregated IgG/ml in serum samples. This method is inexpensive, convenient and most importantly, avoids the biohazards of using an isotope.

Serum levels of circulating immune complexes (CIC) assayed by the Raji cell radioimmunoassay, total haemolytic complement (TCH50), Clq and C3 were correlated with clinical stage, histological type, age, sex and treatment of eighty-six children with Hodgkin's disease over a period of 4 years. Most significant findings were the changes of levels of CIC, TCH50, Clq and C3 during disease activity and following treatment. Significant perturbations were also seen in association with relapse. Levels of C and CIC were significantly elevated (P less than 0.001) at the time of diagnosis prior to splenectomy and/or any treatment. In the group before treatment, 81 percent of CIC levels were above 16 micrograms/ml with a maximum value of 1120 micrograms/ml. During treatment 33 percent were still above normal with a maximum of 320 micrograms/ml. Within 1 year after cessation of treatment, 37 percent also remained above normal levels with a maximum of 240 micrograms/ml. At relapse prior to treatment, 63 percent were again elevated with a maximum of 1280 micrograms/ml. The most significant difference on TCH50 levels relates to treatment periods. Sera of patients with active disease who are previously untreated show elevation of TCH50 levels (P less than 0.001) (average 127 CH50 mu/ml. During and after treatment eht TCH50 levels drop to 96 and 102 CH50 mu/ml, as compared to normal control of 100 CH50 mu/ml. In sera of patients at the first, second or third relapse, the combined TCH50 levels are significantly different from controls and across treatment periods (P less than 0.005).

Levels of circulating immune complexes were determined in the Trinidadian population with a high incidence of acute post-streptococcal sequelae, acute rheumatic fever and acute post-streptococcal glomerulonephritis. The studies were done on acute phase and serial bleedings up to 6 months after the acute illness. C1q solid phase assay employing radiolabelled protein A and the Raji cell radioimmunoassay were used in the detection of immune complexes. Both groups of patients had significantly elevated levels of immune complexes during the acute phase and showed an equivalent decline to slightly elevated levels during the 6 months of observation. The incidence and molecular size of the immune complexes in the two post-streptococcal sequelae were equivalent. The Raji cell assay tended to show much higher levels of complexes on an absolute basis, but both assays demonstrated an equivalent decline from the acute phase. These studies suggest that the presence of equivalent levels of complexes in two entirely different post-streptococcal sequelae indicates that other factors, such as the nature of the antigen in the complex, are more important in the pathogenesis of the post-streptococcal sequelae than the actual presence or the absolute levels of complexes.

Total haemolytic complement was reduced in blister fluids of four pemphigus vulgaris patients when compared to serum complement levels and other serum and blister fluid proteins. Complement levels in most control blister fluids, on the other hand, more closely approached their corresponding serum levels. Haemolytic C1, C4, C2, C3 and C5, measured in two pemphigus sera and blister fluids, were not measurable in one blister fluid and were extremely low in the second patient. C3 proactivator (C3PA) was absent from both of these blister fluids. Three of the blister fluids exhibited anti-complementary activity when tested with normal human serum. By adding one blister fluid to normal human serum, inhibition of haemolytic C1, C2, C3 and C5 with conversion of C3 and C3PA occurred. Activation of complement locally in pemphigus blister fluids would suggest a pathogenetic role for complement in this disease.