Helicobacter pylori cytotoxin-associated gene A genotype in Egyptian patients with Parkinson’s disease: could eradication benefit?

Abstract

Strong growing evidence supports a link between Helicobacter pylori (HP) infections and Parkinson’s disease (PD). The purpose of this study was to explore the association between infection with HP cytotoxin-associated gene A (cagA) genotype and PD in Egyptian patients and the influence of its eradication on pharmacokinetic and clinical response to l-dopa. This study was performed on 87 idiopathic PD patients and 45 age- and sex-matched controls. HP infection was diagnosed with HP stool antigen test and HP cagA genotype was detected by PCR. PD patients were subjected to UCLA parkinsonism scale, Hoehn and Yahr staging, and l-dopa plasma level detection by high-performance liquid chromatography. HP PD patients were divided into eradicated group (received standard anti-HP therapy) and placebo group (received antioxidant therapy). Four weeks after therapy, patients were reevaluated. Among PD patients, frequency of HP infection was significantly higher than controls (55.2 vs 33.3%, P = 0.02), especially with HP cagA strain (81.2 vs 40%, P = 0.002). PD was more severe in HP infected (P < 0.001), especially in HP cagA-positive patients (P = 0.04) with significant lower l-dopa plasma levels (P < 0.001). cagA strains were associated with higher risk of increased PD severity (OR, 2.139; P = 0.029). Opposing antioxidant therapy, HP eradication treatment improved PD severity (UCLA score decreases by 30%) and increased l-dopa level by 40%. There is a proved link between PD and infection with virulent HP cagA strains. HP could affect l-dopa level by mechanisms other than reactive oxygen radical’s production which need further evaluation.