Detection of anti-kelch-like 12 and anti-hexokinase 1 antibodies in primary biliary cholangitis patients in China.

OBJECTIVES

primary biliary cholangitis (PBC) is a chronic cholestatic disease, characterized by positive anti-mitochondrial autoantibodies (AMA) in 90-95 % patients. Anti-kelch-like 12 (anti-KLHL12) and anti-hexokinase1 (anti-HK1) antibodies have been identified as the two new serum markers in recent years, which are used in the diagnosis of AMA-negative PBC patients. The objective of the study was to examine the performance of these two new biomarkers in China.

METHODS

a total of 192 patients were enrolled and screened for anti-KLHL12 and anti-HK1 antibodies and AMA by ELISA. Receiver operating characteristic (ROC curve) analysis was applied to examine the diagnostic importance of AMA, anti-KLHL12 and anti-HK1 antibodies. Furthermore, correlation analysis between some important biochemical indexes (alanine aminotransferase [ALT], aspartate aminotransferase [AST], alkaline phosphatase [ALP], bilirubin, gamma-glutamil transferasa [γ-GT]), staging of pathological changes of the liver and the expression of novel antibodies in PBC patients were also examined.

RESULTS

the positivity of the anti-HK1 antibody in AMA-positive PBC patients and AMA-negative patients was 44.7 % and 33.3 %, respectively. The specificity, proportion of positive patients (PPV) and proportion of negative patients (NPV) were 93 %, 89 % and 53 %, respectively. In contrast, the positivity to the anti-KLHL12 antibody in AMA-positive and negative PBC patients was 41.2 % and 22.2 %, respectively. Specificity, PPV and NPV were 98 %, 95 % and 52 %, respectively. The area under the curve (AUC) with anti-HK1 and anti-KLHL12 antibodies were 0.720 and 0.703. With the combination with anti-HK1 and anti-KLHL12 antibodies, the AUC of AMA increased from 0.889 to 0.891, increasing the sensitivity from 0.764 to 0.836. Anti-KLHL12 and anti-HK1-positive patients had higher serum levels of ALP, γ-GT and bilirubin, with statistically significant differences (p < 0.01) compared with anti-KLHL12 or anti-HK1-negative patients. Notably, correlation analysis showed a significant positive correlation between antibody expression and ALP, γ-GT and bilirubin serum levels (r = 0.735, 0.491, 0.466; p < 0.01).

CONCLUSIONS

anti-HK1 and anti-KLHL12 antibodies have been identified as two significant biomarkers in PBC patients. Furthermore, the presence of these antibodies is likely to correlate with the severity of PBC.