Anti-phospholipid antibodies in HIV infection and SLE with or without anti-phospholipid syndrome: Comparisons of phospholipid specificity, avidity and reactivity with beta 2-GPI

Increased prevalence of anti-phospholipid antibodies (aPL) and increased le vels of lipid peroxidation have been described in patients with HIV infecti on. To assess the binding specificity and avidity or aPL antibodies in HIV infection, sera from 44 HIV-1 infected patients were evaluated for antibodi es td cardiolipin (aCL), phosphatidyl serine (aPS), phosphatidyl inositol ( aPI) and phosphatidyl choline (aPC) using enzyme linked immunosorbent assay (ELISA) methods, Sera from 30 patients with systemic-lupus erythematosus ( SLE), but without features of anti-phospholipid syndrome (APS) (SLE/non APS ); six with SLE and secondary APS, (SLE/APS) and 11 with primary APS (PAPS) were also evaluated as controls. The resistance of the aPL antibody bindin g to dissociating agents was evaluated by treating the ELISA wells, after s erum incubation with 2M urea-or 0.6 M NaCl for 10 min. An anti-beta 2-glyco protein-I (beta 2-GPI) ELISA was used to assess serum reactivity against be ta 2-GPI, a plasma protein considered as the true antigen of aCL antibodies occurring in APS and SLE patients, The prevalence of aCL, aPS, aPI and aPC antibodies in HIV-1 infection was 36%, 56%, 34% and 43% respectively, whic h was:comparable to that found in SLE/APS and PAPS,patients and significant ly higher than that observed in SLE/non-APS patients. Anti-beta 2-GPI antib odies occurred in 5% of HIV-1 infected vs. 17% in SLE/non-APS (P=0.11), 50% in SLE/APS (P = 0.009) and 70% in PAPS patients (P = 0.0014). A significan t decrease of aPL binding after urea and NaCl treatment was observed in the sera of HIV-1-infected, compared to that of APS patients, indicating that aPL antibodies from HIV-1 infected individuals have low resistance to disso ciating agents. Ln conclusion, aPL antibodies (1) occur in HIV-1 infection; (2)tend-to recognize various phospholipids but not beta 2-GPI; and (3) are of low resistance to dissociating agents-a finding probably reflecting low antibody avidity. Finally, these, like the autoimmune-type aCL antibodies, tend to recognize the oxidized CL-a finding probably indicating autoantibo dy generation as a result of neoepitope formation by oxidized PLs; (C) 1999 Academic Press.