Use of Chloroquine‐Treated Granulocytes and Platelets in the Diagnosis of Immune Cytopenias

A chloroquine modification of the fluorescent antiglobulin technique has been used to demonstrate cell-specific antibodies in the presence of HLA antibodies. This is of particular value in the diagnosis of alloimmune neonatal thrombocytopenia and neutropenia, post-transfusion purpura, and in the investigation of febrile non-haemolytic transfusion reactions and of patients refractory to platelet transfusions.