| Abstract: | In a patient suffering from rheumatoid arthritis thorough investigations led to the discovery of complete deficiency in the 7th component of the complement. A study of the patient's family tree confirmed the hereditary, codominant autosomal character of the deficiency, unrelated to the HLA system. The complement-dependent serum functions were investigated: the opsonizing and chemotactic activities were preserved, but bactericidal properties were lacking. Coagulation studies showed disorders in platelet aggregation in the presence of thrombin, and these were corrected by the addition of C7. The association of a dysimmune disease with C7 deficiency is probably not fortuitous; it might result from a common gene abnormality or, in some cases, from repeated infections. |
