Clinical and pathological features of Churg Strauss syndrome among a Japanese population: a case series of 18 patients.

Background: Many autoimmune diseases differ in individual of different races, but there has been very scarce information on the clinicopathological features of Churg Strauss syndrome (CSS) among Asians patients.

Objective: To clarify the clinicopathological details of Japanese CSS patients.

Methods: The medical records of CSS patients hospitalized in 1980-2007 were carefully reviewed.

Results: Seventeen patients fulfilled the Japanese Ministry of Health, Labour and Welfare (MHLW) criteria and all 18 fulfilled the American College of Rheumatology criteria. Sixteen patients (89%) had the history of asthma. Frequently involved organs were peripheral nerves (PNS) (94%), skin (50%), gastrointestinal tract (33%), kidney (22%), and heart (17%). The mean (range) eosinophil count, C-reactive protein, and number of damaged organs was 18,108 (3,820-36,760)/microL, 51 (0-126) mg/L, and 2.7 (1-6), respectively. Four patients died, of whom three had heart involvement while only one without it died (100 versus 9%, respectively, p = 0.0088). Regarding the pathology, vasculitis was observed in six of seven skin but in only 2 of 10 PNS biopsies. Eosinophilia was found in all of the tissues except for PNS and muscle (40%). Granuloma was observed in only three of the total of 29 biopsies.

Conclusion: The usefulness of MHLW criteria was verified. The clinical features of Japanese CSS patients were mostly similar to those previously reported, except for lower asthma- and ANCA-positivity rates. Regarding the pathology, vasculitis and eosinophilia were much more frequently observed in skin.