SARS-CoV-2 Ct values and COVID-19 symptoms in patients with haematological malignancies in South Africa

Abstract

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) reverse transcriptase polymerase chain reaction (RT-PCR) cycle threshold (Ct) values serve as surrogate markers for estimating viral load. Their usefulness in patients with haematological malignancies and COVID-19 has not been studied in the South African context.

Objectives: To evaluate if a Ct value < 30 can predict COVID-19 symptom development in adult patients with haematological malignancies.

Method: A retrospective cohort study on adult patients with haematological malignancies and COVID-19 was conducted at Chris Hani Baragwanath Academic Hospital from 01 July 2020 to 31 July 2021. The relationship between Ct values, symptoms and disease severity, along with changes over time were evaluated.

Results: Among 53 patients (50.9% male, median age of 38 years), Ct values < 30 did not significantly predict COVID-19 symptom development (p = 0.417). However, severe disease correlated with lower Ct values (p = 0.002). No significant difference in the duration (days) from positive to negative tests was found between symptomatic and asymptomatic patients, and by severity of disease in the symptomatic patients. Lymphopenia was associated with severe disease, and those with lymphoid malignancies experienced longer viral shedding.

Conclusion: Patients with haematological malignancies can exhibit symptoms at any Ct value but lower Ct values indicate more severe disease. This information can be critical for chemotherapy timing to minimize adverse outcomes.

Contribution: The findings suggest a potential benefit in delaying chemotherapy at any Ct value as patients could present with acute SARS-CoV-2 infection at higher Ct values, and therefore face increased risk of adverse outcomes with early chemotherapy initiation.