Duodenal Biopsy in the Evaluation of Chronic Diarrhoea in Immunosuppressed Patients from a Tertiary Care Center in Southern India

Introduction: Chronic diarrhoea in immunocompromised patients is due to a variety of causes including opportunistic pathogens that flourish in such a milieu. While stool examination may diagnose some pathogens, at times this may be negative and upper GI endoscopy and colonoscopy findings maybe unremarkable. Aim: To evaluate the effectiveness of a duodenal biopsy in determining the aetiology of otherwise not diagnosable chronic diarrhoea in a background of immunosuppression and to note the variety of causes in this setting. Materials and Methods: The study was done in the Department of Histopathology over a period of 26 months (February 2010 to March 2012). This study includes duodenal biopsies from 42 immunosuppressed patients. These patients presented with chronic diarrhoea undiagnosable by routine non-invasive investigations such as stool routine examination, stool culture and sensitivity, etc. Data entry was done in MS excel sheet and data analysis was done. Results: Infectious aetiology was identified in 18 cases (43%). The most frequently found pathogens were protozoans (15 cases, 35.7%), followed by viruses (two cases, 4.8%) and helminths (one case, 2.4%). Kaposi sarcoma was noted in one biopsy. Conclusion: The duodenum is a good site for biopsy in the investigation of chronic diarrhoea in a setting of immunosuppression. In this study a diagnostic yield of a duodenal biopsy alone was 45.24% for specific aetiology. The diagnostic features in these situations are often scanty or subtle, requiring careful systematic examination of multiple sections at high power and the use of special stains not otherwise performed.