[Infections in non-transplanted oncohaematological patients]

Oncohaematological patients present a high incidence of infections, which are one of the principle causes of morbidity and mortality. There are different types of immunodepression related to the disease, the moment of its evolution and the treatment received. For practical purposes we will distinguish between patients with severe neutropenia, those with some alteration to humoral immunity and, finally, cellular immunodeficiencies. There are no immunodeficiencies associated to each disease, instead several immunitarian deficiencies can be associated in a single clinical entity. Neutropenic patients, generally with acute leukaemias and following intensive chemotherapy, have bacterial and fungal infections conditioned by the intensity and duration of the neutropenia. In the case of patients with humoral immunodeficiency (multiple myeloma, chronic lymphatic leukaemia, splenectomised) there are frequent infections by encapsulated germs. When there is cellular immunodepression (Hodgkin's disease, advanced chronic lymphoproliferative syndromes, treatment with glucocorticoids, analogues of the purines and treatment with monoclonal antibodies) the risk of infection by opportunist germs is conditioned by the reduction of the figure of CD4 lymphocytes. We review the different strategies of prophylaxis and treatment in each of the situations.