Calretinin, S100 and protein gene product 9.5 immunostaining of rectal suction biopsies in the diagnosis of Hirschsprung' disease.

Evaluation of rectal suction biopsies for the ganglion cells and neural hypertrophy is the basic modality for the diagnosis of Hirschsprung's disease (HD). However, the traditional hematoxylin and eosin staining coupled with acetylcholinesterase histochemistry remain challenging, especially in newborns. Thus we conducted a prospective study to evaluate the usefulness of calretinin combined with S100 and protein gene product 9.5 (PGP9.5) immunostaining of rectal suction biopsies for the diagnosis of HD. A total of 195 patients were enrolled in our study. Of the 195 patients 69% had ganglion cells on the initial diagnostic protocol. Sixty cases were devoid of ganglion cells, and of these, 90% and 91% showed submucosal neural hypertrophy on S-100 staining and PGP9.5 staining, respectively. Eighty-one patients underwent a colonic resection, and of these, 59 had confirmed aganglionic segment, the other 22 patients were diagnosed as intestinal neuronal dysplasia type B (n=13) and isolated hypoganglionosis (n=9). Of the rest 114 patients, 51 cases underwent a full-thickness biopsy, and HD was excluded; sixty-three patients were thoroughly followed-up with no evidence of HD. We encountered two false-negatives and they were proved to be short segment HD after the surgery. The sensitivity and specificity rates of our diagnostic protocol was 96.49% (95% CI, 0.88-0.99) and 100% (95% CI, 0.97-1.00), respectively, excluding 5 patients with inconclusive results. Our findings demonstrated that calretinin coupled with S100 and PGP9.5 immunostaining on suction rectal biopsies is sensitive and specific for diagnosing HD.