One of the most common host cells that mycobacteria encounter is macrophages. The process of monocyte-derived macrophages phagocytosing M. leprae is controlled by protein kinase and can be facilitated by complement receptors CR1 (CD35), CR3 (CD11b/CD18), and CR4 (CD11c/CD18). A Th2 cytokine profile appears to be correlated with nonreactivity to M.Leprea.
The Ridley-Jopling classification (1962) divides leprosy into six forms: Tuberculoid (TT), Borderline Tuberculoid (BT), Borderline-borderline Mid-borderline (BB), Borderline-Lepromatous (BL), Subpolar Lepromatous (LLs), and Polar Lepromatous (LLp). These categories are based on clinical, histopathological, and immunological criteria. According to WHO, leprosy is classified into two groups: the paucibacillary (PB) and multibacillary (MB) types, to aid in treatment.
Leprosy is treated as an outpatient procedure using WHO-standardized regimens from 1982, which essentially consist of three first-line medications: clofazimine, rifampicin, and dapsone. This relationship is referred to as polychemotherapy, or MDT (PCT). With minimal bactericidal activity, sulfone (diaminodiphenyl sulfone, or DDS), commonly referred to as dapsone, primarily acts as a bacteriostatic agent.
It most likely functions as an antagonist of para- aminobenzoic acid (PABA), preventing M. leprae from using it to synthesize folic acid. It is well-tolerated and has a number of adverse effects, most of which do not require stopping treatment.
The primary bactericidal effect of rifampicin (RMP), a semi-synthetic derivative of rifamycin B, is observed. It functions by preventing the RNA-polymerase enzyme in the bacillus from growing. RMP has been used to treat leprosy since 1963. Most of the bacilli become non-viable after a few days of therapy, and its use is crucial in all clinical types of leprosy. Clofazimine (CLF) is an iminophenazine dye . It has a mild bactericidal action, acting slowly on M. leprae and destroying 99% of the bacteria in approximately five months. Its efficacy is similar to DDS. CLF has an important anti-inflammatory action.
With an estimated heritability of up to 57%, family studies and community epidemiological surveys have amply established the significant role that host genetics plays in an individual's vulnerability to leprosy.
RAB32 is a low molecular weight G protein belonging to the Ras superfamily. It is necessary for the production of autophagic vacuoles and the control of autophagy's removal of aggregated proteins. Rab32 may play a similar role in the pathogenesis of leprosy, according to a recent study that found the protein controls the recruitment of cathepsin D to phagosomes containing Mycobacterium tuberculosis.