Value of fumarate hydratase antibody in differential diagnosis of autoimmune hepatitis and drug-induced liver injury

Objective To investigate the value of fumarate hydratase antibody (anti-FH) in the differential diagnosis of autoimmune hepatitis (AIH) and drug-induced liver injury (DILI) . Methods From March 2014 to December 2016, 105 patients with AIH who were hospitalized in Beijing You'an Hospital were enrolled as AIH group, and 92 patients with DILI were enrolled as DILI group. A total of 128 healthy individuals were enrolled as control group. ELISA was used to measure the serum level of anti-FH. The t-test or the Mann-Whitney U test was used for comparison of continuous data between two groups, and the chi-square test or the Fisher's exact test was used for comparison of categorical data between groups. A consistency analysis of diagnostic compliance of anti-FH based on the Kappa test. The sensitivity, specificity, positive predictive value, and negative predictive value of anti-FH in the diagnosis of AIH were analyzed. Results Compared with the DILI group, the AIH group had significantly higher positive rate of anti-nuclear antibody (72. 4% vs 55. 4%, χ2=6. 147, P = 0. 013) and level of IgG ( (18. 3 ± 6. 1) g/L vs (15. 2 ± 5. 4) g/L, t =-2. 566, P = 0. 011) ) . The AIH group had a significantly higher positive rate of anti-FH than the DILI group and the control group (36. 2% (38/67) vs 6. 5% (6/92) and 2. 3% (3/128) , χ2= 59. 959, P < 0. 001) . In the diagnosis of AIH, anti-FH had a sensitivity of 36. 2%, a specificity of 93. 5%, a positive predictive value of 86. 4%, and a negative predictive value of 93. 5%. Conclusion Serum anti-FH has a certain reference value in the differential diagnosis of AIH and DILI.