RESUMO
Current therapies for treating antineutrophil cytoplasm autoantibody (ANCA)-associated vasculitis include cyclophosphamide and corticosteroids. Unfortunately, these agents are associated with severe adverse effects, despite inducing remission in most patients. Histone deacetylase inhibitors are effective in rodent models of inflammation and act synergistically with many pharmacological agents, including alkylating agents like cyclophosphamide. EDO-S101 is an alkylating fusion histone deacetylase inhibitor molecule combining the DNA alkylating effect of Bendamustine with a pan-histone deacetylase inhibitor, Vorinostat. Here we studied the effects of EDO-S101 in two established rodent models of ANCA-associated vasculitis: a passive mouse model of anti-myeloperoxidase IgG-induced glomerulonephritis and an active rat model of myeloperoxidase-ANCA microscopic polyangiitis. Although pretreatment with EDO-S101 reduced circulating leukocytes, it did not prevent the development of passive IgG-induced glomerulonephritis in mice. On the other hand, treatment in rats significantly reduced glomerulonephritis and lung hemorrhage. EDO-S101 also significantly depleted rat B and T cells, and induced DNA damage and apoptosis in proliferating human B cells, suggesting a selective effect on the adaptive immune response. Thus, EDO-S101 may have a role in treatment of ANCA-associated vasculitis, operating primarily through its effects on the adaptive immune response to the autoantigen myeloperoxidase.
Assuntos
Vasculite Associada a Anticorpo Anticitoplasma de Neutrófilos/tratamento farmacológico , Benzimidazóis/uso terapêutico , Inibidores de Histona Desacetilases/uso terapêutico , Peroxidase/imunologia , Imunidade Adaptativa/efeitos dos fármacos , Alquilação , Animais , Vasculite Associada a Anticorpo Anticitoplasma de Neutrófilos/patologia , Apoptose/efeitos dos fármacos , Benzimidazóis/farmacologia , Reparo do DNA/efeitos dos fármacos , Feminino , Células HL-60 , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Ratos , Ratos Endogâmicos WKYRESUMO
Background: Anti-neutrophil cytoplasmic antibody associated vasculitis (AAV) is a typical disease of the elderly. In AAV, there is an age-specific increase in disease incidence with age being a predictor of disease outcome. In this study, we aimed to determine the contribution of age to the development of AAV employing a mouse model of anti-myeloperoxidase (MPO) antibody-mediated glomerulonephritis. Methods: Anti-MPO IgG and lipopolysaccharide (LPS)-mediated glomerulonephritis was induced in 3- and 18-month-old C57Bl6 mice. Clinical and pathological parameters of disease severity, alterations in the immune system and kidney specific changes in these mice were evaluated. Results: Eighteen-month-old mice developed increased disease severity upon injection of anti-MPO IgG/LPS compared with 3-month-old mice. This was evidenced by increased albuminuria, more extensive glomerular capillary necrosis and increased glomerular neutrophil accumulation. Glomerular crescent formation was mild in both young and old mice. Old mice displayed higher plasma interleukin-6 levels as well as higher proportions of circulating neutrophils and activated monocytes compared with young mice. In addition, renal mRNA levels of inflammatory genes and endothelial adhesion molecules were higher in 18-month-old mice compared with 3-month-old mice. Conclusion: In conclusion, our results indicate that aged mice develop more severe clinical and pathological disease upon induction of anti-MPO IgG/LPS-mediated glomerulonephritis. These findings may be attributed to age-related changes in the immune system as well as in the kidney itself.
Assuntos
Autoanticorpos/efeitos adversos , Modelos Animais de Doenças , Glomerulonefrite/etiologia , Imunoglobulina G/efeitos adversos , Peroxidase/fisiologia , Índice de Gravidade de Doença , Envelhecimento , Animais , Feminino , Glomerulonefrite/patologia , Camundongos , Camundongos Endogâmicos C57BLRESUMO
High mobility group box 1 (HMGB1) is a nuclear DNA binding protein that acts as an alarmin when secreted. HMGB1 is increased in systemic lupus erythematosus and might represent a potential therapeutic target. We investigated whether treatment with an anti-HMGB1 antibody affects the development of lupus nephritis in MRL/lpr mice. Seven-week-old MRL/lpr mice were injected intraperitoneally twice weekly for 10 wks with 50 µg monoclonal anti-HMGB1 (2G7, mouse IgG2b) (n = 12) or control antibody (n = 11). Control MRL/MPJ mice (n = 10) were left untreated. Every 2 wks, blood was drawn and urine was collected at wk 7, 11 and 17. Mice were sacrificed at 17 wks for complete disease evaluation. Plasma HMGB1 and anti-HMGB1 levels were increased in MRL/lpr mice compared with control MRL/MPJ mice. There were no differences in albuminuria, urine HMGB1 and plasma levels of complement C3, anti-dsDNA and proinflammatory cytokines between untreated and treated mice at any time point. Lupus nephritis of mice treated with anti-HMGB1 monoclonal antibody (mAb) was classified as class III (n = 3) and class IV (n = 9), while mice treated with control mAb were classified as class II (n = 4), class III (n = 2) and class IV (n = 5). IgG and C3 deposits in kidneys were similar in mice treated with anti-HMGB1 mAb or control mAb. In conclusion, treatment with monoclonal anti-HMGB-1 antibody 2G7 does not affect development of lupus nephritis, disease progression or proinflammatory cytokine levels in MRL/lpr mice. This result indicates that blocking of HMGB1 by this neutralizing antibody does not affect lupus nephritis in MRL/lpr mice.
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PURPOSE OF REVIEW: Infections have been suggested to contribute to disease induction and reactivation in many of the idiopathic vasculitides. This review describes and evaluates the evidence that microbes are involved in the etiopathogenesis of these diseases. RECENT FINDINGS: Large-vessel vasculitis has recently been associated with two specific bacteria. Mycobacterium tuberculosis is thought to have an inducing role in Takayasu arteritis and a Burkholderia bacterium might be involved in giant cell arteritis. Hepatitis B and C viruses have been linked to polyarteritis nodosa. In antineutrophil cytoplasmic autoantibody-associated vasculitis, and more specifically granulomatosis with polyangiitis (GPA), Staphylococcus aureus has been the focus of many studies. Chronic nasal carriage of S. aureus is related to endonasal activity and disease relapses in GPA patients. Moreover, antibacterial treatment is known to reduce the risk for disease relapses. If and how pathogens trigger vasculitis is still unclear, but several potential mechanisms have been suggested and are briefly reviewed here. SUMMARY: Although many observations suggest a link between infections and the development of vasculitis, no direct proof exists. Transcriptomic and proteomic studies of the pathogens involved could aid in identifying specific or common traits of pathogens that are relevant for the development and reactivation of vasculitis.
Assuntos
Hepatite B/complicações , Hepatite C/complicações , Infecções por Mycobacterium/complicações , Infecções Estafilocócicas/complicações , Vasculite/etiologia , Humanos , Vasculite/imunologiaRESUMO
PURPOSE OF REVIEW: To provide an update on animal models of antineutrophil cytoplasmic autoantibody (ANCA)-mediated vasculitis and highlight recent insights gained from studies in these models pertaining to immunopathogenesis. RECENT FINDINGS: Animal models support the pathogenic potential of myeloperoxidase (MPO)-ANCA. Alternative pathway complement activation has been identified as a novel inflammatory pathway in disease induction and a potential target for intervention. Interventions targeting B cells, antibodies, and signal transduction pathways may hold promise as well. The role of T cells is beginning to be explored, and studies indicate a prominent role for Th17 responses. The link between infection and ANCA vasculitis is well established. In animal models, Toll-like receptor (TLR)4 ligation is involved in disease induction. Ligation of TLRs contributes to the initiation of anti-MPO autoimmune responses in which TLR2 activation induces a Th17 response and TLR9 activation directs a Th1 response. An animal model for PR3-ANCA vasculitis is not available yet but models with a humanized immune system are being developed and show promising first results. SUMMARY: Animal models of MPO-ANCA vasculitis have contributed substantially to our understanding of disease immunopathogenesis and have illuminated novel targets for intervention. The development of PR3-ANCA animal models remains a challenge but recent observations in humanized model systems offer hope.
Assuntos
Vasculite Associada a Anticorpo Anticitoplasma de Neutrófilos/imunologia , Modelos Animais de Doenças , Animais , Via Alternativa do Complemento/imunologia , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Peroxidase/imunologia , Ratos , Ratos Endogâmicos WKY , Transdução de Sinais/imunologia , Células Th17/imunologiaRESUMO
OBJECTIVE: To determine whether inhibition of p38 mitogen-activated protein kinase (p38MAPK) reduces the pathogenicity of anti-neutrophil cytoplasmic autoantibodies (ANCAs) in vitro and in vivo. METHODS: The effects of the p38MAPK-specific inhibitor AR-447 were studied in vitro using neutrophil respiratory burst and degranulation assays, and in lipopolysaccharide (LPS)-stimulated human glomerular endothelial cells. In vivo, p38MAPK inhibition was investigated in a mouse anti-myeloperoxidase (MPO) IgG/LPS glomerulonephritis model. Mice were treated orally with AR-447 daily, starting before (pretreatment group) or 24 h after disease onset (treatment group), and killed after 1 or 7 day(s). RESULTS: In vitro, AR-447 diminished neutrophil respiratory burst and degranulation induced by patient-derived MPO-ANCA and proteinase 3 (Pr3)-ANCA. In glomerular endothelial cells, AR-447 reduced LPS-induced secretion of IL-6 and IL-8, but not of MCP-1. In mice, pretreatment with AR-447 reduced albuminuria 1 day after induction of glomerulonephritis. After 7 days, no effects on urinary abnormalities were observed upon AR-447 pretreatment or treatment. Also, glomerular neutrophil accumulation was not diminished. In contrast, glomerular macrophage accumulation and the formation of glomerular crescents was significantly reduced by AR-447 pretreatment (vehicle: 12.5 ± 5.6% crescentic glomeruli; AR-447: 7.7 ± 2.7%) and treatment (vehicle 14.6 ± 1.8%; AR-447 6.0 ± 3.4%) at 7 days. CONCLUSION: This study shows that p38MAPK inhibition markedly reduces ANCA-induced neutrophil activation in vitro. In vivo, p38MAPK inhibition partly reduced crescent formation when the drug was administered prior to disease induction and after disease onset, suggesting that besides p38MAPK activity other signalling pathways contribute to the disease activity.
Assuntos
Vasculite Associada a Anticorpo Anticitoplasma de Neutrófilos/prevenção & controle , Anticorpos Anticitoplasma de Neutrófilos/imunologia , Inibidores de Proteínas Quinases/farmacologia , Proteínas Quinases p38 Ativadas por Mitógeno/antagonistas & inibidores , Animais , Vasculite Associada a Anticorpo Anticitoplasma de Neutrófilos/enzimologia , Vasculite Associada a Anticorpo Anticitoplasma de Neutrófilos/imunologia , Células Cultivadas , Citocinas/biossíntese , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos/métodos , Feminino , Glomerulonefrite/enzimologia , Glomerulonefrite/imunologia , Glomerulonefrite/prevenção & controle , Humanos , Imunoglobulina G/imunologia , Glomérulos Renais/imunologia , Lipopolissacarídeos/imunologia , Sistema de Sinalização das MAP Quinases/fisiologia , Camundongos , Camundongos Knockout , Ativação de Neutrófilo/imunologia , Peroxidase/imunologia , Inibidores de Proteínas Quinases/uso terapêutico , Explosão Respiratória/imunologia , Proteínas Quinases p38 Ativadas por Mitógeno/fisiologiaRESUMO
Kidney injury molecule-1 (KIM-1) is a marker for renal proximal tubular damage, the hallmark of virtually all proteinuric, toxic and ischaemic kidney diseases. KIM-1 has gained increasing interest because of its possible pathophysiological role in modulating tubular damage and repair. In this respect, it is interesting that the best biomarkers often turn out to be important in modulation of damage and some even become therapeutic targets. The emphasis of this review is on structural and biochemical aspects of KIM-1, its expression pattern and its pathophysiological role in renal disease. We also discuss the prognostic impact of KIM-1 in relation to urinary protein excretion. Glomerular (proteinuria) and interstitial markers (KIM-1) might have independent prognostic impact and so may provide independent treatment targets. Finally, the potential of KIM-1 as biomarker of renal damage, as a predictor of renal function decline and its perspectives for monitoring therapy response, are discussed.
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Nefropatias/metabolismo , Glicoproteínas de Membrana/metabolismo , Receptores Virais/metabolismo , Biomarcadores/metabolismo , Monitoramento de Medicamentos/métodos , Receptor Celular 1 do Vírus da Hepatite A , Humanos , Nefropatias/diagnóstico , Nefropatias/tratamento farmacológico , Túbulos Renais/metabolismo , Glicoproteínas de Membrana/fisiologia , Fagocitose/fisiologia , Prognóstico , Receptores Virais/fisiologiaRESUMO
Anti-neutrophil cytoplasmic autoantibodies (ANCA) directed against myeloperoxidase (MPO) and proteinase 3 (Pr3) are considered pathogenic in ANCA-associated necrotizing and crescentic glomerulonephritis (NCGN) and vasculitis. Modulation of ANCA IgG glycosylation may potentially reduce its pathogenicity by abolishing Fc receptor-mediated activation of leukocytes and complement. Here, we investigated whether IgG hydrolysis by the bacterial enzyme endoglycosidase S (EndoS) attenuates ANCA-mediated NCGN. In vitro, treatment of ANCA IgG with EndoS significantly attenuated ANCA-mediated neutrophil activation without affecting antigen-binding capacity. In a mouse model of anti-MPO IgG/LPS-induced NCGN, we induced disease with either unmodified or EndoS-treated (deglycosylated) anti-MPO IgG. In separate experiments, we administered EndoS systemically after disease induction with unmodified anti-MPO IgG. Pretreatment of anti-MPO IgG with EndoS reduced hematuria, leukocyturia, and albuminuria and attenuated both neutrophil influx and formation of glomerular crescents. After inducing disease with unmodified anti-MPO IgG, systemic treatment with EndoS reduced albuminuria and glomerular crescent formation when initiated after 3 but not 24 hours. In conclusion, IgG glycan hydrolysis by EndoS attenuates ANCA-induced neutrophil activation in vitro and prevents induction of anti-MPO IgG/LPS-mediated NCGN in vivo. Systemic treatment with EndoS early after disease induction attenuates the development of disease. Thus, modulation of IgG glycosylation is a promising strategy to interfere with ANCA-mediated inflammatory processes.
Assuntos
Anticorpos Anticitoplasma de Neutrófilos/metabolismo , Glomerulonefrite/metabolismo , Glomerulonefrite/prevenção & controle , Imunoglobulina G/metabolismo , Polissacarídeos/metabolismo , Adulto , Idoso , Animais , Proteínas de Bactérias/farmacologia , Estudos de Casos e Controles , Modelos Animais de Doenças , Feminino , Glomerulonefrite/induzido quimicamente , Glicosídeo Hidrolases/farmacologia , Humanos , Hidrólise/efeitos dos fármacos , Lipopolissacarídeos/efeitos adversos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Pessoa de Meia-Idade , Neutrófilos/patologia , Peroxidase/imunologia , Fatores de TempoRESUMO
SUMMARY: Small-vessel vasculitides associated with anti-neutrophil cytoplasmic auto-antibodies (ANCA) are severe systemic diseases that may affect any organ. Increasing evidence from clinical, animal and in vitro studies indicates that ANCA are causally involved in disease pathogenesis mainly through activation of neutrophils resulting in endothelial cell injury. Recent studies suggest a previously unsuspected but crucial role for alternative pathway complement activation in ANCA disease pathogenesis. In this brief review, we will discuss the evidence for complement system activation in ANCA-associated vasculitides and propose a working model that links ANCA, neutrophils and complement activation in causing an inflammatory amplification loop that may explain the severe leukocytoclastic inflammation that is typical for ANCA-associated vasculitis.
Assuntos
Anticorpos Anticitoplasma de Neutrófilos/fisiologia , Ativação do Complemento , Vasculite/etiologia , Animais , Glomerulonefrite/etiologia , Humanos , Neutrófilos/fisiologia , Peroxidase/imunologiaRESUMO
Autoreactivity to myeloperoxidase (MPO) causes anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV), with rapidly progressive glomerulonephritis. Here, we show that a Staphylococcus aureus peptide, homologous to an immunodominant MPO T-cell epitope (MPO409-428), can induce anti-MPO autoimmunity. The peptide (6PGD391-410) is part of a plasmid-encoded 6-phosphogluconate dehydrogenase found in some S. aureus strains. It induces anti-MPO T-cell autoimmunity and MPO-ANCA in mice, whereas related sequences do not. Mice immunized with 6PGD391-410, or with S. aureus containing a plasmid expressing 6PGD391-410, develop glomerulonephritis when MPO is deposited in glomeruli. The peptide induces anti-MPO autoreactivity in the context of three MHC class II allomorphs. Furthermore, we show that 6PGD391-410 is immunogenic in humans, as healthy human and AAV patient sera contain anti-6PGD and anti-6PGD391-410 antibodies. Therefore, our results support the idea that bacterial plasmids might have a function in autoimmune disease.
Assuntos
Autoimunidade/imunologia , Proteínas de Bactérias/imunologia , Complexo Antigênico da Nefrite de Heymann/imunologia , Peptídeos/imunologia , Peroxidase/imunologia , Staphylococcus aureus/imunologia , Sequência de Aminoácidos , Animais , Vasculite Associada a Anticorpo Anticitoplasma de Neutrófilos/sangue , Vasculite Associada a Anticorpo Anticitoplasma de Neutrófilos/imunologia , Proteínas de Bactérias/genética , Epitopos de Linfócito T/genética , Epitopos de Linfócito T/imunologia , Glomerulonefrite/imunologia , Complexo Antigênico da Nefrite de Heymann/metabolismo , Humanos , Masculino , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Peptídeos/genética , Peroxidase/metabolismo , Plasmídeos/genética , Staphylococcus aureus/genética , Staphylococcus aureus/fisiologiaRESUMO
BACKGROUND: Under proteinuric conditions, ultrafiltrated albumin can induce an inflammatory and fibrotic response in proximal tubular cells. It is unclear whether albumin per se or compounds bound to albumin are nephrotoxic. Some studies have supported the toxicity of albumin-bound fatty acids; however, these compared untreated, fatty acid containing, albumin and delipidated albumin. To prevent confounding by the delipidation procedure, we compared delipidated albumin and oleic acid (OA)-loaded delipidated albumin in two models: the classical rat protein overload and the Axolotl. The latter had an amphibian kidney with a subset of nephrons that drained the peritoneal cavity, so that i.p. injection of albumin selectively targeted open but not closed nephrons and was used to prevent removal of fatty acids from albumin in the circulation. METHODS: Protein overload was induced in Wistar rats (groups n = 8, for 12 weeks) and Axolotl (groups n = 10, for 10 days) by daily i.p. injections of 1 g (rat) or 50 mg (Axolotl) of fatty acid-free bovine serum albumin (BSA), fatty acid-free BSA with addition of six molecules of oleic acid (OA-BSA) or saline (SAL). RESULTS: After 12 weeks, proteinuria and SBP were increased in BSA and OA-BSA rats compared to saline-injected controls (P < 0.05), but OA loading had no additional effect compared to albumin alone. This was also true for glomerular and interstitial inflammation, fibrotic changes and focal glomerulosclerosis (OA-BSA versus BSA, all P = ns). Axolotls injected with OA-loaded albumin showed comparable protein storage in tubular epithelial cells, tubular dilatation and peritubular fibrosis around tubules draining the peritoneal cavity compared with Axolotls injected with albumin alone. This was also true for TGF-beta (inflammation marker) and collagen I (fibrosis marker) (OA-BSA versus BSA, all P = ns). CONCLUSIONS: In the Axolotl and chronic rat model, OA loading of albumin did not aggravate renal damage compared to albumin alone. Although in vitro studies clearly show induction of changes in cultured tubular epithelial cells exposed to albumin-bound fatty acids that are consistent with a role in induction of tubulointerstitial disease, our experiments suggest that currently available models for demonstrating such an effect in vivo are insufficient.
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Rim/efeitos dos fármacos , Rim/lesões , Ácido Oleico/toxicidade , Soroalbumina Bovina/toxicidade , Ambystoma , Animais , Bovinos , Modelos Animais de Doenças , Interações Medicamentosas , Ácidos Graxos/metabolismo , Feminino , Rim/patologia , Rim/fisiopatologia , Masculino , Ácido Oleico/administração & dosagem , Proteinúria/etiologia , Proteinúria/fisiopatologia , Ratos , Ratos Wistar , Soroalbumina Bovina/administração & dosagem , Soroalbumina Bovina/química , Especificidade da EspécieRESUMO
BACKGROUND: Chronic transplant dysfunction is characterized by renal function decline and proteinuria. Kidney injury molecule (KIM)-1, a transmembrane tubular protein with unknown function, is undetectable in normal kidneys, but markedly induced after injury. Urinary KIM-1 excretion has been quantified as biomarker of renal damage. We prospectively studied whether urinary KIM-1 predicts graft loss, independent of renal function and proteinuria. METHODS: Renal transplant recipients (n=145) visiting our outpatient clinic between August 2001 and July 2003 collected 24-hour urine samples for assessment of baseline urinary KIM-1 excretion (microsphere-based Luminex technology), and were followed for graft loss. RESULTS: Recipients participated at a median (interquartile range) of 6.0 (2.5-12.0) years posttransplant in baseline measurements. Follow-up beyond baseline was 4.0 (3.2-4.5) years. Urinary KIM-1 excretion was 0.72 (0.42-1.37) ng per 24 hours. Occurrence of graft loss increased over tertiles of KIM-1 excretion: 3 (6.3%), 11 (22.4%), and 17 cases (35.4%; P=0.001), respectively. High KIM-1 excretion was associated with proteinuria, low creatinine clearance, and high donor age (all P<0.01). In multivariate Cox regression analyses, prediction of graft loss by KIM-1 appeared independent of creatinine clearance, proteinuria, and donor age. Hazard ratios (95% CI) for the second and third tertile of KIM-1 excretion were 3.6 (0.9-13.5) and 5.1 (1.5-17.8) in the final model. CONCLUSIONS: Urinary excretion of KIM-1 is an independent predictor of long-term graft loss and therefore a promising new biomarker in early prediction of graft loss.
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Transplante de Rim/patologia , Transplante de Rim/fisiologia , Glicoproteínas de Membrana/urina , Adulto , Biomarcadores/urina , Creatinina/metabolismo , Feminino , Seguimentos , Taxa de Filtração Glomerular , Rejeição de Enxerto/urina , Receptor Celular 1 do Vírus da Hepatite A , Humanos , Transplante de Rim/mortalidade , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Prospectivos , Proteinúria , Receptores Virais , Análise de Sobrevida , Fatores de Tempo , Falha de TratamentoRESUMO
BACKGROUND: Macrophages may present two distinct phenotypes indicated as M1 and M2 under different stimuli. M1 and M2 macrophages have divergent functions that range from enhancement of inflammation for M1 to tissue repair and remodeling for M2 macrophages. The objective of this study was to evaluate the distribution of M1 and M2 macrophage phenotypes in biopsies from the airways of patients with active granulomatosis with polyangiitis (GPA) and to analyze their associations with T and B cells in those biopsies, and with nasal carriage of Staphylococcus aureus, disease parameters and therapy. METHODS: Consecutive GPA patients (n = 35) with active airway disease, who underwent respiratory tract biopsy were included. Immunohistochemical evaluation was performed to assess the distribution of macrophages and T and B cells using the markers CD68, CD3 and CD20, respectively. CD86 was used as the M1 marker and CD163 as the M2 marker while Tbet and GATA-3 were used as Th1 and Th2 markers, respectively. At the time of the biopsy patients were assessed for nasal carriage of Staphylococcus aureus and treatment. RESULTS: Percentages of macrophages and T cells were significantly higher than those of B cells in lesional tissue from the respiratory tract in GPA. M2 macrophages and Th2 cells were more frequent than M1 macrophages (p = 0.0007) and Th1 cells (p < 0.0001), respectively. Percentages of T cells were higher in nose biopsies than in biopsies from other sites (p = 0.021); macrophages and CD163+ macrophages were more predominant in biopsy sites other than the nose (p = 0.039 and p = 0.012, respectively). Carriage of Staphylococcus aureus was associated with higher T cell scores (p = 0.014). The frequency of macrophages, especially M2 macrophages, was higher in GPA patients treated with immunosuppressive agents (p = 0.010); daily prednisolone dose was positively correlated with all macrophage markers. However, in multivariate analysis no independent associations were found between disease parameters and therapy with macrophage markers or T cells. CONCLUSION: In GPA, M2 is the predominant macrophage phenotype in the respiratory tract. Although some associations were observed between macrophages and T cells with therapy and nasal carriage of Staphylococcus aureus, they were not independently significant in multivariate analysis.
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Granulomatose com Poliangiite/patologia , Macrófagos/patologia , Fenótipo , Sistema Respiratório/patologia , Adulto , Feminino , Granulomatose com Poliangiite/tratamento farmacológico , Granulomatose com Poliangiite/imunologia , Humanos , Imunossupressores/farmacologia , Imunossupressores/uso terapêutico , Inflamação/tratamento farmacológico , Inflamação/imunologia , Inflamação/patologia , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Masculino , Pessoa de Meia-Idade , Sistema Respiratório/efeitos dos fármacos , Sistema Respiratório/imunologiaRESUMO
The proteinase 3 (PR3)-positive anti-neutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis (AAV) granulomatosis with polyangiitis (GPA) has been associated with chronic nasal S. aureus carriage, which is a risk factor for disease relapse. The present study was aimed at comparing the genetic make-up of S. aureus isolates from PR3-ANCA-positive GPA patients with that of isolates from patients suffering from myeloperoxidase (MPO)-ANCA-positive AAV, and isolates from healthy controls. Based on a DNA microarray-based approach, we show that not only PR3-ANCA-positive GPA patients, but also MPO-ANCA-positive AAV patients mainly carried S. aureus types that are prevalent in the general population. Nonetheless, our data suggests that MPO-ANCA-associated S. aureus isolates may be distinct from healthy control- and PR3-ANCA-associated isolates. Furthermore, several genetic loci of S. aureus are associated with either PR3-ANCA- or MPO-ANCA-positive AAV, indicating a possible role for pore-forming toxins, such as leukocidins, in PR3-ANCA-positive GPA. Contrary to previous studies, no association between AAV and superantigens was detected. Our findings also show that a lowered humoral immune response to S. aureus is common for PR3-ANCA- and MPO-ANCA-positive AAV. Altogether, our observations imply that the presence or absence of particular virulence genes of S. aureus isolates from AAV patients contributes to disease progression and/or relapse.
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Anticorpos Anticitoplasma de Neutrófilos/sangue , Loci Gênicos/imunologia , Granulomatose com Poliangiite/microbiologia , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/genética , Adulto , Idoso , Anticorpos Anticitoplasma de Neutrófilos/imunologia , Portador Sadio/sangue , Portador Sadio/imunologia , Portador Sadio/microbiologia , Feminino , Granulomatose com Poliangiite/sangue , Granulomatose com Poliangiite/imunologia , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/imunologia , Humanos , Masculino , Pessoa de Meia-Idade , Mieloblastina/imunologia , Peroxidase/imunologia , Recidiva , Estudos Retrospectivos , Infecções Estafilocócicas/sangue , Infecções Estafilocócicas/imunologia , Staphylococcus aureus/imunologia , Staphylococcus aureus/isolamento & purificação , Adulto JovemRESUMO
Chronic nasal carriage of the bacterium Staphylococcus aureus in patients with the autoimmune disease granulomatosis with polyangiitis (GPA) is a risk factor for disease relapse. To date, it was neither known whether GPA patients show similar humoral immune responses to S. aureus as healthy carriers, nor whether specific S. aureus types are associated with GPA. Therefore, this study was aimed at assessing humoral immune responses of GPA patients against S. aureus antigens in relation to the genetic diversity of their nasal S. aureus isolates. A retrospective cohort study was conducted, including 85 GPA patients and 18 healthy controls (HC). Humoral immune responses against S. aureus were investigated by determining serum IgG levels against 59 S. aureus antigens. Unexpectedly, patient sera contained lower anti-staphylococcal IgG levels than sera from HC, regardless of the patients' treatment, while total IgG levels were similar or higher. Furthermore, 210 S. aureus isolates obtained from GPA patients were characterized by different typing approaches. This showed that the S. aureus population of GPA patients is highly diverse and mirrors the general S. aureus population. Our combined findings imply that GPA patients are less capable of mounting a potentially protective antibody response to S. aureus than healthy individuals.
Assuntos
Anticorpos Antibacterianos/sangue , Granulomatose com Poliangiite/patologia , Imunoglobulina G/sangue , Staphylococcus aureus/imunologia , Adulto , Idoso , Antibacterianos/farmacologia , Estudos de Coortes , Farmacorresistência Bacteriana , Feminino , Granulomatose com Poliangiite/metabolismo , Humanos , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Estudos Retrospectivos , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/isolamento & purificaçãoRESUMO
Although biomaterials have been used in the clinical setting for a long time, little is known of the molecular mechanisms underlying the foreign-body reaction (FBR). A good understanding of these mechanisms is requisite for the controlled regulation of the FBR needed to prevent adverse tissue reactions and thus to improve the function of the biomaterial. Macrophages are essential in the inflammatory reaction in, as well as around, the implants, and they also are believed to initiate most of the adverse responses. Typically, during the FBR macrophages become activated and fuse into multinucleated giant cells (MnGCs). CD44, an integral membrane glycoprotein expressed on a broad spectrum of cell types, is involved in MnGC formation in vitro and in inflammation processes in general. In vivo it is not known whether CD44 is part of a specific protein machinery that enables macrophage fusion or whether it has additional functions in the FBR. In the present in vivo study, CD44 expression patterns were followed in rats and mice during the FBR to a degradable collagen type I biomaterial. We found that CD44 is upregulated on all migrating cells and on newly formed blood vessels at the onset of the FBR and that MnGCs, up to week 15 postimplantation, expressed CD44. Although no evidence was found that CD44 participates in macrophage fusion leading to multinucleation, it nevertheless may be an interesting target molecule for modulating the FBR in vivo, possibly by affecting cell activation, cell migration towards the biomaterial, vascularization, and MnGC formation.
Assuntos
Materiais Biocompatíveis/metabolismo , Reação a Corpo Estranho/metabolismo , Receptores de Hialuronatos/metabolismo , Implantes Absorvíveis , Animais , Bovinos , Colágeno Tipo I/imunologia , Colágeno Tipo I/metabolismo , Reação a Corpo Estranho/imunologia , Receptores de Hialuronatos/genética , Receptores de Hialuronatos/imunologia , Imuno-Histoquímica , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Ratos , Ratos Endogâmicos , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
The objective of this study was to evaluate whether levels of high mobility group box 1 (HMGB1) in granulomatosis with polyangiitis (GPA) patients are associated with carotid atherosclerosis, related to levels of soluble receptor for advanced glycation end-products (sRAGE) and influenced by immunosuppressive or lipid-lowering therapy. Twenty-three GPA patients and 20 controls were evaluated for HMGB1- and sRAGE levels and for carotid atherosclerosis using ultrasound to determine intima-media thickness (IMT). In vitro the effect of atorvastatin on the production of HMGB1 by lipopolysaccharide (LPS)-stimulated human umbilical vein endothelial cells (HUVEC) was assessed. Serum HMGB1 and sRAGE levels did not differ between patients and controls. A negative correlation was found between sRAGE and maximum IMT but HMGB1 and carotid IMT were not related. HMGB1 levels were reduced in GPA patients on statins and prednisolone. In vitro, atorvastatin reduced HMGB1 levels in supernatants of activated HUVEC. In conclusion, carotid IMT is inversely correlated with sRAGE levels but not with HMGB1 levels. Statins and prednisolone are associated with reduced serum HMGB1 levels and atorvastatin decreases HMGB1 release by activated HUVEC in vitro, indicating an additional anti-inflammatory effect of statins.
Assuntos
Aterosclerose/sangue , Aterosclerose/complicações , Granulomatose com Poliangiite/complicações , Proteína HMGB1/sangue , Receptores Imunológicos/sangue , Receptores Imunológicos/química , Aterosclerose/tratamento farmacológico , Atorvastatina , Feminino , Ácidos Heptanoicos/farmacologia , Ácidos Heptanoicos/uso terapêutico , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Masculino , Pessoa de Meia-Idade , Prednisolona/farmacologia , Prednisolona/uso terapêutico , Pirróis/farmacologia , Pirróis/uso terapêutico , Receptor para Produtos Finais de Glicação Avançada , SolubilidadeRESUMO
Anti-neutrophil cytoplasmic antibody-associated (ANCA-associated) small vessel necrotizing vasculitis is caused by immune-mediated inflammation of the vessel wall and is diagnosed in some cases by the presence of myeloperoxidase-specific antibodies (MPO-ANCA). This multicenter study sought to determine whether differences in ANCA epitope specificity explain why, in some cases, conventional serologic assays do not correlate with disease activity, why naturally occurring anti-MPO autoantibodies can exist in disease-free individuals, and why ANCA are undetected in patients with ANCA-negative disease. Autoantibodies from human and murine samples were epitope mapped using a highly sensitive epitope excision/mass spectrometry approach. Data indicated that MPO autoantibodies from healthy individuals had epitope specificities different from those present in ANCA disease. Importantly, this methodology led to the discovery of MPO-ANCA in ANCA-negative disease that reacted against a sole linear sequence. Autoantibodies against this epitope had pathogenic properties, as demonstrated by their capacity to activate neutrophils in vitro and to induce nephritis in mice. The confounder for serological detection of these autoantibodies was the presence of a fragment of ceruloplasmin in serum, which was eliminated in purified IgG, allowing detection. These findings implicate immunodominant epitopes in the pathology of ANCA-associated vasculitis and suggest that autoantibody diversity may be common to other autoimmune diseases.
Assuntos
Vasculite Associada a Anticorpo Anticitoplasma de Neutrófilos/imunologia , Autoanticorpos/imunologia , Epitopos/imunologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Sequência de Aminoácidos , Animais , Vasculite Associada a Anticorpo Anticitoplasma de Neutrófilos/sangue , Especificidade de Anticorpos , Autoanticorpos/sangue , Autoanticorpos/isolamento & purificação , Estudos de Casos e Controles , Ceruloplasmina/química , Criança , Epitopos/química , Feminino , Humanos , Masculino , Camundongos , Camundongos Transgênicos , Pessoa de Meia-Idade , Dados de Sequência Molecular , Fragmentos de Peptídeos/sangue , Peroxidase/química , Peroxidase/imunologia , Adulto JovemRESUMO
Tubulointerstitial lesions are important in the progression of proteinuric renal disease. Tubular kidney injury molecule-1 (Kim-1) is induced in acute renal injury and reversible as a natural course. Kim-1 is also present in chronic renal damage; however, the dynamics of Kim-1 in chronic renal damage and effects of antiproteinuric treatment on Kim-1 are unknown. We studied Kim-1 in adriamycin nephrosis (AN) before and after renin-angiotensin system blockade. A renal biopsy was taken 6 wk after adriamycin injection to study renal damage and Kim-1 expression. Subsequently, ACE inhibition (ACEi; n = 23), angiotensin II antagonist (AT(1A); n = 23), or vehicle (n = 10) was given for 6 wk; healthy rats served as controls (CON; n = 8). In AN, renal Kim-1 mRNA was induced 26-fold vs. CON at week 6, with further increase in vehicle to week 12 (40-fold) but was reduced by ACEi and AT(1A) to 10- and 12-fold vs. CON (P < 0.05 vs. week 6). Kim-1 protein was undetectable in CON; in AN, it was present in brush border of dilated tubules in areas with adjacent interstitial lesions. Renal Kim-1 protein levels increased from weeks 6-12 in vehicle and decreased in ACEi- and AT(1A)-treated groups (P < 0.05). In vehicle, urinary Kim-1 was increased (P < 0.05 vs. CON), with a reduction by ACEi and AT(1A) (P < 0.05 vs. vehicle). Renal and urinary Kim-1 correlated with proteinuria and interstitial damage cross-sectionally. Reductions in proteinuria and renal Kim-1 correlated, which was not associated by corresponding changes in tubulointerstitial fibrosis. In conclusion, on longitudinal follow-up during antiproteinuric treatment increased renal Kim-1 expression is reversible in proportion to proteinuria reduction, likely reflecting reversibility of early tubular injury, supporting its potential as a biomarker for tubulointerstitial processes of damage and repair.
Assuntos
Moléculas de Adesão Celular/genética , Moléculas de Adesão Celular/metabolismo , Túbulos Renais Proximais/fisiologia , Proteinúria/fisiopatologia , Insuficiência Renal Crônica/fisiopatologia , Animais , Antibióticos Antineoplásicos/toxicidade , Biomarcadores/metabolismo , Biópsia , Moléculas de Adesão Celular/urina , Doxorrubicina/toxicidade , Fibrose , Imuno-Histoquímica , Túbulos Renais Proximais/patologia , Masculino , Proteinúria/induzido quimicamente , Proteinúria/patologia , RNA Mensageiro/metabolismo , Ratos , Ratos Wistar , Insuficiência Renal Crônica/induzido quimicamente , Insuficiência Renal Crônica/patologia , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
Kidney injury molecule-1 (Kim-1) is associated with ischemic and proteinuric tubular injury; however, whether dysregulation of the renin-angiotensin system (RAS) can also induce Kim-1 is unknown. We studied Kim-1 expression in homozygous Ren2 rats, characterized by renal damage through excessive RAS activation. We also investigated whether antifibrotic treatment (RAS blockade or p38 MAP kinase inhibition) would affect Kim-1 expression. At 7 wk of age, homozygous Ren2 rats received a nonhypotensive dose of candesartan (0.05 mg x kg(-1) x day(-1) sc) or the p38 inhibitor SB-239063 (15 mg x kg(-1) x day(-1) sc) for 4 wk; untreated Ren2 and Sprague-Dawley (SD) rats served as controls. Kim-1 mRNA and protein expression were determined by quantitative PCR and immunohistochemistry, respectively, and related to markers of prefibrotic renal damage. Urinary Kim-1 was measured in 8-wk-old Ren2 and SD rats with and without angiotensin-converting enzyme inhibition (ramipril, 1 mg x kg(-1) x day(-1) in drinking water for 4 wk). Untreated Ren2 rats showed a >20-fold increase in renal Kim-1 mRNA (expressed as Kim-1-to-GAPDH ratio): 75.5 +/- 43.6 vs. 3.1 +/- 1.0 in SD rats (P < 0.01). Candesartan and SB-239063 strongly reduced Kim-1 mRNA: 3.1 +/- 1.5 (P < 0.01) and 9.8 +/- 4.2 (P < 0.05), respectively. Kim-1 protein expression in damaged tubules paralleled mRNA expression. Kim-1 expression correlated with renal osteopontin, alpha-smooth muscle actin, and collagen III expression and with tubulointerstitial fibrosis. Damaged tubular segments expressing activated p38 also expressed Kim-1. Urinary Kim-1 was increased in Ren2 vs. SD (458 +/- 70 vs. 27 +/- 2 pg/ml, P < 0.01) rats and abolished in Ren2 rats treated with ramipril (33 +/- 5 pg/ml, P < 0.01). Kim-1 is associated with development of RAS-mediated renal damage. Antifibrotic treatment through RAS blockade or p38 MAP kinase inhibition reduced Kim-1 in the homozygous Ren2 model.