乳児痔瘻の成因に関する研究 : 臨床免疫学的検討を中心として

抄録

Perianal fistula and abscess in infancy (PAFA) share the pathogenesis in common, and the former results from the later. PAFA is an usual disorder in pediatric surgery, but the etiology remains unclear. As a reason for it, there has been little cocern for PAFA which is a non-serious disease. This study was designed get a clue of solving the cause under an assumption that poor development of local immunity of the gut may have to do with PAFA. For this purpose, 324 patients with PAFA were analyzed to elucidate a clinical feature and 141 patients were also examined immunologically, including immunoglobulin in serum, IgA in saliva and mucus in the rectum, IgA-containg cells and secretory component in rectal wall. Furthermore, in 34 patients with PAFA, IgA pellets were administered as a trial for their watery diarrhea which usually accompanies PAFA. And following results were obtained. 1) A characteristic age-distribution which is thought to relate to immunological development was found. Namely, age at the time of onset was within three months after birth in about two-thirds of the cases, and the age at cure was younger than 14-month-old in 96% of the cases when they were treated conservatively. As to sex, an outstanding predominance in male (98% of cases) was noted, though the reason was not clear. 2) The lesions were located at the bilateral regions of the anus in 62% of the cases. The distributions of perianal fistulas and crypts were identical, whereas from of the anus in infancy showed an ellipse of 4:1, with long axis being longitudinal. As the result, it was assumed that perianal fistulas tended to developed in the lateral directions of the anus. 3) The level of IgA concentration was lower in patients whose PAFA did not heal within 12 months, in comparison with that of normal control. 4) As to IgA concentration in saliva, there were big dispersions in patients with PAFA in comparison with low values in normal infants. 5) IgA in mucus in the rectum was detected from two weeks after birth in normal babies, which means "mucosal blanket" developed at this age. On the contrary, in patients with PAFA IgA in mucus was not detected at 12 weeks after birth, apd remained low even after 13 weeks, if detected. 6) Concerning the localizations and distridutions of IgA-containg cells and secretory component in the rectum, there was no significant difference between normal infants and patients with PAFA. From these findings, it was assumed that there might be problems in transportation and fixation of IgA to the mucosa of rectum. 7) Oral administration of IgA pellets was effective for diarrhea in patients with PAFA but IgA suppositorties were not effective. From there results, it was strongly suggested that a poor development or an insufficiency of the mucosal blanket of local immunity in rectum may play an important etiological role in causing perianal fistula and abscess in infancy.