RESUMO
Tyro3, Axl, MERTK (TAM) receptor tyrosine kinases are implicated in the regulation of the innate immune response through clearance of apoptotic cellular debris and control of cytokine signaling cascades. As a result they are pivotal in regulating the inflammatory response to tissue injury. Within the liver, immune regulatory signaling is employed to prevent the overactivation of innate immunity in response to continual antigenic challenge from the gastrointestinal tract. In this review we appraise current understanding of the role of TAM receptor function in the regulation of both innate and adaptive immunity, with a focus on its impact upon hepatic inflammatory pathology.
Assuntos
Hepatopatias/imunologia , Proteínas Proto-Oncogênicas/metabolismo , Receptores Proteína Tirosina Quinases/metabolismo , Animais , Citocinas/genética , Citocinas/metabolismo , Humanos , Imunidade Inata , Hepatopatias/patologia , Proteínas Proto-Oncogênicas/genética , Receptores Proteína Tirosina Quinases/genética , Transdução de Sinais , c-Mer Tirosina Quinase , Receptor Tirosina Quinase AxlRESUMO
BACKGROUND & AIM: Immunoparesis contributes to prognosis in acute liver failure (ALF) and decompensated cirrhosis, a phenomenon thought to be mediated by the anti-inflammatory cytokine interleukin (IL)-10. We investigated the prognostic value of admission IL-10 levels and their evolution during the early phase of treatment in intensive care, in comparison to the pro-inflammatory cytokines IL-6 and tumour necrosis factor (TNF)-alpha. METHODS: We measured these cytokines within 48 h of admission in 51 ALF and 39 decompensated cirrhosis patients admitted to intensive care, and obtained follow-up measurement a median of 2 days later in 35 patients. RESULTS: Levels of all cytokines were higher in those with a poor outcome. IL-10 performed as well as TNF-alpha and IL-6 in the whole cohort (area under receiver operator curve 0.73 vs 0.66 and 0.72). However IL-10 outperfomed pro-inflammatory cytokines in the subgroups with ALF (0.80 vs 0.63 and 0.70) and acetaminophen-induced ALF (0.92 vs 0.67 and 0.81). Levels of all cytokines rose significantly in non-surviving patients (n=15); IL-10 by a factor of 2, TNF-alpha by 2.6 and IL-6 by 1.13. No significant changes were seen in the surviving patients. In ALF, IL-10 was an independent predictor of outcome in multivariate analysis. CONCLUSION: The magnitude of the compensatory anti-inflammatory response at admission, and its development during the early phase of treatment, predicts outcome as well as the pro-inflammatory response in acute hepatic syndromes and supports a vital role for this immunological phenomenon in the outcome of these patients.
Assuntos
Interleucina-10/sangue , Cirrose Hepática/imunologia , Falência Hepática Aguda/imunologia , Estudos de Coortes , Antígenos HLA-DR/análise , Humanos , Interleucina-6/sangue , Admissão do Paciente , Fator de Necrose Tumoral alfa/sangueRESUMO
Current treatment for patients with chronic hepatitis C virus (HCV) infection consists of the combination of pegylated interferon and ribavirin. This treatment regimen achieves a sustained virological response, defined as undetectable HCV RNA 6 months after treatment cessation, in 50% of patients overall. There is therefore a need for new treatments to improve the sustained virological response rate and reduce the number of adverse effects associated with pegylated interferon and ribavirin. This review examines the current management of chronic HCV infection, including who is eligible for treatment, the optimum duration of treatment, and management of side effects. New drugs in development, such as HCV-specific protease inhibitors, polymerase inhibitors, immune modulators and ribavirin analogues, are outlined, and their role in the treatment armamentarium is discussed, whether used alone or in combination with existing treatments.