IgA deficiency in children. A clinical study with special reference to intestinal findings.

Clinical, immunological, and intestinal studies on 26 children with IgA deficiency in the age range 2 to 16 years are reported. 9 of these children were suffering from autoimmune disease, namely thyroiditis (5), thyrotoxicosis (1), rheumatoid arthritis (2), and probable Sjögren's syndrome (1). The last-mentioned patient had defective cellular immunity. Altogether 11 patients were subject to recurrent respiratory tract infections. The symptomatology of the remaining patients was variable. In a boy with growth retardation, a chromosome anomaly was found, and endocrinological studies indicated total absence of growth hormone. In 21 patients IgA was undetectable, while 5 had trace amounts of IgA in their sera. IgG was raised in 11 patients, and one patient had low serum IgG. IgM levels were mostly normal. Precipitating antibodies to cow's milk proteins were present in all but one serum. Small intestinal biopsy was performed on all patients. In 3 cases total villous atrophy was detected and these probably had coeliac disease, though malabsorption symptoms were not always evident. Disaccharidase assay of biopsy specimens revealed 2 cases of isolated lactase deficiency among 8 tested. Results show that the increased incidence of autoimmune disease reported in IgA deficiency in adults also holds true in children; i.e. that there is a raised incidence of coeliac disease with or without symptoms in IgA deficiency.