Activation of T-cells and Activity of Macrophages among Smokers with Leptospirosis: a Synergistic Dynamics in the Impairment of Human Immune System

Continuous heavy rains along with poor road construction and sewage system had resulted in the frequent occurrence of floods in many areas of the Philippines. As a consequence, leptospirosis remains an infectious disease endemic in the Philippines with numerous cases reported as aftermaths of typhoons especially after heavy flooding. Leptospirosis is known for its invasiveness in penetrating mucous membranes and abraded skin, in inducing macrophage response activity, and in activating T-cell proliferation. Chronic exposure to tobacco smoking weakens the immune system by reducing macrophage phagocytic activity and conferring T-cell insensitivity. In this study, a system of ordinary differential equations was developed to describe the synergy of leptospirosis and smoking in the impairment of immune system. The rate capacities of macrophages and T-cells in response to both smoking and leptospirosis were calculated. In the disease-free model, population of macrophages remains larger when compared with T-cells, and this predominance persists in the synergistic immune response to both smoking and leptospirosis. Leptospira infection in human immune cells is dose-dependent, and is more rapid in smoking-impaired than the normal cells. Findings of the study on these parameter estimates characterize the functions of macrophage and T-cell populations, although further molecular studies are warranted, which are necessary to address the inadequacy of antibiotic therapy in advanced and severe leptospirosis cases.