Central venoarterial extracorporeal life support in pediatric refractory septic shock: a single center experience.

OBJECTIVE: Venoarterial extracorporeal membrane oxygenation (VA ECMO) is recognized as a potential support therapy for pediatric patients with refractory septic shock (RSS). This review aims to report our experience with central VA cannulation in pediatric patients with RSS, and to compare this with peripheral VA ECMO cannulations for this condition at our institution. DESIGN: Retrospective case series. SETTING: Pediatric and cardiac intensive care units in an academic pediatric hospital. PATIENTS: All patients 0-18 years old meeting criteria of RSS placed on VA ECMO between January 2011 and December 2018. INTERVENTIONS: None. MEASUREMENTS: Demographics, relevant clinical variables, ECMO run details, and outcomes were collected. RESULTS: Between 2011 and 2018, 14 children were placed on VA ECMO for RSS. Nine were cannulated centrally, with the rest placed on peripheral VA ECMO. Overall survival to hospital discharge was 57.1% (8/14), with 66.7% of the central cannulation cohort surviving versus 40% in the peripheral cannulation (p = 0.34). Median ECMO duration was 147.1 hours (IQR: 91.9-178.6 hours), with survivors having a median length of 147.1 (IQR: 138.5-185.7) versus non survivors 114.7 hours (IQR: 63.7-163.5), p = 0.48. Overall median ICU length of stay (LOS) was 19 days (IQR: 10.5-42.2). The median % maximum flow achieved on VA ECMO was higher in the central cannulation group at 179.6% (IQR: 154.4-188.1) versus the peripheral with 133.5% (98.1-149.1), p = 0.01. Functional status scale (FSS) was used to capture morbidity. All survivors had a mean increase in their FSS from baseline. In the centrally cannulated group, 50% (4/8) received mediastinal exploration, but none developed mediastinitis. In terms of blood product utilization, the central cannulation received more platelets compared to the peripherally cannulated group (median 15.6 vs 3.3 mL/kg/day, p = 0.03). CONCLUSION: A central approach to VA ECMO cannulation is feasible and has potential for good patient outcomes in selected patients.

Interventions for the control of Aedes aegypti in Latin America and the Caribbean: systematic review and meta-analysis.

OBJECTIVE: To determine the effectiveness and degree of implementation of interventions for the control of Aedes aegypti in Latin America and the Caribbean (LAC) as reported in scientific literature. METHODS: We searched MEDLINE, EMBASE, CENTRAL, SOCINDEX, and LILACS, for experimental and observational studies, economic assessments and qualitative experiences carried out in LAC from 2000 to 2016. We assessed incidence and morbimortality of Aedes aegypti-related diseases and entomological indices: Breteau (containers), House, and Pupae per Person. We used GRADE methodology for assessing quality of evidence. RESULTS: Of 1826 records retrieved, 75 were included and 9 cluster randomised clinical trials could be meta-analysed. We did not identify any intervention supported by a high certainty of evidence. In consistency with qualitative evidence, health education and community engagement probably reduces the entomological indices, as do the use of insecticide-treated materials, indoor residual spraying and the management of containers. There is low certainty of evidence supporting the use of ovitraps or larvitraps, and the integrated epidemiological surveillance strategy to improve indices and reduce the incidence of dengue. The reported degree of implementation of these vector control interventions was variable and most did not extend to whole cities and were not sustained beyond 2 years. CONCLUSIONS: We found a general lack of evidence on effectiveness of vector control in the region, despite a few interventions that showed moderate to low certainty of evidence. It is important to engage and educate the community, apart from achieving the implementation of integrated actions between the health and other sectors at national and regional level.

OBJECTIF: Déterminer l'efficacité et le degré d'implémentation des interventions de lutte contre Aedes aegypti en Amérique latine et dans les Caraïbes (ALC), tels que décrits dans la littérature scientifique. MÉTHODES: Nous avons effectué des recherches dans MEDLINE, EMBASE, CENTRAL, SOCINDEX et LILACS pour des études expérimentales et d'observation, des évaluations économiques et des expériences qualitatives réalisées dans la région ALC de 2000 à 2016. Nous avons évalué l'incidence et la morbimortalité des maladies liées à Aedes aegypti et les indices entomologiques: Breteau (conteneurs), Maison et Pupe par Personne. Nous avons utilisé la méthodologie GRADE pour évaluer la qualité des données. RÉSULTATS: Sur 1.826 articles retrouvés, 75 ont été inclus et 9 essais cliniques randomisés en grappes ont pu être méta-analysés. Nous n'avons identifié aucune intervention étayée par une certitude élevée. De manière cohérente avec les preuves qualitatives, l'éducation pour la santé et la participation de la communauté réduisent probablement les indices entomologiques, de même que l'utilisation de matériaux traités à l'insecticide, la pulvérisation de résidus à l'intérieur et la gestion des conteneurs. Il existe peu de certitude quant aux données soutenant l'utilisation des ovitraps ou des larvitraps et de la stratégie de surveillance épidémiologique intégrée visant à améliorer les indices et à réduire l'incidence de la dengue. Le degré d'implémentation rapporté pour ces interventions de lutte antivectorielle était variable et la plupart ne s'étendaient pas à l'entièreté des villes et ne duraient pas plus de deux ans. CONCLUSIONS: Nous avons constaté un manque général de preuves sur l'efficacité de la lutte antivectorielle dans la région, malgré quelques interventions montrant une certitude modérée à faible. Il est important d'impliquer et d'éduquer la communauté, outre la mise en œuvre d'actions intégrées entre le secteur de la santé et d'autres secteurs aux niveaux national et régional.

OX40 ligand is inhibitory during the effector phase of crescentic glomerulonephritis.

BACKGROUND: The functional relevance of OX40 ligand (OX40L) in the effector phase of crescentic glomerulonephritis (GN) is unknown. These studies defined the role of endogenous OX40L during the effector stage of murine crescentic GN. METHODS: GN was induced by immunization with sheep globulin/adjuvant on Day 0 and injection of sheep anti-mouse glomerular basement membrane immunoglobulin (Ig) on Day 10. Rat IgG or neutralizing anti-OX40L antibody was administered on Days 10-18 and immune responses and renal injury assessed on Day 20. RESULTS: Compared with naïve animals, OX40L was upregulated in the lymph nodes (LNs) and on leucocytes and resident non-immune cells in the kidneys of mice with GN. Inhibition of OX40L in GN augmented renal injury, as indicated by increased crescent formation, proteinuria and glomerular leucocyte accumulation. In line with increased injury, anti-OX40L treatment increased proliferation and decreased apoptosis of CD4 T cells in the LNs, without affecting LN CD4 cytokine production and CD8 T-cell responses. Blockade of OX40L decreased LN regulatory T-cell (Treg) proliferation, transforming growth factor ß production and foxp3 expression. OX40L inhibition did not affect B cell expansion or circulating antibody levels. In the kidney, neutralization of OX40L augmented interferon γ (IFNγ) expression by CD4 and CD8 T cells and shifted macrophage polarization towards the pro-inflammatory M1 phenotype. CONCLUSIONS: OX40L is protective during the effector phase of murine crescentic GN by reducing the expansion of CD4 T cells and enhancing Treg responses in the LNs, and by locally inhibiting T-cell IFNγ production and pro-inflammatory macrophage phenotype in the kidney.

Acquired von Willebrand Syndrome in Pediatric Extracorporeal Membrane Oxygenation Patients: A Single Institution's Experience.

OBJECTIVES: 1) Describe the prevalence of acquired von Willebrand syndrome in pediatric patients undergoing extracorporeal membrane oxygenation deemed to be at increased risk for the disease in our institution, 2) discuss the challenges of testing for acquired von Willebrand syndrome diagnosis, 3) describe the characteristics of the patient population found to have acquired von Willebrand syndrome and their outcomes, and 4) discuss the potential implications of acquired von Willebrand syndrome on bleeding complications. DESIGN: Retrospective chart review. SETTING: PICU and cardiovascular ICU in a single institution. PATIENTS: All PICU and cardiovascular ICU extracorporeal membrane oxygenation patients 0-18 years old who underwent screening for acquired von Willebrand syndrome between January 2014 and December 2016. INTERVENTIONS: Humate P administration to a small subset of acquired von Willebrand syndrome positive subjects. MEASUREMENTS AND MAIN RESULTS: Laboratory data of identified patients were analyzed. The diagnosis of acquired von Willebrand syndrome was made based on decreased ristocetin cofactor activity to von Willebrand factor antigen ratio and/or abnormal multimer analysis. Clinical data were extracted from the chart and through the Pediatric Extracorporeal Membrane Oxygenation Outcome Registry to describe the demographics, comorbidities, and outcomes of this patient population. In the 2 years, 29 patients had laboratory testing performed for surveillance and in cases of clinical bleeding. Of these, 23 (79%) were positive by criteria. No significant difference in mortality rate was found between patients with acquired von Willebrand syndrome versus without. We also did not find a significant difference in the blood product utilization or bleeding complications between patients with acquired von Willebrand syndrome versus without. Humate P was administered in 39% of patients (9/23) who were positive for acquired von Willebrand syndrome, but no significant difference was seen in blood product utilization or bleeding complications between acquired von Willebrand syndrome patients receiving Humate P versus those who did not. CONCLUSIONS: Acquired von Willebrand syndrome is a common but under recognized disorder in pediatric extracorporeal membrane oxygenation patients. The clinical implications of this disorder on bleeding and its potential treatments are still unclear.

[Income and smoking prevalence in Latin America: a systematic review and meta-analysis]. / Niveles de ingreso y prevalencia de tabaquismo en América Latina: revisión sistemática y metaanálisis.

OBJECTIVE: Determine the relationship between tobacco-use prevalence and smoker income level in Latin America and the Caribbean (LAC). METHODS: A systematic search was carried out in MEDLINE, EMBASE, CENTRAL, SOCINDEX, and LILACS databases. Studies from LAC published from January 1989 to December 2015 were included and were analyzed by subgroups disaggregated by decade of data, country, bias risk, sex, and age group. RESULTS: Of 1 254 studies evaluated by full text, 29 articles were included, of which 25 were chosen for meta-analysis. All included studies were cross-sectional or surveillance, primarily from Brazil and Mexico.Low income was associated with higher prevalence of active smoking (odds ratio [OR] 1.62; 95% confidence interval [95%CI] 1.34-1.96) than high income (reference). A dose-response effect trend was observed: middle income (OR 1.23; 95%CI 1.00-1.52) and low income (OR 1.64; 95%CI 1.17-2.30). This association was greater in men (OR 2.22; 95%CI 1.77-2.78) than in women (OR 1.6; 95%CI 1.11-2.47). CONCLUSIONS: An inverse relationship was observed between income and tobacco-use prevalence. Further efforts are required to determine this relationship in special populations, such as adolescents and pregnant women. This research can be useful for policymakers by improving tobacco control strategies and for characterizing public health equity issues.

Extracorporeal therapies in pediatric severe sepsis: findings from the pediatric health-care information system.

INTRODUCTION: Pediatric severe sepsis (PSS) continues to be a major health problem. Extracorporeal therapies (ETs), defined as extracorporeal membrane oxygenation (ECMO) and RRenal replacement therapyenal replacement therapy (RRT), are becoming more available for utilization in a variety of health conditions. We aim to describe (1) rates of utilization of ET in PSS, (2) outcomes for PSS patients receiving ET, and (3) epidemiologic characteristics of patients receiving ET. METHODS: We conducted a retrospective review of a prospectively collected database. Data from the Pediatric Health Information System (PHIS) database collected by the Children's Hospital Association (CHA) from 2004-2012 from 43 US children's hospitals' pediatric intensive care units (PICUs) were used. Patients with PSS were defined by (1) International Classification of Diseases, 9th Revision (ICD-9) codes reflecting severe sepsis and septic shock and (2) ICD-9 codes of infection and organ dysfunction as defined by updated Angus criteria. Among the patients with PSS, those with a PHIS flag of ECMO or RRT were identified further as our main cohort. RESULTS: From 2004 to 2012, 636,842 patients were identified from 43 hospitals, and PSS prevalence was 7.7 % (49,153 patients). Nine point eight percent (4795 patients) received at least one form of ET, and the associated mortality rate was 39 %. Mortality rates were 47.8 % for those who received ECMO, 32.3 % in RRT, and 58.0 % in RRT + ECMO. Underlying co-morbidities were found in 3745 patients (78.1 %) who received ET (81 % for ECMO, 77.9 % in RRT, and 71.2 % in those who received both). There was a statistically significant increase in ECMO utilization in patients with at least three organ dysfunctions from 2004 to 2012 (6.9 % versus 10.3 %, P < 0.001) while RRT use declined (24.5 % versus 13.2 %, P < 0.001). After 2009, there was a significant increase in ECMO utilization (3.6 % in 2004-2008 versus 4.0 % in 2009-2012, P = 0.004). ECMO and RRT were used simultaneously in only 500 patients with PSS (1 %). CONCLUSIONS: ETs were used in a significant portion of PSS patients with multiple organ dysfunction syndrome (MODS) during this time period. Mortality was significant and increased with increasing organ failure. ECMO use in PSS patients with MODS increased from 2004 to 2012. Further evaluation of ET use in PSS is warranted.

Pediatric severe sepsis: current trends and outcomes from the Pediatric Health Information Systems database.

OBJECTIVE: To 1) describe the characteristics and outcomes over time of PICU patients with severe sepsis within the dedicated U.S. children's hospitals, 2) identify patient subgroups at risk for mortality from pediatric severe sepsis, and 3) describe overall pediatric severe sepsis resource utilization. DESIGN: Retrospective review of a prospectively collected multi-institutional children's hospital database. SETTING: PICUs in 43 U.S. children's hospitals. PATIENTS: PICU patients from birth to younger than 19 years were identified with severe sepsis by modified Angus criteria and International Classification of Diseases, 9th Revision, codes for severe sepsis and septic shock. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Data from the Pediatric Health Information System database collected by the Children's Hospital Association from 2004 to 2012. Pediatric severe sepsis was defined by 1) International Classification of Diseases, 9th Revision, codes reflecting severe sepsis and septic shock and 2) International Classification of Diseases, 9th Revision, codes of infection and organ dysfunction as defined by modified Angus criteria. From 2004 to 2012, 636,842 patients were identified from 43 hospitals. Pediatric severe sepsis prevalence was 7.7% (49,153) with an associated mortality rate of 14.4%. Age less than 1 year (vs age 10 to < 19) (odds ratio, 1.4), underlying cardiovascular condition (odds ratio, 1.4) and multiple organ dysfunction, conferred higher odds of mortality. Resource burden was significant with median hospital length of stay of 17 days (interquartile range, 8-36 d) and PICU length of stay of 7 days (interquartile range, 2-17 d), with median cost/day of $4,516 and median total hospitalization cost of $77,446. There was a significant increase in the severe sepsis prevalence rate from 6.2% to 7.7% from 2004 to 2012 (p < 0.001) and a significant decrease in mortality from 18.9% to 12.0% (p < 0.001). Center mortality was negatively correlated with prevalence (rs = -0.48) and volume (rs = -0.39) and positively correlated with cost (rs = 0.36). CONCLUSIONS: In this largest reported pediatric severe sepsis cohort to date, prevalence increased from 2004 to 2012 while associated mortality decreased. Age, cardiovascular comorbidity, and organ dysfunction were significant prognostic factors. Pediatric severe sepsis remains an important cause for PICU admission and mortality and leads to a substantial burden in healthcare costs. Individual center's prevalence and volume are associated with improved outcomes.

Performance of intron 7 of the ß-fibrinogen gene for phylogenetic analysis: An example using gladiator frogs, Boana Gray, 1825 (Anura, Hylidae, Cophomantinae).

Boana, the third largest genus of Hylinae, has cryptic morphological species. The potential applicability of b-fibrinogen intron 7 - FGBI7 is explored to propose a robust phylogeny of Boana. The phylogenetic potential of FGBI7 was evaluated using maximum parsimony, MrBayes, and maximum likelihood analysis. Comparison of polymorphic sites and topologies obtained with concatenated analysis of FGBI7 and other nuclear genes (CXCR4, CXCR4, RHO, SIAH1, TYR, and 28S) allowed evaluation of the phylogenetic signal of FGBI7. Mean evolutionary rates were calculated using the sequences of the mitochondrial genes ND1 and CYTB available for Boana in GenBank. Dating of Boana and some of its groups was performed using the RelTime method with secondary calibration. FGBI7 analysis revealed high values at informative sites for parsimony. The absolute values of the mean evolutionary rate were higher for mitochondrial genes than for FGBI7. Dating of congruent Boana groups for ND1, CYTB, and FGBI7 revealed closer values between mitochondrial genes and slightly different values from those of FGBI7. Divergence times of basal groups tended to be overestimated when mtDNA was used and were more accurate when nDNA was used. Although there is evidence of phylogenetic potential arising from concatenation of specific genes, FGBI7 provides well-resolved independent gene trees. These results lead to a paradigm for linking data in phylogenomics that focuses on the uniqueness of species histories and ignores the multiplicities of individual gene histories.

Early and late acute kidney injury: temporal profile in the critically ill pediatric patient.

BACKGROUND: Increasing AKI diagnosis precision to refine the understanding of associated epidemiology and outcomes is a focus of recent critical care nephrology research. Timing of onset of acute kidney injury (AKI) during pediatric critical illness and impact on outcomes has not been fully explored. METHODS: This was a secondary analysis of the Assessment of Worldwide Acute Kidney Injury, Renal Angina and Epidemiology (AWARE) database. AKI was defined as per Kidney Disease: Improving Global Outcomes criteria. Early AKI was defined as diagnosed at ≤48 h after intensive care unit (ICU) admission, with any diagnosis >48 h denoted as late AKI. Transient AKI was defined as return to baseline serum creatinine ≤48 h of onset, and those without recovery fell into the persistent category. A second incidence of AKI ≥48 h after recovery was denoted as recurrent. Patients were subsequently sorted into distinct phenotypes as early-transient, late-transient, early-persistent, late-persistent and recurrent. Primary outcome was major adverse kidney events (MAKE) at 28 days (MAKE28) or at study exit, with secondary outcomes including AKI-free days, ICU length of stay and inpatient renal replacement therapy. RESULTS: A total of 1262 patients had AKI and were included. Overall mortality rate was 6.4% (n = 81), with 34.2% (n = 432) fulfilling at least one MAKE28 criteria. The majority of patients fell in the early-transient cohort (n = 704, 55.8%). The early-persistent phenotype had the highest odds of MAKE28 (odds ratio 7.84, 95% confidence interval 5.45-11.3), and the highest mortality rate (18.8%). Oncologic and nephrologic/urologic comorbidities at AKI diagnosis were associated with MAKE28. CONCLUSION: Temporal nature and trajectory of AKI during a critical care course are significantly associated with patient outcomes, with several subtypes at higher risk for poorer outcomes. Stratification of pediatric critical care-associated AKI into distinct phenotypes is possible and may become an important prognostic tool.

Gout-mimicking sarcoma recurrence at a prosthesis bone interface remote from any joint.

Gout is known to occur in a variety of organs but most commonly presents as an inflammatory arthropathy. A few reported cases have documented its occurrence in prosthetic neo-joints or juxta-articular to this. We present the first reported case at a bone prosthesis interface remote from any joint and mimicking sarcoma recurrence because of its unusual location.

Intervenciones para el control de Aedes aegypti en América Latina y el Caribe: revisión sistemática y estudio cualitativo / Interventions for the control of Aedes aegypti in Latin America and the Caribbean: systematic review and qualitative study

RESUMEN Antecedentes Al momento no se ha logrado sintetizar toda la información cuali-cuantitativa relacionada al control de Aedes aegypti (A. aegypti) en América Latina y el Caribe (ALC). Objetivo Describir la existencia y el grado de ejecución de los programas específicos o actividades de control vectorial en ALC como parte de programas sanitarios, establecer los costos y/o costoefectividad de las estrategias de control vectorial e identificar barreras y facilitadores para la implementación de las estrategias. Métodos El estudio se llevará a cabo en dos fases complementarias. La primera fase será cuantitativa en la forma de una revisión sistemática, cuyos detalles han sido publicados en la base PROSPERO (CRD42016038067). La segunda fase será cualitativa y consistirá en la realización de entrevistas en profundidad semiestructuradas a informantes clave como investigadores, responsables programáticos,referentes nacionales, agentes del sistema sanitario y representantes de organizaciones no gubernamentales. Discusión El abordaje cualicuantitativo permitirá describir las estrategias y el nivel de implementación para el control de vector y su efectividad, sus costos programáticos y costo-efectividad. Permitirá también analizar factores influyentes en la implementación de programas.

Niveles de ingreso y prevalencia de tabaquismo en América Latina: revisión sistemática y metaanálisis / Income and smoking prevalence in Latin America: a systematic review and meta-analysis

RESUMEN Objetivo Determinar la relación entre la prevalencia de consumo actual de tabaco y los niveles de ingresos monetarios de fumadores en América Latina y el Caribe (ALC). Métodos Se realizó una búsqueda sistemática en bases de datos incluyendo MEDLINE, EMBASE, CENTRAL, SOCINDEX y LILACS. Se incluyeron estudios de ALC publicados desde enero 1989 hasta diciembre de 2015. Se realizaron análisis de subgrupos planeados por década calendario de los datos, país, riesgo de sesgo, sexo y grupos de edad. Resultados De un total de 1 254 estudios evaluados por texto completo se incluyeron 29 artículos, de los cuales 25 fueron incorporados en metaanálisis. Todos los estudios incluidos fueron de corte transversal o de vigilancia, la mayoría provenientes de Brasil y de México. Un bajo nivel de ingresos se asoció con una mayor prevalencia de tabaquismo activo (odds ratio [OR] 1,62; intervalo de confianza de 95% [IC95%] 1,34–1,96) con respecto al nivel alto (referencia). Se observó una tendencia de efecto dosis-respuesta: nivel medio de ingresos (OR 1,23; IC95% 1,00-1,52) y nivel bajo de ingresos (OR 1,64; IC95% 1,17-2,30). Esta asociación fue mayor en hombres (OR 2,22; IC95% 1,77-2,78) que en mujeres (OR 1,6; IC95% 1,11-2,47). Conclusiones Se observó una relación inversa entre el nivel de ingresos y la prevalencia de consumo de tabaco. Se requieren mayores esfuerzos para determinar esta relación en poblaciones especiales como adolescentes o embarazadas. Esta investigación puede ser útil para los decisores políticos al mejorar las estrategias de control del tabaco y para caracterizar cuestiones de equidad en la salud pública.

ABSTRACT Objective Determine the relationship between tobacco-use prevalence and smoker income level in Latin America and the Caribbean (LAC). Methods A systematic search was carried out in MEDLINE, EMBASE, CENTRAL, SOCINDEX, and LILACS databases. Studies from LAC published from January 1989 to December 2015 were included and were analyzed by subgroups disaggregated by decade of data, country, bias risk, sex, and age group. Results Of 1 254 studies evaluated by full text, 29 articles were included, of which 25 were chosen for meta-analysis. All included studies were cross-sectional or surveillance, primarily from Brazil and Mexico. Low income was associated with higher prevalence of active smoking (odds ratio [OR] 1.62; 95% confidence interval [95%CI] 1.34–1.96) than high income (reference). A dose-response effect trend was observed: middle income (OR 1.23; 95%CI 1.00-1.52) and low income (OR 1.64; 95%CI 1.17-2.30). This association was greater in men (OR 2.22; 95%CI 1.77-2.78) than in women (OR 1.6; 95%CI 1.11-2.47). Conclusions An inverse relationship was observed between income and tobacco-use prevalence. Further efforts are required to determine this relationship in special populations, such as adolescents and pregnant women. This research can be useful for policymakers by improving tobacco control strategies and for characterizing public health equity issues.

Anti-neutrophil cytoplasmic antibodies and effector CD4+ cells play nonredundant roles in anti-myeloperoxidase crescentic glomerulonephritis.

Most humans with microscopic polyarteritis and anti-myeloperoxidase (anti-MPO), anti-neutrophil cytoplasmic antibodies (ANCA) develop "pauci-immune" crescentic glomerulonephritis. For dissection of the roles of ANCA and cell-mediated effectors in microscopic polyarteritis, experimental autoimmune anti-MPO glomerulonephritis was induced by immunizing C57BL/6 mice with human MPO. Autoimmunity to mouse MPO (ANCA and CD4+ cell reactivity) was induced. Challenge with anti-glomerular basement membrane globulin resulted in accumulation of neutrophils, CD4+ cells and macrophages, and significant numbers of crescentic glomeruli compared with similarly challenged control-immunized mice. MPO-deficient (Mpo(-/-)) mice immunized with MPO developed similar immune responses to MPO but failed to recruit effector cells to glomeruli or develop significant crescent formation, suggesting that MPO is acting as a planted glomerular autoantigen. Effector CD4+ cell depletion in this model attenuated crescentic glomerulonephritis and effector cell influx without altering ANCA titers. However, B cell-deficient mice, with no ANCA, still developed severe crescentic glomerulonephritis with accumulation of effector cells. Intravital microscopy studies demonstrated that passive transfer of sera from MPO-immunized Mpo(-/-) mice to LPS-primed mice rapidly induced glomerular neutrophil accumulation and release of MPO. These studies provide in vivo evidence in a relevant vascular bed for both humoral and cellular anti-MPO responses as key inducers of injury. ANCA induces glomerular neutrophil infiltration and MPO deposition. Subsequently, anti-MPO CD4+ cells recognize MPO as a planted glomerular antigen and act with macrophages to amplify severe glomerular injury.

Intrinsic renal cell expression of CD40 directs Th1 effectors inducing experimental crescentic glomerulonephritis.

Evidence suggests that human and experimental crescentic GN results from Th1-predominant immunity to glomerular antigens. CD40/CD154 signaling plays a key role in initiating Th1 responses and may direct Th1 effector responses. The role of CD40 in the development of GN was assessed in murine experimental anti-glomerular basement membrane GN. In this model, C57BL/6 wild-type (WT) mice sensitized to sheep globulin develop crescentic GN resulting from Th1 effector responses when challenged with sheep globulin planted in glomeruli. CD40-/- mice do not develop immunity in response to sheep globulin and thus fail to develop effector responses or significant GN. CD40 is expressed in nephritic glomeruli, suggesting a potential role for intrarenal CD40-CD154 interactions in injurious effector responses. Immune neutralization of the CD40 ligand (CD154) at the time of challenge significantly reduced accumulation of Th1 effectors and injury. The role of CD40 expression by renal cells was assessed by comparing GN in WT-->CD40-/- chimeras (absent renal but intact bone marrow CD40) and sham chimeric mice (WT-->WT). Both groups developed strong antigen-specific immune responses (antibody and IFN-gamma production). However, WT-->CD40-/- chimeras demonstrated reduced renal monocyte chemotactic protein 1 and IFN-inducible protein 10 mRNA levels and minimal T cell and macrophage influx and were protected from renal injury. Sham chimeric mice developed reduced GFR, with prominent renal expression of monocyte chemotactic protein 1 and IFN-inducible protein 10 mRNA and effector cell accumulation. In conclusion, the expression of CD40 by nonimmune renal cells plays a major role in Th1 effector responses by inducing Th1 chemokine production. Therefore, CD40-CD154 interactions are a potential therapeutic target in GN.

An IL-12-independent role for CD40-CD154 in mediating effector responses: studies in cell-mediated glomerulonephritis and dermal delayed-type hypersensitivity.

Crescentic glomerulonephritis (GN) results from IL-12-driven Th1-directed cell-mediated responses (akin to delayed-type hypersensitivity (DTH)) directed against glomerular Ags. CD40-CD154 interactions are critical for IL-12 production and Th1 polarization of immune responses. Crescentic anti-glomerular basement membrane GN was induced in C57BL/6 (wild-type (WT)) mice (sensitized to sheep globulin) by planting this Ag (as sheep anti-mouse glomerular basement membrane globulin) in their glomeruli. Crescentic GN did not develop in CD40(-/-) mice due to significantly reduced nephritogenic Th1 responses. IL-12 was administered to CD40(-/-) mice with GN to dissect interactions between IL-12 and CD40 in inducing nephritogenic immunity and injury. Administration of IL-12 to CD40(-/-) mice restored Th cell IFN-gamma production, and up-regulated intrarenal chemokines and glomerular T cell and macrophage accumulation compared with WT control mice. Despite this, renal macrophages were not activated and renal injury and dermal DTH were not restored. Thus, CD40-directed IL-12 drives Th1 generation and effector cell recruitment but CD40 is required for activation. To test this hypothesis, activated OT-II OVA-specific CD4(+) cells and OVA(323-339)-loaded nonresponsive APCs were transferred into footpads of WT, CD40(-/-), and macrophage-depleted WT mice. WT mice developed significant DTH compared with CD40(-/-) and macrophage-depleted WT mice. This study demonstrated that CD40-induced IL-12 is required for generation of systemic Th1 immunity to nephritogenic Ags, and that IL-12 enhances Th1 effector cell recruitment to peripheral sites of Ag presentation via generation of local chemokines. Effector cell activation, renal DTH-like injury, and dermal DTH require direct Th1 CD154/macrophage CD40 interactions.