Autoimmune encephalitis with GABAA receptor antibodies in a 10-year-old girl.

Recent studies have indicated that some cases of nonparaneoplastic autoimmune encephalitis in children can be caused by a systemic autoimmune disorder that generates autoantibodies to cell membrane proteins. We describe the clinical features of a 10-year-old girl with autoimmune encephalitis with autoantibodies against the GABAA receptor in whom type 1 diabetes mellitus developed during the course of the disease. The diagnosis was based on the progressive course of disease, pleocytosis in the cerebrospinal fluid (CSF), inflammatory changes in the brain and autoantibodies against the GABAA receptor detected in serum (absent in CSF). The treatment of encephalitis included intravenous immunoglobulins, intravenous methylprednisolone, oral prednisolone, cycles of plasmapheresis; this led to temporary remission. Finally, rituximab was applied as a second-line therapy with positive results.

Phylogeny and molecular evolution of the hepatitis C virus.

The hepatitis C virus (HCV) is a globally prevalent human pathogen that causes persistent liver infections in most infected individuals. HCV is classified into seven phylogenetically distinct genotypes, which have different geographical distributions and levels of genetic diversity. Some of these genotypes are endemic and highly divergent, whereas others disseminate rapidly on an epidemic scale but display lower variability. HCV phylogeny has an important impact on disease epidemiology and clinical practice because the viral genotype may determine the pathogenesis and severity of the resultant chronic liver disease. In addition, there is a clear association between the HCV genotype and its susceptibility to antiviral treatment. Similarly to other RNA viruses, in a single host, HCV exists as a combination of related but genetically different variants. The whole formation is the actual target of selection exerted by a host organism and antiviral therapeutics. The genetic structure of the viral population is largely shaped by mutations that are constantly introduced during an error-prone replication. However, it appears that genetic recombination may also contribute to this process. This heterogeneous collection of variants has a significant ability to evolve towards the fitness optimum. Interestingly, negative selection, which restricts diversity, emerges as an essential force that drives HCV evolution. It is becoming clear that HCV evolves to become stably adapted to the host environment. In this article we review the HCV phylogeny and molecular evolution in the context of host-virus interactions.