RESUMEN
Chronic granulomatous disease (CGD) is an inherited immunodeficiency linked with mutations in the multi-subunit leucocyte NADPH oxidase. Myeloid-derived phagocytic cells deficient in NADPH oxidase fail to produce sufficient levels of reactive oxygen species to clear engulfed pathogens. In this study we show that oxidase also influences B-cell functions, including responses to single-stranded RNA or unmethylated DNA by endosomal Toll-like receptors (TLRs) 7 and 9. In response to TLR7/9 ligands, B-cell lines derived from patients with CGD with mutations in either the NADPH oxidase p40(phox) or p47(phox) subunits produced only low levels of reactive oxygen species. Remarkably, cytokine secretion and p38 mitogen-activated protein kinase activation by these oxidase-deficient B cells was significantly increased upon TLR7/9 activation when compared with oxidase-sufficient B cells. Increased TLR responsiveness was also detected in B cells from oxidase-deficient mice. NADPH oxidase-deficient patient-derived B cells also expressed enhanced levels of TLR7 and TLR9 mRNA and protein compared with the same cells reconstituted to restore oxidase activity. These data demonstrate that the loss of oxidase function associated with CGD can significantly impact B-cell TLR signalling in response to nucleic acids with potential repercussions for auto-reactivity in patients.
Asunto(s)
Linfocitos B/metabolismo , NADPH Oxidasas/deficiencia , Receptor Toll-Like 7/metabolismo , Receptor Toll-Like 9/metabolismo , Animales , Linfocitos B/patología , Línea Celular Transformada , Citocinas/biosíntesis , Expresión Génica Ectópica , Expresión Génica , Enfermedad Granulomatosa Crónica/genética , Enfermedad Granulomatosa Crónica/inmunología , Enfermedad Granulomatosa Crónica/metabolismo , Humanos , Ratones , Ratones Noqueados , Factor 88 de Diferenciación Mieloide/genética , Factor 88 de Diferenciación Mieloide/metabolismo , NADPH Oxidasas/química , NADPH Oxidasas/genética , NADPH Oxidasas/metabolismo , Fosforilación , Subunidades de Proteína/genética , ARN Mensajero/genética , ARN Mensajero/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Transducción de Señal , Receptor Toll-Like 7/agonistas , Receptor Toll-Like 7/genética , Receptor Toll-Like 9/agonistas , Receptor Toll-Like 9/genética , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismoRESUMEN
Hepatitis B virus (HBV) reactivation may occur with high risk immunosuppression, such as anti-cluster of differentiation (CD)20 antibodies (Abs). Appropriate HBV prophylaxis during anti-CD20 Ab therapy averts hepatitis, chemotherapy disruption, and death. Serologic evidence of prior HBV exposure is present in one in nine veterans in the Veterans Health Administration (VHA). In 2014, most (61%-73%) patients in the VHA who were receiving anti-CD20 Ab treatment underwent HBV testing, yet <20% of eligible patients received HBV antiviral prophylaxis. We aimed to prevent HBV reactivation by increasing HBV testing and antiviral treatment rates among anti-CD20 Ab recipients through prospective interventions. A multidisciplinary team of clinicians, pharmacists, and public health professionals developed comprehensive prevention systems, including national seminars/newsletters/websites; pharmacy criteria for HBV screening/treatment prior to anti-CD20 Ab use; changes to national formulary restrictions to expand HBV prophylaxis prescribing authority; Medication Use Evaluation Tracker to identify omissions; national e-mail alert to all VHA oncology providers detailing specific testing and HBV antiviral treatment needs; and a voluntary electronic medical record "order check" used at interested facilities (n = 11) to automatically assess pretreatment HBV testing and antiviral treatment and only generate a reminder to address deficiencies. Analysis of monthly data from June 2016 through September 2017 among anti-CD20 Ab recipients revealed pre-anti-CD20 Ab treatment HBV testing increased to 91%-96% and appropriate HBV antiviral prophylaxis to 76%-85% nationally following implementation of the intervention. Medical centers using the voluntary electronic medical record order check increased HBV testing rates to 93%-98% and HBV antiviral prophylaxis rates to 99%. Conclusion: Multimodal intervention systems to prevent HBV reactivation among VHA patients receiving anti-CD20 Ab therapies increased national rates of HBV testing to >90% and antiviral prophylaxis to >80%.