HEREDITARY C1Q DEFICIENCY AND SYSTEMIC LUPUS-ERYTHEMATOSUS

We describe a 27-year-old woman with systemic lupus erythematosus, C1q deficiency and cytomegalovirus retinitis. She suffered from severe SL E, with cutaneous and CNS involvement, and died of CNS disease aged 28 . Review of 29 other published cases of C1q deficiency shows that SLE in these patients is often severe (five with CNS disease, ten with glo merulonephritis). The results of autoantibody studies in this and anot her patient with C1q deficiency and SLE are presented-both patients ha d autoantibodies to the extractable nuclear antigens, Sm, RNP and Ro, and one patient had high titres of antibodies to dsDNA. One of the pat ients had previously been treated with fresh frozen plasma, and antibo dies to C1q were present in his serum. Homozygous C1q deficiency is as sociated with a very high prevalence of severe SLE with the full panop ly of autoantibodies characteristic of this disease.