Basophilia as an Index of Resistance.

Abstract

In a recent study of the blood cytology of rabbits 1 which included differential white cell counts with the supravital technic, some observations were made which suggested that the absolute numbers of basophils in the circulating blood might have some relationship to the character of the reaction to infection with Treponema pallidum. In general, it was found that those animals which had the highest preinoculation basophil values developed the mildest syphilis and those animals which had the lowest pre-inoculation basophil values developed the most severe syphilis, as determined by clinical examination. The basophils as well as other cells of the blood have also been studied during the course of the disease, and the result of this investigation will be reported later.

Observations were made on 5 groups of male rabbits, a total of 39 animals. The experiments were done at different periods during 1927-28. The blood was examined a variable number of times before inoculation with T. pallidum, the number of counts ranging from 4 to 36 per animal per group. The average number of basophils in these counts determined the pre-inoculation level for each animal. The lapse of time between the blood counts and inoculation also varied; in 3 groups the cells were counted during the 3 weeks immediately preceding inoculation, in the fourth group more than a month before inoculation, and in the fifth group the counts were made during a 9 months’ period which ended 3 months before inoculation. In each experiment, a tissue emulsion containing actively motile spirochetes was injected in the right testicle. The course of disease was followed systematically over a period of 3 to 4 months.

The relation found between the values for basophils before inoculation and the reaction to the syphilitic infection may be illustrated by a simple comparison of the results obtained with respect to the incubation time of the primary lesion and the metastatic orchitis, and by the occurrence and non-occurrence of such disease manifestations as edema of the inoculated testicle, metastatic orchitis, and generalized lesions.