Primary immunodeficiencies of the B lymphocyte.

The immune response consists of two main components: humoral immunity represented by B lymphocytes and cellular immunity maintained by the T lymphocytes. Immunoglobulins, produced by B-lymphocytes, are the main mediators of humoral immunity, and deficiencies at this level affect the body's response to infection. Plasmocytes produce nine antibody izotypes: immunoglobulins G (IgG1, IgG2, IgG3, IgG4), immunoglobulins M (IgM), immunoglobulins A (IgA1, IgA2), immunoglobulins D (IGD) and immunoglobulins E (IgE).

Prevalence of HBV genotypes in Central and Eastern Europe.

The importance of hepatitis B virus (HBV) genotypes for disease progression and response to interferon-alpha-based treatment is well established. While almost all patients in the Mediterranean area are infected with HBV genotype D, HBV genotype A is dominant in Northern Europe. However, the distribution of HBV genotypes is unknown for several Central and Eastern European countries.