Rituximab-treated patients with lymphoma develop strong CD8 T-cell responses following COVID-19 vaccination

Abstract

B-cell depletion induced by anti-cluster of differentiation 20 (CD20) monoclonal antibody (mAb) therapy of patients with lymphoma is expected to impair humoral responses to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) vaccination, but effects on CD8 T-cell responses are unknown. Here, we investigated humoral and CD8 T-cell responses following two vaccinations in patients with lymphoma undergoing anti-CD20-mAb therapy as single agent or in combination with chemotherapy or other anti-neoplastic agents during the last 9 months prior to inclusion, and in healthy age-matched blood donors. Antibody measurements showed that seven of 110 patients had antibodies to the receptor-binding domain of the SARS-CoV-2 Spike protein 3-6 weeks after the second dose of vaccination. Peripheral blood CD8 T-cell responses against prevalent human leucocyte antigen (HLA) class I SARS-CoV-2 epitopes were determined by peptide-HLA multimer analysis. Strong CD8 T-cell responses were observed in samples from 20/29 patients (69%) and 12/16 (75%) controls, with similar median response magnitudes in the groups and some of the strongest responses observed in patients. We conclude that despite the absence of humoral immune responses in fully SARS-CoV-2-vaccinated, anti-CD20-treated patients with lymphoma, their CD8 T-cell responses reach similar frequencies and magnitudes as for controls. Patients with lymphoma on B-cell depleting therapies are thus likely to benefit from current coronavirus disease 2019 (COVID-19) vaccines, and development of vaccines aimed at eliciting T-cell responses to non-Spike epitopes might provide improved protection.

Keywords: CD8 T-cell response; anti-CD20 antibody; coronavirus disease 2019 (COVID-19) vaccination; humoral response; lymphoma; severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) epitopes.

FIGURE 1

Study flow diagram. Adult patients with CD20‐positive B‐cell lymphoma/leukaemia were recruited at Oslo University Hospital, Akershus University Hospital, Haukeland University Hospital, Stavanger University Hospital, St Olavs University Hospital, and University Hospital of Northern Norway. Participants were undergoing treatment with anti‐CD20 antibody alone or in combination with chemotherapy or other neoplastic agents or had finished such therapies <9 months prior to inclusion. Serum samples (110 patients) and peripheral blood mononuclear cells (PBMC; 29) were analysed for B‐ and T‐cell responses before and after the second dose of severe acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2) vaccination

FIGURE 2

Most rituximab‐treated patients with lymphoma lack antibody responses to Spike or receptor‐binding domain (RBD) after vaccination. (A–D) Relative levels of immunoglobulin G (IgG) antibodies after vaccination to full‐length (FL) Spike from severe acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2) (y‐axis) and the RBD (x‐axis) in patients treated with anti‐CD20 monoclonal antibodies (mAbs) for B‐cell lymphoma (A) or multiple sclerosis (C), compared to healthy controls (B). Relative antibody levels are reported as arbitrary units (au) = (MFI_{viral protein beads})/(MFI_{no protein beads}). Each dot represents one individual. Blue dots indicate sera with antibody levels above the double cut‐off for RBD and FL Spike (au ≥5). (D) Anti‐RBD in patients according to days after last dose of treatment. Orange dots indicate patients on treatment, while grey squares indicate patients where treatment is terminated. MFI, median fluorescence intensity

FIGURE 3

T‐cell responses in vaccinated healthy donors (HD) and patients. (A) Epitope S_269‐277 induces responses of high magnitude in vaccinated individuals after in vitro stimulation. Flow plots show peptide‐HLA (pHLA)‐multimer staining for rituximab (RTX)‐treated patient 91RAD before (T0) and after (T1) vaccination (second strongest responder among RTX‐treated patients) and the HD2 after vaccination (T1; strongest responder among HD controls). (B) Magnitude of CD8 T‐cell responses to six SARS‐CoV‐2 Spike‐specific peptides in RTX‐treated patients and HD. T‐cell responses were determined by pHLA‐multimer staining in HLA‐typed individuals (individual data points with median of responders). ● HD (T1: 3–7 weeks after vaccination; n = 16); Δ RTX‐treated patients (T0: before vaccination, n = 27; T1: 3–6 weeks after vaccination, n = 29). For each peptide the number of responses identified among the number of individuals tested is displayed above the x‐axis. (C) Response distribution among patients after vaccination (T1; left) and HD (T1; right). In the table below the graph, HLA‐type is displayed for each individual. For patients, the treatment regimen (R‐Chemo or not), treatment status (on‐going or completed), and receptor‐binding domain (RBD)‐immunoglobulin G (IgG)‐antibody response (x means no antibody data available) is displayed. (D) Immuno‐prevalence data with exact binomial 95% confidence intervals for every studied epitope in the HD (red) and patient (blue) cohort (Fisher’s exact test p > 0.5). A1, A2 and A3 refer to HLA‐A*01:01, HLA‐A*02:01 and HLA‐A*03:01 respectively