C-reactive protein in the diagnosis and management of infections in granulocytopenic and non-granulocytopenic patients

The serum levels of C-reactive protein (CRP) were assayed in 64 non-granulocytopenic and 35 granulocytopenic patients with or without fever and infection. Most patients showed a direct CRP response within 24 hours after onset of fever (95 % of non-granulocytopenic patients, 100 % of granulocytopenic patients). The mean peak level of CRP in febrile patients with septicemia was 207 mg/l (median 214 mg/l) in non-granulocytopenic patients and 173 mg/l (median 168 mg/l) in granulocytopenic patients, and differed significantly (p<0.001) from that in febrile patients without positive blood cultures. A significant difference between patients with major and minor infections was also found (p<0.01). No significant difference in the CRP level was found between patients with microbiologically and clinically documented infections (p>0.05), nor did the serum CRP levels differ between patients with infections due to gram-positive and gram-negative organisms. The most favorable cut-off limit for detection of an inflammatory process in this study was 25 mg/l. There was no quantitative difference between CRP levels measured by a latex-agglutination method and the nephelometry assay.