Histological Appearance of Distal Second Part of Duodenum with Normal Endoscopic Findings in Bangladeshi People in a Tertiary Care Hospital

Biopsy from the distal second part of duodenum is now widely accepted as a useful and simple way to evaluate patients with malabsorption or other small intestinal diseases.Histological findings of the second part of duodenumin tropical countries are different from that of other countries. Histological appearance of the second part of the duodenum may be changed due toceliac disease, tropical sprue, tropical enteropathy and some other conditions. As Bangladeshi people, we are exposed to different infection always due to its geographical distribution. Normal histological appearance of second part of duodenume.g. standard villous architecture, length, villous crypt ratio, IELcounts of our country in not known. The main objective of our study was to see the normal histological appearance of second part of duodenum in our country so that we can differentiate from abnormal condition. This observational study was carried out in the Department of Gastroenterology & Pathology, Bangabandhu Sheikh Mujib Medical University, (BSMMU)during the period of July 2010 to June 2011. A total of 116 patients were included from out patientdepartment and admitted patient in the department of Gastroenterology during the study period. Among the total numbers, the mean age was 32.7±9.77 (±SD) years.In our study, 48.27% subjects had finger shaped villous with normal height, 27.58% had both normal and broad villous, 22.41% subjects showed mixed findings of normal, broad and blunted villous and only 1.7% subjects showed broad and blunted villous without normal architecture. In our study, the highest IEL count was 62 cells per 100 epithelial cells and lowest value was 16. Mean value IEL/100 cells were 32.52 ±8.63 (±SD) and 95%CI was 1.57. The result of the study was very similar to Asian people but a little different from the western population.


Introduction:
Small intestinal mucosa has typical histological pattern to meet the demand of digestion and absorption of the nutrients.Different diseases cause mucosal distortions of the normal villous pattern impairing digestion and absorption. 1 Distal part of second part of duodenum (D2) represents the same histological structure of the entire small intestine.As a result biopsy from D2 is now widely accepted as a useful and simple way to evaluate patients with primary intestinal malabsorption or other intestinal diseases. 2The epithelial component of the small bowel is composed of villi and crypts (crypts of Liberkuhn).Normal villous to crypt length ratio is approximately 3:1 to 5:1.When four normal villi are identified in a specimen, it usually indicates that the entire specimen has a normal villous architecture except focal lesion. 3The villi are normally ridge or leaf shaped in the human proximal duodenum, leaf or finger shaped in the distal duodenum and proximal jejunum, and finger shaped in the distal jejunum and ileum.Intestinal intraepithelial lymphocytes (IELs) are unique T cell population interspersed between epithelial cells of both the small and large intestine.They have been proposed to have a wide variety of immunological roles, particularly in response to antigen(s) in the gut lumen. 4It is becoming increasingly recognized that high numbers of Intraepithelial lymphocytes (IELs) with normal villous architecture is within the wide spectrum of histological abnormalities observed in Gluten Sensitivity (GS). 4,6,7,8,9Therefore, it is important to recognize this finding in small bowel biopsy samples.Moreover, there are many clinicopathological features with some descriptions of tropicalenteropathy with increased villous intraepithelial lymphocytes. 10 endoscopically normal-appearing mucosa may have histopathological changes. 11Thus, the evaluation of a routine duodenal biopsy specimen is a valuable diagnostic aid in recognizing unsuspected pathology in dyspeptic patients or those with atypical gastrointestinal symptoms. 12

Type of study:
It was an observational, cross sectional study which was carried out in the department of Gastroenterology and Pathology, Bangabandhu Sheikh Mujib Medical University, (BSMMU), Dhaka, Bangladesh from July 2010 to June 2011.A total number of 116 patients attending the Gastroenterology OPD of BSMMU with dyspeptic symptoms and those dyspeptic patients admitted in the Gastroenterology ward and who were found to be normal at upper GITendoscopy were selected for the study.

Ethical consideration:
After proper explanation written informed written consent was obtained from the selected patients for upper GI endoscopy and biopsy.Study design was approved by the ethical committee of BSMMU.

Data processing:
Data were collected using standard data collection sheet.Histological findings of duodenal biopsy specimen according to study design were complied.All the data obtained from the study were analyzed using SPSS version 14.

Results:
Total 116 individuals were included for the study.Among the total numbers, the mean age was 32.7±9.77(±SD) years.
Out of 116 subjects, 84 (72.41%) were male and 32 (27.5%) were female.Ratio of the male and female was 2.6: 1.Table-I shows the sex distribution of the patients.Among the total number of patients, 38.79% came from rural area and 61.20% came from urban area.

Table-I Sex distribution of the subjects
In our study, the normal looking mucosa showed the variable histological appearance.The following table shows the variation of villous height and architecture.

Conclusion:
Biopsy from the distal second part of duodenum is a useful and simple way to evaluate patients with malabsorption or other small intestinal diseases. 2The histological appearance of the second part of duodenum is variable in different part of the world.Histological appearance of normal endoscopic findings in our study is very close to Asian people but different from Western and other part of the world.Villous architecture was variable.We found a good number of people had broad and blunted villous.Mean value IEL/100 cells was more than study of UK, Italy, USA, Australia but closely similar to study in Iran, India and Indonesia.The reasons of variation of villous architecture and IEL were not evaluated.May be, Bangladesh is a tropical country like India, Iran and Indonesia.The people are always exposed to various infectious agents.But actual cause is not known.To validate this further prospective multi-centre trial is required.

Limitations of the study
There are several limitations of this study: Firstly, the sample size was too small and study period was short.
Secondly, to know the normal histological appearance of the second part of duodenum in Bangladeshi people, a population based study should be done in the community.The exact normal histological appearance of this study is not the reflection of the country.Moreover, the study was conducted with dyspeptic patient.Healthy individual's normal histology will give more rational result.
Thirdly, asymptomatic celiac disease was not excluded for the study.
Fourthly, villous height and crypt length were not measured and IEL count was done only by H & E, no immunohistochemical study was done to count the lymphocytes.
Patients having dyspeptic symptoms with normal endoscopic findings.(b)Age of 18-60 years (c)Ambulatory patients of both sexes (d)Patients willing to undergo upper GI endoscopy and biopsy.Exclusion criteria: (a) Patients with contraindications to upper GI endoscopy(b) Patients who had erosion, ulcer or malignancy in the stomach or duodenum (c) Patients who had abnormal looking mucosa in the second part of duodenum(d) Patientsof PUD and its complications like active bleeding and pyloric stenosis (e) Known patient of malabsorption, motility disorder, malignancy or previous gastric surgery (c) Known patient of allergy to certain food like, gluten, cereals, cow's milk, soy products, fish, rice and chicken.(d) Patients who were on NSAIDs, alcohol.(e) Patients who were pregnant (f) Unwilling for endoscopy.
The highest intraepithelial lymphocytes (IEL) count was 62 cells per 100 epithelial cells (EC) and lowest value was 16.Mean value IEL/100 cells was 32.52 ±8.63 (±SD) and 95%CI was 1.57.Pattern of intraepithelial lymphocytes per 100 cells among the 116 patients showed in the table III.
19,18und 82.75% to have normal appearance of crypt, 17.24% to have hyperplasia and there was no villous to crypt ratio alteration in visual assumption.duodenum in Iran.IEL level in Iranian people is very close to our observation.17InAustralia,IanBrownetal(2006)describedmorethan25/100ECIEL in H & E in normal villous architecture of second part of duodenum.This study showed lower number of IEL in comparison to our study.14Veressetal(2004)atSweden described the upper limit of IEL was 25/100 EC in H & E in endoscopically normal second part of duodenum.This study showed very similar result to IanBrown et al. ( 2006)but lower count of IEL in comparison to our study.14,18SanjayKakaret al ( 2003) described the upper limit of IEL was 40/100 EC in H & E in endoscopically normal second part of duodenum.This result looks very similar to our study.19 temperate areas villi were longer, with a finger-like appearance, whereas in tropical areas leaf-like and ridge-like variants are present in the proximal duodenum and the fingerlike variants occur distally.Our findings are comparable to the result of Rubin CE et al, Segal GH et al, Mino M et al study.