Reliability of RUT done on endoscopy guided gastric biopsy in detecting Helicobactor Pylori

that RUT can reliably identify Helicobacter pylori infection in gastric mucosa.


Introduction
Helicobacter pylori is a gram-negative helical bacteria that between surface stomach epithelial cells and the mucous gel layer above them. 1H. pylori infection can cause a variety of symptoms, from asymptomatic gastritis to gastrointestinal infected persons and puts them at risk for duodenal ulcers; therefore duodenal ulcers are also very common.Corpuspredominant gastritis is more common and puts people at risk for stomach ulcers.More than 90% of duodenal ulcer and about 75% of all peptic ulcer patients have H. pylori infection.The chance of ulcer recurrence is greatly reduced when the bacterium is eradicated. 2 With H. pylori infection, the lifetime risk of peptic ulcer disease is 20%, and the risk of gastric cancer is 1-2%. 3Infection with Helicobacter pylori can range from 14 percent in developed countries to 92 percent in developing countries. 4,5 pylori is urease, catalase and oxidase positive.The urease activity is striking, and the amounts produced have allowed accurate diagnosis in patients by direct detection of the enzyme in gastric biopsy specimens and by breath tests using carbon isotopes labeled with urea.Many roles have been proposed for urease enzymes.It is known to be important for colonization and survival of the bacterium in the gastric environment.6 The hydrolysis of urea to the bacterium from acidity.7 In vitro studies have shown that Helicobacter pylori cannot survive in acidic condition without the presence of urea, and urea inhibits its growth in alkaline conditions.8-10 Urease also has been proposed as an important virulence factor.The urease activity of H. pylori, once it enters the human stomach, neutralizes the acidic state that existed at the start of infection.H. pylori then travels toward host gastric epithelial cells between bacterial adhesins and host cell receptors result in H. pylori has developed an acid acclimation system that regulates urease activity to promote periplasmic pH adjustment in the severe acidic environment of the stomach.H. pylori requires intra bacterial urease activity for acid resistance, and this activity is controlled by the proton-gated urea channel UreI, which allows urea entrance only under acidic conditions to avoid deadly alkalization during times of relative neutrality.Phagocytosis is a part of the innate immune system that helps to eliminate invading microorganisms.Urease regulates the pH of phagosomes and the development of megasomes, making it crucial for H. pylori survival in macrophages.Only endoscopy with numerous biopsy specimens collected from one or more regions of the stomach, including the antrum, body, and transition zone (cardia and body), can reliably diagnose H. pylori 11 The resulting sample can be used to test urease activity, histology, and/ or PCR.Here in this study we are more interested in RUT as it is low priced, easy to use, and rapid time to diagnosis.RUT is very helpful and valuable to the patients as it gives a positive result for H.pylori infection before the patient leaves the endoscopic suite.

Histopathological Examination of Biopsy Tissue
Starry stains can detect H. pylori in the stomach mucosa. 12ue to sampling mistake or patchwork distribution of the lesion, false negative results can occur. 13iopsies were obtained in a study, and several stains and that technique should be used routinely for H. pylori detection in antral biopsy. 14

Methods
This study was conducted at Jawaharlal Nehru Medical College (JNMC), Aligarh Muslim University (AMU), Aligarh between May 2021 and May 2022 with a sample size of 230 patients.
In our institute all patients undergoing endoscopy due to gastritis have to go through RUT and Histopathological examination.The patients were asked to report in the endoscopy suite nil per oral for six hours and accompanied by some responsible attendant.Informed and written consent was obtained and the patient was taken up for upper sterile Normal Saline, samples were taken from suspicious areas as erosion, ulceration, hyperemia etc.On the other hand RUT test was done using RUT DRY Test kit VADODARA, INDIA.Color change from yellow to pink denoted a positive urease test (RUT positive).

Statistical analysis
The presentation of the Categorical variables was done in the form of number and percentage.The association of the variables which were qualitative in nature were analyzed predictive value and negative predictive value was assessed H. pylori positive analysis was done with the use of Statistical Package for

Inclusion Criteria:
All patients >14 years of age having symptoms of gastritis A.M.U.Aligarh.

Exclusion Criteria:
Patients previously diagnosed as a case of Helicobacter Pylori gastritis and received the anti H. Pylori treatment.

Results
The study was conducted in J.N Medical College, AMU, Aligarh from May 2021 to May 2022.230 patients of age >14 years having gastritis were included in the study.Intra Procedure was done.Endoscopic Findings noted and biopsy taken from gastritis lesions, RUT performed results noted and histopathological status of H. Pylori were noted.In majority [156(67.83%)] of patients, RUT was positive.
Among the patients who had H. pylori positive status, 67.31% of patients had positive RUT.If RUT was positive, then there was 78.36% probability of H. pylori positive status and if RUT was negative, then 46.88% chances of H. pylori negative status.Among patients who had negative H. pylori status, 60.81% of patients had negative RUT (Figure 1).

Discussion
RUT is an indirect test for the presence of H. pylori based on the presence of urease in or on the stomach mucosa.It has a distinct advantage over serology in that it only detects current infection.This test is based on H. pylori producing urease, which catalyzes a chemical reaction in which urea is digested to produce CO2 and ammonium ions.If the organism is present, material acquired by endoscopic biopsy changes color from yellow to red when placed in an appropriate medium. 16When the pH rises, phenol red, a color indicator that shifts from yellow to pink or red, is used in the test.This is visible to the naked eye.Mcnulty commercial preparations such as CLO, OMERT, 17 and Christensen's medium are available, with results ranging from a few minutes to 24 hours.Commercially available RUT kits suggest that the decision be made (positive vs. negative) within 24 hours.Most will turn positive within 120 to 180 minutes but it is best to hold those that appear negative for 24 hours. 18,19After 24 hours the test may turn positive from the presence of non-H.pylori urease containing organisms. 20Positive results after 24 hours are most often false positive and should not be used for treatment decisions.It has been postulated that blood leads to decrease sensitivity of RUT possibly related to the presence of albumin, 21 H. pylori killing factors in human plasma, 22 or blood in gastric lumen, 23,24 however, other 25,26 False negative tests are also common after partial gastrectomy probably because of reduced bacterial load often related on the presence of bile. 27,28lue (PPV), negative predictive value (NPV), and negative predictive value of RUT for predicting H. pylori positive status on histopathology.

Table 2 . Distribution of H pylori status on histopathology of study subjects. H pylori status on histopathology Frequency Percentage
In majority (134(58.26%)) of patients, H pylori status on histopathology was positive.H pylori status on histopathology was negative in only 96 out of 230 patients (41.74%) (Table2).