Levels of secretory IgA1 (SIgA1) in the saliva have not been measured previ
ously in either coeliac disease (CD) or inflammatory bowel disease (IBD). S
aliva was collected from coeliacs, IBD patients and controls. The concentra
tion of total SIgA in saliva was measured by enzyme linked immunosorbent as
say (ELISA) with an anti-human SIgA antibody as the bound phase and human S
IgA isolated from colostrum as the standard, The concentration of SIgA1 was
determined using an ELISA with a lectin with a high affinity for human SIg
A1. The IBD patients have a significantly higher concentration of SIgA1 tha
n the controls. The rate of secretion of saliva and %SIgA1 was significantl
y lower in coeliacs than in the control and IBD groups. The rate of secreti
on of SIgA1 was significantly higher in the IBD than in the coeliacs. We de
scribe hitherto unreported levels of SIgA1 in CD and IBD.