GRANULOCYTE AGGREGATION IS EDETIC ACID AND TEMPERATURE-DEPENDENT

Nineteen cases of leukocyte agglutination were observed in the last 6 years, while performing routine blood cell counts with an autoanalyzer (Technicon H6000). The phenomenon occurred only in edetic acid-antico agulated samples and only at room temperature. Leukocyte aggregation c ould be reproduced by incubating patient serum samples or edetic acid- plasma with whole blood from ABO-compatible healthy control subjects. When patient serum samples or plasma samples were first preincubated w ith anti-IgM serum and then mixed with normal blood, leukoagglutinates were not observed, suggesting that a plasma factor, probably an IgM, was responsible for the phenomenon. Nonetheless, IgM presence could no t be correlated with any particular disease or the use of specific dru gs.