Clinical characteristics, laboratory findings, and tolerance acquisition in infants with cow's milk protein allergy in a private center in Lima, Peru for the period 2021-2022.

BACKGROUND: Cow's milk protein allergy (CMPA) remains relatively understudied in Latin America. METHODS: In this observational study, we enrolled 64 patients with a median age of 3 months, of whom 60% were male. Patients included had a history of IgE-mediated reactions with IgE sensitization or non-IgE-mediated reactions or symptoms following exposure to cow's milk. They underwent skin prick test, ImmunoCAP, fecal calprotectin (FC), and fecal eosinophil-derived neurotoxin (EDN), in addition to double-blinded placebo-controlled oral food challenges (DBPCFC), with clinical evolution and tolerance acquisition observed over 1 year. RESULTS: Malnutrition was present in 78.1% of patients, and 87.5% had a family history of atopy, with 51.6% receiving exclusive breastfeeding. Gastrointestinal manifestations were prevalent in 90.6% of patients, followed by dermatological manifestations (10.9%), with only 2 experiencing anaphylaxis. IgE-mediated CMPA was observed in only six patients. In those with non-IgE-mediated CMPA, FC had a median of 284 mg/dL (IQR: 138.5-415.5), while EDN had a median of 508.5 mg/dL (IQR: 160.25-868). One year after diagnosis, median FC significantly decreased (p < 0.0001), and malnutrition prevalence reduced to 17.1%. Moreover, 81% of patients acquired tolerance following DBPCFC, with 52% utilizing nutritional replacement formulas at diagnosis. Notably, 94% of those extensively hydrolyzed casein-based formulas achieved tolerance (p = 0.08). CONCLUSION: Our findings provide a foundational framework for future investigations into CMPA diagnosis, tolerance acquisition, and the utilization of hypoallergenic formulas tailored to the unique characteristics of our region.

Sensibilización a aeroalérgenos en una población pediátrica peruana con enfermedades alérgicas / Sensitization to aeroallergens in a peruvian pediatric population with allergic diseases

RESUMEN Con el objetivo de determinar el perfil de sensibilización a aeroalérgenos en pacientes pediátricos con asma y/o rinitis alérgica se realizó un estudio transversal en 411 pacientes usando una prueba cutánea de alergia. Se analizó la edad, sexo, nivel de IgE total y eosinófilos. La edad media fue de 8,1 ± 3,7 años y el 60,6% fueron varones. La media de los eosinófilos y el nivel de IgE total fue de 450,1 ± 377,3 células/mm3 y 861,7 ± 757,6 IU/mL, respectivamente. Los ácaros fueron los alérgenos sensibilizantes más frecuentes (79,8%) y el Dermatophagoides farinae (65,2%) fue el más común. La polisensibilización estuvo presente en el 76,2% de los pacientes. La sensibilización se evidenció en la mayoría de los pacientes con asma y/o rinitis alérgica y estuvo asociada con la edad, grupos etarios y nivel de IgE total.

ABSTRACT In order to determine the profile of sensitization to aeroallergens in pediatric patients with asthma and / or allergic rhinitis, a cross-sectional study was carried out in 411 patients using an allergy skin test. Age, sex, total IgE level and eosinophils were analyzed. The mean age was 8.1 ± 3.7 years and 60.6% were male. The average of the eosinophils and the level of total IgE was 450.1 ± 377.3 cells / mm3 and 861.7 ± 757.6 IU / mL, respectively. Mites were the most frequent sensitizing allergens (79.8%) and Dermatophagoides farinae (65.2%) was the most common. Polysensitization was present in 76.2% of patients. Sensitization was evident in the majority of patients with asthma and / or allergic rhinitis and was associated with age, age groups and total IgE level.

Diagnóstico genético de pacientes con agammaglobulinemia primaria atendidos en centros peruanos de tercer nivel / Genetic diagnosis of patients with primary agammaglobulinemia treated at third level peruvian centers

Las agammaglobulinemias primarias (AP) resultan de alteraciones específicas en las células B, lo cual, conduce a baja producción de anticuerpos. La sospecha diagnóstica se establece con el antecedente de infecciones a repetición, inmunoglobulinas bajas y la ausencia linfocitos B CD19+. El diagnóstico se confirma mediante el análisis genético y la detección de una mutación ligada en el cromosoma X o autosómico recesiva o dominante. En Perú, no hay literatura sobre AP ni reportes sobre el genotipo de los pacientes con sospecha de AP. Bajo este escenario, se realizó un estudio que describió el genotipo de pacientes con sospecha de AP. Se encontraron 20 pacientes con mutaciones en el gen BTK y una mutación autosómica recesiva IGHM. Se hallaron 13 mutaciones hereditarias y siete mutaciones de novo. Se concluye que las AP son, en su mayoría, mutaciones en el gen BTK que corresponden con AP ligadas al cromosoma X.

Primary agammaglobulinemia result from specific alterations in B cells, which lead to low antibody production. Diagnostic suspicion is established with a history of repeated infections, low immunoglobulins, and absence of CD19+ B lymphocytes. The diagnosis is confirmed by genetic analysis and the detection of a mutation linked to the X or autosomal recessive or dominant chromosome. In Peru, there is no literature on primary agammaglobulinemia and no reports on the genotype of patients with suspected primary agammaglobulinemia. Under this scenario, a study was performed to describe the genotype of patients with suspected primary agammaglobulinemia. Twenty (20) patients were found with mutations in the BTK gene and an autosomal recessive IGHM mutation. Thirteen (13) hereditary mutations and seven de novo mutations were found. It is concluded that the group of primary agammaglobulinemia are mostly mutations in the BTK gene, corresponding to X-linked agammaglobulinemia.

Recuento poblacional linfocitario como primera aproximación al diagnóstico de inmunodeficiencias primarias / Lymphocyte population count as a first approach to the diagnosis of primary immunodeficiencies

RESUMEN Las inmunodeficiencias primarias (IDP) se caracterizan por alteraciones de los componentes del sistema inmunitario. El recuento poblacional linfocitario por citometría de flujo es una aproximación al diagnóstico molecular y se expresa por inmunofenotipos. El objetivo del estudio fue describir el recuento poblacional linfocitario y los inmunofenotipos compatibles con IDP en pacientes con sospecha de IDP en un hospital de referencia nacional peruano. Se revisaron los registros de 261 casos que cumplían con los criterios de sospecha clínica para IDP de la Jeffrey Modell Foundation entre abril y diciembre de 2016. De los 261 casos con sospecha de IDP se hallaron 54,8% de varones. Se encontró 93 pacientes (35,6%) con inmunofenotipos compatibles con alguna IDP. El inmunofenotipo de inmunodeficiencia común variable fue más frecuente (36,6%), seguido de agammaglobulinemias (18,3%). Las deficiencias de anticuerpos fueron las IDP más frecuentes. Es necesario realizar otras pruebas moleculares para el diagnóstico genético específico.

ABSTRACT Primary immunodeficiencies (PID) are characterized by alterations in the components of the immune system. The lymphocyte population count by flow cytometry is an approach to molecular diagnosis and is expressed by immunophenotypes. The objective of the study was to describe the lymphocyte population count and immunophenotyping compatible with PID in patients with suspected PID in a Peruvian national reference hospital. Records of 261 cases meeting the Jeffrey Modell Foundation's PID clinical suspicion criteria were reviewed between April and December of 2016. Of the 261 suspected cases of PID, 54.8% were males. We found 93 patients (35.6%) with PID-compatible immunophenotyping. The common variable immunodeficiency immunophenotype was the most frequent (36.6%), followed by agammaglobulinemias (18.3%). Antibody deficiencies were the most common PID. Other molecular tests are needed for a specific genetic diagnosis.