Risk factors of impaired humoral response to COVID-19 vaccination in rituximab treated patients.

ABSTRACT:

Objective

To identify which factors influence humoral response to COVID-19 vaccination in RTX-treated patients.

Methods

Observational prospective usual care study including consecutive patients with inflammatory rheumatic diseases in maintenance therapy with RTX. All patients received a two-dose regimen COVID-19 vaccination. Serum IgG antibody levels against SARS-CoV-2 spike proteins were measured at the time of the new RTX infusion.

Results

From the recruited patients, 16/45 (36%) produced antibodies reaching the assay cut-off value of 15 AU/ml and 29/45 (64%) had a negative serology. Within RTX treated patients, 25 (56%) had undetectable B cells. Negative serology was associated with undetectable B cells (24/25 vs 5/20, p< 0.001). Moreover, SARS-CoV-2 spike antibodies correlated with CD19 counts (r = 0.86, p< 0.001). The effect of RTX and Methotrexate was additive in terms of seroconversion rates (23% vs 50% in patients receiving RTX in monotherapy, p= 0.12) and SARS-CoV-2 spike antibody levels (3.80 AU/ml, 95% confidence interval, CI 3.80-7.50 AU/ml vs 75 AU/ml, 95% CI 3.8-353 AU/ml in patients receiving RTX in monotherapy p= 0.025). Multivariate analyses including demographics, disease characteristics, gammaglobulin levels, RTX and other therapies used, CD19 counts, and the time between the last RTX infusion and vaccination, identified detectable B cells as the only variable independently associated with seropositivity (Odds ratio: 35.2, 95% CI: 3.59-344.20).

Conclusions

B cell depletion is the main independent contributing factor of antibody response to SARS-COV-2 vaccination in RTX treated patients. Monitoring CD19 may be of interest to identify the most appropriate period to perform vaccination.

SUBMITTER: Avouac J 

PROVIDER: S-EPMC8689920 | biostudies-literature |

REPOSITORIES: biostudies-literature