Abstract

The rosette inhibition test was used to measure serum immunosuppressive activity after azathioprine (1·5 mg/kg) in 20 patients with liver disease (10 with active chronic hepatitis, six with primary biliary cirrhosis, and four with miscellaneous hepatic disorders) and in nine healthy normal volunteers. Where possible testing was repeated after one week and after at least two months of treatment. The titre of immunosuppression was related to the degree of impairment of hepatic function, and was found to be low in those with severe and normal in those with mild disturbance of hepatic function. Titres were unrelated to the presence of immunological abnormalities such as smooth muscle antibodies. In patients treated for at least two months there was no relationship between the initial titre of immunosuppressive activity and the response to treatment. Thus some patients improved despite failure to develop immunosuppressive activity, while others deteriorated even though immunosuppressive activity was normal when first studied. The development of immunosuppressive activity after azathioprine seems to be dependent on adequate hepatic function and the favourable response of some patients with liver disease to the drug may not be due entirely to immunosuppression.