Platelet therapy: current opinions on laboratory and clinical aspects

The rapid development in blood component technologies has lead to production of various types of platelet concentrates which are highly heterogenous in terms of cellular content, subpopulation of platelet and leucocytes and in vitro characteristics and storage stability. This emphasizes the need for a stringent in-process validation and statistical process control to ensure that optimal process efficiency and platelet functional integrity are continuously attained and maintained throughout the 5 days shelf life. Several unresolved issues such as development of cytokines and microparticles, some with immunomodulatory effects; fears of bacterial contamination of leucodepleted platelets, in particular in storage media; lack of progress in reduction of some unquantified risk of all types of transfusion transmitted infection (TTI), still remain the focus of current interest. While some processing results recently succeeded in killing both viruses and bacteria through a recently developed viral inactivation and filtration process, nevertheless much still remains to be elucidated in respect to long term effects of such treatments. Apart from development of purer products to reduce transfusion reactions, some complimentory alternatives to platelet transfusion are becoming available, which in the near future, may influence the demand for platelet support.