Safety and efficacy of immunoadsorption as an add-on to medical treatment in patients with idiopathic pulmonary arterial hypertension

The objective of this prospective, open-label, single-arm, multicenter trial was to evaluate safety and efficacy of immunoadsorption (IA) as an add-on to optimized medical treatment in patients with idiopathic pulmonary arterial hypertension (IPAH). Methods: IPAH-patients received IA over 5 days for 1-2h/day using the medical device TheraSorb®. Clinical parameters including hemodynamics measured by right heart catheter were assessed at baseline and after three and six months. Primary end point was the change in pulmonary vascular resistance (PVR). Secondary endpoints included the change of six-minute walking distance (6MWD); quality of life (SF-36), plasma levels of Immunoglobulin G and autoantibodies and safety. Results: Evaluation of 10 IPAH-patients (75% female, 51±12 years, 166±10cm, WHO-FC III, 53% PAH combination therapy) revealed that IA was a safe procedure that efficiently removed IgG and autoantibodies from the circulation. After three months, mean PVR significantly improved by 13.2% (p=0.03), cardiac index improved by 13.1%, no significant changes were found in 6MWT or quality of life. Quality of life subscale physical functioning significantly improved after 6 months. Serious adverse events in 3 patients were possibly related to IA and included pneumonia, temporary disturbance in attention and thrombocytopenia. Conclusions: The results of this pilot study indicate that IA as add-on to medical treatment for patients with IPAH is rather safe and effective procedure with beneficial effects on hemodynamics, especially in patients with high levels of autoantibodies.