Routine blood analysis greatly reduces the false-negative rate of RT-PCR testing for Covid-19.

Routine blood analysis greatly reduces the false-negative rate of RT-PCR testing for Covid-19.


  • Davide Ferrari SCVSA Department, University of Parma, Parma, Italy; 2 Laboratory Medicine Service, San Raffaele Hospital, Milano, Italy; 3 Vita-Salute University, San Raffaele, Milano, Italy; IRCCS Istituto Ortopedico Galeazzi, Milano, Italy
  • Eleonora Sabetta San Raffaele Hospital
  • Daniele Ceriotti San Raffaele Hospital
  • Andrea Motta San Raffaele Hospital
  • Marta Strollo San Raffaele Hospital
  • Giuseppe Banfi San Raffaele Hospital
  • Massimo Locatelli San Raffaele Hospital


COVID-19, RT-PCR, blood test, WBC, aspartate aminotransferase, lactate dehydrogenase


Background: The COVID-19 outbreak is now a pandemic disease reaching as much as 210 countries worldwide with more than 2.5 million infected people and nearly 200.000 deaths. Amplification of viral RNA by RT-PCR represents the gold standard for confirmation of infection, yet it showed false-negative rates as large as 15-20% which may jeopardize the effect of the restrictive measures taken by governments. We previously showed that several hematological parameters were significantly different between COVID-19 positive and negative patients. Among them aspartate aminotransferase and lactate dehydrogenase had predictive values as large as 90%. Thus a combination of RT-PCR and blood tests could reduce the false-negative rate of the genetic test. Methods: We retrospectively analyzed 24 patients showing multiple and inconsistent RT-PCR, test during their first hospitalization period, and compared the genetic tests results with their AST and LDH levels. Results: We showed that when considering the hematological parameters, the RT-PCR false-negative rates were reduced by almost 4-fold. Conclusions: The study represents a preliminary work aiming at the development of strategies that, by combining RT-PCR tests with routine blood tests, will lower or even abolish the rate of RT-PCR false-negative results and thus will identify, with high accuracy, patients infected by COVID-19.


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How to Cite

Ferrari D, Sabetta E, Ceriotti D, Motta A, Strollo M, Banfi G, et al. Routine blood analysis greatly reduces the false-negative rate of RT-PCR testing for Covid-19. Acta Biomed [Internet]. 2020 Sep. 7 [cited 2024 Jul. 20];91(3):e2020003. Available from: