Infliximab use tied to reversal of clotting abnormalities in IBD patients

Treatment with infliximab to control inflammation effectively reduces parameters that are associated with a higher risk of venous thromboembolism in patients with inflammatory bowel disease (IBD), results of a study have shown.

Sixty-two patients with active IBD initiating infliximab, vedolizumab, or methylprednisolone and 22 health controls were included in this prospective study. The investigators collected plasma before (w0) and after induction therapy (w14).

Clot lysis assay was used to determine amplitude (marker for clot intensity), time to peak (T_max; marker for clot formation rate), area under the curve (AUC; global marker for coagulation/fibrinolysis), and 50-percent clot lysis time (50%CLT; marker for fibrinolytic capacity). Plasminogen activator inhibitor-1 (PAI-1) and fibronectin were measured using ELISA. Clinical remission was assessed at w14.

AUC, amplitude and 50%CLT at baseline were significantly higher in IBD patients than in healthy controls. In 34 remitters, AUC (165 percent vs 97 percent; p=0.001), amplitude (119 percent vs 95 percent; p=0.002), and 50%CLT (122 percent vs 100 percent; p=0.001) were reduced significantly and even normalized to healthy control level.

An inverse association was found between vedolizumab trough concentration and fibronectin concentration (r, –0.732; p=0.002). The increase in T_max for infliximab-treated remitters showed a significant difference from the decrease in T_max for vedolizumab-treated remitters (p=0.028). Moreover, the 50%CLT increased (p=0.038) when remitters were concomitantly treated with methylprednisolone.

“Active IBD represent an independent risk factor for venous thromboembolism,” the investigators said.