Correlation between serum ANKRD22 and SERPING1 levels and drug resistance in pulmonary tuberculosis: A retrospective cross-sectional study.

Drug-resistant tuberculosis (TB) lacks rapid blood-based biomarkers. This study examined whether serum levels of ankyrin repeat domain 22 (ANKRD22) and serpin family G member 1 (SERPING1) are associated with drug resistance in TB patients. In this retrospective cross-sectional study, 170 culture-confirmed TB patients treated from January 2023 to December 2023 were classified as drug-resistant (n = 34) or drug-susceptible (n = 136) by phenotypic drug susceptibility testing. We quantified serum ANKRD22 and SERPING1 levels by enzyme-linked immunosorbent assay, used multivariate logistic regression to identify independent risk factors, and assessed diagnostic performance with receiver operating characteristic curve analysis. Both biomarkers were significantly higher in the drug-resistant group (P < .001) and positively correlated with resistance (ANKRD22 R = 0.551, SERPING1 R = 0.520). Area under the curve values were 0.898 for ANKRD22, 0.875 for SERPING1, and 0.912 for combined detection. After adjustment, elevated ANKRD22 and SERPING1 remained independent predictors, along with smoking, chronic obstructive pulmonary disease, cavitary disease, previous TB exposure, and treatment interruption. Serum ANKRD22 and SERPING1 are independently associated with TB drug resistance; their combined measurement improves diagnostic accuracy and may facilitate early detection of drug-resistant TB.