Prevalencia de aspergilosis broncopulmonar alérgica en niños con fibrosis quística / Prevalence of bronchopulmonary aspergillosis in children with cystic fibrosis

La aspergilosis broncopulmonar alérgica (ABPA) es una reacción de hipersensibilidad secundaria al Aspergillus fumigatus (Af) que complica la evolución en fibrosis quística (FQ). Existen pocos estudios pediátricos de su prevalencia publicados en el mundo y en Chile se desconoce. El objetivo de este trabajo fue estimar la prevalencia de ABPA en niños con FQ en un hospital de referencia, explorar factores de riesgo y describir los criterios diagnósticos, tratamiento y evolución. Se incluyeron retrospectivamente los niños con FQ atendidos en un hospital terciario en Santiago de Chile (Hospital Roberto del Río) entre los años 2011 a 2019, se identificaron aquellos con diagnóstico de ABPA. Se registraron criterios diagnósticos según la Cystic Fibrosis Foundation, presencia de factores de riesgo, tratamientos recibidos y efectos adversos. De 65 pacientes con FQ atendidos en este período, la prevalencia de ABPA fue del 12%. El promedio de edad al diagnóstico fue ± 11 años (5-17 años), predominando la edad adolescente y el género masculino. El 50% cumplieron con los criterios clásicos, el 87,5% usaron antibióticos y el 62,5% corticoides inhalados. La respuesta favorable al tratamiento inicial con corticoides y antifúngico vía oral fue 62,5%, con una exacerbación al momento del estudio. El 25% se comportaron como refractario y el 12,5% respondieron a tratamiento con pulsos de metilprednisolona. El 37,5% presentaron eventos adversos relacionados a corticoides. La prevalencia de ABPA observada es comparable a las series publicadas. Se necesitan trabajos prospectivos para conocer la prevalencia nacional y su tendencia a lo largo de los años, identificando factores de riesgo.

Allergic bronchopulmonary aspergillosis (ABPA) is a hypersensitivity response to Aspergillus fumigatus (Af) and worsens outcome in children with cystic fibrosis (CF). Its prevalence varies in the literature, but we do not know it in Chile. The aim of the study was to know the prevalence of ABPA in children with CF and to describe risk factors, diagnostic criteria, treatment and outcome. We included all patients with CF seen in a tertiary hospital in Santiago, Chile (Hospital Roberto del Río), between 2011 and 2019; ABPA cases (CF Foundation diagnostic criteria) were identified for the estimation of the prevalence. Risk factors, diagnostic criteria and treatment were recorded, as proposed by the Cystic Fibrosis Foundation. A total of 65 patients with CF were identified in the study period, with a prevalence of 12% (8 cases). Mean age at diagnosis ± 11 years (5-17), more frequent in adolescence and male. CF Foundation criteria diagnostic were identified in 50% of cases, with high frequency of antibiotic use (87,5%) and inhaled steroids (62,5%). Positive oral steroids and antifungal treatment response was 62,5%. Refractary response was 25% and 12,5% needed intravenous metilprednisolone pulses. A 37,5% of cases presented adverse effects to steroids. Prevalence of ABPA is comparable to literature. A prospective study is needed to identified national prevalence and trends, identifying risks factors.

MLN64 induces mitochondrial dysfunction associated with increased mitochondrial cholesterol content.

MLN64 is a late endosomal cholesterol-binding membrane protein that has been implicated in cholesterol transport from endosomal membranes to the plasma membrane and/or mitochondria, in toxin-induced resistance, and in mitochondrial dysfunction. Down-regulation of MLN64 in Niemann-Pick C1 deficient cells decreased mitochondrial cholesterol content, suggesting that MLN64 functions independently of NPC1. However, the role of MLN64 in the maintenance of endosomal cholesterol flow and intracellular cholesterol homeostasis remains unclear. We have previously described that hepatic MLN64 overexpression increases liver cholesterol content and induces liver damage. Here, we studied the function of MLN64 in normal and NPC1-deficient cells and we evaluated whether MLN64 overexpressing cells exhibit alterations in mitochondrial function. We used recombinant-adenovirus-mediated MLN64 gene transfer to overexpress MLN64 in mouse liver and hepatic cells; and RNA interference to down-regulate MLN64 in NPC1-deficient cells. In MLN64-overexpressing cells, we found increased mitochondrial cholesterol content and decreased glutathione (GSH) levels and ATPase activity. Furthermore, we found decreased mitochondrial membrane potential and mitochondrial fragmentation and increased mitochondrial superoxide levels in MLN64-overexpressing cells and in NPC1-deficient cells. Consequently, MLN64 expression was increased in NPC1-deficient cells and reduction of its expression restore mitochondrial membrane potential and mitochondrial superoxide levels. Our findings suggest that MLN64 overexpression induces an increase in mitochondrial cholesterol content and consequently a decrease in mitochondrial GSH content leading to mitochondrial dysfunction. In addition, we demonstrate that MLN64 expression is increased in NPC cells and plays a key role in cholesterol transport into the mitochondria.