Systematic review on heparin-induced thrombocytopenia in children: a call to action.
BACKGROUND
Heparin-induced thrombocytopenia (HIT) has increasingly been reported in children as an indication for use of new alternative anticoagulant drugs (NAADs).


OBJECTIVE
To systematically review the literature regarding: (i) the incidence and prevalence of seroconversion and HIT and (ii) the clinical/laboratory findings and management of HIT in children.


METHODS
MEDLINE and EMBASE databases were searched for studies that reported pediatric cases of HIT. Methodological reliability assessment of studies was performed with the Loney scale.


RESULTS
The incidence of seroconversion in neonates ranged between 0% and 1.7%. There were no cases of neonatal HIT in the included cohorts. The incidence range of seroconversion in the non-neonatal population was 1.3-52%. The incidence of HIT in non-neonates after cardiopulmonary bypass was 0.33% (95%CI, < 0.01-2.04). Whereas more than half of pediatric cases labeled as HIT (30/52) did not include pivotal features of this syndrome, 80% of them received NAADs.


CONCLUSIONS
The incidence of HIT is likely to have been overestimated in children, leading to potential misuse of NAADs in many cases. Clinical findings and laboratory assessment of pediatric cases are poorly described in the literature at present. Thorough laboratory investigation, proper reporting of cases and adequate design of studies are mandatory to elucidate the clinical/laboratory picture of pediatric HIT.
Division of Hematology/Oncology, Department of Pediatrics, The Hospital for Sick Children, Toronto, ON, Canada.
M L
ML
Avila
V
V
Shah
L R
LR
Brandão
D000925:Anticoagulants / Q000009:adverse effects*; D002648:Child; D006493:Heparin / Q000009:adverse effects*; D006801:Humans; D015994:Incidence; D013921:Thrombocytopenia / Q000139:chemically induced* / Q000453:epidemiology
D000925:Anticoagulants; D006493:Heparin