Background

CD36 is a transmembrane glycoprotein which is present in a variety of cell types, including platelets, and haematopoietic progenitors. CD36-deficiency can lead to CD36 iso-immunizations e.g. from allogeneic platelet transfusion. Platelet cryopreservation can be used as an alternative to room temperature storage of platelet concentrates. Especially, in the absence of compatible platelet products, the cryopreservation of autologous platelet concentrates can be crucial for patient care.

Methods

We report the case of a 21-year-old patient with acute myeloid leukemia and a type I CD36-deficiency. Autologous platelets were collected at three different days by apheresis for cryopreservation prior to the conditioning therapy for an allogeneic transplantation of stem cells from a CD36-positive donor. Platelet concentrates (PC) were irradiated and cryopreserved with a final concentration of 5% DMSO, automatically frozen and stored at -170°C. Platelet concentration was measured with a haematology analyser and swirling was assessed before and after cryopreservation. To estimate platelet activation, the P-selectin (CD62P) degranulation assay and the delta granules mepacrine-uptake and release assay were carried out with ADP and TRAP6.

Results

PC concentrations showed no significant decrease after cryopreservation. Without stimulation, an increased degranulation assessed by surface expression of CD62P was observed before and even higher after cryopreservation. Additionally, degranulation was less induced with ADP and TRAP6 after cryopreservation. After TRAP6 stimulation of mepacrine loaded platelets, cryopreserved PC show only minor release of delta granules compared to fresh platelet concentrates. Swirling and lack of aggregates was observed after thawing PC. Three out of eight autologous platelet concentrates were given at day eight and nine after allogeneic hematopoietic cell transplantation and showed an adequate increment of platelets with no clinical signs of bleeding.

Conclusion

Transfusion of platelet concentrates is a supportive prophylactic therapy for patients with hematologic diseases. With no available compatible platelet products, the cryopreservation of autologous platelet concentrates is a feasible supportive therapy option. In case of a CD36-deficency with CD36 iso-antibodies, autologous platelet concentrates can be applied after previous allogeneic hematopoietic stem cell transplantation from a CD36-positive donor.

Offenlegung Interessenkonflikt:

The authors declare that no conflict of interest exist.