Raised stool and serum IgA levels in undernourished infants with chronic diarrhoea and associated parasitic infestations.

Sixty children with chronic diarrhoea, age ranging from 9 months to 3 years and 15 normal healthy children of same age group, all belonging to the low socio-economic families formed the basis of this study. Fifty-six out of these 60 children were undernourished and were marasmic. Stool examination showed enteropathogenic E. coli in 24 (40 per cent), Ascaria lumbricoides in 12 (20 per cent) and Giardia lamblia in 6 (10 per cent). Coeliac disease was detected in 2 (3 per cent) and combined IgA-IgG deficiencies were found in one case (2 per cent). No cause could be found in 15 (25 per cent) cases. Multiple aetiological factors were found in 7 (12 per cent) cases. Stool IgA levels were significantly elevated in the patients than in the controls and more so in the patients with giardiasis and also in patients with coeliac disease. Serum IgA levels were remarkably raised in the patients with diarrhoea due to enteropathogenic E. coli, indicating probable spilling of gut-associated IgA into the circulation. No IgA was detected in the stool of a dysgammaglobulimic patient, who had both serum IgA and IgG deficiencies.