Value of measurement of C-reactive protein in febrile patients with hematological malignancies.

The maximum serum levels of C-reactive protein (CRP) in 126 patients with hematological malignancies who had 554 febrile episodes were analyzed retrospectively with regard to documented infections and fever of unknown origin. The CRP levels were significantly higher when the blood culture was positive than when it was negative (p = 0.002). The CRP levels were significantly higher when the infection focus was identified than when it was not (p = 0.010). In patients with fever of unknown origin the CRP was significantly lower than in patients with microbiologically documented infections (p < 0.001). Cytotoxic treatment neither reduced nor enhanced the CRP reaction. The serial measurement of CRP is a reliable and readily available means for differentiating between bacterial infections and other causes of fever in patients with hematological malignancies, also during neutropenia and after cytotoxic treatment.