Rosette formation by sensitized human red cells- effects of source of peripheral leukocyte monolayers

Employing standardized IgG-coated 51Cr-labelled human red blood cells (RBC), variation in rosette formation among monolayers obtained from 10 healthy donors was defined, as well as variation among 24 sequential monolayers obtained from one healthy donor and 8 sequential monolayers from a second healthy donor over a 4-month period. Rosette formation, expressed as eluate cpm per plate, average 220 (range 35-472) for the 10 donors; 24 determinations on one donor average 201 (range 59-420), 8 determinations on the second donor averaged 244 (range 69-395). Striking increases in rosette formation were observed employing monolayers from 4 of 4 normal subjects during the course of viral infections, with peak values exceeding 5, 8, 13 and 14 X the normal mean. Elevations were also observed with monolayers prepared from blood of selected patients with hematologic disorders; a remarkable value 168 X the normal mean was repeatedly obtained for a patient with myeloid metaplasia whose monolayer consisted almost exclusively of mature granulocytic rosette-forming cells. The results emphasize the influence of monolayer donor variables on rosette formation.