Role of Immunohistochemistry and serology in subclassifying the Inflammatory Bowel Disease cases diagnosed as Inflammatory Bowel Diseases---unclassified on colonic biopsies.

BACKGROUND

Inflammatory bowel diseases (IBDs) mainly consist of Crohn's Disease (CD) and Ulcerative Colitis (UC). These two categories have overlapping histopathological features and sometimes it is difficult to diagnose them into distinct category and such biopsies are categorised as Inflammatory Bowel Disease (IBD-U). Recently, there has been an increase in interest to discover new biomarkers of IBD to differentiate UC and CD and predict their prognosis.

METHOD

In the present study, 273 non-neoplastic colonic biopsies with clinicoendoscopic features of IBD were studied and categorized into UC (88; 32.3%) and CD (03; 1.1%) but a major chunk remained in category of IBD-U (182; 66.6%). 161 (58.9%) of these biopsies were then subjected to IHC for RB protein and β-catenin and Serology for pANCA and ASCA was done in only 85 (31.13%) of these selected cases for identification of UC and CD on colonic biopsies.

RESULT

161 biopsies that were subjected to IHC analysis included 57 cases of UC, 03 cases of CD, and rest 101 cases of IBD-U. Out of 101 cases of IBD-U, 87 (86.13%) cases were reclassified as UC (61; 60.3%) and CD (14; 13.86%) on the basis of results of IHC and Serology.

CONCLUSION

The two major tools IHC for β-catenin and RB protein and the assay of serum ASCA and p-ANCA along with proper history and clinical presentation can act as a good adjunct to conventional H and E in subclassifying cases of IBD-U into UC and CD.