The reaction of tubercular serums to phenols.

Abstract

In continuing the investigations on the precipitin reaction in tuberculosis begun by Larson, Montank and Nelson, 1 it was found that certain non-specific substances would serve as “antigens”.

If a serum from a tuberculous patient is covered with dilute solution of thymol, toluene, phenol or tricresol a cloud is formed at the interface of the two fluids. The reaction occurred with such regularity in the tests on tuberculous serum that it was considered worthy of further investigation. Tricresol was selected as the reagent to be used and made up to a concentration of 0.2 of one per cent in physiologic saline solution. The serums to be tested were covered with the reagent and incubated at 37° C. for a period up to 2 hours. The positive reactions often appeared in the first few minutes. In the far advanced cases the reaction developed more slowly, and in some cases, a week or more before death ensued, a negative result was obtained. Normal guinea pig, sheep, and rabbit blood serums gave negative results when tested with the reagent. Serum from guinea pigs with moderately advanced tuberculosis gave positive reactions, while those in the last stages of the disease usually gave negative tests.

Thus far the blood serum of 3030 human cases have been examined. Of these, 2286 were students entering the university. Four hundred and eighty-eight were patients in the University Hospital and Dispensary, but not in the tubercular clinic. Two hundred and fifty-six cases, representing all stages of tuberculosis, were from local sanatoriums. From the 2,286 students seven positive reactions were obtained. Two of these have since been found to have tuberculosis, although at the time of the test there were no other symptoms of tuberculosis to be found.