Serum procalcitonin and C-reactive protein in the evaluation of bacterial infection in generalized pustular psoriasis

An Bras Dermatol. 2019 Sep-Oct;94(5):542-548. doi: 10.1016/j.abd.2019.09.022. Epub 2019 Sep 30.

Abstract

Background: There is an obvious need for more prompt and specific biomarkers of bacterial infections in generalized pustular psoriasis patients.

Objective: The aim of this study was to evaluate the diagnostic properties and define appropriate cut-off values of procalcitonin and C-reactive protein in predicting bacterial infection in generalized pustular psoriasis patients.

Methods: Sixty-four generalized pustular psoriasis patients hospitalized from June 2014 to May 2017 were included in this retrospective study. The values of procalcitonin, C-reactive protein, details of infection, and other clinical parameters were analyzed.

Results: Receiver operating characteristic curve analysis generated similar areas (p=0.051) under the curve for procalcitonin 0.896 (95% CI 0.782-1.000) and C-reactive protein 0.748 (95% CI 0.613-0.883). A cut-off value of 1.50ng/mL for procalcitonin and 46.75mg/dL for C-reactive protein gave the best combination of sensitivity (75.0% for procalcitonin, 91.7% for C-reactive protein) and specificity (100% for procalcitonin, 53.8% for C-reactive protein). Procalcitonin was significantly positively correlated with C-reactive protein levels both in the infected (r=0.843, p=0.040) and non-infected group (r=0.799, p=0.000).

Study limitations: The sample size and the retrospective design are limitations.

Conclusions: The serum levels of procalcitonin and C-reactive protein performed equally well to differentiate bacterial infection from non-infection in generalized pustular psoriasis patients. The reference value of procalcitonin and C-reactive protein applied to predicting bacterial infection in most clinical cases may not be suitable for generalized pustular psoriasis patients. C-reactive protein had better diagnostic sensitivity than procalcitonin; however, the specificity of procalcitonin was superior to that of C-reactive protein.

Keywords: Bacterial infections; C-reactive protein; Calcitonin; Psoriasis.

Publication types

  • Comparative Study
  • Evaluation Study

MeSH terms

  • Adult
  • Bacterial Infections / blood*
  • Biomarkers / blood
  • Body Temperature
  • C-Reactive Protein / analysis*
  • Female
  • Humans
  • Leukocyte Count
  • Male
  • Middle Aged
  • Neutrophils
  • Procalcitonin / blood*
  • Psoriasis / blood*
  • Psoriasis / microbiology*
  • Reference Values
  • Reproducibility of Results
  • Retrospective Studies
  • Sensitivity and Specificity
  • Statistics, Nonparametric
  • Young Adult

Substances

  • Biomarkers
  • Procalcitonin
  • C-Reactive Protein