A comparison of liver ultrasound with liver biopsy histology in psoriatics receiving long-term methotrexate therapy.

A comparison of liver ultrasound and liver biopsy histology was made on 54 paired investigations from 28 patients about to receive or already receiving methotrexate for severe psoriasis. Ultrasound scans were reported as normal, or abnormal showing either fatty change or fibrosis. Eighteen of the scans were reported as normal and in no instance did the simultaneously-obtained liver biopsy show significant fibrosis. Thirty-one of the scans were reported as showing fatty change without fibrosis; in 12 cases the liver histology showed mild but significant fibrosis and in four cases fibrosis was of sufficient severity to necessitate methotrexate withdrawal. Five of the scans were reported as showing fibrosis and in all the biopsy showed significant fibrosis. This was of sufficient degree to necessitate methotrexate withdrawal in two cases. No patient with a normal ultrasound scan showed significant fibrosis and thus we concluded that such patients may be spared liver biopsy and safely continue with methotrexate therapy. Ultrasound cannot reliably distinguish between fatty change and fibrosis, so all patients with abnormal scans require liver biopsy.