Evaluation of Clinical, Laboratory Findings and Prognosis of Paediatric Thrombosis

The number of cases suffering from thrombotic events during childhood is gradually increasing. Despite being quite uncommon among children compared to adults, symptomatic thrombosis may lead to mortality and life-long disabling sequela when occurs at pediatric ages as well.The aim of our study is determining the risk groups for childhood thrombotic events along with their prognosis by examining clinical and laboratory features of cases. Files belonging to all patients aged 0 to 18 years with a diagnosis of thrombotic event confirmed between the dates of 1 January 2009 and 30 June 2016 at Hacettepe University, Department of Paediatric Hematology were studied retrospectively.A total of 227 patients are included. 95 (41.9%) of them are girls and 132 (%58.1) are boys. Median age of diagnosis is 41 months (1month-240 months) where 69 patients are aged under one year (≤1 year), 103 patents are aged between 1 and 12 years (˃1-≤12 years ) and 55 patients are adolescents (˃12 years) at the age of diagnosis. When classified due to thrombosis origin, it is noticed that 50 patients (22%) had arterial thrombosis while 177 patients (88%) had venous. 90% of patients (n=205) presented with acute thrombosis while 10% of patients (n=22) were suffering from chronic thrombosis. An underlying disease is detected at 195 patients (86%), cardiac diseases and malignities occupying first and second ranks when listed. The frequency of sufferring from an underlying disease or an acute infection is found to be significantly higher at children aged under one year compared to other age groups. Besides, the frequency of congenital diseases of heart as the underlying cause of thrombosis is found to be significantly higher at children aged under one year and aged between 1 and 12 years, compared to adolescents. It is revealed that the incidence for implementation of a catheter into the circulatory system is significantly higher for patients suffering from venous thrombosis compared with those from arterial thrombosis. However, significantly higher numbers of complications are observed at patients with arterial thrombosis in comparison to those with venous thrombosis. It is detected that venous thrombotic cases are occasionally treated with LMWH. No statistically significant difference is found between arterial and venous thrombotic cases in terms of FV Leiden or Protrombin 20210A mutation prevalences.There are a total of 36 patients applied with recurrence, 14 (39%) of them being girls and 22 (61%) being boys. 22 of patients has suffered from recurrence for once while 14 of them has referred with a recurrence more than once. For both group of patients suffering from recurrence for once and more than once, the most frequent site of the first thrombotic episode is observed to be deep venous thrombosis. Adolescents are demonstrated to be more prone to recurrence for more than once wih a statistically significant higher rate compared with other age groups. Coexistence of MTHFR C677T mutation heterozygosity and MTHFR A1298C mutation heterozygosity (compound heterozygotic pattern for MTHFR) is discovered to be a risk factor for recurrence given the statistically significant relative higher incidence in this specific group.Death of 47 (23%) patients are recorded within the median follow-up duration of patients which is 12 months. 77% of those patients passed away due to their underlying primary disease. Venous thrombotic cases are found to have a significantly higher mortality rate compared to arterial thrombotic cases. It is also found that mortality rate is significantly higher among children under age of one year in comparison with other age groups regardless of thrombosis origin.206 of 227 patients are evaluated for overall survival. Mean survival duration is came out to be 72.5 ±3.1 months with probability of overall survival for one years duration calculated to be 76.6% for all patients. Factors affecting mortality probability are evaluated via Cox regression (proportional hazard) analysis. When age, sex, recurrence and origin of thrombosis are used for estimation altogether as factors which could affect mortality, probability of death under age of one year is increased by 3.46 times than adolescence. Using same method, death risk due to venous thrombosis is calculated to be 3.8 times higher than arterial thrombosis