Pulmonary alveolar proteinosis in Israel: ethnic clustering

Pulmonary alveolar proteinosis is a rare disease in which a surfactant-like phospholipid-rich protein accumulates in the lungs. The disease is amenable to effective therapy by total lung lavage. To investigate the prevalence, ethnic distribution and course of PAP in Israel. A countrywide survey was conducted during which pulmonologists were questioned about patients with PAP. The patients were examined and their charts, radiological images, pathological slides and physiological data were reviewed. The survey yielded 15 patients (8 females) during the period 1976-98 (14 in the last decade), giving a prevalence of 3.7 x 10(6) and an incidence of 0.36 x 10(6)/year. Mean age of the patients was 33 +/- 13 years (range 0.5-46 years). Seven patients were North African (two were siblings), four were from Iraq and two were Arabs; there was only one Ashkenazi Jew (a child). Symptoms at the onset were dyspnea and chest pain. Spontaneous remission occurred in at least 3 patients, and 10 patients required 1-4 bronchoalveolar lavage treatments. The subjective and physiological response was favorable, but there was less consistent radiological improvement. The prevalence of PAP in Israel is approximately 3.7 x 10(6). Most cases occurred in Jews who had immigrated from North Africa or Iraq, and two were siblings. The prevalence among the Arab population appears to be similar. This clustering suggests the existence of a genetic predisposition. The course of the disease appears to be similar to that reported elsewhere.