The lack of correlation between the positivity of anti-platelet antibodies and the presence of thrombocytopenia in course of HIV infection.

The presence of anti-platelet autoantibodies has been reported in many cases of HIV infection, but there is no accordance about their pathogenic role in the onset of thrombocytopenia in the patients studied. In the present study surface anti-platelet antibodies (PAIgG) and serum anti-platelet antibodies (sPAIgG) were assayed in a group of 135 HIV-infected patients (109 men, 26 women), in different clinical stages by using an immunofluorescence test (PSIFT). In order to investigate the possible correlation of the positivity of these autoantibodies and the onset of thrombocytopenia, some of these patients were controlled in a follow-up study, with two successful controls: 10 months (II control: 89 patients) and 20 months (III control: 59 patients) after the first time. In the I control PAIgG were positive in 68 subjects (50.4%) and sPAIgG in 34 (25.2%); both PAIgG and sPAIgG were present in 23 patients (17%). 56 patients did not present anti-plt antibodies (41.5%). No significantly different distribution of these autoantibodies in each stage of disease was observed. The mean value of platelet count resulted in the normal range both in the anti-plt antibody positive and in the anti-plt antibody negative patients, but the value found in the anti-plt antibody positive patients was significantly lower than the one found in the anti-plt antibody negative group (p < 0.01). This difference was more marked between the group with PAIgG and anti-plt antibody negative patients than between the group with sPAIgG and the anti-plt antibody negative patients (p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)