title: Substantially elevated C-reactive protein (CRP), together with low levels of procalcitonin (PCT), contributes to diagnosis of fungal infection in immunocompromised patients.
abstract: OBJECTIVE
  Serum procalcitonin (PCT) has become a routinely utilized parameter with a high prediction value of the severity of bacterial infectious complications and their immediate outcomes. Whereas the utility of PCT in differentiating between bacterial and viral infection is generally accepted, its significance in fungal infections has yet to be determined. The aim of the study was to determine the role of PCT testing in patients at high risk for invasive fungal infections.
  
  
  METHODS
  Immunocompromised hematological patients undergoing cyclic chemotherapy treatment or allogeneic hemopoietic stem cell transplantation with infectious complications in which the infectious agents were identified during the disease course were evaluated. In patients with bacterial infection, positive hemocultures were documented, and in patients with fungal infection, the presence of either proven or probable disease was confirmed according to Ascioglu criteria. C-reactive protein (CRP) and PCT were prospectively assessed from the day following fever onset, for four consecutive days.
  
  
  RESULTS
  Overall, 34 patients were evaluated, 21 with bacterial and 13 with fungal infections. Significant elevations of CRP concentrations (i.e., above the upper normal limit) were observed in all patients, with a tendency toward higher levels in bacterial (both gram-positive [Gr+] and Gr-negative [Gr-]) than in fungal infections. PCT levels were significantly elevated in patients with bacterial infections (e.g., predominantly in Gr- compared to Gr+), whereas in patients with fungal infections, we identified minimal or no PCT elevations, p < 0.01. For the fungal infections, according to constructed receiver operating characteristic curves, a combination of PCT <0.5 μg/L and CRP 100-300 mg/L offers the best specificity, sensitivity and positive and negative predictive values (81, 85, 73, and 89 %, respectively).
  
  
  CONCLUSIONS
  Altogether, our data suggest that the finding of substantially elevated CRP combined with low PCT in immunocompromised patients may indicate systemic fungal infection. The use of this combination might simplify the diagnostic process, which otherwise can often be lengthy and arduous.
authors.affiliation: Institute of Haematology and Blood Transfusion, 1st Faculty of Medicine of Charles University in Prague, U nemocnice 1, Praha 2, 128 20, Czech Republic, marketa.markova@uhkt.cz.
authors.forename: Markéta
authors.initials: M
authors.lastname: Marková
authors.forename: Helena
authors.initials: H
authors.lastname: Brodská
authors.forename: Karin
authors.initials: K
authors.lastname: Malíčková
authors.forename: Veronika
authors.initials: V
authors.lastname: Válková
authors.forename: Petr
authors.initials: P
authors.lastname: Cetkovský
authors.forename: Michal
authors.initials: M
authors.lastname: Kolář
authors.forename: Martin
authors.initials: M
authors.lastname: Haluzík
mesh_terms: D000328:Adult; D000368:Aged; D001424:Bacterial Infections / Q000097:blood / Q000276:immunology; D002097:C-Reactive Protein / Q000378:metabolism*; D002116:Calcitonin / Q000097:blood*; D015740:Calcitonin Gene-Related Peptide; D005260:Female; D005334:Fever / Q000097:blood / Q000276:immunology / Q000382:microbiology; D006086:Graft vs Host Disease / Q000097:blood / Q000276:immunology / Q000382:microbiology; D019337:Hematologic Neoplasms / Q000097:blood* / Q000276:immunology / Q000382:microbiology*; D018380:Hematopoietic Stem Cell Transplantation; D006801:Humans; D016867:Immunocompromised Host; D008297:Male; D008875:Middle Aged; D009181:Mycoses / Q000097:blood* / Q000276:immunology; D011237:Predictive Value of Tests; D011498:Protein Precursors / Q000097:blood*; D012372:ROC Curve; D055815:Young Adult
chemical_list: C000606589:CALCA protein, human; D011498:Protein Precursors; D002116:Calcitonin; D002097:C-Reactive Protein; D015740:Calcitonin Gene-Related Peptide