1961 Volume 30 Issue 3-4 Pages 163-168
To establish the best method of the preparation, standardization and preservation of lepromin, comparative studies on the skin reactions in leprosy patients were commenced using the following lepromin samples:
1) In the first experiment, two lepromins mady by different methods (Mw, by Wade in 1956 and M8, by the Mitsuda-Hayashi's method in 1958) were compared with each other. With respect to the early reaction, the two lepromins gave no significant difference. The Mw, however, elicited weaker late reactions than the M8. The results of bacillary counting of the Mw and M8 were 150 and 220 millions per ml, respectively.
2) To ascertain the effect of heat on the potency of lepromin, fresh nodules from leprosy patients were homogenized and divided into two parts, the one was autoclaved to make the Wade's lepromin (Ma) and the other was boiled with saline to make the Mitsuda-Hayashi's (Mb). The bacillary counting of the two lepromins gave nearly equal results, 276 millions per ml in Ma and 289 in Mb. The Ma antigen, however, elicited stronger late reactions than the Mb, while no difference was found with respect to the early reactions. From these results and from practical considerations, lepromin used actually in Japan are always made by the Wade's method.
3) An attempt was made to preserve the standard lepromin by freezdrying in vaccuo. After the storage in ice-box during one year, the dried lepromin was resuspended in 0.5% carbol water and its potency was compared to the standard lepromin stored in ice-box during one year. No significant difference was observed between the two lepromins with respect to the early as well as late reactions
