Browsing by Author "Marchant, Pamela"
Now showing 1 - 3 of 3
Results Per Page
Sort Options
Item Association of Cow's Milk Protein Allergy Prevalence With Socioeconomic Status in a Cohort of Chilean Infants(2020-09) Arancibia, María; Yalda, Lucero; Miquel, Isabel; Marchant, Pamela; Rodríguez, Lorena; Alliende, Francisco; Ríos, Gloria; Maturana, AndrésObjectives: The aim of the study was to compare the cow's milk protein allergy (CMPA) prevalence in 2 cohorts of children from different socioeconomic strata. Methods: Prospective birth cohort that included patients from 2 hospitals providing care for a low- and high-income population, respectively. Healthy newborns >= 34 gestational weeks were recruited and followed up to 12 months by a monthly telephone survey. If >= 2 predefined symptoms/signs suggestive of CMPA were detected, the patient was evaluated by a pediatric gastroenterologist. Diagnosis was confirmed by exclusion diet followed by open oral food challenge. Results: Overall the prevalence of CMPA was 5.2%, with a 6 times higher prevalence in the high income cohort (9.2%) compared with the low-income group (1.5%; relative risk 6.2; 95% confidence interval 1.8-20.7;P = 0.0005). All the cases were non-immunoglobulin E-mediated with predominantly gastrointestinal symptoms. High-income cohort did have higher frequency of Csection, mother's previous chronic disease, mother's history of atopy/food allergy, older age, and higher educational level of parents. Parent smoking and presence of pets at home were more frequent in the low-income cohort. Multiple logistic regression showed that the high-income cohort did have older age and higher educational level of both parents. Conclusion: In these cohorts the prevalence of CMPA was higher than reported previously in other developing countries and significantly higher in the high-income group. Our findings were associated with sociodemographic characteristics of the parents.Publication Concordance of Helicobacter pylori Detection Methods in Symptomatic Children and Adolescents(2025) Cabrera, Camila; Campusano, Yanira; Torres, Joaquín; Ivulic, Dinka; Galvez, Valeria; Tapia, Diego; Rodríguez, Vicente; Lagomarcino, Anne; Gallardo, Alejandra; Alliende, Francisco; Toledo, Marcela; Román, Gabriela; Jaime, Francisca; González, Mónica; Marchant, Pamela; Rojas, Marianela; Juanet, Juan Ignacio; Villanueva, Mónica; Ossa, Juan Cristóbal; Del Canto, Felipe; Viver, Tomeu; O’Ryan, Miguel; Lucero, YaldaBackground: Helicobacter pylori is the most prevalent chronic bacterial infection globally, acquired mostly during childhood. It is associated with chronic gastritis, peptic ulcer disease, and gastric cancer. Due to challenges in culturing H. pylori, diagnostic reference standards often rely on combining ≥2 non-culture, biopsy-based methods. Histology with Giemsa staining is widely used in clinical settings due to its low cost and reliable performance. Methods: This study evaluated the concordance between histology with Giemsa staining as the reference standard and other diagnostic methods, including the rapid urease test (RUT), ureA RT-PCR, 16S sequencing, and anti-H. pylori serum IgG. Positive percent of agreement (PPA), negative percent of agreement (NPA) and concordance kappa index were calculated. Results: A total of 120 patients (41 positive and 79 negative by Giemsa staining) were analyzed. Among the methods tested, RT-PCR for ureA showed the best performance (PPA = 94.7%, NPA = 98.6%, kappa = 0.939), while RUT underperformed compared with expectations (PPA = 65.9%, NPA = 97.5%, kappa = 0.681). Serology had the lowest performance (PPA = 53.7%, NPA = 96.1%, kappa = 0.548). Conclusions: The combination of histology with Giemsa staining and ureA RT-PCR achieved the highest detection rate and strongest agreement.Publication Prevalence of Cow’s Milk Allergy in Infants from an Urban, Low-Income Population in Chile: A Cohort Study(2025) Cruchet, Sylvia; Arancibia, María Eugenia; Maturana, Andrés; Marchant, Pamela; Rodríguez, Lorena; Lucero, YaldaBackground. Cow’s milk allergy (CMA) is one of the most common food allergies in infancy, with prevalence estimates of 0.5–7.5% in high-income countries. Data from low- and middle-income regions remain limited, and the predominant immune mechanism (IgE or non-IgE mediated) may vary across populations. Objective. We aimed to determine the prevalence and clinical characteristics of CMA in infants from an urban, low-income Chilean population. Methods. A prospective cohort study was conducted at Padre Hurtado Hospital in Santiago, Chile. Healthy term newborns were recruited and followed for up to 12 months. Sociodemographic, perinatal data and parental atopy were recorded. Parents were contacted monthly to screen for CMA symptoms. Infants with ≥two symptoms underwent clinical evaluation, a 4-week cow’s milk protein exclusion diet, and an open oral food challenge (OFC). Diagnosis followed international consensus guidelines. Results. Of 552 enrolled infants (48% male), 27 were diagnosed with CMA, yielding a prevalence of 4.9% (95% CI 3.1–7.0%). All cases exhibited non-IgE-mediated symptoms, including vomiting, dermatitis, colic, and perianal erythema. CMA was diagnosed before 6 months of age in 74% of cases. At 12 months, 40% had developed oral tolerance. Sociodemographic and perinatal characteristics were similar between groups, but some self-reported parental atopic traits were more frequent in CMA cases. Conclusions. CMA prevalence in this Chilean cohort was comparable to that reported in high-income countries, with a predominance of non-IgE-mediated forms. These findings support the need for standardized diagnostic protocols, including OFC, in diverse populations. Future studies should explore long-term outcomes and risk factors in non-IgE-mediated CMA.