Impact of inherited thrombophilia on venous thromboembolism in children: a systematic review and meta-analysis of observational studies.
BACKGROUND
The aim of the present study was to estimate the impact of inherited thrombophilia (IT) on the risk of venous thromboembolism (VTE) onset and recurrence in children by a meta-analysis of published observational studies.


RESULTS
A systematic search of electronic databases (Medline, EMBASE, OVID, Web of Science, The Cochrane Library) for studies published from 1970 to 2007 was conducted using key words in combination as both MeSH terms and text words. Citations were independently screened by 2 authors, and those meeting the inclusion criteria defined a priori were retained. Data on year of publication, study design, country of origin, number of patients/controls, ethnicity, VTE type, and frequency of recurrence were abstracted. Heterogeneity across studies was evaluated, and summary odds ratios and 95% CIs were calculated with both fixed-effects and random-effects models. Thirty-five of 50 studies met inclusion criteria. No significant heterogeneity was discerned across studies. Although >70% of patients had at least 1 clinical risk factor for VTE, a statistically significant association with VTE onset was demonstrated for each IT trait evaluated (and for combined IT traits), with summary odds ratios ranging from 2.63 (95% CI, 1.61 to 4.29) for the factor II variant to 9.44 (95% CI, 3.34 to 26.66) for antithrombin deficiency. Furthermore, a significant association with recurrent VTE was found for all IT traits except the factor V variant and elevated lipoprotein(a).


CONCLUSIONS
The present meta-analysis indicates that detection of IT is clinically meaningful in children with, or at risk for, VTE and underscores the importance of pediatric thrombophilia screening programs.
Young
Guy
G
Division of Hematology/Oncology, Children's Hospital Los Angeles, Los Angeles, CA, USA.
Albisetti
Manuela
M
Bonduel
Mariana
M
Brandao
Leonardo
L
Chan
Anthony
A
Friedrichs
Frauke
F
Goldenberg
Neil A
NA
Grabowski
Eric
E
Heller
Christine
C
Journeycake
Janna
J
Kenet
Gili
G
Krümpel
Anne
A
Kurnik
Karin
K
Lubetsky
Aaron
A
Male
Christoph
C
Manco-Johnson
Marilyn
M
Mathew
Prasad
P
Monagle
Paul
P
van Ommen
Heleen
H
Simioni
Paolo
P
Svirin
Pavel
P
Tormene
Daniela
D
Nowak-Göttl
Ulrike
U
D002648:Child; D020022:Genetic Predisposition to Disease / Q000453:epidemiology; D006801:Humans; D012307:Risk Factors; D019851:Thrombophilia / Q000453:epidemiology* / Q000235:genetics*; D054556:Venous Thromboembolism / Q000453:epidemiology* / Q000235:genetics*