Gastric parietal cell antibodies: demonstration by immunofluorescence of their reactivity with surface of the gastric parietal cells.

Viable, intact gastric cells were obtained by pronase digestion of inverted rat stomach. The cell suspensions contained two main distinct cell population, i.e. 'large' cells (mean diameter 16 microns) and 'small' cells (mean diameter 8.5 microns). By indirect immunofluorescence on smears of dispersed rat gastric cells, the large cells were identified as parietal cells, since all the sera containing parietal cell antibodies (PCA) were seen to react with the cytoplasm of these cells, leaving the cytoplasm of the small cells completely unstained. Thirty-one PCA-positive sera and forty-one PCA-negative sera were tested for gastric cell surface-reactive antibodies by an indirect immunofluorescence technique on suspensions of viable gastric cells. All the PCA-containing sera yielded a membrane immunofluorescence confined to the large cells, while none of the PCA-negative sera induced this fluorescent pattern. The surface reaction persisted unmodified when F(ab')2 fragments processed from IgG PCA-positive sera and FITC-conjugated pepsin fragments of rabbit IgG directed against the F(ab')2 fragments of human IgG were employed for the membrane fluorescence studies. The absorption of PCA-positive sera with viable, intact gastric cells led to the disappearance of both the surface immunofluorescence of the viable large cells and the cytoplasmic fluorescence of the rat parietal cells. These results demonstrate that PCA invariably react with an antigen represented on the surface of parietal cells, and that this antigen is immunologically identical to the intracytoplasmic 'microsomal' antigen

Autoimmunity and AIDS. I. Correlation between anti-cardiolipin antibodies and Pneumocystis carinii pneumonia

The Authors four that IgG anticorardiolipin antibodies (ACA) detected in patients with AIDS are primarily directed against epitopes on Pneumocystis carinii epitopes which are shared by lipoid auto antigens (molecular mimicry)

ANTICARDIOLIPIN ANTIBODIES IN OPPORTUNISTIC INFECTIONS IN AIDS

Autoimmune disorders are involved in the pathogenesis of AIDS. Clinical association between AIDS and and autoimmune diseases including arthritis, polymyositis, hemolytic anemia, vitiligo thrombocytopenic purpura, vasculitis, glomerulonephritis and Sjogren's syndrome, have been described. The authors try to assess a) the frequency of autoantibodies including anticardiolipin antibodies (ACAs) in sera from anti-HIV+ subjects and AIDS patients grouped according to their opportunistic infections and b) to verify the presence of phospholipid (cardiolipin) molecules on P. carinii and to their immunologic properties. The increased ACA in patients suffering from pneumocystosis was statistically significant as compared to all other groups

AUTOIMMUNITY IN MULTIPLE SCLEROSIS: STUDY A WIDE SPECTRUM OF AUTOANTIBODIES

We have followed up 63 pregnancies in women with autoimmune thrombocytopenic purpura (ATP). Of these, 15 were previously splenectomized. The characteristics of the sample can be summed up as follows: average age 27 years (17-41); platelets at the beginning of pregnancy, mean 129.5 x 10(9)/l (range 16-488); platelets at delivery, mean 133 x 10(9)/l (range 8-477); PA-IgG at delivery, mean 320 ng IgG/10(7) platelets (range 10-1000); SPB-IgG at delivery, mean 262 ng IgG/10(7) platelets (range 10-1000). There were 30 spontaneous deliveries and 33 cesarean sections. Forty-two newborns had a platelet count within the normal range while nine had a platelet count less than or equal to 150 x 10(9)/l, while six had less than or equal to 100 x 10(9)/l and a further six less than or equal to 50 x 10(9)/l. The aim of this study is the evaluation of maternal risk and of possible feto-neonatal thrombocytopenia at birth. In this regard, the following parameters were considered: previous maternal splenectomy; the platelet count at the beginning of pregnancy; the platelet count and the titres of PA-IgG and SPB-IgG at delivery. Preliminary statistical evaluation of these parameters enabled us to identify a risk score. From this it was possible to obtain an optimum management of the final stage of pregnancy regarding the therapeutic approach and the timing of delivery