Thesis Synopsis



RAJIV GANDHI UNIVERSITY OF HEALTH SCIENCES

BANGALORE, KARNATAKA.

PROFORMA FOR REGISTRATION OF SUBJECT FOR DISSERTATION.

1. NAME : INDU M

2. ADDRESS : DEPARTMENT OF PATHOLOGY

ST JOHN'S MEDICAL COLLEGE,

BANGALORE-560 034

3. COURSE OF STUDY AND SUBJECT : MD [PATHOLOGY]

4. DATE OF ADMISSION TO COURSE : 19 APRIL 2011

5. TITLE OF THE THESIS

EVALUATION OF EOSINOPHILS IN GASTROINTESTINAL MUCOSAL BIOPSIES WITH CLINICO PATHOLOGICAL CORRELATION

6. BRIEF RESUME OF INTENDED WORK:

6.1 NEED FOR THE STUDY

Eosinophils are integral members of the Gastro intestinal(GI) mucosal immune system, with small numbers of eosinophils being found throughout the GI tract even in physiological states, except in the esophagus.1 GI eosinophilia can be classified as:

- primary GI eosinophilia/ eosinophil associated gastrointestinal disorders (EGID or eosinophilic gastroenteritis)

- GI eosinophilia resulting from hypereosinophilic syndrome (HES)

- GI eosinophilia triggered by other known causes of eosinophilia such as drug interactions, parasitic infections, malignancy etc.1

There is considerable clinical overlap between the various entities. Hence endoscopic evaluation and mucosal biopsies are an important part of the workup for evaluating these diseases.2

There is no clear consensus on the physiological range of the mucosal eosinophil count. Considerable disagreement exists regarding the count required to diagnose eosinophilic gastroenteritis at histology, due to organ specific variations in the cut-off value for different parts of the GIT, as well as variations at a particular site of the gastrointestinal tract. In Western literature the abnormal range for the eosinophil count varies from 15- 25/HPF in various studies with no definite consensus. However a count of

> 20/HPF is considered supportive of a diagnosis of primary eosinophilic gastroenteritis.3

Due to a high burden of parasites, allergens etc there is likely to be a higher incidence of gastrointestinal eosinophilia in the Indian population. Assessing these by Western standards would lead to overdiagnosis of eosinophilic gastroenteritis, the mainstay of the treatment for which is steroids. Indiscriminate usage of steroids in the Indian population, with its high burden of infective disease would be disastrous. There is a marked paucity of Indian literature with regard to the density and distribution of eosinophils in GI endoscopic biopsies.

In general, eosinophils can be easily identified in tissue sections due to the distinct orangeophilic granules in the cytoplasm. However artefactual staining of neutrophil cytoplasm can lead to errors in diagnosis. Giemsa stained eosinophils on tissue sections are known to show fluorescence as described by Rubio et al in a study of 25 cases. In their study the authors compared the eosinophil count on routine H & E staining with Giemsa stained fluorescent sections and found the latter to be more sensitive.3

Hence this study is being undertaken to assess the density and distribution of eosinophils in non-neoplastic gastrointestinal mucosal biopsies in the Indian population and to compare the eosinophil count in Giemsa stained sections with that in routine H& E stained sections.

2. REVIEW OF LITERATURE :

Eosinophils are present in blood as well as tissues and the GI tract is one of the primary sites for eosinophil residence. Eosinophils are normally present in the lamina propria of the stomach, small intestine, cecum and colon. But their presence in the esophagus and Peyer’s patches is pathological.1 The role of eosinophils in the gastrointestinal tract is not well understood and they are believed to be involved in both protective and pathological roles.1,5

Eosinophilic gastroenteritis or EGID are being increasingly recognised in routine clinical practice are defined by three criteria:

1. Presence of gastrointestinal symptoms

2. Biopsies showing eosinophilic infiltration of one or more areas of the gastrointestinal tract from esophagus to colon, or characteristic radiological/endoscopic findings with peripheral eosinophilia and

3. Absence of known causes for eosinophilia.3,4,6. The known causes of eosinophilia include parasitic diseases, allergic conditions, malignancy, drugs, hypereosinophilic syndrome etc.1

The pathogenesis of Gastrointestinal Eosinophilia is not clearly understood. The basic pathophysiological defect is believed to be an alteration in the mucosal integrity, resulting in localization of various antigens in the gut wall with induction of tissue and blood eosinophilia. Specific food antigens can cause mast cell degranulation in the gastrointestinal wall, releasing eosinophil chemotactic factors, leukotrienes and other platelet activating factors.1 The degranulation of eosinophils causes the release of histamine, cationic proteins like major basic protein, eosinophil peroxidase, eosinophil-derived neurotoxin and cytokines such as tumour necrosis factor-α. Cytokines like Granulocyte monocyte colony stimulating factor (GM-CSF) and the interleukines IL-3 and IL-5, induce eosinophil proliferation and differentiation in the bone marrow, and are strong chemotactic agents that attract eosinophils to sites of tissue inflammation.5 These proteins promote inflammation, tissue damage and further mast cell degranulation, resulting in a vicious circle. Eotaxin, a novel 73-amino-acid chemokine, plays a central role in the recruitment of eosinophils into tissues. Eotaxin is a specific eosinophil chemoattractant produced by epithelial cells at the site of inflammation. It induces aggregation of eosinophils and promotes their adhesion to endothelial cell.1,5 The role of cystienyl leukotrienes in the pathogenesis is further supported by the fact that the use of the leukotriene antagonist Montelukast is associated with long term remission of symptoms of eosinophilic gastroenteritis.6

The gastrointestinal symptoms associated with gastrointestinal eosinophilia are diverse and are dependent on the involved layer of GIT. The symptoms include diarrhea, dyspepsia, abdominal pain, nausea, vomiting and bloating.4,5 Rarely strictures and ascites are noted. Peripheral blood eosinophilia is not a universal finding in eosinophilic gastroenteritis.4 The endoscopic appearance of eosinophilic gastroenteritis varies and includes normal looking mucosa, polypoid lesions, erythema, ulceration, multiple erosions, thickened mucosal folds and narrowing of the lumen.5 As mentioned earlier, there is disagreement in the number of eosinophils per high power field which is taken as abnormal eosinophilic infiltration. For example, Orenstein et al. define eosinophilic esophagitis when ≥5 eosinophils per high power field are present in the distal epithelium of the esophagus, Lim et al. and Potter et al. when ≥15 eosinophils are found, Arora et al. Sant’Ana et al .and Zimmermann et al. if >20 eosinophils are recorded and Noel et al. if ≥24 eosinophils per high power field are found.2 However most authors defined abnormal tissue infiltration of eosinophils as 15-20 eosinophils per high power field either diffusely or multifocally.4,7 Within the same organ the eosinophils are distributed within the mucosa, submucosa, muscle layer and subserosa.4 Indian studies on gastrointestinal eosinophilia are limited with a few case series describing eosinophilic gastroenteritis in surgically resected specimens.8,9

Pathologists routinely diagnose gastrointestinal eosinophilia in H&E sections using transmitted light.3 In blood smears the nucleus of eosinophilic granulocytes is bi-lobulated, but in tissue sections, depending upon the level at which the nuclei had been sectioned, some eosinophils appear as having a small, non-lobulated nucleus and others with two minor nuclei. Some observers may disregard, sectioned eosinophils displaying uni-lobulated, small nuclei or two minor nuclei and a minor fraction of cytoplasm, while doing a differential cell counting in H & E stained sections. Eosinophilic granulocytes have the property of fluorescing in Giemsa stained sections using indirect fluorescence light. This method is more sensitive and quicker in counting the eosinophils according to Rubio et al.3

3. OBJECTIVES OF THE STUDY

Primary Objectives:

1. To assess the occurrence of eosinophilia in gastrointestinal endoscopic mucosal biopsies.

2. To assess the mean eosinophil count and eosinophil distribution in routine gastrointestinal endoscopic/colonoscopic biopsies and to correlate these with the clinical and endoscopic features.

Secondary Objectives:

To compare eosinophil counting by Routine H & E staining with Giemsa stained sections using fluorescent light.

7. MATERIALS AND METHODS:

This is a prospective cross sectional study. 300 consecutive patients with gastric, small intestinal or colonic biopsies from non-neoplastic lesions received at the Department of Pathology, St. John’s Medial College, Bangalore will be included for the study. The intestinal biopsies will be assessed for the distribution of eosinophils and graded as mild, moderate and severe. Eosinophils from the most dense areas will be counted in 5 high power fields and the average taken to express eosinophil count/HPF. The distribution of the eosinophils will be assessed as outlined in Appendix I. In addition mucosal architectural changes, epithelial abnormalities and associated pathogens such as H pylori will also be assessed. The clinical features, endoscopic findings and investigations will be assessed as per Appendix II. The eosinophil distribution and count will be correlated with the clinical and endoscopic findings.

7.1a SOURCE OF DATA

Routine endoscopic gastrointestinal mucosal biopsies received at the Department of Pathology, St. John’s Medical College.

7.1b SAMPLE SIZE

A total of 300 consecutive biopsies received at the Department of Pathology, SJMC.

Inclusion Criteria

All patients with gastric, small and large intestinal biopsies obtained on endoscopy.

Exclusion Criteria

1. Endoscopic biopsies with a diagnosis of malignancies.

2. Patients who have received anti parasitic and anti-allergic treatment over the previous 30 days.

3. Inadequate biopsy material/ Inadequate clinical data.

STATISTICAL ANALYSIS

The data will be summarized with number/ percentage of distribution. Linear regression analysis will be used to correlate the eosinophil count and with disease, site and symptoms.

7.3 DOES THE STUDY REQUIRE ANY INVESTIGATIONS OR INTERVENTIONS TO BE CONDUCTED ON PATIENTS OR OTHER HUMANS OR ANIMALS? IF SO, PLEASE DESCRIBE BRIEFLY.

NO

7.4 HAS ETHICAL CLEARENCE BEEN OBTAINED FROM YOUR INSTITUTION IN CASE OF 7.3

NOT APPLICABLE

|DD |MM |YYYY |

|INI |TIA |LS |

CONSENT FORM Not applicable

STUDY TITLE

8. LIST OF REFERENCES

1.Zuo L, Rothenberg ME. Gastrointestinal eosinophilia, Immunol Allergy Clin North Am.2007;27(3):443-455.

2.Baig MA,Qadir A, Rasheed J. A Review of Eosinophilic Gastroenteritis. Journal of the national medical association. 2006;98:10.

3.Rubio CA, Glaessgen A. An improved method to visualize eosinophils in eosinophilic esophagitis in vivo.2006;20:681-686.

4.Talley NJ, Shorter RG, Phillips SF, Zinsmeister AR. Eosinophilic gastroenteritis:a clinicopathological study of patients with disease of the mucosa, muscle layer and sub serosal tissues. Gut.1990;31:54-58.

5.Sheikh RA, Prindiville TP, Pecha RE, Ruebner BH. Unusual presentations of eosinophilic gastroenteritis:case series and review of literature. World journal of gastroenterology.2009;15(17):2156-2161.

6.Quack I, Sellin L, Buchner NJ, Theegarten D, Rump LC, Henning BF. Eosinophilic gastroenteritis in a young girl-long term remission under Monteleukast:case report. BioMed Central.2005;5:24.

7.Spergel J. Diagnosis and treatment of eosinophilic esophagitis. Medicine reports. 2009;1:46.

8.Venkataraman S, Ramakrishna BS, Mathan M, Chacko A, Chandy G, Kurian G, et al. Eosinophilic gastroenteritis - an Indian experience.  Indian J Gastroenterol

 1998;17(4):148-149

9. Amitha K, Shariff SA, Kumar AD. Eosinophilic Gastroenteritis Presenting as Intestinal Obstruction - A Case Series. Online J Health Allied Scs. 2011;10(2):21

9. SIGNATURE OF CANDIDATE

10. REMARKS OF THE GUIDE

11. NAME AND DESIGNATION OF

11.1 GUIDE: Dr. MARJORIE CORREA

PROFESSOR AND HOD

DEPARTMENT OF PATHOLOGY

ST. JOHN’S MEDICAL COLLEGE

BANGALORE

11.2 SIGNATURE:

11.3 CO GUIDE Dr. HARSHAD DEVARBHAVI

PROFESSOR AND HOD

DEPARTMENT OF GASTROENTEROLOGY

ST. JOHN’S MEDICAL COLLEGE

BANGALORE

11.4 SIGNATURE

11.5 HEAD OF THE DEPARTMENT: Dr. MARJORIE CORREA

DEPARTMENT OF PATHOLOGY

ST JOHN’S MEDICAL COLLEGE

BANGALORE

11.6 SIGNATURE

12.1 REMARKS OF THE CHAIRMAN AND PRINCIPAL

12.2 SIGNATURE

................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download