Simplified Autoimmune Hepatitis (AIH) Score Calculator

Simplified AIH Score items

The simplified AIH score helps simplify diagnosis in patients with established hepatitis and liver biopsy results with histological evidence.

The score helps reduce the complexity of AIH diagnoses, partly due to the lack of gold standard anatomic criterion and the multifactorial and competing diagnoses rich nature of AIH.

The 6 items and their assigned points are described in the table below:

Please note that if ANA or SMA/F-actin is positive or strongly positive, LKM1 ≥1:40, and SLA is positive, only 2 points are assigned, not 5.

If liver histology is normal, then AIH is not the diagnosis.

The Simplified AIH score has been evaluated in several studies, including comparisons with its predecessor, the conventional score. Validations are generally conducted in referral populations through database and chart reviews. The goal of the simplified score is to enhance specificity and reduce false positives, especially in the 'probable AIH' category.

The scoring system

The simplified AIH score is retrieved by adding the individual 6 item points to a final score. Again, please ensure that if the sum of the first 3 items is 5, this is automatically reduced to 2 for the final score. Likelihood of diagnosis is summarised below:

About the original study and further validation

The simplified diagnosis score was developed by Hennes et al. following a study of the International Autoimmune Hepatitis Group (IAIHG) diagnosis criteria. The training set included 250 AIH patients and 193 controls from 11 centers worldwide.

Several scores were built from variables showing predictive ability in univariate analysis then the diagnostic value of each score was evaluated by the area under the receiver operating characteristic (ROC) curve analysis.

The best score was then validated on data from additional 109 AIH patients and 284 controls. The area under the curve for prediction of AIH was 0.946 in the training set and 0.91 in the validation set.

The score showed 88% sensitivity and 97% specificity ( at a cutoff ≥6) and 81% sensitivity and 99% specificity ( at a cutoff ≥7) respectively, in the validation set.

The simplified criteria for the diagnosis of autoimmune hepatitis (AIH) include immunofluorescence testing (IFT) of antinuclear and smooth muscle autoantibodies (ANA and SMA) on rodent tissue sections.

A further 2021 study set by Galaski et al. set out to establish scoring criteria for the implementation of ANA IFT on human epithelioma-2 (HEp-2) cells and ELISA-based testing. The study showed that ELISA-based anti-F-actin evaluation was a strong predictor of AIH (AUC 0.88) and performed better than SMA assessment by IFT (AUC 0.77-0.87). At adjusted cut-offs, both ANA IFT using HEp-2 cells and ELISA-based autoantibody evaluation for ANA and SMA are potential alternatives to tissue-based IFT, for AIH diagnosis.

A validation study looked into the sensitivity, specificity, and positive and negative predictive values for the cut-off scores of ≥6 (probable AIH) and ≥7 (definite AIH).

Data from a total of 549 patients with chronic liver disease was analysed, (221 with AIH, 26 with variant syndromes, and 302 with non-AIH). For scores ≥6, sensitivity was 90%, and specificity was 98% with positive and negative predictive values of 97% and 92%, respectively. For scores ≥7; sensitivity was 70%, and specificity was 100% with positive and negative predictive values of 100% and 74%, respectively. Seven false positive diagnoses of AIH occurred, all with simplified scores of 6. The study concluded that the simplified criteria diagnosis model retains high specificity but exhibit lower sensitivity for scores of ≥7.

As the simplified criteria was only tested in adults, another validation study looked into its potential use in pediatric hepatology too. The study concluded that the 2008 criteria diagnose AIH in children with high levels of sensitivity and specificity.

References

Original reference

Hennes EM, Zeniya M, Czaja AJ, Parés A, Dalekos GN, Krawitt EL, Bittencourt PL, Porta G, Boberg KM, Hofer H, Bianchi FB, Shibata M, Schramm C, Eisenmann de Torres B, Galle PR, McFarlane I, Dienes HP, Lohse AW; International Autoimmune Hepatitis Group. Simplified criteria for the diagnosis of autoimmune hepatitis. Hepatology. 2008; 48(1):169-76.

Galaski J, Weiler-Normann C, Schakat M, Zachou K, Muratori P, Lampalzer S, Haag F, Schramm C, Lenzi M, Dalekos GN, Lohse AW. Update of the simplified criteria for autoimmune hepatitis: Evaluation of the methodology for immunoserological testing. J Hepatol. 2021; 74(2):312-320.

Validation

Yeoman AD, Westbrook RH, Al-Chalabi T, Carey I, Heaton ND, Portmann BC, Heneghan MA. Diagnostic value and utility of the simplified International Autoimmune Hepatitis Group (IAIHG) criteria in acute and chronic liver disease. Hepatology. 2009; 50(2):538-45.

Mileti E, Rosenthal P, Peters MG. Validation and modification of simplified diagnostic criteria for autoimmune hepatitis in children. Clin Gastroenterol Hepatol. 2012; 10(4):417-21.e1-2.