A recent study posted to the Preprints with The Lancet* server assessed the clinical outcomes in patients hospitalized with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections, who were previously treated with B-cell depletion therapy.
Various therapy approaches target B cells or B lymphocytes to treat indications ranging from rheumatologic diseases to malignancy. However, patients treated with similar therapies are rendered with a weak immune system which could potentially increase their risk of coronavirus disease 2019 (COVID-19) severity.
About the study
The present study compared the outcomes of hospitalized COVID-19 patients with a history of prior B-cell depleting therapy with matched patients to assess the impact of B-cell depletion on SARS-CoV-2 outcomes.
The team gathered the inpatient and outpatient clinical records of COVID-19 patients. Patients eligible for the study were treated in the Johns Hopkins health system between 1 March 2020 and 30 November 2021. The team identified patients who had previously received B-cell depletion therapy and were subsequently hospitalized after a laboratory-confirmed COVID-19 diagnosis. Treatment therapy for B-cell depletion included drugs like rituximab, obinutuzumab, ocrelizumab, ibritumomab, ofatumumab, and some generic formulations.
The control population consisted of patients who had not undergone B-cell depletion therapy and who were matched with the study patients based on variables like age, the timing of hospitalization, gender, race, the severity of disease, and type of COVID-19 therapy.
The primary outcome of the study was the duration from hospital admission to the death of the patient. The secondary outcome was the duration from hospital admission to a compound manifestation of severe illness or death of the patient. Patients who received a discharge from the hospital were monitored for 30 days post-discharge.
Another outcome of the study was the duration of clinical improvement from the admission of the patient. This clinical improvement is represented by a 2-point reduction in the World Health Organization (WHO) severity score or the discharge of the patient from the hospital within 30 days.
According to the WHO severity scale, a score of 6 and above indicated severe illness while the highest score noted in the first 12 hours of patient admission defined disease severity at admission. A lack of clinical improvement was monitored on the last day of the follow-up or at 30 days, whichever occurred first, while the death of the patient was censored at 30 days.
A prespecified subgroup analysis was also performed to assess the impact of B-cell depletion treatment on COVID-19 patients within 90 days before COVID-19 hospitalization.
The study results showed that 50 patients eligible for the study had a history of receiving B-cell depletion therapy and were COVID-19 positive. A total of 212 patients with SARS-CoV-2 infection but no B-cell depletion therapy exposure were selected as the control group.
A 30-day mortality rate of 6% was found in patients with a history of receiving B-cell depletion therapy as compared to 4.2% in the control cohort. The time to the manifestation of severe illness or death in the B-cell depletion group since hospital admission was 2.4 days and 2.1 days in the control group. Also, patients with a history of B-cell depletion treatment required a longer time to show clinical improvement as compared to the control group; the median time taken by the B-cell depleted group for clinical improvement was 6.3 days, and that by the control cohort was 4.1 days.
Subgroup analysis performed within 90 days of hospitalization of the B-cell depleted group for COVID-19 also showed that these patients required 6.3 days to exhibit clinical improvement while the control cohort required 4.1 days.
The study findings showed that patients with a history of receiving B-cell depletion therapy experienced longer durations of COVID-19-related hospitalizations; however, no significant difference was observed in their mortality rates as compared to the control patients.
The researchers believe that close clinical monitoring and hospitalization of such individuals can help them receive B-cell depleting therapies amid the SARS-CoV-2 pandemic. Extensive research on the impact of SARS-CoV-2 vaccination on COVID-19 disease outcomes, the efficiency of prophylactic treatment with tixagevimab and cilgavimab, and the effect of emerging SARS-CoV-2 variants on the outcomes is essential to provide sufficient protection to this population.
Preprints with The Lancet publish preliminary scientific reports that are not peer-reviewed and, therefore, should not be regarded as conclusive, guide clinical practice/health-related behavior, or treated as established information.