High prevalence of anti-cardiolipin antibody, C1q-, C3d-, and mRF-IgG immune complexes, and anti-nuclear antibody in hemophiliacs irrespective of infection with human immunodeficiency virus type 1.

We investigated the prevalence of various autoantibodies [anti-cardiolipin antibody (aCL), lupus anticoagulant (LA), immune complexes (ICs), anti-nuclear antibody (ANA), and anti-deoxyribonucleic acid antibody (aDNA)] in hemophiliac individuals with (n = 50) and without (n = 42) infection by human immunodeficiency virus type 1 (HIV-1). The positivity rate for ANA was similar in both groups, and none of the patients was positive for LA and aDNA. aCL was positive in 35 of 50 (70%) HIV-1-positive hemophiliac individuals and 33 of 42 (79%) HIV-1-negative hemophiliac individuals. However, the majority of the aCL was revealed to be beta 2-glycoprotein I independent, thus corresponding to a syphilis type aCL that does not cause the so-called antiphospholipid syndrome. A total of 39 of the 45 HIV-1 positive hemophiliac individuals (87%) and 34 of 41 HIV-1-negative hemophiliac individuals (83%) had at least one type of IC [C1q-, C3d-, and/or murine monoclonal rheumatoid factor (mRF)- IgG]. The mechanism producing various autoantibodies in hemophiliac persons irrespective of their HIV-1 status is still unclear, but pathogens (e.g., HIV-1, hepatitis B, and hepatitis C) and alloantigens in the blood products that these patients require may be possible candidates. The clinical significance of the presence of these autoantibodies and the underlying mechanisms involved both need to be clarified further.