Numerous studies indicate that several drugs and particularly arsenic compounds, may stimulate antibody production and that their curative effect in the treatment of disease and particularly syphilis and experimental trypanosomiasis, may be ascribed to this influence upon antibody production in addition to their direct parasiticidal influence.
In our experiments, the intravenous administration of arsphenamine to normal rabbits in doses varying from 0.01 gram to 0.004 gram per kilogram of body weight (equivalent to 0.6 to 0.24 gram per 60 kilos), did not result in an increased output of immune hemolysin to sheep cells, but rather suppressed hemolysin production; smaller doses did not appear to retard hemolysin production to sheep's and human cells but likewise they did not result in an increase. The smaller doses, however, generally produced a slight increase of agglutinin for sheep's and human cells.
Similar results were observed with mercuric chloride; large doses appeared to suppress hemolysin and agglutinin production while smaller doses tended to increase the production of hemagglutinins but not that of the hemolysins.
A single large dose of arsphenamine (0.06 gram per kilo) administered intravenously to rabbits reduced the hemolytic activity of their sera within a period of twenty-four hours after injection, probably by an influence upon the hemolytic complement; the administration of a smaller dose (0.6 gram) to syphilitic persons as part of the treatment of their infection, was found generally to produce a depression in the hemolytic activity of the serum as tested one hour after injection followed by a general increase within eighteen hours.
Large doses of arsphenamine and mercuric chlorid to rabbits tended to limit agglutinin production for typhoid bacilli; single doses of arsphenamine (0.6 gram) in adults did not influence the amount of normal typhoid agglutinin in their sera.
The general result of these experiments indicates that while massive doses of arsphenamine and mercuric chlorid tend to suppress antibody production and cause a decrease in hemolytic complement, smaller doses tend to increase the production of antibody (agglutinins) and augment the complement content after a primary decrease. It is probable that both drugs administered in the treatment of syphilis, owe part of their therapeutic efficacy to their influence upon increasing antibody production and complement.3