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. 2022 Aug;191(4):1751-1758.
doi: 10.1007/s11845-021-02777-y. Epub 2021 Sep 15.

A comparative study of laboratory findings in PCR-positive and PCR-negative COVID-19 hospitalized patients

Hassan Abolghasemi  1 , Davood Bashash  2 , Ramezan Jafari  3 , Parisa Naseri  4 , Mahdieh Farzanehpour  5 , Masomeh Bolandian  5 , Majdedin Ghalavand  5 , Mohammad Mahdi Pourhaji Chaghush  6 , Hossein Aghamollaei  7 , Hamid Sedighian  1 , Abbas Ali Imani Fooladi  8
Affiliations

A comparative study of laboratory findings in PCR-positive and PCR-negative COVID-19 hospitalized patients

Hassan Abolghasemi et al. Ir J Med Sci. 2022 Aug.

Abstract

Introduction: Given the many misconceptions in terms of both diagnosis and treatment, SARS-CoV-2 continues to infect and victimize. Notwithstanding molecular testing is the gold standard method of in vitro diagnostic, the often long-waiting time, as well as false-negative results are daunting challenges facing us. In this study, we aimed to report the diagnostic value of laboratory findings in COVID-19 patients, with an extensive focus on the differences between PCR-positive and PCR-negative cases.

Patients and methods: We did a retrospective single-centre study on a large cohort of 1546 COVID-19 patients in Tehran, Iran. Based on clinical symptoms, chest CTs were performed for all the patients. Also, molecular testing of swab specimens was also performed for 1450 cases.

Results: All the data on laboratory results were retrospectively extracted from medical records. Of the 1546 patients, 1040 (67.5%) were male and 506 (32.5%) were female with the mean age of 55.67. On admission, 31.4% of the whole study population displayed lymphopenia and 38.9% showed neutrophilia. Decreased hemoglobin and mild thrombocytopenia were also found in 40% and 18.6% of cases, respectively. Elevated lactate dehydrogenase in nearly 75% of COVID-19 cases was the most common alteration amongst biochemical parameters which together with increased ESR and CRP could serve as diagnostic markers in SARS-CoV-2 infection. Of the 1450 patients with a PCR result, 439 (28.3%) were PCR-negative and 1011 (65.3%) were PCR-positive. Notably, lymphopenia and increased AST were higher in the PCR-positive group than their negative counterparts. Albeit being in the normal range, a significant decrease in the number of monocytes was also evident in the PCR-positive cases.

Conclusions: As far we are aware, this is the first time that we reported a comprehensive exploration of laboratory characteristics of a large cohort of hospitalized COVID-19 patients from Iran, hoping that these data will cast more light on the diagnostic significance of these parameters.

Keywords: COVID-19; Diagnosis; Iran; Laboratory; PCR; Polymerase chain reaction; SARS-CoV-2.

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Figures

Fig. 1
Fig. 1
A timeline of SARS-CoV-2 outbreak in Iran (https://en.wikipedia.org/wiki/COVID-19_pandemic_in_Iran)
See this image and copyright information in PMC

References

    1. World Health Organization (2020) Director-General’s remarks at the media briefing on 2019-nCoV on 11 February 2020. https://www.who.int/director-general/speeches/detail/who-director-genera...
    1. O’Shea PM, Lee GR, Griffin TP, Tormey V, Hayat A, Costelloe SJ, et al. COVID-19 in adults: test menu for hospital blood science laboratories. Ir J Med Sci (1971-) . 2020;189:1147–1152. doi: 10.1007/s11845-020-02252-0. - DOI - PMC - PubMed
    1. Lu H, Stratton CW, Tang YW. The Wuhan SARS-CoV-2—what’s next for China. J Med Virol. 2020;92(6):546–547. doi: 10.1002/jmv.25738. - DOI - PMC - PubMed
    1. Bashash D, Abolghasemi H, Naseri P, Cheraghali AM, Soltanpoor MJ, Fooladi AAI (2021) The association of age sex and RT-PCR results with the lymphocyte and neutrophil counts in SARS-CoV-2 infection: a cross-sectional analysis of 1450 Iranian patients with COVID-19. Iran J Allergy Asthma Immunol 1–11 - PubMed
    1. Cucinotta D, Vanelli M. WHO declares COVID-19 a pandemic. Acta Biomed Atenei Parmensis. 2020;91(1):157–160. - PMC - PubMed