Timing of rituximab treatment and immunoglobulin (Ig) levels may be associated with an increased risk for COVID)-19-related death in patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV), according to a research letter published in Rheumatology.
Several studies have suggested that rituximab, an anti-CD20 therapy approved for remission induction of AAV, may be associated with increased risk for severe COVID-19.
In the current research letter, the authors assessed the effect of timing of rituximab and the level of baseline immunoglobulins on risk for COVID-19-related death in patients with AAV.
Study authors evaluated 100 patients (53 women); 56 patients had a diagnosis of granulomatosis with polyangiitis, 31 had granulomatosis eosinophilic with polyangiitis, and 13 had microscopic polyangiitis. Infection with SARS-CoV-2 was diagnosed in 2 patients (2%); however, study authors observed that the incidence of infection rate was higher in the general population of the same geographic area (6.3%). Both patients with SARS-CoV-2 received rituximab as remission maintenance.
The first patient was a 73-year-old woman who received the last rituximab infusion on November 9, 2020, and her IgG level was 456 mg/dL before the infusion. She was diagnosed with COVID-19 on December 24, 2020 (45 days after the last rituximab infusion). At the time of diagnosis, the patient was B-depleted and IgG level was 455 mg/dL. The patient was admitted to the intensive care unit, and during the course of treatment no anti-SARS-CoV-2 IgM or IgG production above the cutoff was observed. The patient died on January 17, 2021.
The second patient was a 74-year-old woman who received the last rituximab infusion on August 17, 2020, with a diagnosis of COVID-19 made on November 25, 2020 (100 days after the last rituximab infusion). The patient was asymptomatic and testing was performed because of her contact with a COVID-19-confirmed patient. At the time of COVID-19 diagnosis, the patient’s IgG levels was 866 mg/dL, and during the follow-up, low levels of anti-SARS-CoV-2 IgG antibodies were detected.
As limitations, the authors noted that the timing of rituximab and IgG levels were different between the 2 patients, which may have had a significant effect on the outcomes, and the fact that information about SARS-CoV-2 viral load was not available for the study.
“[W]hile patients [with AAV] do not appear at higher risk [for] COVID-19 than the general population, those patients undergoing anti-CD20 therapy could be at higher risk of developing critically ill COVID-19. Thus, patients needing RTX [rituximab] require prioritization for SARS-CoV-2 vaccination,” the authors concluded.
Quartuccio L, Treppo E, Binutti M, Del Frate G, De Vita S. Timing of rituximab and immunoglobulin level influence the risk of death for COVID-19 in ANCA-associated vasculitis. Letter. Rheumatology (Oxford). Published online 20 February, 2021. doi:10.1093/rheumatology/keab175