Use of activated partial thrombin time and prothrombin time for quality assessment of fresh frozen plasma

The aim of this study was to evaluate the usefulness of activated partial thromboplastin time (APTT) and prothrombin time (PT) for determining the quality of fresh frozen plasma (FFP) units in low-income countries. Quality control was conducted for 66 randomly selected FFP units after 3 months of freezing at - 20 °C. The average volume of the FFP units was 177.8 ± 17.3 mL, with average concentrations of 79.9 ± 40.2 IU/dL for factor VIII, 83.4 ± 29.3 IU/dL for factor IX, and 2.3 ± 0.7 g/L for fibrinogen. Fifty-six percent of the FFP units had a factor VIII level greater than or equal to 70 IU/dL. Unlike PT, the PT ratio, and the international normalized ratio, both APTT and the APTT ratio provided useful information regarding factor VIII level compliance, with areas under the curve of 71% and 73%, respectively. The optimal cutoff values for FFP unit compliance assessment were 40 s for APTT and 1.23 for the APTT ratio. Accuracy rates were 65% and 70%, with Cohen's kappa coefficients of 0.31 and 0.40 for the APTT and APTT ratios, respectively. APTT outperformed PT, and showed fair to moderate agreement with factor VIII level compliance in FFP units.