Quantitation of reticulated platelets: methodology and clinical application.

A practical technique for the preparation and analysis of reticulated platelets is described. The use of fixed platelet-rich plasma has given optimal results and sample stability. This technique has detected consumptive causes of a platelet count < 80 x 10(9)/l with a positive predictive value of 96% and negative predictive value of 100%. The course of the reticulated platelet percentage (RP%) in patients with resolving thrombocytopenic states is described, contrasting the elevation seen in consumptive disorders with the fall in aplastic states. In patients undergoing stem cell transplant procedures a rise in the RP% precedes the rise in the platelet count, indicating that the reticulated platelets represent cells that are recently released from the bone marrow. The RP% peak in patients receiving autologous peripheral blood progenitor cell transplants is higher and more closely temporally related to the recovery of platelet count than it is in patients receiving autologous bone marrow transplants.