The Prevalence of Congenital Trombophilia in Children Treated for Acute Lymphoblastic Leukemia with Thrombosis As a Complication

The aim of the study was to evaluate factors predisposing to thrombosis, especially congenital trombophilia, in children treated for acute lymphoblastic leukemia according to ALL IC BFM 2002 and 2009.

An analysis of 36 cases of thrombosis in 242 children (15%) treated due to ALL in the Department in years 2007-2013 was carried out. Age at onset, location, cause and treatment methods were taken into consideration. All analyzed patients underwent screening for congenital thrombophilia.

The age of patients ranged from 1.5 to 17 years with the median of 8.5 years. Arterial thrombosis occurred in 2 persons (1%), venous thrombosis in 34 (99%) patients. Thromboembolism was usually related to the central venous catheter (n = 31, 91%). Massive thrombosis occurred in 7 patients (20%). Relapses occurred in 3 children.

The most common causes of thrombosis were: the presence of the central catheter (n = 31, 91%) and L-asparaginase treatment (n = 19, 55%). The factor V Leiden mutation was diagnosed in 1 patient, protein C deficiency in 1 patient as well, and elevated levels of factor VIII were detected in 4 cases.

The mean concentrations of factor VIII, von Willebrand factor and antithrombin were not different in the groups with and without thrombosis (table 1 ). The concentration of fibrinogen measured after finishing the chemotherapy was similar in both groups.

Conclusions 1. A risk factor for thrombosis in children with ALL is the treatment of L-asparaginase and the presence of central venous catheter.

2. Screening for congenital thrombophilia in children treated for ALL should not be done routinely because the coexistence of this two conditions is rare.