Blood Agglutinins in Blackwater Fever

Abstract

The serums from two cases of blackwater fever were tested for content of α, β, and cold agglutinins.∗ To 2 drops of the serum dilutions one drop of a 2% suspension of Groups A, B, and O erythrocytes was added. The suspensions in Wassermann tubes were incubated in a water bath at 37°C for 30 minutes followed by storage in the icebox at 6°C overnight. Examinations of suspensions for the presence of agglutinated erythrocytes was done after exposure to 37°C and 6°C with the aid of a dissecting microscope at a magnification of X20.

Since both serums contained α and β agglutinins, it was necessary to absorb these in order to test for cold agglutinins, Small portions of serums were treated three times with one-half volume of packed fresh Group AB erythrocytes. During each absorption, the mixture was incubated at 37°C for 30 minutes, then centrifuged and the supernatant was treated again with fresh Group AB erythrocytes. Small portions of serum were also treated with a polysaccharide isolated from Ascaris summ which has been shown to inhibit specifically the α and β agglutinins in human serums. 1 enough of the polysaccharide was added to make a 4% suspension. The mixture was incubated at 37°C for 30 minutes and then tested. The serums treated with the Group AB erythrocytes and with the ascarid polysaccharide, as well as the untreated control serums, were then tested with Group A, B, and O erythrocytes and examined after exposures to 37°C for 30 minutes and at 6°C overnight.

Table I shows that the serums from the 2 cases of blackwater fever had markedly increased α isoagglutinin titers of 1:8112 and 1:2028, respectively. After treatment of the serums 3 times with the Group AB erythrocytes, as well as after a single treatment with the ascarid polysaccharide, no α, β, or anti-0 agglutinins were detected after incubation at 37°C.