A SURVEY OF PLATELET SEROLOGY IN UK LABORATORIES (1987) - AN ASSESSMENT OF THE EFFICACY OF USING CHLOROQUINE-TREATED PLATELETS TO DISTINGUISH BETWEEN PLATELET-SPECIFIC AND ANTI-HLA ANTIBODIES

This survey was designed to determine the ability of participants to distinguish between platelet specific and anti-HLA antibodies. Four well characterized reference reagents and 10 unknown samples were sent to 29 laboratories affiliated to the UK Platelet and Granulocyte Serology Working Group and to three overseas reference laboratories. Results were obtained from 27 Working Group laboratories and from 2 reference laboratories. Overall, the results indicate that the use of chloroquine-treated platelets alone, without an independent test for anti-HLA antibodies, was insufficiently reliable to elucidate mixtures of platelet specific and anti-HLA antibodies. Laboratories using chloroquine treated platelets were no more successful in elucidating the antibody composition of sera containing platelet-specific and anti-HLA antibodies than those laboratories which did not use this technique. The results may indicate a lack of experience with the chloroquine technique and suggest that further studies into the performance of the technique are required. The survey also provided insights into other areas of platelet serology: (1) There was a decrease in the incidence of false-positive results compared to earlier UK surveys. (2) All laboratories detected potent platelet-specific antibodies but weakly reactive antibodies were less readily detected. (3) Laboratories using fluorescent antiglobulin techniques recorded fewer errors than laboratories using ELISA techniques. (4) Laboratories using paraformaldehyde (PFA)-treated platelets in fluorescent antiglobulin techniques did not perform better than laboratories using untreated platelets.