Allergic proctitis, a clinical and immunopathological entity

Area of Science:

• Gastroenterology
• Immunology
• Colorectal Diseases

Background:

• Isolated ulcerative proctitis presents heterogeneously, with some cases progressing to ulcerative colitis and others remaining benign.
• Clinical presentation often includes mild, intermittent rectal blood loss.
• Endoscopic findings reveal inflammation confined to the rectum and distal sigmoid colon.

Purpose of the Study:

• To investigate the immunopathological characteristics of isolated proctitis.
• To evaluate the efficacy of disodium cromoglycate (DSCG) in treating isolated proctitis.
• To identify a subset of proctitis patients responsive to DSCG, termed 'allergic proctitis'.

Main Methods:

• Studied 12 patients with isolated proctitis over a mean of seven years.
• Utilized endoscopy to define the extent of mucosal inflammation.
• Performed histological analysis of rectal biopsies, including immunoperoxidase staining for IgE cells.
• Administered oral disodium cromoglycate (DSCG) to eight patients.

Main Results:

• Histology of rectal biopsies resembled ulcerative colitis.
• Increased IgE-containing cells were found in rectal mucosa, suggesting an IgE-mediated mechanism.
• All eight patients treated with DSCG showed clinical improvement.
• Four patients with milder disease did not require treatment.

Conclusions:

• Isolated proctitis can be differentiated based on clinical and immunopathological criteria.
• A subset of patients with isolated proctitis exhibits an IgE-mediated immune response.
• Disodium cromoglycate (DSCG) is effective in treating this specific group, supporting the designation 'allergic proctitis'.