Circulating autoantibodies directed against conjugated fatty acids in sera of HIV-1-infected patients.

Several reports have demonstrated that major changes occur in the fatty acid content of HIV-infected cells. In order to evaluate if these changes are recognized by the immune system, we have attempted to assay the possible presence of autoantibodies (autoAb) directed against conjugated fatty acids (CFA). Using an adapted ELISA, anti-CFA autoAb were assayed in sera of 150 HIV-1-infected patients and 116 controls (healthy donors and patients suffering from other diseases). Significantly increased anti-CFA autoAb of IgG class were found in HIV-1-infected patients (alpha < 0.001). Using our ELISA method and CFA differing in their length and their degree of unsaturation (lauric, myristic, palmitic, palmitoleic, stearic, oleic, linolenic, linoleic, lignoceric, arachidonic, eicosapentaenoic and docosahexaenoic acids), it was demonstrated that the acyl chain of CFA is the immunodominant part recognized by these autoAb. Anti-CFA autoAb were present in 15/52 asymptomatic carriers, 14/36 symptomatic carriers, 16/39 ARC patients, but only 3/23 AIDS patients. Anti-CFA activity seemed to be linked with the CD4+ T cell count, and was not related to the total IgG amounts. Anti-CFA autoAb could result from self-antigen presentation to immunological cells, and may reflect lipid membrane modifications occurring in HIV-infected cells.