Cancer antigen 125 (CA-125) is usually elevated in ovarian cancer. However, there are several reports that serum CA-125 is elevated in tuberculosis. This study investigated the clinical significance of serum CA-125 measurements in patients with active pulmonary tuberculosis (TB).

Between September 2008 and March 2011, Serum CA-125 was measured in patients with active pulmonary TB before treatment (baseline), and 6 and 12 months after initiation of anti-TB treatment. Patients with pulmonary TB confirmed by culture or polymerase chain reaction for Mycobacterium tuberculosis (TB-PCR) were included.

The study enrolled 100 patients. The mean serum CA-125 was 38.9 ± 41.4 U/ml (reference value, <35 U/ml). Thirty-eight patients showed elevated CA-125. Significantly more of those with elevated CA-125 were female (p < 0.001), and had a positive sputum smear for acid-fast bacilli (AFB) (p = 0.030). They also significantly more showed extensive pulmonary lesions on chest X-ray (p = 0.004). Elevated CA-125 was independently associated with female gender (OR = 12.5, 95% CI: 3.4–45.2), positive acid-fast staining of sputum (OR = 6.0, 95% CI: 1.8–19.7), cavitary lung lesion (OR = 4.0, 95% CI: 1.2–12.9), and involvement of more than one lung on chest X-ray (OR = 9.4, 95% CI: 2.2–40.1). The CA-125 level decreased with anti-TB treatment (p = 0.001).

Serum CA-125 was related to the activity and severity of pulmonary TB, and it may be useful in the monitoring of therapeutic responses in certain cases of active pulmonary TB, especially in female patients of active pulmonary TB.