C-reactive protein and lactate dehydrogenase as prognostic indicators in COVID-2019 outpatients

  1. Keiko Suzuki
  2. Takaya Ichikawa
  3. Satoshi Suzuki
  4. Yoko Tanino
  5. Yasutaka Kakinoki

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Abstract

Background

It is critical for clinicians seeing outpatients with coronavirus disease 2019 (COVID-19) to identify those who will require oxygen therapy after the hospital visit. Although studies on biomarkers predicting mortality or ventilator requirement in hospitalized patients with COVID-19 have been conducted, research on biomarkers predicting the need for oxygen therapy in outpatients is sparse.

Methods

Patients with COVID-19 who visited Asahikawa City Hospital on an outpatient basis were included in the study. In total, 287 new outpatients visited between April 2021 and September 2021, and 142 underwent blood testing. All blood tests were performed before any treatments for COVID-19 were started. Demographic information, laboratory data, and clinical treatment information were extracted from the electronic medical records. Risk factors associated with oxygen therapy were explored.

Results

In total, 40 of 142 patients who underwent blood testing required oxygen therapy within 7 days after blood samples were taken, and all other patients recovered without oxygen therapy. C-reactive protein (CRP) and lactate dehydrogenase (LDH) levels were significantly higher in patients who required oxygen therapy, and their cutoffs were 36 mg/L (sensitivity, 0.802; specificity, 0.725) and 267 U/L (sensitivity, 0.713; specificity, 0.750), respectively. Multivariate logistic regression identified age, body mass index, CRP ≥ 36 mg/L, and LDH ≥ 267 U/L as significant risk factors for oxygen therapy requirement. This study suggests that elevated CRP and LDH levels are independent risk factors for oxygen therapy in outpatients with COVID-19. Further confirmatory studies are needed.

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  1. Version published to 10.1101/2021.11.17.21265553v2 on medRxiv
  2. ScreenIT

    SciScore for 10.1101/2021.11.17.21265553: (What is this?)

    Please note, not all rigor criteria are appropriate for all manuscripts.

    Table 1: Rigor

    EthicsIRB: Ethics: This study was approved by the ethics committee of Asahikawa City Hospital and conducted in accordance with the ethical standards set forth in the Declaration of Helsinki (1983).
    Consent: The opt-out method was used to obtain patient consent in this study.
    Sex as a biological variablenot detected.
    Randomizationnot detected.
    Blindingnot detected.
    Power Analysisnot detected.

    Table 2: Resources

    No key resources detected.

    Results from OddPub: We did not detect open data. We also did not detect open code. Researchers are encouraged to share open data when possible (see Nature blog).

    Results from LimitationRecognizer: We detected the following sentences addressing limitations in the study:
    Regarding study limitations, the number of cases was limited, and this study was performed retrospectively at a single hospital. Only some patients underwent blood testing at their visit based on the judgment of the physicians. Only 4.93% of patients received SARS-CoV-2 vaccines in this study, and the cutoffs might differ according to the receipt of vaccination. Ferritin and d-dimer levels also significantly differed between patients who did and did not receive oxygen therapy; however, the physicians did not measure these parameters in 14.7% of patients. Because all patients were ethnically Japanese, the results should be verified in other populations. Further studies are needed to confirm our findings. In conclusion, our data suggest that CRP and LDH are useful biomarkers for predicting the need for oxygen therapy among outpatients with COVID-19. Further clinical studies are necessary to confirm our findings.

    Results from TrialIdentifier: No clinical trial numbers were referenced.

    Results from Barzooka: We did not find any issues relating to the usage of bar graphs.

    Results from JetFighter: We did not find any issues relating to colormaps.

    Results from rtransparent:
    • Thank you for including a conflict of interest statement. Authors are encouraged to include this statement when submitting to a journal.
    • Thank you for including a funding statement. Authors are encouraged to include this statement when submitting to a journal.
    • Thank you for including a protocol registration statement.

    Results from scite Reference Check: We found no unreliable references.

    About SciScore

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  3. Version published to 10.1101/2021.11.17.21265553v1 on medRxiv