Figure 1.

Bronchus-associated lymphoid tissues (BALT) are more conspicuous in pulmonary hypertension (PH). BALTs are increased in number (A, top left, and hematoxylin and eosin sections, top right) in rats with PH compared with control animals. (B) BALTs are readily apparent in humans and in bovine (representative images from cows, rats, and mice with PH). Representative images and measurements in A taken from lung sections from n = 6 animals per group, with two to three sections per rat from three independent experiments. Bars = 20 μm. Representative image using human section (B, left) taken from analysis of n = 3 patient samples, three sections per sample. *P less than 0.05 compared with control, Student t test. IPAH = idiopathic pulmonary arterial hypertension; MCT = monocrotaline.