Antibodies to retrovirus proteins in scleroderma

In 8 out of 29 patients with scleroderma we found antibodies to HIV retroviral proteins in the Western blot analysis. The sera reacted only to one or two of the following bands: p 18, p 24, p 55, p 65 in relatively weak grades. There were no evident clinical correlations with the reactivity of certain bands, nor signs of direct HIV infection in our patients. Apart from 3 cases with positive CMV reactivity (IgM), there was no cross-reactivity to HTLV I or EBV (IgM) and to topoisomerase (Scl 70) or other autoantibodies to various nuclear antigens related to scleroderma. It is not clear whether retroviruses are involved in the pathogenesis of scleroderma or whether these antibodies are due to molecular mimicry.