Leprosy patients can be classified into one of the five groups of the clinical spectrum depending on the stage in disease progression and host cell-mediated immunity. At one end of the spectrum is tuberculoid leprosy, paucibacillary or designated TT, characterized by a small number of bacilli, a few skin lesions with well-defined edges, asymmetric neural involvement, AFB (acid fast bacilli) absent or in small numbers in the skin and nerves. The local production of cytokines in this pole of the disease is type 1, including interferon-gamma (IFN-Î³), interleukins (IL-2, IL-7, IL-12, IL-15 and IL-18) and specific cellular immune response characteristics are preserved. At the other end is the lepromatous pole, also known as LL or multibacillary leprosy, characterized by large numbers of bacilli and nerves in the skin, many lesions extensively infiltrated with macrophages and mycobacteria spongy tissue easily detected within this and nerves. Therefore, important impairment of type-2 cytokine production cell mediated immunity (IL-4, IL-5, IL-10) occurs, so that the affected individuals are anergic to M. leprae and have high titers of circulating antibody.
Last date updated on February, 2021