Assessment of the accuracy of segmental perfusion under an occluding balloon for measuring the intrajejunal secretion of albumin and immunoglobulin A.

The suitability was investigated of the segmental perfusion technique under an occluding balloon (which prevents the contamination of the test segment by upper digestive secretions and pancreatic proteolytic enzymes) for measuring immunoglobulin A (IgA) and serum albumin outputs into the jejunal lumen. The influence of the perfusion rate and of the transintestinal water movements in the 40 cm long test segment was studied in 11 healthy subjects. IgA and serum albumin outputs did not differ significantly when the same isotonic solution was perfused at rates of 5 or 10 ml/min, nor when water absorption was stimulated by the presence of glucose. A possible artefact linked to intestinal wall distension by the occluding balloon was evaluated in eight subjects with complete exocrine pancreas insufficiency. IgA and serum albumin outputs obtained under the occluding balloon were compared with those found with the triple non-occlusive method. Care was taken to achieve a similar flow rate and solute composition of the fluid entering the test segments with both techniques in each subject. Under these conditions, IgA and serum albumin outputs measured with both methods did not differ significantly. These findings validate the use of the segmental perfusion technique under an occluding balloon to measure IgA and serum albumin outputs into the human small intestine.