Nikolai Naoumov | PubMed Health

PubMed2005

Shared alterations in NK cell frequency, phenotype, and function in chronic human immunodeficiency virus and hepatitis C virus infections.

Human immunodeficiency virus (HIV) and hepatitis C virus (HCV) cause clinically important persistent infections. The effects of virus persistence on innate immunity, including NK cell responses, and the underlying mechanisms are not fully understood. We examined the frequency, phenotype, and function of peripheral blood CD3- CD56+ NK subsets in HIV+ and HCV+ patients and identified significantly reduced numbers of total NK cells and a striking shift in NK subsets, with a marked decrease in the CD56(dim) cell fraction compared to CD56(bright) cells, in both infections. This shift influenced the phenotype and functional capacity (gamma interferon production, killing) of the total NK pool. In addition, abnormalities in the functional capacity of the CD56(dim) NK subset were observed in HIV+ patients. The shared NK alterations were found to be associated with a significant reduction in serum levels of the innate cytokine interleukin 15 (IL-15). In vitro stimulation with IL-15 rescued NK cells of HIV+ and HCV+ patients from apoptosis and enhanced proliferation and functional activity. We hypothesize that the reduced levels of IL-15 present in the serum during HIV and HCV infections might impact NK cell homeostasis, contributing to the common alterations of the NK pool observed in these unrelated infections.

CD3 Complex↗

PubMed2004

Successful pregnancy in a liver transplant recipient treated with lamivudine for de novo hepatitis B in the graft.

Pregnancy is often successful after liver transplantation, despite the potentially toxic effects of immunosuppressive drug therapy. Liver transplant recipients with recurrent hepatitis C or hepatitis B nonetheless appear to be at risk of a worse graft function in the event of pregnancy, and antiviral drugs are generally contraindicated in pregnancy because of their teratogenic effects. A 33-year-old woman had undergone liver transplantation for Caroli's disease 6 years previously. Two years later the patient experienced de novo HBV hepatitis. Lamivudine treatment (100 mg/day) was started and clearance of HBsAg was documented 1 year later. Four years after starting antiviral treatment the patient became pregnant, despite of the risk of teratogenic effects; lamivudine, cyclosporine and azathioprine were not discontinued for risk of break-through hepatitis and acute or chronic rejection. The course of gestation was uneventful and caesarean section was performed after 36 weeks. The newborn infant was a healthy male weighing 3,080 g and measuring 50 cm.

Adult↗