Single variant association testing using logistic regression analysis identified rs8176719 insertion/deletion (indel) variant in the ABO gene associated with CVT (age and sex adjusted OR 2.03; 95% CI 1.52-2.73; P = 2.07 × 10<sup>-6</sup>; Bonferroni P = 0.008).
Notably, more than half of the CVTs were diagnosed prior the administration of asparaginase which accentuates the role of other risk factors on the pathophysiology of CVT compared to truncal or central venous line (CVL) VTs in adult ALL patients.
For genetic factors, CVT risk increased in the presence of factor V Leiden (G1691A) by 2.5-fold (1.9-3.3), protein C deficiency 10.7-fold (3.1-37.7), protein S deficiency 5.7-fold (1.4-22.4), antithrombin deficiency 3.8-fold (1.0-13.8), prothrombin (G20210A) 5.5-fold (4.0-7.27) and TAFI gene variant (C1040T) 1.6-fold (1.0-2.4).
We suggest that NLR, PLR, CRP, ESR, and bilirubin can be used in clinical practice for prediction of CVT in suspected patients as they are inexpensive parameters and widely available.
In the CVT group, two Caucasian patients (20%) were heterozygous for the prothrombin variant, odds ratio of 9.7 (95% CI: 0.95 to 89.71) and one patient was carrier of factor V Leiden (P = 0.49).
Statistically significant associations with CVT were found for factor V Leiden/G1691A (OR=2.40; 95% CI, 1.75 to 3.30; P<0.00001) and prothrombin/G20210A (OR=5.48; 95% CI, 3.88 to 7.74; P<0.00001).