Some Observations on the Value and the Mechanism of the Red-Cell Adhesion Test for Trypanosomiasis of Man and other Animals

Abstract

1. The results of further tests with the red-cell adhesion phenomenon in trypanosomiasis of man and other animals, described first by Duke and Wallace (1930) and later by Wallace and Wormall (1931), are discussed. 2. The conclusion is reached that the tests should always be made with several different strains of trypanosomes; in this way the number of negative results with undoubted cases of trypanosomiasis is decreased considerably. It is also advisable to have available stock adhesin sera (human or monkey) so that preliminary tests can be made to determine whether the trypanosomes in any animal are capable of giving adhesion. In doubtful cases of trypanosomiasis, treatment with trypanocidal drugs should be started. This treatment usually results in a marked improvement in the power of the serum or plasma of men and monkeys infected with trypanosomes to give red-cell adhesion. 3. If a suitable small amount of phenol is added to the serum of a trypanosomiasis patient, this serum can be kept at the ordinary temperatures for 3 weeks or more without appreciable loss of its power to give red-cell adhesion. In this way it is possible to carry out tests at a central laboratory on sera which have been collected at outlying stations. 4. Experiments have been carried out to determine the amounts of adhesin and complement (or “X factor”) required for red-cell adhesion. 5. The adhesin is non-dialysable, and in this, and many other respects it behaves like a true immune body.