Cycle threshold predicted mortality in a cohort of patients with hematologic malignancies infected with SARS-CoV-2

When a SARS-CoV-2 RT-qPCR test is performed, it may determine an indirect measure of viral load called cycle threshold (Ct). Respiratory samples with Ct <25.0 cycles are considered to contain a high viral load. We aimed to determine whether SARS-CoV-2 Ct at diagnosis could predict mortality in patients with hematologic malignancies (lymphomas, leukemias, multiple myeloma) who contracted COVID-19. We included 35 adults with COVID-19 confirmed by RT-qPCR performed at diagnosis. We evaluated mortality due to COVID-19 rather than mortality due to the hematologic neoplasm or all-cause mortality. Twenty-seven (27) patients survived and 8 died. The global mean Ct was 22.8 cycles with a median of 21.7. Among the survivors, the mean Ct was 24.2, and the median Ct value was 22.9 cycles. In the deceased patients, the mean Ct was 18.0 and the median Ct value was 17.0 cycles. Using the Wilcoxon Rank Sum test, we found a significant difference (p=0.035). SARS-CoV-2 Ct measured in nasal swabs obtained at diagnosis from patients with hematologic malignancies may be used to predict mortality.

[Skin lesions associated with invasive candidiasis in a neutropenic patient with acute myeloid leukemia]

A 51-year-old male with profound and prolonged neutropenia 12 days after receiving chemotherapy for an acute myeloid leukemia developed a nodular, erythematous lesion with a necrotic center on the base of the neck, associated with fever, chills, and myalgia. An invasive fungal infection was diagnosed after growth of Candia tropicalis in blood cultures. He evolved with multiple reddish papular lesions concentrated mainly on the trunk, although they also spread to the extremities. The most common skin lesions of disseminated candidiasis are erythematous-violaceous papules with vesicular centers, which, in some cases, can progress to necrosis. Other forms of cutaneous presentation of invasive candidiasis are ecthyma gangrenosum-like lesions, hemorrhagic plaques or bullae, rash resembling folliculitis, and subcutaneous nodules.

Descriptive analysis of Cycle Threshold in patients with hematologic malignancies infected with SARS-COV-2

INTRODUCTION

SARS-CoV-2 has caused over 200 million documented infections, more than 4 million deaths, and unprecedented consequences worldwide. The cycle threshold (Ct), the number of amplification cycles required to obtain a product detectable through fluorescence during a quantitative RT-PCR test, is an indirect measurement of viral load. Patients with hematologic malignancies have an increased risk of death by the SARS-CoV-2.

CASES PRESENTATION

We conducted a retrospective, observational, descriptive analysis of the Ct obtained from patients with history of hematologic malignancies who tested positive for SARS-CoV-2 in our hospital, from March 3rd, 2020, to August 17th, 2021. We used the mean Ct at diagnosis. 15 adults, with previous diagnosis of lymphomas, acute leukemias and chronic lymphocytic leukemia, were included. 9 of the 15 patients (60 %) developed pneumonia, 6 of them required supplementary oxygen and 5 mechanical ventilation. 5 patients died between 7-86 days from symptom onset. Ct was lower among the group of patients who died (15.5 cycles; SD= 2.28, CI95%= 9.17-21.86) compared with those who survived (20.2 cycles; SD= 8.87, CI95%= 13.9-26.6). Ct was also lower in the pneumonia group (18.2 cycles; SD= 2.28, CI95%= 12.98-23.51) than in the no-pneumonia group (19.3 cycles; SD= 4.11; CI95%= 8.73-29.9).

DISCUSSION

Ct was lowest in severe forms of CoViD-19. Further studies with larger populations of patients with hematologic malignancies could establish the validity of Ct as a quantitative laboratory determination as a course-prediction and infectivity tool.

Screening for SARS-COV-2 Using RT-qPCR in Patients with Hematologic Neoplasms Receiving Chemotherapy

It has been recommended that patients with leukaemias and lymphomas undergo universal screening for SARS-COV-2 using RT-qPCR before each treatment on the grounds of their high risk of experiencing severe forms of COVID-19. This raises a conflict with different recommendations which prioritise testing symptomatic patients. We found that among 56 RT-qPCR obtained in asymptomatic patients with hematologic neoplasms before chemotherapy administration, 2 (3.5%) were positive. A negative result did not exclude SARS-COV-2 infection in 1 patient (1.8%). It is unclear what the benefit of screening for SARS-COV-2 using RT-qPCR in patients with hematologic neoplasms who receive chemotherapy is.

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

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.