Evaluation of the presence of hereditary and acquired thrombophilias in Brazilian children and adolescents with diagnoses of portal vein thrombosis.
OBJECTIVE
The aim of this study was to describe the prevalence of main hereditary thrombophilias, Janus kinase 2 (JAK2) V617F mutation, antiphospholipid antibody syndrome (APS), and hyperhomocysteinemia in Brazilian children and adolescents diagnosed with portal vein thrombosis (PVT) without associated hepatic disease.


METHODS
A cross-sectional study was carried out with 32 children with PVT in accompaniment at Hospital das Clínicas of the Universidade Federal de Minas Gerais from January 1990 to July 2011. Laboratory evaluation of thrombophilias was performed from September 2010 to July 2011.


RESULTS
Thirty-two patients were evaluated; 59% were boys. Median age at diagnosis was 2.4 years. Mean time of patients' accompaniment was between 4.7 and 5.2 years. The presence of hereditary and acquired thrombophilias occurred in 34.4% of patients, and 9 of them also showed other risk factors in the previous history evaluation. Risk factors were absent in the previous history of 18 patients (56.3%). Two patients showed persistent high titres of anticardiolipin antibodies. Hyperhomocysteinemia was not observed. One patient was heterozygous for factor V Leiden and prothrombin G20210A mutation (3.1%). Eleven patients (34.4%) showed heterozygous methylenetetrahydrofolate reductase (MTHFR) C677T, and no patient had the JAK2V617F mutation.


CONCLUSIONS
Even after investigation of main hereditary and acquired thrombophilia, PVT remains without apparent cause in most patients. Nevertheless, association of local and systemic risk factors seems to be important also in the pediatric age group. Therefore, despite the low prevalence, a complete investigation, which includes both hereditary and acquired thrombophilias, may be necessary.
Department of Pediatric Gastroenterology, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil. pmferri.liu@gmail.com
Priscila Menezes
PM
Ferri
Alexandre
A
Rodrigues Ferreira
Eleonora Druve Tavares
ED
Fagundes
Sandra Guerra
SG
Xavier
Daniel
D
Dias Ribeiro
Ana Paula
AP
Fernandes
Karina Braga Gomes
KB
Borges
Shinfay Maximilian
SM
Liu
Maria do Carmo Barros
Mdo C
de Melo
Mariza Leitão Valadares
ML
Roquete
Francisco José
FJ
Penna
D000293:Adolescent; D000906:Antibodies / Q000097:blood; D001938:Brazil / Q000453:epidemiology; D002308:Cardiolipins / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005165:Factor V / Q000235:genetics; D005260:Female; D006579:Heterozygote; D006801:Humans; D020138:Hyperhomocysteinemia / Q000150:complications; D007223:Infant; D007231:Infant, Newborn; D053614:Janus Kinase 2 / Q000235:genetics; D008297:Male; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics; D009154:Mutation; D011169:Portal Vein / Q000473:pathology*; D015995:Prevalence; D011516:Prothrombin / Q000235:genetics; D012307:Risk Factors; D019851:Thrombophilia / Q000150:complications* / Q000453:epidemiology / Q000235:genetics / Q000276:immunology; D020246:Venous Thrombosis / Q000209:etiology* / Q000235:genetics / Q000276:immunology
D000906:Antibodies; D002308:Cardiolipins; C095381:factor V Leiden; D005165:Factor V; D011516:Prothrombin; D042965:Methylenetetrahydrofolate Reductase (NADPH2); D053614:Janus Kinase 2