Prague Med. Rep. 2022, 123, 250-257

Clinical Course of COVID-19 and Cycle Threshold in Patients with Haematological Neoplasms

Ignacio Martín Santarelli1,2, Mariela Sierra2,3, María Lucía Gallo Vaulet4,5, Marcelo Rodríguez Fermepin4,5, Sofía Isabel Fernández1,2

1Departamento de Medicina, Universidad de Buenos Aires, Hospital de Clínicas “José de San Martín”, Buenos Aires, Argentina
2Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
3División de Infectología, Universidad de Buenos Aires, Hospital de Clínicas “José de San Martín”, Buenos Aires, Argentina
4Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Bioquímica Clínica, Cátedra de Microbiología Clínica, Buenos Aires, Argentina
5Universidad de Buenos Aires, Instituto de Fisiopatología y Bioquímica Clínica (INFIBIOC), Buenos Aires, Argentina

Received April 26, 2022
Accepted October 18, 2022

The SARS-CoV-2 viral load in a respiratory sample can be inversely quantified using the cycle threshold (Ct), defined as the number of amplification cycles required to detect the viral genome in a quantitative PCR assay using reverse transcriptase (RT-qPCR). It may be classified as high (Ct < 25), intermediate (25–30) and low (Ct > 30). We describe the clinical course of 3 patients with haematological neoplasms who contracted COVID-19. None of them had been vaccinated. Firstly, a 22-year-old male with a refractory acute lymphoblastic leukaemia experienced an oligosymptomatic COVID-19 and had a Ct of 23 with an ascending curve. Another male, aged 23, had recently begun treatment for a promyelocytic leukaemia. He had a subacute course with high oxygen requirements. His Ct dropped from 28, when he only experienced fever, to 14.8, during the most critical period and on the edge of ventilatory support. Viral clearance was documented 126 days after the beginning of the symptoms. Finally, a 60-year-old male had received rituximab as maintenance therapy for a follicular lymphoma 3 months before contracting COVID-19. He had a fulminant course and required mechanical ventilation a few days later. We highlight the association between the course of CoViD-19 and the Ct. Viral shedding was longer than in immunocompetent hosts.


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