The Complement Fixation Test in Yellow Fever. ∗

Abstract

Yellow fever offers opportunity for study of the immune reactions of a virus disease under circumstances which eliminate error due to collateral antigens. According to Schultz 1 collateral antigens have been a frequent source of error in previous studies of the complement fixation reaction in virus diseases. Material quite free from collateral antigens can be obtained in yellow fever as antigen for the complement fixation test.

Aragao 2 has reported unfavorably upon the complement fixation test in yellow fever with antigens prepared from phenolated tissues. On the supposition that the antigenic substances in tissues affected by virus diseases might be within the cells, Ciuca 3 has made use of a process described as septic maceration in order to liberate the cellular contents. He reports success in differentiating between the 3 principal types of foot and mouth disease by complement fixation with antigens prepared in this way. The method of preparing the antigen for our tests is based on a procedure followed by Hindle 4 in making vaccine from yellow fever tissues. He produced rupture of the cells by causing a sudden change in the osmotic pressure of the fluid in which the tissues were suspended.

In preparing antigen, pieces of liver and spleen were taken at autopsy from monkeys which had died from experimental yellow fever. This material was ground thoroughly with sterile sand and soaked over night in the refrigerator in half its weight of 9.0% sodium chloride solution. The mixture was then suddenly diluted to the physiological concentration of salt by the addition of distilled water. The suspension of tissue thus prepared was centrifuged and passed through Berkefeld “V” filters. The filtrate constituted the antigen.