Diagnostic Utility of CD3 Immunohistochemical Marker with Association to Modified Marsh- Oberhuber Classification for Malabsorption Syndrome

Introduction: Duodenal intraepithelial lymphocytes (IELs) are T cells found in the duodenum that play a role in the immune response. Some identifiable causes of raised IELs include coeliac disease (CD), non-steroidal anti-inflammatory drugs (NSAIDs), H. pylori, autoimmune disorders, immunodeficiency, gastrointestinal infections, and inflammatory bowel disease (IBD). Immunohistochemical (IHC) marker like CD3 is very useful for highlighting the IELs during evaluation of biopsies. Aim and Objectives: To compare IEL counts in Hematoxylin and eosin (H & E) stain and CD3 immunohistochemical (IHC) stain in duodenal biopsies of suspected malabsorption cases and compare them with clinical, immunological and biochemical parameters. The study also aims to associate it with Modified Marsh-Oberhuber Classification for Malabsorption syndrome (Celiac disease). Materials & Method: We used initial histopathological reporting for duodenal biopsies followed by immunohistochemical staining using CD3. Application of Modified Marsh-Oberhuber classification used to associate the pathological findings for celiac disease. Statistical analysis was done using Chisquare test. Observations and results: 74 duodenal biopsies were assessed, of which 26 cases showed raised IELs. Male preponderance with a median age of 33 years was noted. Most common presenting symptom was anaemia followed by chronic diarrhoea. Serological correlation was done in cases of raised IELs. Conclusion: Malabsorption syndrome is a histopathological entity that affects small bowel with microscopic and submicroscopic changes and may be associated with significant symptoms. Finding of a raised IEL count with normal villous architecture is of sufficient clinical importance so it should be highlighted in routine histopathological report of duodenal biopsies for further evaluation. Immunohistochemical demonstration of CD3 is one method of confirmation of raised IELs. Duodenal biopsy reporting requires an upgraded approach in view of the new research data of diagnosis.