Phenotypes of Sarcoidosis-Associated Pulmonary Hypertension-A Challenging Mystery

Sarcoidosis has been a well-recognised risk factor for pulmonary hypertension (PH) for a long time, but still, the knowledge about this concatenation is incomplete. Sarcoidosis-associated PH (SAPH) is an uncommon but serious complication associated with increased morbidity and mortality among sarcoidosis patients. The real epidemiology of SAPH remains unknown, and its pathomechanisms are not fully explained. Sarcoidosis is a heterogeneous and dynamic condition, and SAPH pathogenesis is believed to be multifactorial. The main roles in SAPH development play: parenchymal lung disease with the destruction of pulmonary vessels, the extrinsic compression of pulmonary vessels by conglomerate masses, lymphadenopathy or fibrosing mediastinitis, pulmonary vasculopathy, LV dysfunction, and portal hypertension. Recently, it has been recommended to individually tailor SAPH management according to the predominant pathomechanism, i.e., SAPH phenotype. Unfortunately, SAPH phenotyping is not a straightforward process. First, there are gaps in our understanding of undergoing processes. Second, the assessment of such a pivotal element as pulmonary vasculature on a microscopic level is non-feasible in SAPH patients antemortem. Finally, SAPH is a dynamic condition, multiple phenotypes usually coexist, and patients can switch between phenotypes during the course of sarcoidosis. In this article, we summarise the basic knowledge of SAPH, describe SAPH phenotypes, and highlight some practical problems related to SAPH phenotyping.

Automated summary

Sarcoidosis is a recognized risk factor for pulmonary hypertension, but our understanding of this connection is incomplete. Sarcoidosis-associated pulmonary hypertension is a serious complication that increases morbidity and mortality among sarcoidosis patients. The epidemiology and pathophysiology of this condition are not fully understood, and multiple factors are believed to play a role in its development. Phenotyping SAPH is challenging due to gaps in our understanding of the underlying processes and the inability to assess pulmonary vasculature in living patients. Additionally, SAPH is a dynamic condition with multiple phenotypes that can switch during the course of sarcoidosis.