Increase of drug use and genotype 3 in HCV-infected patients from Central West and Northeast Mexico.

BACKGROUND: The evolving pattern of HCV genotypes (GTs) and risk factors (RFs) in HCV-infected patients in Mexico is poorly understood. This study aimed to access the temporal trend of HCV GTs and RFs in HCV patients from two care centers. MATERIAL AND METHODS: Chronic HCV patients [177 and 153 patients from the Northeast (NE) and Central West (CW) regions, respectively] were selected. Baseline features were demographics, date of birth (DOB), blood transfusion before 1992 (BTb1992), RFs, sexual promiscuity (SP), dental procedure (DP), injection drug use (IDU), viral load (VL), GTs, cirrhosis status and antiviral therapy (AT). Data were analyzed by Chi-square test for trends, unpaired T-test, and logistic regression. RESULTS: HCV GT distribution was: GT1, 67%; GT2, 16%; GT3, 12% and GT4, 1%. RFs were BTb1992, 56%; surgeries, 56%; tattooing, 18% and IDU, 16%. GT1a mostly prevailed in CW than NE patients. GT1b, surgeries, BTb1992 and cirrhosis were more prevalent in older patients (p < 0.05); GT3, male gender IDU, SP, and tattooing showed an upward trend as younger were the patients in both regions (p < 0.05), contrariwise to the prevalence of GT1b. BTb1992 and surgeries were seen in elder women; BTb1992 was an independent RF for GT1. Age ≥ 50 years old, GT1 and exposure to AT (p < 0.05) were associated with cirrhosis. CONCLUSION: GT1a prevalence in CW Mexico remained stable, whereas GT3 increased and GT1b decreased in younger patients in both regions, along with associated RFs. Further regional molecular epidemiology and RF analyses are required in order to avoid the dissemination of new cases of HCV infection.

[C677T polymorphism of the MTHFR gene and the risk of developing distal gastric cancer in a Mexican population]. / Polimorfismo C677T del gen MTHFR y el riesgo al desa- rrollo de cáncer gástrico distal en una población mexicana.

BACKGROUND: The 5,10-methylenetetrahydrofolate reductase (MTHFR) 677C-->T polymorphism has been associated to a higher risk to develop proximal gastric cancer. AIM: To study the role of the MTHFR C677T polymorphism as a risk factor for the development of distal gastric cancer (DGC) in a Mexican population. PATIENTS AND METHODS: Fifty-one histologically confirmed DGC (mean age = 57.6y, F:M = 0.76) and 83 ethnically matched non-GC controls (mean age 51.5y, F:M = 0.59) were studied. The MTHFR C677T polymorphism was typed by PCR-RFLP. The infection by Helicobacter pylori was defined by the positive result of at least two of the next diagnostic tests: histology, rapid urease test and culture. RESULTS: Among the GC patients, 16 (31.4%) were homozygous for C and 23 (45.1%) were CT Among the non-cancer control patients 17 (20.5%) were CC and 49 (59%) were CT. No difference was found in the frequency of the mutated variant MTHFR 677T between the GC cases and the non-cancer control patients (23.5% vs. 20.5 respectively) (p = 0.84; odds ratio: 1.19, 95% confidence interval: 0.48-2.98). The frequency of MTHFR 677TT genotype was not influenced by the infection by H. pylori. CONCLUSION: The mutated genotype TT of the MTHFR is frequent in Mexican population. Our study provides evidence that there is no association between the MTHFR C677T polymorphism and the development of gastric cancer in the Mexican population studied.

Diagnostic utility of invasive tests and serology for the diagnosis of Helicobacter pylori infection in different clinical presentations.

BACKGROUND: Invasive and noninvasive tests are used for the diagnosis of Helicobacter pylori infection. The aim of this study was to determine the diagnostic utility of rapid urease test (RUT), culture, histology and serology for the diagnosis of H. pylori in patients with different clinical presentations. METHODS: We studied 527 consecutive patients (mean age, 52.5 years; F:M, 1.3; age range 15-89 years) enrolled at the Hospital Universitario, Universidad Autónoma de Nuevo León. Patients had gastric cancer (GC, 9.1%), non-ulcer dyspepsia (NUD, 81.4%), or peptic ulcer disease (PUD, 9.1%). The infection by H. pylori was determined by histology, rapid urease test, culture, and serology. Patients were determined as infected with H. pylori if at least a) two invasive tests were positive and b) two tests were positive (invasive or non-invasive). Diagnostic utility was calculated for each assay. RESULTS: Prevalence of infection in the whole studied population was 50.9%. In NUD patients the prevalence was 51.3%, in PUD patients 58.3%, and in GC patients 39.6%. When we used the first diagnostic criteria, for the whole studied population, the RUT was the most reliable test, followed by the culture. Histology had the best sensitivity for the whole studied population and NUD patients and RUT had the best sensitivity value for the GC patients. In the whole studied population, NUD and GC patients, RUT and culture had the best specificity, accuracy and PPV. For PUD patients, serology had the best performance. When we used the second diagnostic criteria, histology and serology had a better performance compared with the results obtained with the first diagnostic criteria. CONCLUSIONS: Diagnostic utility of the tests varies according to the clinical presentations, which should be considered in the selection of the diagnostic test for the detection of H. pylori.