Purpose Autoimmunity is an alternative etiology of gastric inflammation, the initiating event in the gastric carcinogenic cascade. This mechanism may be an increasingly important cause of gastric cancer with the waning prevalence of its primary etiologic factor, chronic Helicobacter pylori infection. Materials and Methods PubMed and EMBASE were searched up to September 2018. Autoimmunity and 96 specific manifestations were considered for associations with gastric cancer risk. Random effects analysis was used to calculate pooled relative risk estimates (RR) and 95% confidence intervals (CI). Results We found a total of 52 observational studies representing 30 different autoimmune diseases. Overall, the presence of an autoimmune condition was associated with a gastric cancer pooled RR of 1.37 (95% CI, 1.24 to 1.52). Among the 24 autoimmune conditions with two or more independent reports, nine were significantly associated with increased gastric cancer risk: dermatomyositis (RR, 3.69; 95% CI, 1.74 to 7.79), pernicious anemia (RR, 2.84; 95% CI, 2.30 to 3.50), Addison disease (RR, 2.11; 95% CI, 1.26 to 3.53), dermatitis herpetiformis (RR, 1.74; 95% CI, 1.02 to 2.97; n=3), IgG4-related disease (RR, 1.69; 95% CI, 1.00 to 2.87), primary biliary cirrhosis (RR, 1.64; 95% CI, 1.13 to 2.37), diabetes mellitus type 1 (RR, 1.41; 95% CI, 1.20 to 1.67), systemic lupus erythematosus (RR, 1.37; 95% CI, 1.01 to 1.84), and Graves disease (RR, 1.27; 95% CI, 1.06 to 1.52). Conclusion Our analysis documents the wide range of autoimmune diseases associated with gastric cancer. These associations may reflect unreported links between these conditions and autoimmune gastritis. Further studies are warranted to investigate potential causal mechanisms.

OBJECTIVE Thyroid dysfunction and obesity during pregnancy have been associated with negative neonatal and obstetric outcomes. Thyroid hormone reference ranges have not been established for the pregnant Hispanic population. This study defines thyroid hormone reference ranges during early pregnancy in Chilean women and evaluates associations of BMI with thyroid function. DESIGN, PATIENTS, MEASUREMENTS This is a prospective observational study of 720 healthy Chilean women attending their first prenatal consultation at an outpatient clinic. Thyroid function (TSH, Free T4, Total T4, and TPOAb) and BMI were assessed at 8.8 ± 2.4 weeks of gestational age. RESULTS Median, 2.5th percentile (p2.5), and 97.5th percentile (p97.5) TSH values were higher, while median, p2.5, and p97.5 free T4 values were lower in obese patients compared with normal weight patients. Obesity was associated with a median TSH 16% higher (p=0.035) and a median free T4 6.5% lower (p<0.01) than values from patients with normal weight. BMI had a small, but statistically significant effect on TSH (p=0.04) and free T4 (p<0.01) when adjusted by maternal age, TPO antibodies, parity, sex of the newborn, gestational age, and smoking. In all TPOAb (-) patients, median (p2.5–p.97.5) TSH was: 1.96 mIU/L (0.11 – 5.96 mIU/L) and median (p2.5–p.97.5) free T4 was: 14.54 pmol/L (11.1 – 19.02 pmol/L). Applying these reference limits, we found a prevalence of overt and subclinical hypothyroidism of 0.9% and 3.05%, respectively. CONCLUSIONS TSH distributes at higher values and free T4 at lower values in obese pregnant women compared to normal weight pregnant women. Thyroid hormone reference ranges derived from Chilean patients with negative TPOAb are different from the fixed internationally proposed reference ranges and may be used in the Hispanic population.

Background and Study Aims: Lactase non-persistence (LNP), or primary hypolactasia, is a genetic condition that mediates lactose malabsorption and can cause lactose intolerance. Here we report the prevalence of lactose intolerance in a double-blind placebo study. Methods: The LCT C>T_-13910 variant was genotyped by RT-PCR in 121 volunteers and lactose malabsorption was assessed using the hydrogen breath test (HBT) after consuming 25 g of lactose. Lactose intolerance was assessed by scoring symptoms (SS) using a standardized questionnaire following challenge with a lactose solution or saccharose placebo. Results: The LNP genotype was observed in 57% of the volunteers, among whom 87% were HBT(+). In the HBT(+) group the median SS was 9 and in the HBT(-) group the median SS was 3 (p < 0.001). No difference was observed in the SS when both groups were challenged with the placebo. The most common symptoms included audible bowel sounds, abdominal pain and meteorism. In the ROC curve analysis, an SS ≥6 demonstrated 72% sensitivity and 81% specificity for predicting a positive HBT. To estimate prevalence, lactose intolerance was defined as the presence of an SS ≥6 points after subtracting the placebo effect and 34% of the study population met this definition. Conclusions: The LNP genotype was present in more than half of subjects evaluated and the observed prevalence of lactose intolerance was 34%.

Background: Feedback is one of the most important tools to improve teaching in medical education (Rev Med Chile 2015; 143: 1005-1014

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Educational impact after 10 years of implementation of a portfolio for undergraduate medical students Background: A portfolio is a compilation of academic work that demonstrates student's knowledge, reflection and critical thinking. Aim: To describe the development and implementation of an undergraduate portfolio in the School of Medicine at the Pontificia Universidad Católica de Chile, its temporal evolution and its educational impact after 10 years of experience. Material and Methods: The development and implementation of a portfolio for 4 th-year undergraduate medical student was analyzed. Its design, teaching and learning methodologies, results and perceptions of students and teachers were assessed. The educational impact was measured using Kirkpatrick´s levels. Results: A total of 1,320 students participated between 2007 and 2017, supported by six teachers and 190 assistant-students. The portfolio included clinical cases, narrative medicine, palliative care and evidence-based medicine (EBM). The overall student's perception was positive, highlighting the development of critical analysis, clinical reasoning and professionalism. The delivery of feedback and learning assessment, allowed students to obtain excellent grades. There were only two cases of plagiarism reported. Fifteen EBM articles and two books with 52 narrative medicine essays were published. The greatest organizational impact of this teaching innovation, was that it evolved to become an established and continuous assessment instrument in 10 consecutive years. Conclusions: This portfolio is a project with a high educational impact, with a favorable perception by students and tutors, excellent results related to grades, stimulating both scientific writing and reflective practice.

INTRODUCTION: Autoimmune gastritis (AIG) is associated with nutritional deficiencies, autoimmune diseases, and gastric malignancies. The aims of the study were to test the hypothesis that mucocutaneous (MC) manifestations occur more often in patients with vs without AIG and to delineate patterns of MC manifestations in AIG. Methods: A single-center, prospective 2:1 case-control study was conducted. Cases were patients with the diagnosis of AIG based on consistent serologic and histologic findings. Controls had a normal gastric biopsy. MC manifestations were independently evaluated by 3 experienced dermatologists. We conducted a multivariable logistic regression model adjusted for age, sex, Helicobacter pylori, tobacco use, and alcohol consumption to estimate the association between AIG (vs no AIG) and MC manifestations (adjusted odds ratio; 95% confidence interval). RESULTS: We prospectively enrolled 60 cases and 30 controls (mean age 53.5 ± 15.8 vs 53.4 ± 14.5 years; 75% vs 73.3% women). The pooled prevalence of MC immune-mediated diseases was higher in patients with vs without AIG (66.7% vs 23.3%; adjusted odds ratio 12.01 [95% confidence interval: 3.51–41.13]). In patients with AIG, seropositive vs seronegative anti-intrinsic factor antibodies more often had concomitant immunological diseases with MC manifestations (100% vs 58.5%; P = 0.016). The most common MC immune-mediated diseases in AIG were Sjögren syndrome (n = 5, 8.3%), alopecia areata (n = 5, 8.3%), and vitiligo (n = 4, 6.7%). Nutritional deficiency-related MC findings, mainly xerosis, lingual, and nail disorders, were also more common in AIG. DISCUSSION: This is the first comparative study specifically designed to evaluate MC manifestations in AIG. We demonstrated that AIG is more frequently associated with both immune- and nutritional deficiency-related MC manifestations, which might have both diagnostic and therapeutic clinical implications.

The cover image, by Laura Boucai et al., is based on the Original Article, Early pregnancy thyroid hormone reference ranges in Chilean women: The influence of body mass index, DOI Image authored by Daniela Silberman.