Fig. 1.

Infiltration of inflammatory and immune cells into the wall and perivascular space of pulmonary arteries in PH. A schematic cross-section shows a pulmonary artery with its different layers (intima, media, and adventitia) and the characteristic accumulation of inflammatory and immune cells, namely macrophages, dendritic cells, T cells, B cells, mast cells, and plasma cells, as well as the infiltration of fibroblasts and myofibroblasts and the production of (auto-)antibodies in PH disease.