An international team of researchers have identified three risk factors that they say are significantly associated with a worse prognosis in CLL patients with COVID-19.

Older age, history of cardiac failure and CLL treatment were the key risk factors for COVID-19-related fatality, according to the retrospective study published in the journal Leukaemia.

The study included 941 patients with CLL and confirmed COVID-19, with data collected from the beginning of the pandemic until March 16 this year from 91 global centers.

In total, the case fatality rate for all patients was 27.3% (257/941), with the vast majority of deaths occurring in patients with severe COVID-19 (236/617).

In the multivariate model, age (OR 1.04), hypogammaglobulinemia (1.69) and coronary artery disease (2.83) were found to be statistically significant risk factors for COVID-19 severity, while age (OR 1.04), cardiac failure (3.82) and treatment in the prior 12 months (2.13) were risk factors for COVID-19-related mortality.

The researchers also found that the severity of COVID-19 was not affected by any CLL treatment. However, treated patients (in any treatment category) had a worse overall survival (OS) when compared to those who were untreated, with a 46% lower risk of death (based on a hazard ratio of 0.54).

Also, dexamethasone and tocilizumab were the only treatments that showed a mortality benefit in CLL patients with COVID-19. “The impact of COVID-19 treatments in our cohort was not among the objectives, with information on the administered treatment for COVID-19 missing at least in part. Nonetheless, we observed that different types of therapies against COVID-19 did not affect the CFR,” the researchers noted.

The researchers concluded that “taken together, our findings suggest that in patients with CLL and COVID-19, older age confers a worse prognosis, with increased mortality,” and that “untreated patients had a better chance of survival than those on treatment or recently treated”.