FP375 : Anti -Helicobacter Pylori IGG Antibody Titres in Aqueous Humor and Serum of Patients with Primary Open Angle Glaucoma and Cont

Dr. Swati R, S13229, Dr. Sirish Nelivigi, Dr. Sri Ganesh

Introduction

Helicobacter pylori(H.pylori)(HP)isa spiral Gram-negative, microaerophilic bacterium. It is a common bacterium, in the sense that almost 50% of world’s population is estimated to be infected.^[1] Infection rate in South Indian population is estimated to be as high as 83.3%.^[2]It is known to cause various upper gastrointestinal diseases like gastritis, peptic ulcer and even carcinoma stomach. It has also been implicated in diseases like ischemic heart disease, cerebrovascular disease, Alzheimer’s disease and migraine.

Over the last decade, various researchers have examined the existence of possible link between H.pylori infection and glaucoma. If proved so, the clinical implication is that H.pylori eradication might have a role in glaucoma management. Some studies have supported such an association, others deny it. Contradictory results from different studies leave room for further investigation.

There are many diagnostic tests to detect H.pylori infection, out of which endoscopic biopsy is considered to be the gold standard. But it is complicated and doesn’t reveal the presence of previous infection. Urea breath test is a reliable, non-invasive test, but detects only current infection. Enzyme linked immunosorbent assay(ELISA)detects IgGantibodies against H. pylori. The advantages of this test are that it is rapid and itdetects H. pylori regardless of treatment, with very high sensitivity and specificity (> 90%).Hence we employed ELISA to detect H.pylori antibodies in aqueous humor and serum of patients with primary open angle glaucoma and controls.

Purpose & Methods

• PURPOSE: to compare the Anti- H.pylori IgG antibody titres in aqueous humor & serum of Primary Open Angle Glaucoma (POAG) patients & controls
• METHODS: Prospective case-control comparative study

Cases: 47 patients of POAG who required trabeculectomy

Controls: 47 age-matched uncomplicated cataract patients posted for phacoemulsification with foldable intraocular lens implantation as controls after ruling out glaucoma by thorough clinical examination

Titres of anti-H.pylori IgG antibody in aqueous humor& serum were estimated by ELISA test.

Results

The mean anti-H.pylori IgG antibody levels in aqueous humor among controls was 13.7±26.9 (median 4) and among cases of glaucoma was 64.05±90.15 (median 15.96). This difference was statistically significant.Table 1.

Aqueous humor Antibody in U/ml	N	Mean	SD	95% Confidence Interval for Mean		Min	Maxi	Median
				Lower Bound	Upper Bound
Control	47	13.71	26.90	5.81	21.60	2.00	156.00	4
Cases	47	64.05	90.15	37.58	90.52	1.24	373.30	15.96
Total	94	38.88	70.84	24.37	53.39	1.24	373.30

P=0.004

Mann Whitney test

Table 1: Aqueous humor antibody levels in cases and controls

To calculate the odds ratio for having glaucoma with high anti-H.pylori antibody levels in aqueous humor, cross tabulation was done. Table 2. Value of >5 U/ml was taken as cut off based on ROC curve.

The odds ratio for having glaucoma with high anti-H.pylori antibody levels in aqueous humor is 3.8. Table 3.

		Aqueous humor antibody		Total
		Low	High
group	Control	31	16	47
	Cases	16	31	47
Total		47	47	94

Table 2: Aqueous humor antibody levels- cross tabulation

Risk Estimate
	Value	95% Confidence Interval
		Lower	Upper
Odds Ratio for glaucoma with higher antibody level in aqueous humor	3.754	1.599	8.811

Table 3: Odds ratio for having glaucoma with high anti-H.pylori antibody levels in aqueous humor

The mean serum anti-H.pylori  IgG antibody levels in controls was 35.97±44.8 (median 19.4) and among cases of glaucoma was 97.2±90.15 (median 72.7). This difference was statistically significant.  Table 4.

Serum Antibody in U/ml	N	Mean	SD	95% Confidence Interval for Mean		Min	Maxi	Median
Control	47	35.97	44.76	22.82	49.11	2.00	188.00	19.4
Cases	47	97.19	95.94	69.02	125.36	2.00	309.60	72.7
Total	94	66.58	80.56	50.08	83.08	2.00	309.60

P=0.01

Mann Whitney test

Table 4: Serum antibody levels in cases and controls

To calculate the odds ratio for having glaucoma with high anti-H.pylori antibody levels in serum, cross tabulation was done. Table 5.  Values >30U/ml  was taken as cut off based on ROC curve.

The odds ratio for having glaucoma with high anti-H.pylori antibody levels in serum is 2.6

		group		Total
		Low	High
Serum antibody	Control	30	17	47
	Cases	19	28	47
Total		49	45	94

Table 5: Serum antibody levels- cross tabulation

Odds ratio
	Value	95% Confidence Interval
		Lower	Upper
Odds Ratio for Glaucoma with high antibody level in serum	2.601	1.131	5.980

Table 6: Odds ratio for having glaucoma with high anti-H.pylori antibody levels in serum

Pearson correlation calculation shows that there is excellent correlation between aqueous and serum antibody levels among cases and controls. Table 7, 8 and chart 1.

Correlations
		Aqueous humor	serum
Aqueous humor	Pearson Correlation	1	.845**
	p		.000
	N	94	94

Table 7: Correlation between aqueous humor and serum antibody levels

Chart 1: Correlation between aqueous humor and serum antibody levels

Correlations
group			Aqueous humor	serum
Control	Aqueous humor	Pearson Correlation	1	.714**
		p		<0.0001
		N	47	47
Cases	Aqueous humor	Pearson Correlation	1	.845**
		p		<0.0001
		N	47	47
**. Correlation is significant at the 0.01 level (2-tailed). Table 8:  Correlation between aqueous humor and serum antibody levels among cases and controls

Discussion

Kountouras et al. from Greece were the first to investigate the putative association between HP infection and glaucoma. Theyreported that HP infection is more frequently encountered among glaucoma patients than in the general population; this finding was based on both biopsies as well as on serological examinations. Also Glaucoma patients had more frequent antral gastritis and peptic ulcers. Conversely, other studies reported a lack of association^[5],[6]

A recent meta-analysis published in 2015 throws more light on this debate. This Meta-analysis includes 10 articles; total695 glaucoma patients and 1580 controls which showed statistically significant association between H. pylori infection and open angle glaucoma incidence.^[7] Table 9 and 10

Study	Aqueous  humor antibody in U/ml Cases	Aqueous humor antibody in U/ml Controls	Odds Ratio for glaucoma with high aqueous humor antibody	Serum antibody in U/ml Cases	Serum antibody in U/ml Controls	Odds Ratio for glaucoma with high serum antibody
Our study	15.96	4	3.8	72.7	19.4	2.6
Kountouras et al. [8]	14.27+/-3.86	4.67+/-1.07		69.96+/-9.69	44.16+/-6.48
Deshpande et al. [9]	3.93±5.14	2.65±2.87	2.07	52.26±52.5	33.83±41.7

Table 9: Results from similar studies

Study	Odds Ratio for glaucoma with high anti-H.pylori antibody	95% confidence interval
Our study	3.8 for aqueous humor antibody 2.6 for serum antibody	1.599-8.811 1.131-5.980
Meta-analysis[7]	3.06	1.27–2.46
Deshpande et al. [9]	2.07 for aqueous humor antibody	0.36 to 12.13
Samurai et al. [10]	5.69 for serum antibody	1.58 to 20.50

Table 10: Results from similar studies

Is there a causal relationship or do they share common predisposing factors and pathophysiological backgrounds? Answer is unknown till date. Several possible mechanisms support the fact that H. pylori infection increases the risk of OAG. First mechanism could be that H.pylori infection releases inflammatory factors like cytokines, endothelin 1, C- reactive protein, nitric oxide, oxygen free radicals, which create oxidative stress, leading to destruction of mitochondrial DNA, resulting in apoptosis. H. pylori infection stimulates platelet leukocyte aggregation, with subsequent reduction in ocular blood flow. Another mechanism proposed is sharing of common genetic factor, which makes them more susceptible to both H.pylori infection and glaucoma. Toxic materials secreted cause antibody-induced

 

• If H.pylori has a role in causation of glaucoma, its eradication should improve glaucoma. That is what is shown again by Kountouras et al. in their study. In patients with successful h pylori eradication, but not in other patients, mean intraocular pressure and mean visual field parameters improved. H.pylori eradication therapy improves outflow facility suggesting a possible causal link between H.pylori and glaucoma. 

Conclusion

• • Anti-H.pylori IgG titres in aqueous humor &  serum of POAG patients is ignificantly higher compared to controls
  • Possibly support the role of H.pylori in causative mechanism of glaucoma
  • Future studies with larger sample size needed

References        

1. Nomura A, Stemmermann GN, Chyou PH, Perez-Perez GI Blaser MJ. Helicobacter pylori infection and the risk for duodenal and gastric ulceration. Ann Intern Med. 1994;120:977–81.
2. Prasad S, Mathan M, Chandy G, et al. Prevalence of Helicobacter pylori in southern Indian controls and patients with gastro duodenal disease. J Gastroenterol Hepatol. 1994;9:501–6.
3. Kim JM, Kim SH, Park KH, Han SY, Shim HS; Investigation of the Association between Helicobacter pylori Infection and Normal Tension Glaucoma. Invest. Ophthalmol. Vis. Sci. 2011;52(2):665-8. doi: 10.1167/iovs.10-6096.
4. Kountouras J, Mylopoulos N, Boura P, et al. Relationship between Helicobacter pylori infection and glaucoma. Ophthalmology. 2001;108(3):599–604.
5. Galloway PH1, Warner SJ, Morshed MG, Mikelberg FS. Helicobacter pylori infection and the risk for open-angle glaucoma. Ophthalmology. 2003 May;110(5):922-5.
6. Kurtz S1, Regenbogen M, Goldiner I, Horowitz N, Moshkowitz M. No association between Helicobacter pylori infection or CagA-bearing strains and glaucoma. J Glaucoma. 2008 Apr-May;17(3):223-6. doi: 10.1097/IJG.0b013e31815a34ac
7. Jun Zeng, Hanhan Liu, Xiao Liu, Chun Ding; The Relationship Between Helicobacter pylori Infection and Open-Angle Glaucoma: A Meta-Analysis. Invest. Ophthalmol. Vis. Sci. 2015;56(9):5238-45. doi: 10.1167/iovs.15
8. Kountouras J, Mylopoulos N, Konstas AG, Zavos C, Chatzopoulos D, Boukla A. Increased levels of Helicobacter pylori IgG antibodies in aqueous humor of patients with primary open-angle and exfoliation glaucoma. Graefes Arch Clin Exp Ophthalmol. 2003;241(11):884–90.
9. Deshpande N, Lalitha L, Krishna Das SR, Jethani J, Pillar RM, Robin A, Karthik. Helicobacter pylori IgG Antibodies in Aqueous Humor and Serum of Subjects With Primary Open Angle and Pseudoexfoliation Glaucoma in a South Indian Population. J Glaucoma. 2008 Dec; 17(8): 605-10.
10. Samarai V, Sharifi N, Nateghi Sh. Association between helicobacter pylori infection and primary open angle glaucoma. Glob J Health Sci. 2014 Sep 18;6(7 Spec No):13-7. doi:10.5539/gjhs.v6n7p13.
11. Kountouras J, Mylopoulos N, Chatzopoulos D . Eradication of Helicobacter pylori may be beneficial in the management of chronic open-angle glaucoma. Arch Intern Med. 2002;162:1237–44.