A chloroquine elution technique for platelet serology

The authors describe a prototype elution method employing chloroquine, a quinoline derivative, to elute IgG antibodies from the platelet surface. This chloroquine elution technique is relatively easy to perform and is effective in the removal of alloantibodies from the platelet surface. Eluted alloantibody was immunologically active once the chloroquine was removed from the eluate. The major advantage of this technique is that serologic testing of platelets after elution is possible, as 50 percent of the platelets remain after exposure to hypertonic acid chloroquine solution. Antigens on the platelet surface maintained their antigenicity subsequent to treatment, although measurable reductions in PIA1 reactivity occur. The elution technique was also successful in removing IgG from the platelet surface in patients with diseases involving elevated levels of platelet-associated IgG.