Evaluation of the Crithidia Assay to Distinguish Between Autoimmune Chronic Active Hepatitis and Systemic Lupus-Erythematosus

The aim of this study was to determine if the Crithidia luciliae assay for auto‐antibodies to double‐stranded DNA, often positive in systemic lupus erythematosus, is always negative in auto‐immune chronic active hepatitis (CAH) as has recently been suggested. Twenty‐five patients were identified as having auto‐immune CAH. Mean duration of follow‐up was 10.5 years. Antinuclear antibodies were detected in 92%, smooth muscle antibodies in 76% and antimitochondrial antibodies in 16%. Antibodies to double‐stranded DNA were detected by the Crithidia assay in four patients (16%). Two of these patients had positive tests on only one occasion and no features of systemic lupus erythematosus. In the other two the assay was persistently positive. During follow‐up both developed arthritis and serositis but the liver lesion remained the dominant clinical feature. It was concluded that there is significant serological overlap between auto‐immune CAH and systemic lupus erythematosus making the Crithidia assay unreliable in distinguishing between them. Copyrigh