Leukocyte antibodies in human sera and in immune rabbit sera

A study of leukocyte antibodies is presented using (1) the sera of rabbits immunized with human leukocytes, and (2) the sera of three patients screened forthe presence of such antibodies from among 36 patients with hematologic disease,31 of whom (including the 3 studied in detail) had received multiple transfusions.The following technics are described and were employed: Leukoagglutination,leukoprecipitation including tube and agar-plate methods, agglutination ofantigen-coated tanned and untanned sheep erythrocytes, the effect of antiseraupon phagocytosis of heat-killed staphylococci by leukocytes, and upon ameboidmotility of leukocytes.

The leukoagglutinin test gives reliable clearcut results providing that appropriate controls are included and certain criteria adhered to, in order to facilitatethe recognition of clumping due to other factors than true antigen-antibodyunion.

No leukoprecipitins were detected in human sera with the technics used inthis study. Immune rabbit sera, on the other hand, gave two reaction-lines inagar media, when set up against leukocyte extract.

Immune rabbit sera reacted strongly with antigen-coated tanned sheep redblood cells. Human sera did not so react. One of the three selected human serareacted with antigen-coated untanned erythrocytes, suggesting the presence of apolysaccharide antigen extractable from human leukocytes and capable of stimulating antibody formation in the human. Immune rabbit sera, and otherhuman sera, did not react in this test.

A suggestive but perhaps not a conclusive effect upon phagocytosis of bacteriaby leukocytes exposed to human leukocyte antibody for 1 hour could be demonstrated.

By means of ameboid motility studies, a cytotoxic effect of the human antiseraupon human leukocytes could be demonstrated after 18 hours of incubation, butnot after 3 hours. This was interpreted as evidence of a delayed reaction.

Certain cardinal points from a clinical and theoretical standpoint with regardto the genesis of leukocyte antibodies in man are briefly reviewed. A possibleanalogy between leukocyte antibody formation and the homograft reaction isdiscussed. It is suggested that the rarity of leukocyte iso-antibody formationfollowing transfusion is related to the fact that the intravenous pathway may bea poor route of immunization for these antigens.

Submitted on April 4, 1957 Accepted on July 1, 1957