THE HISTOPATHOLOGICAL STUDY OF THE MITSUDA REACTION (PART 1)

Abstract

1) Observations were made on 34 specimens of biopsies obtained from 8 cases of neural leprosy, each taken from the cutaneous sites of Mitsuda reactions following various lapses of time after above reaction. Simultaneously, control tests were performed with emulsions of inactivated organisms such as Mycobacterium leprae muris, Mycobacterium phlei (Timoty) and BCG. The following results were obtained.
2) Within the first three days after injection, an inflammation of the non-specific, acute exsudative type was observed, while on the other hand a granulation similar to that in tuberculosis was observed to begin to appear approximately 8 days after injection and to fully establish itself after 2 weeks. However, only very rarely had this granulation been seen to display caseous degeneration.
3) Occurrence of this tuberculosis-like granulation was found to differ very slightly in comparison with the histological changes found in experimentally inoculated BCG, Mycobacterium leprae muris or Mycobacterium phlei (Timoty), either in their chronological or quantitative aspects.
4) Intracellular sojourn of inoculated organism in the epitheloid cells or giant cells was found to be relatively long.
5) Mitsuda reaction in the case of neural leprosy, may be considered as a normal reaction rather than that of an allergic nature.
6) There could be detected no differences in the histological picture in the Mitsuda reaction, no matter what the outcome of the tuberculin test.