Summary
Understanding of developmental haemostasis is critical to ensure optimal prevention,
diagnosis, and treatment of haemorrhagic and thrombotic diseases in children. As coagulation
test results are known to be dependent on the reagents/analysers used, it is recommended
for each laboratory to define the age-dependent reference ranges by using its own
technical condition. That study was carried out in seven centers to establish age-specific
reference ranges using the same reagents and analyser. Plasma samples were obtained
from 1437 paediatric patients from the following age groups: 15 days-4 weeks (n=36),
1–5 months (n=320), 6–12 months (n=176), 1–5 years (n=507), 6–10 years (n=132) and
11–17 years (n=262). Indication of coagulation testing was pre-operative screening
for non-acute diseases in most cases. PT values were similar in the different age
groups to those in adults, whereas longer aPTTs were demonstrated in the younger children.
Plasma levels of all clotting factors, except for FV, were significantly decreased
(p<0.0001) in the youngest children, adult values being usually reached before the
end of the first year. The same applied to antithrombin, protein C/S, and plasminogen.
In contrast, FVIII and VWF levels were elevated in the youngest children and returned
to adult values within six months. The same applied to D-dimer levels, which were
found elevated, particularly until six months of life, until puberty. These data suggest
that most coagulation test results are highly dependent on age, mainly during the
first year of life, and that age-specific reference ranges must be used to ensure
proper evaluation of coagulation in children.
Keywords
Coagulation - childhood - paediatrics - reference ranges - developmental haemostasis
