Sarcoidosis is an inflammatory disease that involves the formation of non-caseating granulomas, a cluster of macrophages, in response to a foreign substance or antigen in the body, They can be found in any organ system, but 90% of people diagnosed have it in their lungs. The granulomas (also called nodules) can be found in the interstitial tissues (around the air sacs), thoracic lymph nodes, and the vascular system of the lungs.
Pulmonary arterial hypertension (PAH) is increased pulmonary arterial pressure that is characterized by increased pulmonary vascular resistance that can lead to failure of the right ventricle of the heart. It can be life-threatening if not treated. PAH is seen as a complication in sarcoidosis from 5-28% of patients and at rates as high as 74% of those with advanced disease. Sarcoidosis-associated PAH has been shown to worsen its prognosis and may increase the risk of death 7-fold.
Management of PAH in sarcoidosis is not well understood, and there are currently no specific treatments approved. Kishan Parikh and colleagues published the results of their study on patient characteristics, clinical outcomes, treatment, and management strategies of sarcoidosis-associated PAH in the journal, Scientific Reports. They followed a large cohort of biopsy-proven sarcoidosis patients with PAH from Duke University for 11 years. "Our primary outcomes of interest were change in 6-minute walk distance (6MWD) and change in N-terminal pro-brain natriuretic peptide (NT-proBNP) by after therapy," states Dr. Parikh.
Out of the 95 participants who met the criteria for the study, 70% had stage IV pulmonary sarcoidosis, and 77% had functional class III/IV symptoms (marked or severe activity limitations and comfortable only at rest). The median NT-proBNP value was elevated (910 pg/mL), and right ventricular dysfunction was moderate/severe in 55% of patients. The mortality rate over an average of three years was 32% with a mean time to hospitalization or death at six months.
The authors report three major findings: (1) high morbidity that reflects the disease burden with both pulmonary hypertension and stage IV pulmonary sarcoidosis, (2) no change in the six-minute walk test with PAH-specific treatment, and (3) 37 patients receiving PAH-specific therapy had a 51% improvement in their NT-proBNP.
In this lecture by Dr. Maddipati from the Division of Pulmonary and Critical Care Medicine at East Carolina University, he gives an overview of sarcoidosis-associated PAH and current treatment strategies. Ultimately, patients who are diagnosed with sarcoidosis-associated PAH should be evaluated for possible lung transplantation.
