ORTHOTOPIC LIVER-TRANSPLANTATION FOR ADULT-ONSET TYPE-II CITRULLINEMIA

Citrullinaemia is a rare autosomal recessive disorder due to a deficie ncy of argininosuccinate synthetase (ASS). While the clinical course o f the adult onset form (Type II) is unpredictable, many patients under go sudden deterioration with progressive cerebral oedema. Two patients with Type II citrullinaemia were referred for liver transplantation. One patient was successfully transplanted, and his plasma citrulline l evel decreased from 300 to 69 mu mol/l (normal range 20-60 mu mol/l); Fisher's ratio increased to a normal range within 24 h of transplantat ion. The other patient died from cerebral oedema, despite optimal phar macological measures, while awaiting a suitable donor organ. Dietary a nd pharmacological treatment is vital before liver transplantation. Th e level of serum arginine requires regulation, as it can rise secondar y to citrullinaemia in Type II disease. An immunocytochemical study of the liver in both patients showed a clustered distribution of ASS whi ch is associated with a dismal prognosis compared with patients who ha ve a homogenous distribution. Distribution of ASS was normal in the tr ansplanted liver. Liver transplantation is effective therapy for adult -onset Type II citrullinaemia. A clustered pattern of ASS distribution in a liver biopsy is a significant feature to activate early referral for liver transplantation.