High-Altitude Pulmonary Edema An Immunogenetically Mediated Disease?

High-altitude pulmonary edema (HAPE), a potentiallylife-threatening complication of acute mountain sick-ness, is postulated to be a noncardiogenic permeabil-ity edema caused by acute pulmonary arteriolar vasoconstric-tion and resultant pulmonary hypertension in response to the hypoxia of rapid ascent to high altitudes.1–4 HAPE typically occurs unexpectedly in young, otherwise healthy mountain-eers. A constitutional susceptibility has been noted for some time5,6; the disease tends to recur in the same individuals on reexposure to high altitude, whereas others appear not to be susceptible at all. The basis for this predisposition to HAPE, whether genetic or environmental, and its underlying patho-physiology remain poorly understood. See p 1124 In this issue of Circulation, Hanaoka and colleagues7 present interesting new evidence that certain human leuko-cyte antigens (HLA) are increased in Japanese patients wit