Side-effects and venous access issues with immune tolerance therapy

Immune tolerance therapy (ITT) is the most effective approach to eradicate inhibitors in patients with haemophilia who develop high-titre inhibitors. Yet ITT is associated with many adverse side-effects. Rarely, adverse side-effects arise from the various factor concentrates that patients on ITT receive or from adjuvant immunosuppressive agents used during ITT. Most adverse side-effects of ITT are related to the need for frequent and repetitive venous access, which often results in the need for central venous access devices (CVAD). These devices greatly facilitate the ability to give repeated doses of factor concentrates to patients and are particularly useful in young children who often have small and poorly functioning peripheral veins. These devices can become infected, can malfunction or can lead to venous thrombosis. These complications, although rarely causing mortality, may lead to significant morbidity including the need to have the devices removed and new ones inserted. As well, such CVAD complications may lead to reduced effectiveness of ITT through interruptions in ITT.