Pulmonary alveolar proteinosis in Israel: Ethnic clustering

Background: Pulmonary alveolar proteinosis is a rare disease in which a sur factant-like phospholipid-rich protein accumulates in the lungs. The diseas e is amenable to effective therapy by total lung lavage. Objectives: To inv estigate the prevalence, ethnic distribution and course of PAP(1) in Israel . Methods: A countrywide survey was conducted during which pulmonologists wer e questioned about patients with PAP. The patients were examined and their charts, radiological images, pathological slides and physiological data wer e reviewed. Results: The survey yielded 15 patients (8 females) during the period 1976- 98 (14 in the last decade), giving a prevalence of 3.7x10(6) and an inciden ce of 0.36x10(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 we re 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 bronchoalveol ar lavage treatments. The subjective and physiological response was favorab le, but there was less consistent radiological improvement. Conclusion: The prevalence of PAP in Israel is approximately 3.7x10(6). Mos t 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 s imilar. This clustering suggests the existence of a genetic predisposition. The course of the disease appears to be similar to that reported elsewhere .