Tatemichi Masayuki, Hamada Gerson Shigeaki, Nishimoto Inês Nobuko, Kowalski Luiz Paulo, Iriya Kiyoshi, Rodrigues Joaquim Josê Gama, Tsugane Shoichiro
Epidemiology and Biostatistics Division, National Cancer Center Research Institute East, 6-5-1 Kashiwanoha, Kashiwa, Chiba 277-8577.
Cancer Sci. 2003 Jan;94(1):64-9. doi: 10.1111/j.1349-7006.2003.tb01353.x.
The usefulness of serology against CagA of Helicobacter pylori as a biomarker to identify high-risk individuals for non-cardia gastric cancer (ncGC) remains unclear among several ethnic populations with a high prevalence of cagA-positive strains. We investigated ethnic differences of CagA serology in two sets of case-control subjects, Japanese-Brazilians (JB) and non-Japanese Brazilians (NJB). We performed a cross-sectional comparison of IgG antibody titers to CagA (CagA-Ab) and the combination of CagA-Ab with conventional surface antigen (Hp-Ab) in 80 JB and 178 NJB ncGC patients and their controls (160 JB and 178 NJB). The level of CagA-Ab titer in cancer cases was significantly higher in NJB than in JB. The strength of the association between CagA-Ab seropositivity (+) (> or = 10 U/ml) and ncGC was almost 2-fold higher in NJB than in JB [odds ratio (OR) (95% confidence interval), 4.5 (2.6-7.8) and 2.1 (1.2-3.6), respectively]. However, in both JB and NJB, the OR was highest in CagA-Ab(+) subjects with low titer (10-29 U/ml), and decreased inversely with elevating CagA-Ab titer. In addition, the serological status of CagA-Ab(+) and Hp-Ab(-) showed a similar close association with ncGC between JB and NJB [5.4 (1.9-15.3) and 5.4 (2.0-15.0), respectively]. These results suggest that although the roles of CagA in the carcinogenic process of ncGC might be different between JB and NJB, the CagA-Ab could be a useful marker for ncGC, independently of ethnicity, particularly in high-risk individuals with the serological status of CagA-Ab(+) with low IgG titer or combined with Hp-Ab(-).
在cagA阳性菌株高流行率的几个种族群体中，幽门螺杆菌CagA血清学作为一种生物标志物来识别非贲门胃癌（ncGC）高危个体的有用性仍不清楚。我们在两组病例对照受试者中调查了CagA血清学的种族差异，这两组受试者分别是日裔巴西人（JB）和非日裔巴西人（NJB）。我们对80名JB和178名NJB的ncGC患者及其对照（160名JB和178名NJB）进行了CagA IgG抗体滴度（CagA-Ab）以及CagA-Ab与传统表面抗原（Hp-Ab）组合的横断面比较。NJB癌症病例中的CagA-Ab滴度水平显著高于JB。CagA-Ab血清阳性（+）（≥10 U/ml）与ncGC之间的关联强度在NJB中几乎是JB中的2倍[比值比（OR）（95%置信区间）分别为4.5（2.6 - 7.8）和2.1（1.2 - 3.6）]。然而，在JB和NJB中，OR在低滴度（10 - 29 U/ml）的CagA-Ab（+）受试者中最高，并且随着CagA-Ab滴度升高而呈反比下降。此外，CagA-Ab（+）和Hp-Ab（-）的血清学状态在JB和NJB中与ncGC显示出相似的密切关联[分别为5.4（1.9 - 15.3）和5.4（2.0 - 15.0）]。这些结果表明，尽管CagA在ncGC致癌过程中的作用在JB和NJB之间可能不同，但CagA-Ab可能是ncGC的一个有用标志物，与种族无关，特别是对于具有低IgG滴度的CagA-Ab（+）血清学状态或与Hp-Ab（-）组合的高危个体。
