Abstract
Primary (PAD) and secondary antibody immunodeficiency (SAD) are among the most common disorders of the immune system, which share a number of common features, including not only impaired antibody production but also increased susceptibility, especially to bacterial infections. The therapeutic approach based on prophylactic administration of antibiotics and immunoglobulin replacement therapy is similar.
Both groups differ mainly in etiopathogenesis, where PADs arise on the basis of innate genetic predisposition, while SADs arise within other diseases or external factors. Another significant difference is the extent of the disease, where secondary immunodeficiencies usually retain the production of specific antibodies, which is associated with a smaller extent of the disease and a better prognosis.
The determination of a specific antibody response is thus crucial not only in the diagnosis of PAD but also of SAD.