Norma E. Riera

Anti-leukocyte antibodies as a consequence of HIV infection in HIV+ individuals

Antibodies (Ab) that induce antibody-dependent cell-mediated cytotoxicity (ADCC) against non-T lymphocytes, anti-HLA class II specific Ab and anti-PMN were tested in hemophilic (He) patients who were alloimmunized because they had received replacement treatment with blood derivates and become infected with HIV, as well as in those who remained seronegative. In addition, the serum reactivity of spouses of HIV+ individuals and their children was studied to determine the effect of HIV infection in the absence of concomitant alloimmunization. The results of this study indicate that ADCC Ab were already present in HIV- He, suggesting the influence of alloimmunization. Their titer increased after appearance of HIV disease. While low reactivity against class II antigens was observed in HIV- He, activity augmented sharply after HIV infection and increased further with disease progression. Anti-PMN reactivity followed a similar pattern. Anti-class II, ADCC Ab and anti-PMN were also detected in the asymptomatic HIV+ spouses of HIV+ patients in titers that were similar to those of asymptomatic HIV+ He. In children born to HIV+ mothers in whom HIV infection was confirmed, anti-class II, ADCC Ab and anti-PMN reactivity were also observed, and activity increased after the onset of disease. These results suggest that induction of anti-leukocyte Ab occurs in the absence of massive allostimulation after HIV infection. HIV infection may enhance preexisting class II and anti-leukocyte response in allostimulated individuals.

Leukoagglutinins in patients with hemophilia

Anti-leukocyte antibodies may occur in hemophilic patients as a consequence of replacement therapy with blood derivates. In this report we describe the presence of leukoagglutinins (LA) in serum of HIV-infected hemophiliacs (HIV + He) and their absence in HIV-negative patients (HIV-He). LA activity was recovered in IgG fractions from HIV + He, in the polyethylene glycol (PEG) precipitates from these sera, and in some cases in the supernatant fractions of PEG precipitates. Although the amount of PEG precipitates corresponding to circulating immune complexes (CIC) was higher in HIV + He than in HIV-He and normals, there was no direct relationship between CIC levels and LA. LA reacted both with autologous and with allogeneic polymorphonuclear leukocytes (PMN). In contrast to PMN isolated from HIV-He, HIV + He PMN had membrane associated IgG. In HIV + He, LA activity was more frequently observed in patients with more advanced stages of HIV infection than in asymptomatic individuals. Our results suggest that LA activity could be one of the manifestations of autoreactivity associated with progressing HIV infection in patients with hemophilia.

Anti-polymorphonuclear neutrophil antibodies in patients with leukopenia or neutropenia

Introduction:  Immune humoral neutropenia (Np) could be the consequence of anti‐polymorphonuclear neutrophil (PMN) antibodies, circulating immune complexes (CIC) and/or antibodies against myeloid precursors. Granulocyte immunofluorescence test (GIFT) and a leukoagglutination technique (LAGT) assays are recommended for its diagnosis.

Increased CD4-positive monocytes in HIV-infected haemophilic patients

The monocyte–macrophage system is known to play a central role in HIV infection, and expression of CD4 on the surface of monocytes/macrophages is important, since this molecule is a key factor for the entrance of HIV into susceptible cells. In this paper we evaluated the expression of CD4 in monocytes of haemophiliac patients (He) who had been infected with HIV (HIV+ He) through transfusion of contaminated plasma concentrates. Thirty seropositive patients (HIV+ He), 10 seronegative He patients (HIV− He) and 20 voluntary normal blood donors were studied. Phenotypic evaluation of monocytes was performed by flow cytometry of peripheral blood stained with anti‐CD45, ‐CD3, ‐CD4 and ‐CD14 monoclonal antibodies. The percentage of CD4 monocytes was increased in all HIV+ patient groups, but it was highest in those belonging to Groups III and IV A of the CDC classification. Furthermore, the median of fluorescence intensity of CD4+ monocytes from individual patients was shifted to the right, indicating expression of increased numbers of CD4 molecules on the cell membrane of monocytes. This could in turn favour HIV infection and viral persistence, facilitating in vivo dissemination of the virus.