Long-term remission of infantile Takayasu arteritis associated with germline CBL syndrome after allogeneic hematopoietic stem cell transplantation: A case report and literature review.

Takayasu arteritis (TA) is a large-vessel vasculitis that rarely presents in infancy. Casitas B-lineage lymphoma (CBL) syndrome is a rare genetic disorder due to heterozygous CBL gene germline pathogenic variants that is characterized by a predisposition to develop juvenile myelomonocytic leukemia (JMML). Vasculitis, including TA, has been reported in several patients. Herein, we describe a patient with CBL syndrome, JMML, and TA, developing long-term remission of this vasculitis after allogeneic hematopoietic stem cell transplant (HSCT), and perform a literature review of CBL syndrome with vasculitis or vasculopathy. We report a female patient with growth delay, developmental issues, and congenital heart disease who was admitted at 14 months of age with massive splenomegaly, lymphadenopathy, fever, and hypertension. Body imaging studies revealed arterial stenosis and wall inflammation of the aorta and multiple thoracic and abdominal branches. Whole exome sequencing revealed a pathogenic variant in CBL with loss of heterozygosity in blood cells, diagnosing CBL syndrome, complicated by JMML and TA. Allogeneic HSCT induced remission of JMML and TA, permitting discontinuation of immunosuppression after 12 months. Six years later, her TA is in complete remission off therapy. A literature review identified 18 additional cases of CBL syndrome with vasculitis or vasculopathy. The pathogenesis of vasculitis in CBL syndrome appears to involve dysregulated T cell function and possibly increased angiogenesis. This case advances the understanding of vascular involvement in CBL syndrome and of the genetic, immune, and vascular interplay in TA, offering insights for treating CBL syndrome and broader TA.

Is there an association between indoor allergens and the severity of atopic dermatitis?

BACKGROUND: Atopic dermatitis (AD) is a multifactorial inflammatory skin disease with frequent hypersensitivity to allergens. However, the role of exposure to indoor allergens on AD severity is unclear. METHODS: Children aged 0-17 years with active AD from central Chile were recruited; disease severity was evaluated with SCORAD and POEM scores. A home environment survey was applied to parents. Bedroom dust samples were collected for all subjects and analyzed by multiplex assay to quantify dust mite (Der p1, Der f1), dog (Can f1), cat (Fel d1), and alternaria alternata (Alt a1) allergens. RESULTS: Twenty-five children aged 3.9 ± 3.8 years were included. Fifty-two percent were female. Mean SCORAD was 29 ± 14 (range 11-61), and mean POEM was 10.7 ± 6.2. No direct association was found between tobacco exposure, pet ownership, aerosol use, visible dust, or home carpets/rugs with SCORAD (all P > 0.05). Dust samples from all homes had Can f1 and Fel d1 allergens, regardless of pet ownership. Homes that had indoor dogs or cats had significantly higher amounts of these allergens (P < 0.001). Forty percent of homes had dust mite allergens, and none had alternaria alternata. Children with AD living in homes with elevated dust mite and animal dander allergen concentrations had higher SCORAD than those from homes with low allergen concentrations (40 ± 13 vs. 26 ± 13, P = 0.025). CONCLUSIONS: High concentrations of indoor allergens may influence AD severity in children. Further studies assessing indoor allergens and allergen sensitization are warranted to fully evaluate the role of indoor allergens on AD.

Estudio de validez diagnóstica de la prueba de hemorragia oculta fecal en lactantes con proctocolitis alérgica inducida por proteína alimentaria / Diagnostic validity of fecal occult blood test in infants with food protein-induced allergic proctocolitis

Resumen: Introducción: La proctocolitis alérgica inducida por proteína alimentaria (PCA) es la forma más fre cuente de alergia alimentaria no mediada por IgE. El diagnóstico se realiza por prueba de provocación oral, sin embargo, no existe una prueba diagnóstica no invasiva para su diagnóstico. Frecuentemente en Chile se utiliza la prueba de hemorragia oculta fecal (PHOF) para confirmar PCA, pero no hay estudios que respalden su indicación. Objetivo: Determinar la validez diagnóstica de la PHOF en la evaluación de lactantes con PCA. Pacientes y Método: Estudio de casos y controles con recluta miento prospectivo de lactantes con rectorragia y sospecha de PCA y lactantes sanos, en quienes se realizó una PHOF. Se indicó dieta de exclusión a los casos y luego se confirmó diagnóstico de PCA mediante contraprueba. Resultados: Se incluyó a 25 casos y 29 controles sin diferencias signi ficativas en edad, sexo, tipo de parto, alimentación o edad materna. Los casos presentaron con mayor frecuencia comorbilidades alérgicas, uso de medicamentos y antecedentes familiares de alergia. La PHOF fue positiva en 84% de casos y en 34% de controles (p<0,001). La sensibilidad de la PHOF para diagnosticar PCA fue 84%, especificidad 66%, valor predictivo positivo 68% y valor predictivo nega tivo 83%. El área bajo la curva ROC fue de 0,75 (IC 95% 0,61-0,88). Conclusiones: Si bien la PHOF tiene sensibilidad adecuada para detectar PCA en lactantes con rectorragia, resulta alterada en más de un tercio de lactantes sanos por lo que no se recomienda su uso habitual para el diagnóstico de PCA.

Abstract: Introduction: Food protein-induced allergic proctocolitis (FPIAP) is the most frequent presenta tion of non-IgE mediated food allergy (FA). The diagnosis is made by oral food challenge, however, non-invasive diagnostic tests are not available. In Chile, the fecal occult blood test (FOBT) is fre quently used to confirm FPIAP, however, there are no studies that support this practice. Objective: To establish the diagnostic validity of FOBT in the evaluation of infants with FPIAP. Patients and Method: Case-control study with prospective recruitment of infants with rectal bleeding and suspicion of FPIAP, and controls were healthy infants, in whom the FOBT was conducted. All cases underwent an elimination diet, after which the diagnosis of FPIAP was confirmed by oral food cha llenge. Results: 25 cases and 29 controls were included without significant differences in age, gen der, type of delivery, feeding, and maternal age. The cases had higher rates of allergic comorbidities, medication use, and family history of allergy. The FOBT was positive in 84% of cases and in 34% of controls (p < 0.001). The sensitivity of the FOBT for the diagnosis of FPIAP was 84%, specificity was 66%, positive predictive value 68%, and the negative predictive value 83%. The area under the ROC curve was 0.75 (CI 95% 0.61-0.88). Conclusions: Although the FOBT has an adequate sensitivity to diagnose FPIAP in infants with rectal bleeding, this test had abnormal results in more than a third of healthy infants. Therefore, the routine use of FOBT is not recommended for the diagnosis of FPIAP.