Diagnostic Value of C-Reactive Protein as Marker of Infections in Patients with De Novo Acute Myeloid Leukemias

Aim. To determine diagnostically relevant C-protein levels (CRP) as an early infection marker in patients with de novo acute myeloid leukemias (AML), to evaluate the dependence of CRP concentrations on the WBC count and leukemic blast cells in the peripheral blood. Methods. CRP was tested in 39 patients with de novo AML (17 males and 22 females) at the age of 20 to 76 years (median age is 49). AML types according to the FAB grading were as follows: М0 — 2, М1 — 4, М2 — 23, М4 — 8, and М5 — 2 patients. Results. CRP concentrations in patients without symptoms of an infection (n = 16) were within the range from 0 to 43 mg/l (median 5.5 mg/l). The Spearman’s rank correlation coefficients between the CRP level and WBC and blast cell counts were 0.664 (p = 0.006) and 0.473 (p = 0.062), respectively. The obtained data confirm activation of CRP synthesis in case of leukemia. In patients with an infection and/or fever (n = 23), CRP levels were significantly higher than those in patients without an infection: 8–383 mg/l (median 81 mg/l). No correlation between the CRP level and WBC and blast cell counts was found. Therefore, the CRP synthesis during the onset of AML is significantly increased as a response to the infection. In groups of patients with and without infections, 95% CI were equal to 0–40 mg/l and 12–315 mg/l, respectively. Since they overlap within the range from 12 to 40 mg/l, they may be considered a «grey zone». The CRP concentrations within this range suggest infection. CRP levels lower than 12 mg/l or higher than 40 mg/l with a high degree of probability confirm either absence or presence of infectious complications, respectively. Conclusion. Therefore, CRP is an accessible and informative marker of infection in patients with AML during the onset of the disease. Monitoring of its levels permits to start a timely antimicrobial therapy; at that, the efficacy of the therapy can be assessed based on the dynamics of this parameter.