Seronegative Autoimmune Hepatitis A Clinically Challenging Difficult Diagnosis.

Autoimmune hepatitis (AIH) is a complex liver disease of unknown cause which results in immune-mediated liver injury with varied clinical presentations. Seronegative AIH follows a similar course to autoantibody-positive disease and diagnosis may be challenging. There are no single serologic tests of sufficient diagnostic specificity, and delay in appropriate treatment may lead to progression of the liver disease and liver failure. The revised conventional diagnostic criteria (RDC) scoring for AIH is complex and not routinely used in the clinical practice. The more recent simplified diagnostic criteria (SDC) scoring proposed by International Autoimmune Hepatitis Group in 2008 has wider application in routine practice facilitating the diagnosis of AIH with a specificity and sensitivity of ~90%. In this report, we describe a case of seronegative autoimmune hepatitis diagnosed using RDC. SDC score calculated in our case was 4 and was not diagnostic for AIH. We subsequently used the complex revised diagnostic criteria for definitive diagnosis. Some of the patients previously diagnosed as cryptogenic active hepatitis of unknown etiology probably had an unrecognized diagnosis of seronegative autoimmune hepatitis. SDC scoring may not be applicable in patients with seronegative autoimmune hepatitis. These patients should be reassessed by using RDC.