Study looks at a theory that adding immunoadsorption, or the process of filtering out antibodies from the blood, in addition to other PH therapies may help improve outcomes for people with idiopathic pulmonary arterial hypertension.
by Phyllis Hanlon, Contributing Writer
People with idiopathic pulmonary arterial hypertension (IPAH), a type of WHO Group 1 PH (PAH, pulmonary arterial hypertension), have an increase in pulmonary vascular resistance (PVR) which eventually leads to right heart failure. Research shows that this disease is accompanied in some patients by antibodies (proteins that are part of the body’s immune response to bacteria, viruses and other foreign substances) that work against the body’s own tissues (autoantibodies) and may cause further damage to blood vessel cells. In an effort to help patients with IPAH, a team of researchers from Germany looked at the theory that adding immunoadsorption (IA – filtering out antibodies from the blood) in addition to other PH therapies might help improve outcomes by removing inflammatory autoantibodies.
In this report, Christian Nagel, M.D. and his colleagues looked at IA involving a medical device called TheraSorb™ – Ig Flex Adsorber, which removes circulating human immunoglobulin (IgG, IgA, IgE, and IgM –types of antibodies) from the bloodstream. During the process, plasma (the liquid part of the blood) and red blood cells are separated into two different columns. IgG is filtered out of the plasma and the remaining plasma is combined with the red blood cells and put back into the patient’s blood stream.
Dr. Nagel and his team of researchers pointed out that IA has previously been used for other medical conditions like chronic heart failure with good results. They conducted this study to look for evidence to support their theory that IA may also benefit patients with IPAH. They had two patient goals in mind: the first was to note any changes in pulmonary vascular resistance (PVR) and the second was to observe changes in the six-minute walk distance (6MWD), IgG plasma levels, safety factors, and quality of life.
The research team looked at data on ten patients with severe IPAH and right heart dysfunction who were in the World Health Organization functional class (WHO-FC) III and were already taking targeted PH-medication to stabilize their disease. These patients were hospitalized for a minimum of five days while they underwent daily, two-hour IA treatment sessions. The researchers indicated that patients’ safety was assessed every day while they were in the hospital and then again at day nine, one month, three months and six months after the treatment. All patients knew they were on the therapy, and no patients were in a “placebo” group.
Dr. Nagel and his colleagues reported overall favorable results at the end of their study. Specifically, the treatment proved to be safe, well tolerated and efficiently removed antibodies from the bloodstream. After three months, the patients’ average (mean) PVR decreased by 13.2 percent and the right heart function as measured by cardiac index improved by 13.1 percent.
When analyzing the changes in 6MWD, the researchers did not find significant changes in the distance patients could walk before the treatment compared to after. Also, quality of life showed trends towards improvement after six months; but these improvements were not determined to be significant.
While the treatment was deemed safe, there were 38 non-serious and three serious adverse events, which included attention problems, mild thrombocytopenia (i.e., abnormally low levels of platelets in the blood) and mild uncommon viral pneumonia. In spite of these events, IA did not negatively impact IPAH or right heart pump function.
Overall, the use of IA as an add-on treatment for patients with severe IPAH under targeted combined PH-medication was found to be safe and effective in this small study and “is a promising therapeutic approach.” However, since the number of participants in the study was purposefully set so small, more research is needed to confirm that this therapy is a reasonable add-on treatment option before it is used on a regular basis, according to the researchers.
Each PH patient is different. It is essential that you talk to your own doctor about what treatment options are best for you. For more information on finding a doctor or an accredited care center, visit https://www.phassociation.org/PHCareCenters/Patients.