Elevated serum CA 19-9 levels in patients with pulmonary nontuberculous mycobacterial disease

Increased serum CA 19-9 levels in patients with nonmalignant diseases have been investigated in previous reports. This study evaluates the clinical significance of serum CA 19-9 elevation in pulmonary nontuberculous mycobacterial disease and pulmonary tuberculosis. The median CA 19-9 level was higher in patients with pulmonary nontuberculous mycobacterial disease than in patients with pulmonary tuberculosis (pulmonary nontuberculous mycobacterial disease: 13.80, tuberculosis: 5.85, p < 0.001). A multivariate logistic regression analysis performed in this study showed that Mycobacterium abscessus (OR 9.97, 95% CI: 1.58, 62.80; p = 0.014) and active phase of pulmonary nontuberculous mycobacterial disease (OR 12.18, 95% CI: 1.07, 138.36, p = 0.044) were found to be risk factors for serum CA 19-9 elevation in pulmonary nontuberculous mycobacterial disease. The serum CA 19-9 levels showed a tendency to decrease during successful treatment of pulmonary nontuberculous mycobacterial disease but not in pulmonary tuberculosis. These findings suggest that CA 19-9 may be a useful marker for monitoring therapeutic responses in pulmonary nontuberculous mycobacterial disease, although it is not pulmonary nontuberculous mycobacterial disease-specific marker.