N-factor/Anergic Magin or resistance/suscetibility to hanseniasis I. The foundations of the theory

ABSTRACT

The foundations of the the pathogenetical theory N-factor/Anergic Margin postulated in 1937 and completed in 1957 are given. Based on the observation of 2160 persons who had been tested by the author with Mitsuda's and frequently with other alergens , it was hypothesized that all individuals are born Mitsuda negative but gradually become Mitsuda positive with age, after stimulation by Hansen's mycobacterium, Myco tuberculosis BCG or other unknown agents, if they are capable of reacting, depending on the presence of a constitutional natural factor of resistance (N-factor). If infection occurs, the N-factor bearers resist, but tuberculoid lesions may appear if accessory factors coadjuvate. The minority, lacking the N-factor, remains Misuda negative throughout life (Anergic Margin) and, if infected, may progress to the Virchovian aspects after the same coadjuvation . An extensive range of intermediate reactivities should be placed between both extremes of maximal hyperergy and maximal anergy. The eythematous and/or hypochromic macule would be the theoretical initial stage of the tuberculoid, Virchowian and intermediate lesions. The theory contradicted Mitsuda's hypothesis of exhaustion of the Mitsuda positivity to explain the anergy of nodular (Virchovian) patients. It gave support to a genetical basis for predisposition to hanseniasis and was pessimistic about the preventive possibilities of BCG. The general acceptance of the theory - under its original or modified terminology, the pending questions, and the field it represents for future research will be the subjects of following articles of this series