Abstract :Object: Patients with Mycobacterium avium complex (MAC) infection without predisposing lung disease are predominantly elderly and often thin women. Malnutrition is an important cause of immune suppression and increases host susceptibility to infections. Recent evidence indicates that leptin functions as a signal in a feedback loop regulating food intake and body weight, is capable of modulating the immune responses. The objective of this study was to clarify the role of leptin in the infection of MAC.
Patients and Methods: We retrospectively analyzed the serum leptin concentration and other clinical characteristics in 41 patients with definitive primary pulmonary MAC and 28 normal female controls matched for age and body mass index.
Results: Serum leptin and TNF-a concentrations in the patient group (4.00 ± 2.40 ng/ml and 1.17 ± 0.42 pg/ml, respectively) were significantly lower than those in the control group (4.86 ± 3.90 ng/ml and 1.33 ± 0.97 pg/ml) (p=0.043 and 0.021). No significant differences in other clinical characteristics were observed between two groups.
Conclusion: These findings suggest that leptin is one of the defense mechanisms against MAC infection in individuals without predisposing lung disease.