Saber Taisir, Ghonaim Mabrouk M, Yousef Amany R, Khalifa Amany, Al Qurashi Hesham, Shaqhan Mohammad, Samaha Mohammad
Medical Laboratories Department, Faculty of Applied Medical Sciences, Taif University, Saudi Arabia.
Medical Microbiology & Immunology Department, Faculty of Medicine, Zagazig University, Egypt.
J Microbiol Biotechnol. 2015 Jul;25(7):1146-53. doi: 10.4014/jmb.1501.01099.
This study was conducted to assess the relationship between occurrence of gastric cancer and peptic ulcer, and the presence of H. pylori cagA gene and anti-CagA IgG, and to estimate the value of these antibodies in detecting infection by cagA gene-positive H. pylori strains in Saudi patients. The study included 180 patients who were subjected to upper gastrointestinal endoscopy in Taif province and Western region of Saudi Arabia (60 gastric cancer, 60 peptic ulcer, and 60 with non-ulcer dyspepsia). Gastric biopsy specimens were obtained and tested for H. pylori infection by rapid urease test and culture. PCR was performed on the isolated strains and biopsy specimens for detection of the cagA gene. Blood samples were collected and tested for CagA IgG by ELISA. H. pylori infection was detected among 72.8% of patients. The cagA gene and anti-CagA IgG were found in 63.4% and 61.8% of H. pylori-infected patients, respectively. They were significantly (p < 0.01) higher in patients with gastric cancer and peptic ulcer compared with those with non-ulcer dyspepsia. Detection of the CagA IgG was 91.6% sensitive, 89.6% specific, and 90.8% accurate compared with detection of the cagA gene. Its positive and negative predictive values were 93.8% and 86%, respectively. The study showed a significant association between the presence of the cagA gene and gastric cancer and peptic ulcer disease, and between anti-CagA IgG and the cagA gene in Saudi patients. However, a further larger study is required to confirm this finding.
本研究旨在评估胃癌与消化性溃疡的发生、幽门螺杆菌cagA基因及抗CagA IgG的存在之间的关系，并评估这些抗体在检测沙特患者中cagA基因阳性幽门螺杆菌菌株感染方面的价值。该研究纳入了180例在沙特阿拉伯塔伊夫省和西部地区接受上消化道内镜检查的患者（60例胃癌患者、60例消化性溃疡患者和60例非溃疡性消化不良患者）。获取胃活检标本，通过快速尿素酶试验和培养检测幽门螺杆菌感染情况。对分离出的菌株和活检标本进行PCR检测以检测cagA基因。采集血样，通过ELISA检测CagA IgG。72.8%的患者检测出幽门螺杆菌感染。在幽门螺杆菌感染患者中，分别有63.4%和61.8%检测到cagA基因和抗CagA IgG。与非溃疡性消化不良患者相比，胃癌和消化性溃疡患者中的这些指标显著更高（p<0.01）。与检测cagA基因相比，检测CagA IgG的敏感性为91.6%，特异性为89.6%，准确性为90.8%。其阳性和阴性预测值分别为93.8%和86%。该研究表明，在沙特患者中，cagA基因的存在与胃癌和消化性溃疡疾病之间、抗CagA IgG与cagA基因之间存在显著关联。然而，需要进一步开展更大规模的研究来证实这一发现。
