Preliminary communication on a complement deviation reaction exhibited in pregnancy

In a series of twenty-five normal pregnant women at term in which syphilis could be excluded the blood of the mother was taken from the vein during labor and the blood of the infant from the cord at the time of delivery. The sera after separation from the clots were frozen and allowed to remain in the icebox 48 hours before being employed. A series of complement deviation tests were carried out, using both unheated and heated sera of mothers and infants in conjunction with a large variety of antigens with the following results. The unheated mothers'sera invariably contained antibodies capable of causing a well-marked deviation of the complement when used in conjunction with an antigen obtained by extracting human blood clots with alcohol. The unheated infants'sera tested under the same conditions invariably showed completely negative results. A large variety of alcoholic extracts of tissues used as antigens gave similar although somewhat less marked deviation with unheated mothers'sera and absolutely negative results with unheated infants'sera. The deviating body concerned in this reaction is destroyed by heating for 1/2 hour at 58° C. The mother's sera tested after heating were negative to the antigens enumerated above, and those of the infants either negative or very slightly positive, but exhibiting on the whole a somewhat greater capacity to deviate than that possessed by the heated mothers'sera. The deviating capacity of unheated mothers'serum varies greatly, certain cases exhibiting a complete deviation only when employed in concentrations as high as .05 to .075 c.c. of serum, others giving a complete deviation when amounts as small as .001 c.c. of serum were employed. It is important to note that the antibodies in question occasionally fail to make their appearance until after the serum has been frozen for two or three days as indicated above.