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.

NLRP1-associated autoinflammatory disease with epithelial dyskeratosis.

Several gain-of-function variants in NLRP1 cause a distinctive autoinflammatory disease reported under different names featuring mainly skin and mucosal involvement and variable systemic signs. Here, we report a new case of NLRP1-associated autoinflammatory disease in a 6-year-old Peruvian girl, who presented with confluent hyperkeratotic plaques that drained purulent material with subsequent scarring. A c.3641C > G (p. Pro1214Arg) variant that has been previously been reported was found in NLRP1 and was not present in either parent. The term NLRP1-associated autoinflammatory disease with epithelial dyskeratosis (NADED) is proposed to encompass all reported cases, which have received different nomenclature so far.

Awareness of primary immunodeficiency diseases at a national pediatric reference center in Peru.

OBJECTIVE: To investigate the level of awareness of primary immunodeficiency diseases among physicians working at Instituto Nacional de Salud del Niño. METHODS: Cross-sectional study including pediatric residents and pediatricians working at the Instituto Nacional de Salud del Niño during the study period (2017-2019). Physicians working at the immunology unit and surgery departments were excluded. Three aspects of awareness of primary immunodeficiency diseases were investigated: education, general knowledge, and diagnostic suspicion and actions taken in the face of suspicion. RESULTS: This sample comprised 83 physicians with a median age of 33 years. Most physicians were women (71.1%) and half were pediatric residents. During their undergraduate studies, 43.1% had taken primary immunodeficiency disease courses, and 39.2% had attended conferences on this topic. During their residency training, 25.9% had taken primary immunodeficiency disease courses, and 60.3% had participated in conferences on this topic. Among pediatricians, 50% had taken primary immunodeficiency disease courses, and 53.1% had attended conferences on this topic. Only 39.8% of physicians reported being familiar with the list of 10 warning signs developed by the Jeffrey Modell Foundation. More than half of physicians considered the lack of access to laboratory tests the major challenge in making diagnosis of primary immunodeficiency diseases. CONCLUSION: This study revealed limited awareness of primary immunodeficiency diseases among physicians working at Instituto Nacional de Salud del Niño. Although most physicians suspected primary immunodeficiency diseases in patients with a history of recurrent infections and frequent use of antibiotics, not all of them were familiar with the list of 10 warning signs proposed by the Jeffrey Modell Foundation, nor were they able to describe ancillary tests requested in suspected cases.

Pulmonary Infections and Surgical Complications in a Young Girl with Signal Transducer and Activator of Transcription 3 Loss-of-Function Mutation Hyperimmunoglobulin E Syndrome: A Case Report.

Introduction: Hyperimmunoglobulin E syndromes (HIESs) are characterized by a high serum immunoglobulin E (IgE) level, eczematoid rashes, recurrent staphylococcal skin abscesses, and recurrent pneumonia and pneumatocele formation. Autosomal dominant HIES is the most common form of HIES and mainly occurs due to loss-of-function mutations in the Signal Transducer and Activator of Transcription 3 (STAT3) gene (STAT3 LOF). Case Presentation: We report the case of an 11-year-old Peruvian girl diagnosed with STAT3 LOF caused by p.R382W mutation. She presented with recurrent staphylococcal pneumonia and empyema caused by the rarely reported Achromobacter xylosoxidans, which led to severe destruction of the lung parenchyma, multiple lung surgeries, and the development of bronchopleural fistulas. A laparotomy was also performed, which showed evidence of sigmoid colon perforation. The patient received immunoglobulin replacement therapy (IRT) and antibiotic prophylaxis, and the frequency of her infections has decreased over the past 3 years. Conclusion: This is the first case of STAT3 LOF diagnosed by genomic sequencing in Peru. Patients with this mutation have recurrent pulmonary infections, and require multiple surgical procedures with frequent complications. A. xylosoxidans infection could be related to the prolonged stay in intensive care leading to high mortality; therefore, additional care must be taken when treating patients with this infection. In addition, colonic perforation is a rare complication in STAT3 LOF patients. IRT and antibiotic prophylaxis appear to decrease the frequency of infections and hospitalizations.

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

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.

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.

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.

Dysregulated actin dynamics in activated PI3Kδ syndrome.

Activated PI3Kδ syndrome (APDS) Type I results from gain-of-function mutations in PIK3CD, which encodes the p110δ subunit of PI3Kδ. Abnormal actin dynamics have been hypothesized to contribute to the lymphopenia associated with this disease but have not been studied in patients with APDS. We report a patient with APDS who had widespread necrotic skin lesions that were responsive specifically to immunosuppressive therapy. EBV-transformed lymphoblastoid cells (EBV-LCLs) from patients with APDS exhibit increased polymerized actin and increased apoptosis, suggesting a contribution of impaired actin dynamics to this disease.

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

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.

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.

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.

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

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.

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.

Diagnostic Delay of Primary Immunodeficiencies at a Tertiary Care Hospital in Peru- Brief Report.

OBJECTIVE: The aim of the study was to assess the diagnostic delay in pediatric patients with primary immunodeficiencies (PID) at a tertiary care hospital in Peru. METHODS: A descriptive study was carried out in which patients from a third-level referral center in Peru were included. Those without a specific diagnosis of PID were excluded. Data was collected by reviewing the medical records and interviewing patients' family members. RESULTS: A total of 45 patients with a mean of 7.4 years (SD = 4.3) were studied. The most frequent diagnosis was predominant antibody defects (35.5%), and the diagnostic delay had a median of 12.17 months (IQR 5.1-30.3). CONCLUSIONS: The most frequently diagnosed group of PID was predominant antibody deficiency. The overall median diagnostic delays for PID and predominant antibody deficiency were 12 and 14 months, respectively. Even though early detection of PIDs is crucial for effective treatment, current available laboratory tests required for PID diagnosis are both complex and expensive. Early detection and management of these pathologies cannot be achieved without training non-specialist health professionals in the diagnosis of PID, as well as integrating multidisciplinary and multi-center cooperation at both national and international levels.

[Severe congenital neutropenia]. / Neutropenia congénita grave.

Severe congenital neutropenia is a primary immunodeficiency; the lack of maturation of neutrophil precursor in bone marrow and severe neutropenia are the subjacent characteristics which explain a marked susceptibility to severe and recurrent infections; bacteria and fungi are the most common etiologic agents. We report the case of an infant with severe congenital neutropenia that began at 4 days from birth with perianal abscess infections, sepsis, liver abscess, gingivitis and oral ulcers; she required multiple hospitalizations because of the severity of the infections. Isolated agents were Pseudomonas aeruginosa, Staphylococcus hominis and Klebsiella sp. The bone marrow examination showed maturation arrest of myeloid forms, thus confirming the diagnosis of severe congenital neutropenia. Granulocyte colony-stimulating factor was started. The severe congenital neutropenia should be considered in patients with neutropenia and infections in the first month of life. Early diagnosis and treatment improve survival and quality of life of these patients.