COVID-19 Vaccine Responses in those with Renal Autoimmune Diseases 

September 16, 2022

A study published earlier this week investigated how effective a two-dose SARS-CoV-2 vaccine regimen is for patients receiving Rituximab. Rituximab and other anti-CD20 B-cell depleting therapies lead to “impaired maturation of memory B-cells and reduced numbers of antibody-producing plasma cells.” Researchers measured the humoral and cellular immune responses, which correlate to antibody and T-cell production, respectively. T-cells drive an overall immune response.

The study included 34 patients with autoimmune renal disease – including ANCA vasculitis (64.7%), Focal Segmental Glomerulosclerosis (2.9%), Membranous Glomerulopathy (8.8%), Minimal Change Disease (8.8%), Goodpasture Syndrome (11.8%), and Thrombotic Microangiopathy (11.8%).  COVID-19 vaccines in the study include Pfizer (73.5%), Moderna (2.9%), AstraZeneca (8.8%), and Johnson & Johnson (8.8%). 

Those with a history of prior COVID-19 infection were excluded from the study, as well as those receiving antimetabolite therapies within two months before vaccination. All patients received two doses of the same vaccine besides two patients who received a mixed regimen. 

Amongst the cohort, anti-CD20 therapy was either administered every 6 months as part of a standard regimen or prescribed separately for comorbidities. B-cell counts were measured within 5 weeks prior to vaccination, as well as 12 weeks post-vaccination. A humoral response was detected in 11 (32.4%) patients, and cellular response in 23 patients (92%). “One individual had neither response, while an isolated response was observed in another individual. Kidney function, proteinuria, or hematuria, as well as time spans between first and second vaccinations and the time point of testing after vaccination were not altered between response groups.” Kidney function, proteinuria, and hematuria did not correlate with IgG antibodies or IFN-γ (cytokine) release. 

Patients whose B-cell counts at vaccination correlated with the time from their last Rituximab treatment (having a slight B-cell recovery prior to vaccination) had a significantly higher humoral response. Researchers also found a linear correlation between B-cell counts and IgG antibodies. Patients receiving regular anti-CD20 treatments (every 6 months) had a “significantly lower” B-cell count and IgG antibody levels. This shows a strong correlation between humoral response and B-cell counts in regard to the time interval between last Rituximab treatment and vaccination. 

Researchers did not observe “reduced kidney function to be a statistically significant risk factor for impaired vaccination response. However, parallel studies report reduced response to mRNA SARS-CoV-2 vaccines in subjects with both chronic and end stage renal disease.” There were also no significant differences in the humoral response in patients receiving vaccines amongst the four manufacturers included in the study.