A CD36 deficiency is virtually unknown in Caucasians while comparatively frequent in African, Arabian and Eastern Asian populations. CD36 type 1 deficiency enables the formation of CD36 isoantibodies because of immunization by pregnancy or platelet transfusions. However, transfusion of compatible platelets is challenging when CD36 negative donors hardly can be found within central Europe. We describe our strategy to provide CD36 negative platelet concentrates for immunized patients.

Anti-CD36 was found in a patient by a commercial Luminex assay (Immucor, Dreieich, Germany). The patient suffering from a glioma shows refractoriness to platelet transfusions. Flow cytometry with anti-CD36 FITC (clone FA6-152, Stem Cell Technologies, Vancouver, CAN), anti-CD42b PE (clone HIP1, Biolegend, San Diego, USA), and anti-CD14 PE (clone M5E2, Biolegend) was used to test the CD36 expression on the patients" platelets and monocytes. Basesd on this finding, we initiated a donor screening program for donors originating from Arabian and African countries. The CD36 expression was determined using anti-CD36 FITC and anti-CD42b PE. CD36 negative samples were further analyzed with a self-developed NGS Assay.

The patient showed a CD36 type 1 deficiency. Therefore, no compatible donors were available within our regular apheresis donor cohorts. We identified one potential unrelated whole blood donor and luckily, some family members were identified as CD36 negative with a negative MASPAT crossmatch, too. Due to our donor screening program, we were able to identify seven whole blood donors which were clearly negative for the CD36 antigen (= 1.3%) in indirect immunofluorescence. The seven CD36 negative donors were subjected to DNA sequencing and a variety of different mutations were observed. To better understand the mechanisms behind CD36, we are working on CD36 cDNA sequencing from whole blood samples and platelet concentrates.

Supply of CD36 negative platelets to immunized patients is a challenge for middle European blood services. To keep rare donors that have been identified as CD36 negative requires constant efforts. For some patients searching within closely related kins can be promising. We intend to continue our efforts of identifying and recruiting active CD36 negative platelet donors and to better understand the genetic background of CD36 deficiency.

No conflict of interest