FISH SURFACE MUCIN HYPERSENSITIVITY

Most reports of allergy to fish describe systemic symptoms upon ingest ion of fish muscle or contact urticaria in commercial fish handlers. W e report three recreational fishermen with symptoms of asthma, angioed ema, rhinitis and urticaria upon exposure to surface mucin from bluegi lls (Lepomis machrochirus). All three had symptoms upon handling blueg ills. Subsequently, two of them experienced wheezing and/or angioedema while in proximity to contaminated fishing clothing. One of them late r developed symptoms upon eating bluegills. Prick skin testing was pos itive to crude bluegill surface mucin in all three individuals and to bluegill and cod muscle in one. Bluegill surface mucin was defatted in ether and acetone and extracted in phosphate buffered saline. Sodium dodecyl-polyacrylamide gel electrophoresis (SDS-PAGE) showed at least 20 distinct protein bands by Coomassie Blue staining. Many of these we re glycoproteins by periodic acid schiff (PAS) staining. Immunoblottin g showed at least seven IgE binding protein bands with molecular weigh ts between 10 and 100 kDa. Radioallergosorbent (RAST) assay using a bl uegill surface-mucin solid phase demonstrated that serum IgE binding i n the three individuals was 4-25 times that of pooled serum from nonat opic controls. IgE binding using a serum pool from the three allergic patients was inhibited by extracts of bluegill mucin and muscle and co d muscle but not by tuna, crab or peanut. Our results demonstrate that bluegill surface mucin contains specific glycoproteins which bind IgE in sensitive individuals. Hypersensitivity to these surface proteins may cause systemic allergic symptoms.