An affinity-based method for the purification of platelet factor 4 from outdated platelet concentrates

Background & Aims: Platelet factor 4 (PF4) is considered as a chemokine mainly strode in the granules of platelets. Its important role in heparin-induced thrombocytopenia (HIT) was the basis of many investigations about this chemokine. High affinity to heparin was used to extract of PF4 from platelet concentrates (PCs). Despite many advantages of recombinant PF4 (rPF4), some researchers prefer to purify rich proteins of platelets from outdated PCs mainly because of cost effectiveness. The main aim of this study was introducing a home-made method to purify PF4 from PCs in blood banks. Materials & Methods: In this experimental study, we presented a customized procedure based on immunoaffinity chromatography to isolate PF4 that may be useful for laboratory access of PCs from blood bank centers. Briefly, platelet lysate (PL) was extracted from PCs by freeze/thaw cycles and then treated with anti-PF4 antibody to elute PF4 extract in the final product. Data were analyzed by SPSS software (version 26). Student t-test was used to compare the results. A probability of < 0.05 was accepted as significant statistically. Results: Our experiments showed that immunoaffinity chromatography might be considered as an alternative source to provide PF4 particularly in view of cost effectiveness. Conclusion: PF4 is one of the most bulk growth factors stored in platelets. It has the versatile applications both in diagnosis of HIT and in the study of platelet biology. A home-made protocol presented in this investigation can be helpful to obtain PF4 from blood bank in a reasonable scale.