Diagnostic and early prognostic value of serum CRP and LDH levels in patients with possible COVID-19 at the first admission

J Infect Dev Ctries. 2021 Jun 30;15(6):766-772. doi: 10.3855/jidc.14072.


Introduction: COVID-19 is the infection caused by the new coronavirus. Specific treatment for COVID-19 has not been established, yet. It is important to determine the disease severity of the patients at the first admission. Therefore, the exploration of biomarkers is deemed necessary. We aimed to assess the diagnostic and early prognostic value of CRP and LDH levels in possible COVID-19 patients presenting with a severe clinical picture.

Methodology: We evaluated the correlations of relevant routine laboratory test results with disease severity in COVID-19 patients admitted to our infectious diseases clinic. Patients were divided into severe and non-severe disease groups based on clinical findings, oxygen saturation levels in the arterial blood, biochemical test results, and radiological findings. Differences in the findings between the two disease severity groups were examined to determine potential biomarkers.

Results: Median age and the CRP and LDH levels in the severe disease group were statistically significantly higher compared to the nonsevere group (p < 0.0001). No other parameters statistically significant differences have been observed between the two groups (P > 0.05).

Conclusions: CRP and LDH levels were positively correlated with lung lesions in early-stage COVID-19, potentially reflecting disease severity. Because LDH and CRP levels can potentially reflect the pulmonary function, they can be potential predictors of COVID-19- related respiratory failure. For avoiding poor prognosis; LDH and CRP should be considered as potential predictors for identifying the need for thoracic CT scans, close monitoring of pulmonary function, and aggressive supportive therapy early in the course of COVID-19.

Keywords: C-reactive protein; COVID-19; SARS-CoV-2; laboratory findings; lactate dehydrogenase.

Publication types

  • Observational Study

MeSH terms

  • Adult
  • Biomarkers / blood
  • C-Reactive Protein / analysis*
  • COVID-19 / blood*
  • COVID-19 / classification
  • COVID-19 / diagnosis*
  • Female
  • Hospitalization
  • Humans
  • L-Lactate Dehydrogenase / blood*
  • Lung / pathology
  • Lung / virology
  • Male
  • Middle Aged
  • Prognosis
  • Retrospective Studies
  • Risk Factors
  • Severity of Illness Index*
  • Turkey


  • Biomarkers
  • C-Reactive Protein
  • L-Lactate Dehydrogenase