Diagnostic value of the tuberculosis-specific antigen, CFP10, in renal tuberculosis

The aim of this study was to investigate the expression of the tuberculosis-specific antigen, CFP10, in renal tuberculosis lesion tissues through immunohistochemical (IHC) staining and to assess its potential value in the pathological diagnosis of renal tuberculosis.

A retrospective study was conducted on renal tissue specimens that were surgically resected and paraffin-embedded at the Affiliated Hospital of North Sichuan Medical College from January 2016 to November 2023. The study comprised 49 cases in the tuberculosis group and 37 cases in the non-tuberculosis group (renal clear cell carcinoma). Immunohistochemical staining was utilized to detect CFP10 in renal tissues, in conjunction with real-time fluorescent quantitative polymerase chain reaction for the detection of Mycobacterium tuberculosis DNA and acid-fast staining, allowing for a comparison of the efficacy of these three diagnostic methods.

IHC staining revealed CFP10-positive signals localized in areas consistent with acid-fast bacilli distribution, though its expression pattern was more extensive. Correlation analysis demonstrated a significant positive association between acid-fast staining and IHC average optical density. Moreover, acid-fast staining, real-time fluorescent polymerase chain reaction, and CFP10 IHC staining exhibited a sensitivity and specificity of 4.08 and 100.00%, 83.67 and 100.00%, and 91.84 and 91.89%, respectively.

IHC detection of CFP10 may represent a supplementary diagnostic method for renal tuberculosis, especially in patients with negative etiological findings.