LEPRA DE LUCIO: IV. PERFIL INMUNOLOGICO

A group of 24 patients suffering from diffuse lepromatous leprosy complicated with Lucio's phenomenon was studied. They showed severe impairments in several of their immunological parameters. The levels of the total serum proteins were elevated mainly due to an increase in the alpha-2 and gamma-globulin fractions. All of the immunoglobulin cases were elevated but the IgG and IgM cases were the most altered. The complement components (C₃ and C₄) were normal and the 50% hemolytic complement (CH₅₀) was only slightly elevated. The C-reactive protein and rheumatoid factor(s) tests were positive in many cases. 33% of the patients had circulating immune complexes as detected by their reaction with C1q, and all of them had circulating antimycobacterial antibodies. In general, the patients showed low numbers of T-lymphocytes (E-rosettes) and, in some cases, B-lymphocytes (EAC-rosettes) counts were elevated. A great majority of the patients showed negative LIF tests with lepromin as the antigen. The few cases in which the LIF test was positive could well be the result of a cross reactivity to M-tuberculosis antigens. The LIF test with PPD as the antigen and the response to the intradermal injection of PPD and other antigens were comparable to the results obtained in a normal group. These and other studies enable the authors to conclude that the patients with diffuse lepromatous leprosy have a specific depression in their cell-mediated immunity to the M. leprae antigens and that the Lucio's phenomenon could be the result of a type III, immune complexes-mediated, hypersensitivity.