[Clinical study on factor Ⅷ inhibitor in children with hemophilia A]

Objective: To reveal the related factors of inhibitors and differences ofhemorrhage and joint disease before and after the production of inhibitors in children with hemophilia A (HA) . Methods: Retrospective analyses of the clinical data of 381 children with HA under the age of 16 registered in the Registration Management Center of Hemophilia in Henan Provincial from January 2015 to August 2018. Results: A total of the 381 children were enrolled with 116 (30.4%) mild, 196 (51.4%) moderate, and 69 (18.1%) severe cases; 54 patients (14.2%) had inhibitors, including 22 high and 32 low titer inhibitors. Positive family history was positively associated with inhibitors[P<0.001, OR=3.299 (95%CI 1.743-5.983) ], and high-intensity exposure was associated with inhibitors[P=0.002, OR=2.587 (95%CI 1.414-4.731) ]. High-intensity exposure was associated with high titer inhibitor production[P=0.001, OR=8.689 (95%CI 2.464-30.638) ], and high-intensity exposure increased the risk of high titer inhibitors in HA patients. After inhibitors occurred in 54 patients with HA, the rates of overall joint annual bleeding (z=-3.440, P=0.001) and traumatic annual bleeding (z=-2.232, P=0.026) increased, but the rates of the annual joint bleeding (z=-1.342, P=0.180) and spontaneous annual bleeding (z=-1.414, P=0.157) remained to be not statistically significant. The joint ultrasound score did not change significantly after the inhibitor information (z=-0.632, P=0.527) . Conclusions: Positive family history and high-intensity exposure could increase the risk of F Ⅷ inhibitors in HA patients, and high-intensity exposure increased the risk of high titer inhibitors. The rates of the overall joint annual bleeding and traumatic annual bleeding increased after the inhibitor information.