Direct acting antiviral therapy rescues neutrophil dysfunction and reduces hemolysis in hepatitis C infection

Abstract

Chronic hepatitis C virus infection is characterized by multiple extra-hepatic manifestations. Innate immune dysfunction and hemolysis are symptoms which might be associated with each other. We investigated the impact of direct acting antivirals on neutrophil function and its connection to hemolysis. In this prospective study, 85 patients with or without cirrhosis and 21 healthy controls were included. Patients' blood samples were taken at baseline, at the end of therapy and at follow-up 12 weeks after end of therapy. Neutrophil phagocytosis, oxidative burst, and hemolysis parameters were studied. Multivariate analysis was performed to decipher the relationship between hemolysis and neutrophil function. Ex vivo cross-incubation experiments with neutrophils and serum fractions were done. Impaired neutrophil phagocytosis and mild hemolysis were observed in patients with and without cirrhosis. A proteome approach revealed different expression of hemolysis-related serum proteins in patients and controls. Direct acting antiviral therapy restored neutrophil function irrespective of severity of liver disease, achievement of sustained virologic response or type of drug and reduced hemolysis. Treatment with ribavirin delayed the improvement of neutrophil function. Statistical analysis revealed associations of haptoglobin with neutrophil phagocytic capacity. Neutrophil dysfunction could be transferred to healthy cells by incubation with patients' serum fractions (>30 kDa) ex vivo. Neutrophil dysfunction and hemolysis represent extrahepatic manifestations of chronic hepatitis C virus infection and simultaneously improve during direct acting antiviral therapy independently of therapy-related liver function recovery. Therefore, large-scale treatment would not only drive viral eradication but also improve patients' immune system and may reduce susceptibility to infections.

Circulating neutrophil anti-pathogen dysfunction in cirrhosis

“… 50 The decrease in neutrophil phagocytosis of E. coli is more pronounced in patients with cirrhosis who had previous bacterial infections. 34 Neutrophil phagocytic capacity (number of internalised bacteria per cell) of E. coli measured in whole blood or isolated neutrophils of patients with cirrhosis is impaired 51 , 52 , 57 , 59 , 60 or unchanged. 61 , 62 The percentage of phagocytic neutrophils is decreased in the blood of patients with cirrhosis 53 , 55 , 60 , 62 , 63 as well as in those with ACLF; 63 the degree of this dysfunction increases with increasing severity of cirrhosis and is higher in active drinkers compared to abstinent patients, but is not different between the aetiologies of cirrhosis (alcohol, HCV, autoimmune and other).…”

“…Impaired neutrophil ROS production [51] , [52] , [53] , [54] , [55] , 58 , 59 , [65] , [66] , [67] , [68] and degranulation 50 , 64 have been described in cirrhosis and might contribute to impaired bacterial killing. 50 The alteration of ROS production in cirrhosis is characterised by an elevated percentage of neutrophils with basal ROS production (so-called “resting burst”) 51 , 55 , 58 , 60 , 62 , 65 and elevated, 59 , 65 unchanged 61 , 62 or reduced 63 , 67 intracellular basal ROS production (intracellular ROS levels). An increased percentage of neutrophils with basal ROS production has also been reported in ACLF.…”

“…However, other studies show it to be unchanged. 60 The intracellular ROS pool of those neutrophils that respond to fMLF stimulation is slightly increased, 65 decreased 67 or unchanged 62 in patients with cirrhosis. Extracellular superoxide release in response to fMLF [66] , [67] , [68] and TNF-α 66 is decreased in patients with cirrhosis.…”

Neutrophil Recruitment and Participation in Severe Diseases Caused by Flavivirus Infection

“…In a separate study with chronic hepatitis C patients, impaired neutrophil phagocytosis and mild hemolysis were observed in patients with and without cirrhosis. Direct acting antiviral therapy restored neutrophil function irrespective of severity of liver disease, suggesting that neutrophil dysfunction was related to HCV replication in the liver [ 73 ]. TREM1 (Triggering Receptor Expressed on myeloid cells 1) is a proinflammatory receptor expressed by phagocytes whose soluble form is increased in patients suffering from hepatitis B or C. Lymphocytic Choriomeningitis virus (LCMV) infection is used as a model for viral hepatitis in mice and Trem1 -deficient mice infected with LCMV present an attenuated form of hepatitis.…”

Effects of HCV Clearance with Direct-Acting Antivirals (DAAs) on Liver Stiffness, Liver Fibrosis Stage and Metabolic/Cellular Parameters

“…It is known that CHC patients also have signs of mild hemolysis, as indicated by significantly higher heme levels and lower Hp. Serum levels of this acute phase protein were shown to be lower in individuals with more severe liver disease and to be increased after DAAs therapy [ 31 ].…”