Evaluation of serum KL-6 levels in patients with pulmonary tuberculosis

Summary Setting: KL-6, a human MUC-1 mucin preferentially expressed on type II pneumocytes, is a sensitive serum marker for evaluating alveolar damage of interstitial pneumonia and pulmonary fibrosis. Some patients with pulmonary tuberculosis develop severe respiratory dysfunction caused by extensive pulmonary fibrosis, compensatory emphysema and fibrous pleural thickening. Objective: To evaluate the clinico-pathological significance of KL-6 in pulmonary tuberculosis. Design: Serum KL-6 levels were measured in sera from 57 patients with active pulmonary tuberculosis and 38 healthy controls by a sandwich-type enzyme-linked immunosorbent assay. Immunohistochemistry was performed by an avidin-biotin-peroxidase complex method. Results: KL-6 levels were significantly higher in the patients than in the healthy controls (518 ± 693 [SD] vs 227 ± 91 U/ml, P P P Conclusions: In pulmonary tuberculosis, serum KL-6 originates from proliferated type II pneumocytes and cuboidal epithelial cells, and is a useful marker presenting the degree and extent of pulmonary fibroproductive lesions.