부산대학교 도서관

Background:We compared the international flow reference method IRM platelet counts with those obtained from CellDyn Sapphire impedance and optical counts, LH750 impedance counts, and the flowcytometry based ReaPanThrombo Immunoplatelet method ReaMetrix. We further evaluated the degree of agreement of above methods with the IRM at the transfusion thresholds of 10 × 109l−1and 20 × 109l−1.Methods:A total of 104 thrombocytopenic blood samples with platelet count of <50 × 109l−1were selected for the study. All samples were tested in parallel by various methods within 6 h of blood collection.Results:For bias estimation, a Bland–Altman analysis was done by taking the IRM as the standard method. The bias for CDSI counts was 6.505 × 109l−195 LA −2.110 to 15.122, for CDSO counts the bias was −3.779 × 109l−195 LA −8.950 to 1.392, for LH750 the bias was 0.111 × 109l−195 LA −5.862 to 6.084 and that for ReaMetrix was −1.602 × 109l−195 LA −7.400 to 4.194. The LH750 had the least average bias and it overestimated platelet counts marginally. The ReaMetrix method showed the highest degree of agreement with the IRM, at both the threshold points with a Kvalue of 0.960 threshold ≤ 10 × 109l−1 and 0.923 threshold ≤ 20 × 109l−1.Conclusions:Impedance platelet counts from LH750 were more accurate than optical methods in thrombocytopenic patients. ReaMetrix immunoplatelet counts show the maximum degree of agreement with the IRM at clinically relevant transfusion thresholds. We conclude that as current platelet transfusion thresholds are based on results of automated hematology analyzer methods, the true thresholds may be determined using the IRM and CD4161 based singleplatform immunoplatelet methods. © 2010 Clinical Cytometry Society