Some coagulation parameters among apparently healthy medical laboratory science undergraduate students of Rivers State University, Port Harcourt

Abstract

Introduction: Prothrombin time (PT), International normalized ratio (INR) and activated partial thromboplastin time (APTT) are screening tests used to evaluate the overall integrity of the intrinsic, extrinsic and common coagulation pathway as well as monitoring and management of coagulation disorders. This study was aimed at assessing the PT, INR and APTT among apparently healthy undergraduate Medical Laboratory Science students of Rivers State University, Port Harcourt.

Materials and Methods: A total of 100 apparently healthy undergraduate Medical Laboratory Science students of Rivers State University, Port Harcourt comprising of 44 males and 56 females within the age range of 17-40 years were recruited for this study. Five milliliters (5ml) of venous blood was collected from each participant using a standard venipuncture technique into a vacutainer bottle containing 3.2% tri-sodium citrate anticoagulant in a ratio of 1:9 of the anticoagulant and the blood and mixed thoroughly. Prothrombin time and activated partial thromboplastin time were determined by clotting method using the Helena C4 semi-automated, photooptical coagulation analyzer and the Agappe thromboplastin test kit manufactured by Agappe Diagnostics Switzerland while INR was calculated by using the ratio of the study subjects’ PT to the mean of control PT raised to the power of the reagent international sensitivity index (ISI). The data obtained was analyzed using Graphpad Prism Software version 6.00. Data was presented as means, median, range and standard deviation.

Results: The mean ± SD of the PT, INR and APTT were 12.9± 1.624s, 1.01±0.1281 and 37.99±8.898s in the same order. The reference intervals obtained for PT, INR and APTT were 9.7-16.2s, 0.8-1.3 and APTT 20.2-55.8s in the same order. The lower limits were within the ranges established by previous researchers while the upper limitswere higher.  The age range 21-25 had the highest frequency count (54), which was followed by <20 (26), 26-30 (17) and then <30 (3). The overall mean values for the age groups were within the established normal values and as such no statistically significant difference was observed between the various groups.

Conclusion: This study has established the mean values and reference intervals of PT, INR and APTT for apparently healthy Medical Laboratory Science undergraduate students of Rivers State University, Port Harcourt as well as established that age does not have any significant effect on PT, INR and APTT. Due to geography, lifestyle, and genetic diversity, it is recommended that each laboratory establishes geography-specific reference intervals for PT, INR and APTT.