Incidence and significance of different types of connective tissue antibodies in adult and pediatric gastroenterological disorders.

The incidence of connective tissue antibodies was assessed in 3,000 adults and in 388 pediatric patients with gastroenterological disorders. Following a previous classification, connective tissue antibodies were distinguished in 5 different types, R1 and R2 reacting with reticulin components, KC with Kupffer cells, AC and Rs with intra- and extracellular mesenchymal antigens. R1 predominated in children and was observed only in patients with malabsorption; the great majority of them had celiac disease and an abnormal small bowel mucosa. Ac was rarely seen in children and occurred in several unrelated gastrointestinal diseases of the adult; its incidence, however, was significantly higher in disorders with idiopathic and secondary malabsorption. R2, KC and Rs were seen only occasionally in unrelated gastroenterological disorders without malabsorption. R1, therefore, seems to be strongly suggestive of a malabsorption syndrome with abnormal small bowel mucosa and AC is a nonspecific reaction occuring predominantly in primary and secondary malabsorption; the other connective tissue antibodies have no clinical significance in gastroenterological disorders.