N Moorchung, A Srivastava, N Gupta, S Bandopadhyay, B Achyut, B Mittal
caga antibody levels, gastritis, h pylori
N Moorchung, A Srivastava, N Gupta, S Bandopadhyay, B Achyut, B Mittal. The Role Of Helicobacter Pylori And Cag A Antibody Titers In The Pathology Of Chronic Gastritis. The Internet Journal of Tropical Medicine. 2005 Volume 3 Number 1.
Chronic gastritis is a multifactorial disorder, which is influenced primarily by the bacterium Helicobacter pylori. In addition to the density of the organism, the CagA pathogenicity island (PAI) of H pylori is thought to be a primary factor contributing to the antral inflammation. Endoscopic findings are believed to be non contributory in the diagnosis. In this study, we have shown that endoscopic features like erythema, erosions and nodularity maybe contributory in predicting the presence of H pylori in the biopsy specimen. The primary factor influencing the degree of inflammation in gastritis appears to be the density of H pylori in the antrum. The CagA pathogenicity island does not appear to have a role in influencing the severity of the antral inflammation. The role of other H pylori antigens remains undetermined.
Although gastritis was first interpreted to be due to ageing and lifelong exposure to various insults, it is now clear that the most common cause of this inflammatory condition is infection with
The endoscope has been used extensively in visualizing antral gastritis but histopathological examination remains the gold standard for the diagnosis. (10,11). Various gastroscopic features may be interpreted as signs of gastritis. These include erythema (diffuse, spotty, linear), erosions, absence of rugae in the gastric corpus, and presence of visible vessels (12). It remains uncertain if any of the endoscopic features are a predictor for the presence of
The Sydney system for grading and classifying chronic gastritis was devised to provide a standardised approach to the histological interpretation of biopsies in 1990 (13) and it was later upgraded in 1994 (14). Several parameters are assessed in this system including the density of
In this study, we gauged if the density of
Materials And Methods
Between August 2004 and August 2005, 120 patients with non ulcer dyspepsia who underwent upper gastrointestinal endoscopy were studied. The duration of the illness and history of tobacco and alcohol consumption were recorded. Dietary habits noted included a vegetarian or non-vegetarian diet and history of excessive consumption of spices. Vegetarians included patients who consumed only grain, vegetables and milk or milk products with the total exclusion of meat, fish or eggs in their food. A non-vegetarian diet included patients who consumed meat, fish or eggs regularly in addition to grain, vegetables and milk products. Exclusion criteria were present or past history of gastric neoplasm's or gastric surgery, long term therapy with nonsteroidal anti-inflammatory drugs, liver disease and previous treatment with antibiotics or bismuth salts. All subjects had given informed consent for the study and the local ethics committee had approved the protocol.
Endoscopy was performed after an overnight fast with standard upper gastrointestinal endoscopes (Olympus Optical Co Ltd., Tokyo, Japan) and biopsy specimens were obtained with standard biopsy forceps. On endoscopy, the features noted were the presence or absence of erythema, nodularity, exudates, mucosal edema and excessive friability of the mucosa. A visible vascular pattern, intramucosal bleeding and the presence of erosions were also recorded. A special mention was made of the presence of rugal atrophy or hypertrophy. The endoscopic evaluation was done by an experienced endoscopist (NKG) who had performed more than 15,000 endoscopies.
Two to three antral biopsies were taken for histological examination from the distal lesser and greater curvature, 2 to 3 cm from the pylorus. The biopsies were immediately fixed in formalin for histopathological examination. In addition to the biopsy samples, 3 - 4 ml of peripheral blood was collected from each patient. The blood was collected in a sterile tube and allowed to clot. The tubes were then centrifuged at 12000 rpm for 5 minutes to separate the serum. The separated serum was then stored at - 20°C and used for the anti CagA ELISA.
All biopsies were oriented and fixed in 10% buffered formalin. They were processed by routine techniques and stained by the haematoxylin and eosin stain, the modified Giemsa stain for the detection of
For each variable, the highest score was given among the antral biopsies. To minimize the interobservor variability in grading the histopathological features, we used the scoring system as proposed by Aydin et al (18)
Serum samples stored at -20°C were tested for the presence of IgG antibodies against the CagA antigenic fraction of
The association between the clinical, endoscopic and histological findings was assessed by means of the χ2 test for trend (19). A probability value of p≤0.05 was considered statistically significant.
69 males and 51 females were included in the study. The mean age of the patients was 36.14 yrs with a range of 16 yrs to 70 yrs. The mean age of the male patients was 37.55 yrs with a range of 16 yrs to 67 yrs. The mean age of the female patients was 35.55 with a range of 16 yrs to 70 yrs. There was no significant difference in age and sex with regard to the colonization by
There were fifteen smokers and five reformed smokers in the study. One of the female patients was a smoker. The rest of the smokers were males. Of the reformed smokers, one patient was a female and four were males. Ten patients gave a history of alcohol consumption. All the ten patients were male. Five patients were reformed drinkers, which included one female and four male patients. The numbers of the smokers and drinkers was too small to reach a statistical conclusion.
Fifty patients were non-vegetarians. There was no significant difference between the vegetarian and non-vegetarian group with any of the endoscopic or histopathological features.
The commonest endoscopic finding noted was the presence of erythema, which was seen in 49 patients. The presence of erythema was associated with the presence of
The presence of nodularity was also associated with the density of
The presence of edema, friability, mucosal exudates, rugal atrophy and hypertrophy was seen in an insignificant population of patients to have any statistical significance.
67 antral biopsies showed
Serological association - No association between the CagA antibody levels and the density of
The use of endoscopy in the diagnosis of gastritis is debatable. Redeen et al (12) studied 488 patients with gastritis and attempted to correlate the endoscopic features. They concluded that the absence of rugae and the presence of visible vessels correlated with histological gastritis in the corpus and the antrum. No endoscopic features showed a sensitivity of more than 57 % for
In our study, the presence of erythema, nodularity and erosions were statistically associated with the
A strong association has been reported between the
There was also a significant association of the
In Caucasian populations it has been reported that strains that contain the CagA pathogenic island are associated with a more severe disease than strains that lack CagA (26, 27, 28). CagA positive isolates are associated with a higher grade of antral polymorphonuclear inflammation. (27). It has also been reported that there is a strong correlation between the presence of serum antibodies to CagA and the isolation of CagA positive strains from a patient (27). In our study, although there was a strong association between the density of
It has been reported that in Asian populations, the association of CagA positivity and disease risk is much weaker or not present (29, 30). This finding was also seen in this study. The existence of distinct variants of certain genes of the Cag pathogenicity island may offer an explanation for this discrepancy. Analysis of
In conclusion, we suggest that endoscopic features like the presence of erythema, erosions and nodularity maybe a useful predictor for the presence of
Dr Balraj Mittal PhD email@example.com Phone: 091-522 -2668004-8 Ext 2322 Fax - 091-522 -26680017 Department of Medical Genetics Sanjay Gandhi Post Graduate Institute of Medical Sciences Rae Bareilly Road Lucknow 226014 Uttar Pradesh, INDIA