Abstract Number: PB0536
Meeting: ISTH 2020 Congress
Background: Previous studies in the setting of developmental haemostasis have established age-specific differences in the quantity, function of haemostatic proteins and functional assays. Routine and specialized haemostasis assays in the paediatric population should thus be undertaken with these differences in mind. Reagent, analyser and age-specific reference ranges should be established for all clinically utilised laboratory tests.
Aims: This study aimed to establish age-related reference intervals for activated partial thromboplastin time (APTT), prothrombin time (PT) and fibrinogen, using the STA R Max® analyser and Stago reagents, STA® – C.K. Prest®, STA® – NeoPTimal and STA® – Liquid Fib
(Diagnostica Stago, France).
Methods: Citrated plasma samples were obtained via clean venepuncture from 44 healthy neonates and 132 healthy children undergoing elective surgery (e.g. circumcision). Results were divided into the following age groups: newborns (from birth to 1 month of age), infants (greater than 1 month to 2 years of age), children (greater than 2 to 12 years of age) and adolescents (greater than 12 to 21 years of age). Results were analysed using GraphPad Prism version 7.04, and are expressed as mean with intervals including 95% of the population (2.5th percentile – 97.5th percentile) in accordance with CLSI guidelines.
Results: Mean values and reference intervals according to age are presented in Table 1. The mean values for aPTT, PT and fibrinogen differ significantly between newborns and adolescents.
| NEWBORNS Birth to 1 month |
INFANTS >1 Month-2 Years |
CHILDREN >2 Years-12 Years |
ADOLESCENTS >12 Years-21 Years |
|
| APTT (sec) mean reference interval |
n=40 * 37.6 29.9 – 52.7 |
n= 41 34.4 28.2 – 96.5 |
n= 44 32.0 26.9 – 36.5 |
n= 41 31.2 26.2 – 38.7 |
| PT (sec) mean reference interval |
n= 44 * 17.6 12.8 – 24.9 |
n= 45 14.1 12.6 – 16.6 |
n= 43 14.7 13.3 – 16.8 |
n=43 14.6 12.8 – 15.8 |
| Fibrinogen (g/L) mean reference interval |
n= 44 * 3.10 1.92 – 4.81 |
n= 45 2.50 1.75 – 3.34 |
n= 43 2.74 2.03 – 3.77 |
n=43 2.72 1.81 – 3.50 |
| * P-value significantly different from adolescents (p=<0.05) | ||||
[Table 1: Reference intervals for neonates, infants, children and adolescents.]
Conclusions: This study confirms the need to develop analyser and reagent specific reference intervals across the age spectrum, enabling accurate interpretation of coagulation tests and accurate diagnosis for newborns and children.
Other Items for Consideration: Written informed consent was obtained from parents of children. This study was approved by the Royal Children´s Hospital Ethics in Human Research Committee (Reference number 34183). This study was funded by Diagnostica Stago, France.
To cite this abstract in AMA style:
Letunica N, Karlaftis V, Monagle P, Ignjatovic V. Paediatric APTT, PT and Fibrinogen Reference Intervals Using STA® – CK Prest, STA® – NeoPTimal and STA® – Liquid Fib [abstract]. Res Pract Thromb Haemost. 2020; 4 (Suppl 1). https://abstracts.isth.org/abstract/paediatric-aptt-pt-and-fibrinogen-reference-intervals-using-sta-ck-prest-sta-neoptimal-and-sta-liquid-fib/. Accessed October 1, 2023.« Back to ISTH 2020 Congress
ISTH Congress Abstracts - https://abstracts.isth.org/abstract/paediatric-aptt-pt-and-fibrinogen-reference-intervals-using-sta-ck-prest-sta-neoptimal-and-sta-liquid-fib/