Performance parameters of the diagnostic scoring systems for autoimmune hepatitis

The diagnostic criteria for autoimmune hepatitis (AIH) have been codified by an international panel, and a revision of the original scoring system based on 12 clinical components has been promulgated. A simplified scoring system has been proposed recently that is based on four clinical components. The goals of this study were to compare the performance parameters of the revised original and the simplified scoring systems and to determine the prowess of each as a diagnostic instrument. Diagnostic scores were determined using each scoring system in 435 patients with diverse chronic liver diseases, including 153 individuals with AIH by codified clinical criteria. The sensitivity, specificity, and predictability of each scoring system for the pretreatment diagnosis of AIH were determined. The revised original scoring system had greater sensitivity for the diagnosis than the simplified scoring system (100% versus 95%), and seven patients diagnosed as AIH using the revised original system were nondiagnostic by the simplified system (5%). The revised original scoring system also ascribed a diagnosis of AIH to 20 of 21 patients with cryptogenic chronic hepatitis, whereas only five patients were similarly classified by the simplified system (95% versus 24%). The simplified system had greater specificity (90% versus 73%) and predictability (92% versus 82%) for AIH than the revised original system, and it more commonly excluded the diagnosis in other diseases with concurrent immune features (83% versus 64%).

The revised original scoring system performs better in patients with few or atypical features of AIH, and the simplified system is better at excluding the diagnosis in diseases with concurrent immune manifestations. Each system has attributes that can be exploited.