Immunosuppression. Role on the infectious diseases of oncologic children.

Cancer patients show an immune deficit whose beginnings are influenced to one extent or another, by two factors: the cancer itself, and the antimitotic-immunosuppressive treatment to which the patient is subjected. The immune deficit will have repercussions in the anti-infectious defense that these patients show: --Greater number of infections. --Greater severity of infections. --Tendency towards generalization and showing of septicemic states. The problem is most serious in hematological tumors (leukemia, lymphosarcoma) where the primary cause of death is infection. During the period of activity of the disease, and also in relation to the antimitotic treatment, the PMN will decrease in absolute count and will function poorly. The consequence will be a high frequency of bacterial infections, sepsis, pneumonia, skin infections, etc., predominantly caused by gram-negative germs and staphylococcus (any germ considered not to be "very virulent" can be found); and it will result in a high mortality rate. When these children are in remission or have solid tumors, the problem is not so acute, and bears more relation to antimitotic treatment and other extraneous factors (hospitalization, catheters, antibiotics, gastrointestinal ulcers...). Patients most frequently show localized bacterial, viral and protozoon infections (varicella, zooster, herpes simplex, cytomegalia, pneumocystis) because of the predominance of cellular immunity deficit.