SARS-CoV-2 RNA in plasma samples of COVID-19 affected individuals: a cross-sectional proof-of-concept study

Luna Colagrossi, Maria Antonello, Silvia Renica, Marco Merli, Elisa Matarazzo, Giovanna Travi, Marta Vecchi, Jacopo Colombo, Antonio Muscatello, Giacomo Grasselli, Silvia Nerini Molteni, Vittorio Scaravilli, Emanuele Cattaneo, Diana Fanti, Chiara Vismara, Alessandra Bandera, Andrea Gori, Massimo Puoti, Valeria Cento, Claudia AlteriCarlo Federico Perno

Research output: Contribution to journalArticlepeer-review


Background: Recent studies showed that plasma SARS-CoV-2 RNA seems to be associated with worse COVID-19 outcome. However, whether specific population can be at higher risk of viremia are to date unexplored. Methods: This cross-sectional proof-of-concept study included 41 SARS-CoV-2-positive adult individuals (six affected by haematological malignancies) hospitalized at two major hospital in Milan, for those demographic, clinical and laboratory data were available. SARS-CoV-2 load was quantified by ddPCR in paired plasma and respiratory samples. To assess significant differences between patients with and patients without viremia, Fisher exact test and Wilcoxon test were used for categorical and continuous variables, respectively. Results: Plasma SARS-CoV-2 RNA was found in 8 patients (19.5%), with a median (IQR) value of 694 (209–1023) copies/mL. Viremic patients were characterized by an higher mortality rate (50.0% vs 9.1%; p = 0.018) respect to patients without viremia. Viremic patients were more frequently affected by haematological malignancies (62.5% vs. 3.0%; p < 0.001), and had higher viral load in respiratory samples (9,404,000 [586,060-10,000,000] vs 1560 [312–25,160] copies/mL; p = 0.002). Conclusions: Even if based on a small sample population, this proof-of-concept study poses the basis for an early identification of patients at higher risk of SARS-CoV-2 viremia, and therefore likely to develop severe COVID-19, and supports the need of a quantitative viral load determination in blood and respiratory samples of haematologic patients with COVID-19 in order to predict prognosis and consequently to help their further management.

Original languageEnglish
Article number184
JournalBMC Infectious Diseases
Issue number1
Publication statusPublished - Dec 2021


  • COVID-19
  • ddPCR
  • Hematological malignancies
  • Molecular diagnosis
  • SARS-CoV-2
  • Viremia

ASJC Scopus subject areas

  • Infectious Diseases


Dive into the research topics of 'SARS-CoV-2 RNA in plasma samples of COVID-19 affected individuals: a cross-sectional proof-of-concept study'. Together they form a unique fingerprint.

Cite this