C-reactive protein in rapid diagnosis and follow-up of bacterial septicemia in children with leukemia.

C-reactive protein (CRP) was evaluated as an indicator of septic bacterial infections in children with acute lymphoblastic leukemia (ALL). Thirty-five children with newly diagnosed ALL and 10 children receiving antileukemic chemotherapy developed 13 episodes of verified septicemia. Newly diagnosed ALL alone influenced the CRP level moderately; half of the children with no concomitant bacterial infection had measurable CRP values. However, the CRP values in this group were significantly lower than those in children with proved septicemia in whom the CRP level ranged from 15 to 340 mg/liter (median, 125 mg/liter). We conclude that CRP levels exceeding 100 mg/liter indicate bacterial septicemia with a high specificity regardless of the stage of ALL. Moreover, a negative CRP value virtually excludes septicemia. Patients ith moderately elevated CRP values, i.e. under 100 mg/liter, should be closely observed. Sequential CRP determinations are useful in children with invasive bacterial infections.