Serological markers of autoimmunity in renal transplant patients before and after alpha-interferon therapy for chronic hepatitis C.

Abstract

Chronic hepatitis C is the major cause of chronic liver disease after successful cadaveric renal transplantation. The aims of this prospective, open study were to assess in such a population, firstly the prevalence of different organ-specific and nonspecific antibodies and related disorders, and secondly their outcome after inteferon-alpha therapy as well as the incidence of new immunologic disorders under and after this therapy. In 15 cadaveric renal transplant patients (10 men, 5 women, ages 29-65 years) with chronic hepatitis C and histological features of chronic active hepatitis, undergoing chronic immunosuppression (ciclosporine A with or without steroid and azathioprine) and treated with recombinant alpha 2b-interferon (IFN alpha) (mean duration 142 +/- 35 days), we assessed before and after this therapy the serum levels of cryoglobulinemia, rheumatoid factors (RF), thyroid-stimulating hormone (TSH), free thyroxine (fT4), and antinuclear (ANA), antismooth muscle (ASMA), antimitochondrial (AMA), anti-LKM1, antimicrosomal thyroid (MCA), antithyroglobulin (TGA) autoantibodies. At the start of IFN alpha therapy, 14 of 15 patients had detectable autoantibodies (RF: 9; ANA > 1/50: 8; ASMA > 1/50: 4; other autoantibodies: 0); 1 had cryoglobulinemia. At the end of therapy the cryoglobulinemia had disappeared, the preexisting autoantibodies remained present in all patients but 2; 3 patients had developed MCA without evidence of clinical or biological thyroid abnormalities and 3 others had developed either RF (1) or ANA (1) or ASMA (1), without any related symptoms. One patient developed transient type II diabetes mellitus without anti-Langerhans beta-cell antibodies. Finally, the occurrence of autoantibodies in our patients was associated either with HLA DR3 or DR4 or DR7 phenotypes. We found that the prevalence of extrahepatic immunologic abnormalities was high in renal transplant patients with chronic hepatitis C and no exacerbation was observed during of after IFN alpha therapy. The most frequent autoantibody appearing after IFN alpha therapy was MCA although without thyroid abnormalities.