Abstract. Circulating food antibodies, intestinal permeability and HLA status were studied in twelve blood donors previously identified as being selectively IgA deficient from screening 10 000 donations by means of a latex agglutination inhibition test, and confirmed by laser nephelometry. Assessment of intestinal function also included clinical history and standard laboratory tests. The donors proved to be healthy with no evidence of autoimmune disease or allergy. Nine donors (75%) had precipitins to food antigens. None had increased intestinal permeability as measured by the cellobiose/mannitol absorption test. HLA-A, B and DR antigen distribution was normal. IgG sub-class distribution was normal with the exception of an IgG2 level slightly below normal in one donor (0·9 g/1). An unexpected finding was a return of IgA levels to normal in four donors (33%) within 6 months.