Factors influencing the development of leprosy: an overview.

The clinical manifestations of leprosy vary, seemingly depending on the host's immune response. Mode and route of infection, such as skin versus nasal mucosa, insect bites, sexual and gastroenteral transmission, together with genetic factors that may contribute to the outcome of the infection, including HLA, Lewis factor, Nramp1 and more subtle inherited alterations, are discussed. It is theorized that a balance between host responses elicited by different routes of infection and size and spacing of inocula is responsible for the clinical and immunological manifestations of the disease. Genetic factors and contact with environmental microorganisms may modulate these responses. The final result, resistance, delayed-type hypersensitivity, tolerance, disease or no disease, spectrum and reactions, is most likely reached via the orchestration of the induced cyto- and chemokines.

No evidence of linkage between Mitsuda reaction and the NRAMP1 locus.

Thirty sib-pairs were ascertained through unrelated lepromatous probands. They consisted of 22 healthy individuals and 8 leprosy patients. The Mitsuda reactions of all sibs were evaluated both macroscopically and histologically, and high molecular weight genomic DNA was extracted from the white blood cells of all sib-pairs. Three DNA polymorphisms identified by polymerase chain reaction (274C/T, D543N, 1729 + 55del4) were used as chromosome markers at the NRAMP1 locus. Sib-pair comparisons did not disclose any sign of close linkage between the Mitsuda reaction and the genetic markers.

Serial Mitsuda tests for identification of reactional tuberculoid and reactional borderline leprosy forms.

The authors studied the Mitsuda reaction in 37 leprosy patients (18 reactional tuberculoid, 19 reactional borderline cases) and compared the results with clinical findings, histopathology and bacilloscopy. Evaluation of the Mitsuda reaction was carried out on days 30, 60, 90 and 120. Most of the reactional tuberculoid patients showed a Mitsuda reaction of +3 in opposition to the reactional borderline patients who showed only +. Bacilloscopic analysis revealed that in 75% of the reactional tuberculoid cases there were rare or no bacilli; bacilli were present in 95% of the reactional borderline cases. The authors conclude that reactional tuberculoid cases have a greater ability to clear bacilli than reactional borderline cases, and that the Mitsuda reaction is a useful tool for the differentiation between these two types of leprosy.

Results of a surveillance system for adverse effects in leprosy's WHO/MDT.

The implementation of the World Health Organization's multidrug therapy (WHO/MDT) in Brazil began slowly and gradually in 1986, and in 1991 it was adopted officially by the Brazilian Ministry for Health. After 1991, during the intensive phase of WHO/MDT implementation, there was some concern about the number of cases of renal failure observed in several Brazilian states, including some fatalities. This was the motive behind the state of São Paulo's Health Department's decision to carry out a study that would evaluate not only the incidence rate of adverse effects of rifampin in relation to kidney function but also in relation to the use of WHO/MDT in general. Due to the existence in the state of São Paulo of health services with a program for the control of Hansen's disease and an organized and stratified system of epidemiological surveillance, it was possible to elaborate a subsystem for data collecting. During the period from July 1991 to December 1993, 20,667 patients were treated with WHO/MDT. Among this group there were 127 notifications considered as adverse effects, mainly: "flu"-like syndrome (54), acute renal failure (20), cutaneous reactions (15), toxic hepatitis (15), gastrointestinal complaints (8), hemolytic anemia (6), methemoglobinemia (4), thrombocytopenic purpura (2), hypotension (2) and disseminated intravascular coagulation (1). There was a predominance of adverse effects among multibacillary (MB) patients and the majority of the reactions occurred before the 6th dose; 82.7% of MB patients had had previous treatment with dapsone and rifampin and, due the fact that most severe reactions were related to rifampin, a booster mechanism could be an explanation for this occurrence. So far, there are seven published reports on renal failure in the world, and in Brazil only in the state of Søao Paulo there were 20 cases reported among 20,667 patients under WHO/MDT treatment, This striking difference deserves a better explanation, but in no way do these reports undermine the positive aspects of WHO/MDT. However, the authors believe that a world alert about its possible serious side effects is not only necessary but ethically required.

Um dos problemas na classificaçäo da hanseníase / A problem in leprosy classification

O autor, admitindo as reações reversas tipo I, como um dos grandes problemas na classificação das formas clínicas da hanseníase, discute a evolução dos conceitos a elas relacionadas desde a era pré-sulf"nica até os dias atuais. Considera tanto as reações que ocorrem em casos tuberculoides ou dimorfos j estabelecidos, como aqueles que se manifestam agudamente como a única manifestação da doença, antes, durante ou após o tratamento, como expressões de um mesmo fen"meno, ou seja, uma reação de hipersensibilidade tardia a antígenos liberados pela destruição do M.leprae que estava se multiplicando. Baseado na discussão dos fatos apresentados, propõe uma classificação em que cada forma clínica é imut vel e não admite alterações imunológicas durante sua evolução.