Anticardiolipin antibodies in HIV infection are independently associated with antibodies to the membrane proximal external region of gp41 and with cell-associated HIV DNA and immune activation.

Background: The demonstration of in vitro cardiolipin reactivity with 2 human immunodeficiency virus (HIV)-specific, broadly neutralizing antibodies (2F5 and 4E10) has prompted reevaluation of autoimmune manifestations in HIV infection.
Methods: We evaluated autoantibodies, particularly anticardiolipin (aCL), in 67 untreated, asymptomatic, HIV-infected individuals with slow progression of HIV disease and their correlation with 2F5-, 4E10-, b12-, and 2G12-like antibodies directed against epitopes involved in broad neutralization, as well as their correlation with immune activation and virological and clinical indicators. Fifty individuals with chronic HIV infection and standard disease progression were control patients.
Results: The majority of the study patients with slow progression of HIV disease were men (78%); their median age was 37 years, their median CD4+ cell count was 672 cells/mL, and their median plasma HIV load was 6200 copies/mL. The majority of the control patients were also men (76%), and most (62%) were receiving highly active antiretroviral therapy; their median age was 43 years, their median CD4+ cell count was 202 cells/mL, and their median plasma HIV load was 2265 copies/mL. aCL immunoglobulin G was detected at similar levels in 49% of patients with slow progression of HIV disease and in 58% of control patients. Viral load was positively associated with aCL in both groups (P < .001), independent of CD4+ cell counts. In patients with slow progression of HIV disease, aCL levels were also correlated with plasma HIV load and cell-associated DNA level (r = 0.486 and r = 0.516, respectively; P < .001), with the proportion of activated CD4+ cells, human leukocyte antigen-DR+ cells (r = 0.445; P = or < .001) but not activated CD8+ T cells, and with the level of B cell activation (quantified by soluble CD23; r = 0.354; P = .007). The level of aCL antibodies was associated with the level of antibodies to the membrane proximal region of gp41 (P = .003).
Conclusion: aCL is frequently detected in HIV-infected patients, regardless of disease stage, and is strongly linked with the level of viral replication, the level of CD4+ T and B cell activation, and the level of antibodies to the membrane proximal external region of gp41, independent of CD4+ cell deficiency.