Immune regulation in chronic hepatitis C virus infection.

The immunological result of infection with Hepatitis C virus (HCV) depends on the delicate balance between a vigorous immune response that may clear the infection, but with a risk of unspecific inflammation and, or a less inflammatory response that leads to chronic infection. In general, exhaustion and impairment of cytotoxic function of HCV-specific T cells and NK cells are found in patients with chronic HCV infection. In contrast, an increase in immune regulatory functions is found primarily in form of increased IL-10 production possibly due to increased level and function of anti-inflammatory Tregs. Thus, the major immune players during chronic HCV infection are characterized by a decrease of cytotoxic function and increase of inhibitory functions. This may be an approach to diminish intrahepatic and systemic inflammation. Finally, there has been increasing awareness of regulatory functions of epigenetic changes in chronic HCV infection. A vast amount of studies have revealed the complexity of immune regulation in chronic HCV infection, but the interplay between immune regulation in virus and host remains incompletely understood. This review provides an overview of regulatory functions of HCV-specific T cells, NK cells, Tregs, IL-10, and TGF-ß, as well as epigenetic changes in the setting of chronic HCV infection.

Fatal outbreak of botulism in Greenland.

Botulism commonly occurs when the anaerobic, gram-positive bacterium Clostridium botulinum, under suitable conditions, produces botulinum neurotoxins. Named A-F, these toxins are the immediate causative agent of the clinical symptoms of symmetrical, descending neurological deficits, including respiratory muscle paralysis. We present five cases of foodborne botulism occurring in Greenland, two with fatal outcome, caused by ingestion of tradionally preserved eider fowl. In the cases of the survivors, antitoxin and supportive care, including mechanical ventilation, were administered. In these cases recovery was complete. Microbiological assays, including toxin neutralization bioassay, demonstrated the presence of neurotoxin E in two survivors. The third survivor was shown by PCR to have the BoNT type E gene in faeces. This is the first report of cases of fatal botulism in Greenland. It underscores the importance of prompt coordinated case management effort in a geographically isolated area such as Greenland.

[Fatal haemophagocytic lymphohistiocytosis and mononucleosis in a patient with colitis ulcerosa]. / Fatal hæmofagocytisk lymfohistiocytose og mononukleose hos en patient med colitis ulcerosa.

We report a case of Epstein-Barr virus primo infection with the development of lethal haemophagocytic lymphohistiocytosis (HLH) in a 22 year-old man, who was being treated with azathioprin for colitis ulcerosa. HLH is a rare, life-threatening disease, which is caused by an inappropriate activation of the immune system with haemophagocytosis and multiorgan system dysfunction. Early initiation of treatment significantly improves survival.