AUTOIMMUNE-DISEASE IS NOT A FEATURE OF HEPATITIS-C INFECTION IN IRELAND

To determine the prevalence of autoimmune disease, autoantibody positi vity, or both in Irish persons with hepatitis C, we surveyed 98 such p atients (55 recipients of anti-D, 25 intravenous drug abusers, and 18 blood transfusion recipients). We studied them clinically and tested f or anti-nuclear, anti-smooth muscle, and anti-mitochondrial, liver-kid ney microsomal, thyroid microsomal, thyroid globulin, and gastric pari etal antibodies; and also for rheumatoid factor. In the anti-D antibod y group (all female), two patients reported generalized musculoskeleta l symptoms but had no demonstrable physical signs. We did not find cry oglobulins in any patient. We detected thyroid microsomal antibodies i n only 6 of 55 (10.9%) patients. (In two of these, thyroid globulin an tibodies were also positive). These patients were all clinically euthy roid, but two had borderline low-normal thyroid function tests. Titers for anti-nuclear antibodies were weakly positive in 5 of 55 (9.1%) pa tients, and gastric parietal antibodies were positive in 5 of 55 (9.1% ) patients. In particular, we noted no antibodies to liver-kidney micr osome. Rheumatoid factor was detected in eight patients. Forty seven o f 55 patients were genotype 1b, and 8 of 55 were genotype 3. In the in travenous drug abusers (8 women, 17 men), we detected no autoantibodie s. Seven of the 25 genotypes were tested; three were genotype 3 and fo ur were genotype 1b. In the transfusion group (10 women, 8 men), we de tected no autoantibodies apart from weak anti-nuclear antibody Titers (1:10), which we found three patients. Five of 10 genotypes tested wer e of genotype 3 and the other five were of genotype 1b. These findings suggest that in Irish patients with hepatitis C, neither genotype nor source (and dose) of inoculum contributes to the development of autoi mmune disease. How hepatitis C virus is associated with autoimmune dis ease in other studies remains unknown. The answer may, at least in par t, be found in genetic; HLA typing studies should provide useful infor mation.