RESUMO
Natalizumab is a monoclonal antibody highly effective in the treatment of relapsing remitting multiple sclerosis (RRMS) patients. Despite its effectiveness, there are growing concerns regarding the risk of progressive multifocal leukoencephalopathy (PML), a brain infection caused by John Cunningham virus (JCV), particularly after 24 doses and in patients who previously received immunosuppressive drugs. Long-term natalizumab treated, immunosuppressive-pretreated, and JCV antibody-positive patients are asked to rediscuss natalizumab continuation or withdrawal after 24 doses. Until now, there has not been a clear strategy that should be followed to avoid PML risk and in parallel reduce clinical and radiological rebound activity. In this review, we analyzed the results of clinical trials and case reports in relation to the following situations: natalizumab continuation, natalizumab discontinuation followed by full therapeutic suspension or switch to other first or second line MS treatments. Quitting all MS treatment after natalizumab increases MS activity occurrence. The results regarding the therapeutic switch are not homogeneous, so at the moment there are no established guidelines regarding natalizumab treatment after 24 administrations; the choice is currently based on the professional experience of the neurologist, and on patients' clinical features and preferences.
Assuntos
Anticorpos Monoclonais/uso terapêutico , Fatores Imunológicos/uso terapêutico , Esclerose Múltipla/tratamento farmacológico , Natalizumab/uso terapêutico , Corticosteroides/uso terapêutico , Animais , Anticorpos Monoclonais/administração & dosagem , Anticorpos Monoclonais/efeitos adversos , Humanos , Fatores Imunológicos/administração & dosagem , Fatores Imunológicos/efeitos adversos , Vírus JC/isolamento & purificação , Leucoencefalopatia Multifocal Progressiva/diagnóstico , Leucoencefalopatia Multifocal Progressiva/etiologia , Natalizumab/administração & dosagem , Natalizumab/efeitos adversosRESUMO
The mechanisms responsible for the evolution of steatosis towards NASH (non-alcoholic steatohepatitis) and fibrosis are not completely defined. In the present study we evaluated the role of CD4(+) T-helper (Th) cells in this process. We analysed the infiltration of different subsets of CD4(+) Th cells in C57BL/6 mice fed on a MCD (methionine choline-deficient) diet, which is a model reproducing all phases of human NASH progression. There was an increase in Th17 cells at the beginning of NASH development and at the NASH-fibrosis transition, whereas levels of Th22 cells peaked between the first and the second expansion of Th17 cells. An increase in the production of IL (interleukin)-6, TNFα (tumour necrosis factor α), TGFß (transforming growth factor ß) and CCL20 (CC chemokine ligand 20) accompanied the changes in Th17/Th22 cells. Livers of IL-17(-/-) mice were protected from NASH development and characterized by an extensive infiltration of Th22 cells. In vitro, IL-17 exacerbated the JNK (c-Jun N-terminal kinase)-dependent mouse hepatocyte lipotoxicity induced by palmitate. IL-22 prevented lipotoxicity through PI3K (phosphoinositide 3-kinase)-mediated inhibition of JNK, but did not play a protective role in the presence of IL-17, which up-regulated the PI3K/Akt inhibitor PTEN (phosphatase and tensin homologue deleted on chromosome 10). Consistently, livers of IL-17(-/-) mice fed on the MCD diet displayed decreased activation of JNK, reduced expression of PTEN and increased phosphorylation of Akt compared with livers of wild-type mice. Hepatic infiltration of Th17 cells is critical for NASH initiation and development of fibrosis in mice, and reflects an infiltration of Th22 cells. Th22 cells are protective in NASH, but only in the absence of IL-17. These data strongly support the potentiality of clinical applications of IL-17 inhibitors that can prevent NASH by both abolishing the lipotoxic action of IL-17 and allowing IL-22-mediated protection.
Assuntos
Hepatopatia Gordurosa não Alcoólica/imunologia , Linfócitos T Auxiliares-Indutores/fisiologia , Linfócitos T Reguladores/fisiologia , Animais , Modelos Animais de Doenças , Interleucina-17/deficiência , Interleucinas/metabolismo , Fígado/imunologia , Masculino , Camundongos Endogâmicos C57BL , Interleucina 22RESUMO
Hemopexin (Hx) is an acute-phase protein synthesized by hepatocytes in response to the proinflammatory cytokines IL-6, IL-1ß, and TNF-α. Hx is the plasma protein with the highest binding affinity to heme and controls heme-iron availability in tissues and also in T lymphocytes, where it modulates their responsiveness to IFN-γ. Recent data have questioned regarding an anti-inflammatory role of Hx, a role that may be both heme-binding dependent and independent. The aim of this study was to investigate the role of Hx in the development of a T cell-mediated inflammatory autoimmune response. During experimental autoimmune encephalomyelitis (EAE), the mouse model of multiple sclerosis, Hx content in serum increased and remained high. When EAE was induced in Hx knockout (Hx(-/-)) mice, they developed a clinically earlier and exacerbated EAE compared with wild-type mice, associated to a higher amount of CD4(+)-infiltrating T cells. The severe EAE developed by Hx(-/-) mice could be ascribed to an enhanced expansion of Th17 cells accounting for both a higher disposition of naive T cells to differentiate toward the Th17 lineage and a higher production of Th17 differentiating cytokines IL-6 and IL-23 by APCs. When purified human Hx was injected in Hx(-/-) mice before EAE induction, Th17 expansion, as well as disease severity, were comparable with those of wild-type mice. Taken together, these data indicate that Hx has a negative regulatory role in Th17-mediated inflammation and prospect its pharmacological use to limit the expansion of this cell subset in inflammatory and autoimmune disease.
Assuntos
Encefalomielite Autoimune Experimental/imunologia , Hemopexina/metabolismo , Hepatócitos/imunologia , Esclerose Múltipla/imunologia , Células Th17/imunologia , Animais , Células Cultivadas , Citocinas/imunologia , Modelos Animais de Doenças , Progressão da Doença , Encefalomielite Autoimune Experimental/genética , Hemopexina/genética , Hemopexina/imunologia , Humanos , Imunidade Celular/genética , Terapia de Imunossupressão , Mediadores da Inflamação/imunologia , Masculino , Camundongos , Camundongos da Linhagem 129 , Camundongos Knockout , Esclerose Múltipla/genéticaRESUMO
Introduction: Alemtuzumab is highly effective in the treatment of patients with relapsing multiple sclerosis (PwRMS) and selectively targets the CD52 antigen, with a consequent profound lymphopenia, particularly of CD4+ T lymphocytes. However, the immunological basis of its long-term efficacy has not been clearly elucidated. Methods: We followed up 29 alemtuzumab-treated RMS patients over a period of 72 months and studied the immunological reconstitution of their CD4+ T cell subsets by means of phenotypic and functional analysis and through mRNA-related molecule expression, comparing them to healthy subject (HS) values (rate 2:1). Results: In patients receiving only two-course alemtuzumab, the percentage of CD4+ lymphocytes decreased and returned to basal levels only at month 48. Immune reconstitution of the CD4+ subsets was characterized by a significant increase (p < 0.001) in Treg cell percentage at month 24, when compared to baseline, and was accompanied by restoration of the Treg suppressor function that increased within a range from 2- to 6.5-fold compared to baseline and that persisted through to the end of the follow-up. Furthermore, a significant decrease in self-reactive myelin basic protein-specific Th17 (p < 0.0001) and Th1 (p < 0.05) cells reaching HS values was observed starting from month 12. There was a change in mRNA of cytokines, chemokines, and transcriptional factors related to Th17, Th1, and Treg cell subset changes, consequently suggesting a shift toward immunoregulation and a reduction of T cell recruitment to the central nervous system. Conclusions: These data provide further insight into the mechanism that could contribute to the long-term 6-year persistence of the clinical effect of alemtuzumab on RMS disease activity.
Assuntos
Esclerose Múltipla , Alemtuzumab/farmacologia , Alemtuzumab/uso terapêutico , Linfócitos T CD4-Positivos , Seguimentos , Humanos , Esclerose Múltipla/tratamento farmacológico , RNA Mensageiro/uso terapêuticoRESUMO
Increasing evidence supports the anti-inflammatory role of estrogens in Multiple Sclerosis (MS), originating from the observation of reduction in relapse rates among women with MS during pregnancy, but the molecular mechanisms are still not completely understood. Using an integrative data analysis, we identified T helper (Th) 17 and T regulatory (Treg) cell-type-specific regulatory regions (CSR) regulated by estrogen receptor alpha (ERα). These CSRs were validated in polarized Th17 from healthy donors (HD) and in peripheral blood mononuclear cells, Th17 and Treg cells from relapsing remitting (RR) MS patients and HD during pregnancy. 17ß-estradiol induces active histone marks enrichment at Forkhead Box P3 (FOXP3)-CSRs and repressive histone marks enrichment at RAR related orphan receptor C (RORC)-CSRs in polarized Th17 cells. A disease-associated epigenetic profile was found in RRMS patients during pregnancy, suggesting a FOXP3 positive regulation and a RORC negative regulation in the third trimester of pregnancy. Altogether, these data indicate that estrogens act as immunomodulatory factors on the epigenomes of CD4+ T cells in RRMS; the identified CSRs may represent potential biomarkers for monitoring disease progression or new potential therapeutic targets.
Assuntos
Esclerose Múltipla Recidivante-Remitente/sangue , Gravidez/sangue , Linfócitos T Reguladores/fisiologia , Células Th17/fisiologia , Transcriptoma , Adolescente , Adulto , Análise de Variância , Polaridade Celular , Montagem e Desmontagem da Cromatina/genética , Epigênese Genética , Estradiol/metabolismo , Receptor alfa de Estrogênio/metabolismo , Feminino , Fatores de Transcrição Forkhead/genética , Voluntários Saudáveis , Código das Histonas/genética , Humanos , Pessoa de Meia-Idade , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/genética , Polimorfismo de Nucleotídeo Único , Terceiro Trimestre da Gravidez/sangue , Sequências Reguladoras de Ácido Nucleico/genética , Adulto JovemRESUMO
Lipotoxicity and immunoinflammation are associated with the evolution of steatosis toward nonalcoholic steatohepatitis (NASH). This study reports the ability of adenosine A2a receptor (A2aR) activation to inhibit NASH development by modulating the responses of CD4+ T-helper (Th) cells to avoid an immuno-mediated potentiation of lipotoxicity. The effect of the A2aR agonist CGS21680 on immunoinflammatory signals, CD4+Th cell infiltration and immunolipotoxicity was analyzed in steatotic C57BL/6 mice fed with a methionine-choline-deficient (MCD) diet and in mouse hepatocytes exposed to palmitic acid (PA). CGS21680 inhibited NASH development in steatotic mice and decreased cytokines and chemokines involved in Th cell recruitment or polarization (namely CXCL10, CCL2, tumor necrosis factor alfa [TNFα], tumor growth factor [TGFß], and IL-12). CGS21680 also reduced the expansion of Th17, Th22, and Th1 cells and increased the immunosuppressive activity of T regulatory cells. In PA-treated mice hepatocytes, CGS21680 inhibited the production of CXCL10, TNFα, TGFß, IL-12, and CCL2; CGS21680 also prevented JNK-dependent lipotoxicity and its intensification by IL-17 or IL-17 plus IL-22 through Akt/PI3-kinase stimulation and inhibition of the negative regulator of PI3-kinase, (phosphatase and tensin homologue deleted from chromosome 10 (PTEN), which is upregulated by IL-17. In MCD livers, CGS21680 reduced JNK activation and PTEN expression and increased Akt phosphorylation. In conclusion, A2aR stimulation inhibited NASH development by reducing Th17 cell expansion and inhibiting the exacerbation of the IL-17-induced JNK-dependent lipotoxicity. These data promote the implementation of further studies to evaluate the potential clinical application of A2aR agonists that, by being able to function as both cytoprotective and immunomodulatory agents, could efficiently antagonize the multi-faced pathogenesis of NASH.
Assuntos
Lipídeos/toxicidade , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Hepatopatia Gordurosa não Alcoólica/imunologia , Receptor A2A de Adenosina/metabolismo , Transdução de Sinais/efeitos dos fármacos , Adenosina/análogos & derivados , Adenosina/farmacologia , Adenosina/uso terapêutico , Animais , Progressão da Doença , Ativação Enzimática/efeitos dos fármacos , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Inflamação/imunologia , Inflamação/patologia , Masculino , Camundongos Endogâmicos C57BL , Hepatopatia Gordurosa não Alcoólica/enzimologia , Hepatopatia Gordurosa não Alcoólica/patologia , Fenetilaminas/farmacologia , Fenetilaminas/uso terapêutico , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Linfócitos T Auxiliares-Indutores/efeitos dos fármacos , Linfócitos T Auxiliares-Indutores/imunologia , Linfócitos T Reguladores/efeitos dos fármacos , Linfócitos T Reguladores/imunologiaRESUMO
INTRODUCTION: Natalizumab is a humanized monoclonal antibody highly effective in relapsing-remitting multiple sclerosis (MS). Important concerns about its safety have been pointed out mainly because of the risk of progressive multifocal leukoencephalopathy (PML), caused by the opportunistic John-Cunningham virus (JCV). Areas covered: This review analyzes all the safety aspects related to the use and safety of natalizumab in MS patients. Other than PML, post-marketing, safety red-flags have been reported, as liver or haematological serious adverse events. Pregnancy evidences will be pointed out. The risk of PML depends on: concomitant or previous immunosuppression, exposure duration, anti-JCV antibody level. In natalizumab-related PML the average survival is 77%; prognostic features and information for the earliest identification of PML have been identified to maximally reduce its incidence, mortality and morbidity. Expert opinion: Natalizumab is a highly effective drug for MS patients but its safety issues represent a relevant limitation and impose strict clinical surveillance of treated patients. Some post-marketing safety red-flags have been pointed out, with higher attention to severe liver failures and limphoma cases. If PML and its consequences are considered the most relevant issues, a continuous surveillance must be maintained also regarding other possible SAEs like liver diseases and malignancies.
Assuntos
Fatores Imunológicos/administração & dosagem , Leucoencefalopatia Multifocal Progressiva/induzido quimicamente , Esclerose Múltipla Recidivante-Remitente/tratamento farmacológico , Natalizumab/administração & dosagem , Animais , Humanos , Fatores Imunológicos/efeitos adversos , Vírus JC/isolamento & purificação , Leucoencefalopatia Multifocal Progressiva/virologia , Esclerose Múltipla Recidivante-Remitente/fisiopatologia , Natalizumab/efeitos adversos , Infecções Oportunistas/virologia , Prognóstico , Risco , Taxa de SobrevidaRESUMO
Alemtuzumab, a highly effective treatment for relapsing remitting multiple sclerosis (RRMS), induces lymphopenia especially of CD4+ T cells. Here, we report the atypical CD4+ T population behaviour of two patients with persistent disease activity despite repeated alemtuzumab treatments. Whereas lymphocytes count decreased and fluctuated accordingly to alemtuzumab administration, their CD4+ cell percentage was not or just mildly affected and was slightly below the lowest normal limit already before alemtuzumab. These cases anticipate further studies aimed to investigate whether the evaluation of the CD4+ cell percentage could represent a helpful tool to address the individual clinical response to alemtuzumab.
Assuntos
Alemtuzumab/uso terapêutico , Antineoplásicos Imunológicos/uso terapêutico , Linfócitos T CD4-Positivos/efeitos dos fármacos , Linfócitos T CD4-Positivos/patologia , Esclerose Múltipla/tratamento farmacológico , Adulto , Feminino , HumanosRESUMO
OBJECTIVE: To analyze changes in T-helper (Th) subsets, T-regulatory (Treg) cell percentages and function, and mRNA levels of immunologically relevant molecules during a 24-month follow-up after alemtuzumab treatment in patients with relapsing-remitting multiple sclerosis (RRMS). METHODS: Multicenter follow-up of 29 alemtuzumab-treated patients with RRMS in the Comparison of Alemtuzumab and Rebif Efficacy in Multiple Sclerosis (CARE-MS) I and CARE-MS II trials. Peripheral blood (PB) samples were obtained at months 0, 6, 12, 18, and 24. We evaluated (1) mRNA levels of 26 immunologic molecules (cytokines, chemokines, chemokine receptors, and transcriptional factors); (2) Th1, Th17, and Treg cell percentages; and (3) myelin basic protein (MBP)-specific Treg suppressor activity. RESULTS: We observed 12 relapses in 9 patients. mRNA levels of the anti-inflammatory cytokines interleukin (IL)-10, IL-27, and transforming growth factor-ß persistently increased whereas those of proinflammatory molecules related to the Th1 or Th17 subsets persistently decreased after alemtuzumab administration throughout the follow-up period. PB CD4+ cell percentage remained significantly lower than baseline while that of Th1 and Th17 cells did not significantly change. A significant increase in Treg cell percentage was observed at month 24 and was accompanied by an increase in Treg cell suppressive activity against MBP-specific Th1 and Th17 cells. CONCLUSIONS: The long-lasting therapeutic benefit of alemtuzumab in RRMS may involve a shift in the cytokine balance towards inhibition of inflammation associated with a reconstitution of the PB CD4+ T-cell subsets that includes expansion of Treg cells with increased suppressive function.
RESUMO
Th1 and Th17 cells have been considered as effectors in mouse EAE and in the human counterpart, MS. Recently, IL-22, a Th17-related, proinflammatory cytokine, has been associated with a new Th cell subset, defined as Th22, involved in chronic inflammatory conditions, such as psoriasis; the role of IL-22 in MS has not yet been elucidated. Here, we report that similar to Th17 cells, the number of Th22 cells increased in the PB and the CSF of RR MS patients, especially during the active phases of the disease. However, as opposed to Th17 cells, the expansion of Th22 cells occurred before the active phases of the disease. Th22 cells were found to be specific for the autoantigen MBP and also expressed high levels of CCR6 and T-bet, as for Th17 cells, indicating that Th22 self-reactive cells could have CNS-homing properties and be pathogenic in active RRMS patients. Conversely to Th17 cells, Th22 cells displayed lower levels of IFNAR1 and were insensitive to IFN-ß inhibition. These data suggest that expansion of Th22 cells in MS could be one of the factors that critically influence resistance to IFN-ß therapy.