ABSTRACT
OBJECTIVE: To evaluate humoral and T-cell cellular-mediated immune response after three doses of SARS-CoV-2 mRNA vaccines in patients with systemic lupus erythematosus (SLE) under Belimumab. PATIENTS AND METHODS: 12 patients on Belimumab and 13 age-matched healthy volunteers were recruited. Patients were in remission or in low disease activity, and they were taking no corticosteroids or only low doses. None of the patients and controls had detectable anti-SARS-CoV-2 antibodies due to previous exposure to the virus. All the patients received three doses of mRNA anti-SARS-CoV-2 vaccines and the humoral and cellular-mediated response were tested 4 weeks after the second dose (T0), 6 months after the second dose (T1) and 4 weeks after the third dose (T2). Comparison with the control group was performed at time T0 (i.e., 4 weeks after the second dose). Total anti-SARS-CoV-2 RBD antibodies were analyzed using a diagnostic assay, while cellular-mediated response was evaluated using the interferon-gamma release assay (IGRA). RESULTS: A humoral response was documented in all the patients at T0 (median 459; IQR 225.25-758.5), but the antibody titer significantly declined from T0 to T1 (median 44.7; IQR: 30.3-202; p = 0.0066). At T2, the antibody titer significantly increased from T1 (median 2500; IQR: 2500-2500), and it was not different from T0 (respectively p < 0.0001, p = 0.66). Cellular-mediated response significantly declined from T0 to T1 (p = 0.003) but not from T0 to T2 (p = 0.3). No differences were found between patients and controls at T0 as regards both humoral and cellular responses (p = 1.0 and p = 0.09 for humoral and cellular responses, respectively). CONCLUSION: The third dose of mRNA COVID-19 vaccine can restore both humoral and cellular immune response in SLE patients on Belimumab.
ABSTRACT
OBJECTIVE: To evaluate B-cell- and T-cell-mediated immune response to SARS-CoV-2 mRNA vaccination in patients with complex or rare systemic autoimmune diseases previously been treated with or under continuous treatment with B-cell-targeted therapies including rituximab (RTX) and belimumab (BEL). MATERIALS AND METHODS: Twenty-eight consecutive patients receiving RTX (n = 11) or BEL (n = 17) treatment and 13 age-/sex-matched controls (non-rheumatic healthcare personnel) were recruited. None of the patients had detectable anti-SARS-CoV-2 antibodies caused by prior exposure to the virus. All the patients and controls received mRNA vaccines and were tested three to four weeks after completion of vaccination. In all the RTX patients, vaccination was started within 5 months from the last infusion, and B-cell depletion was confirmed in all but one of them. Total anti-SARS-CoV-2 RBD antibodies were analyzed using a diagnostic assay, while T-cell response was evaluated using the interferon-gamma release assay (IGRA). Further, SARS-CoV-2 pseudoviruses were employed to verify the strain-specific neutralizing capacity of the antibodies. RESULTS: Detectable anti-SARS-CoV-2 antibodies were documented in 1 out of the 11 RTX patients and 16 of the 17 BEL patients. The median concentration in the RTX and BEL patients was significantly lower than that in the controls (39.6 AU/ml vs. 1133 AU/ml, p = 0.002). The result of IGRA was positive in 8 of the 11 (72.7%) RTX patients and 16 of the 17 (94.1%) BEL patients, and interferon release in both the RTX and BEL patients was comparable to that in the control participants. CONCLUSION: B-cell-targeted therapies do not preclude SARS-CoV-2 vaccination, since virus-specific cellular immunity can be induced even in the absence of circulating B cells. An important finding was that lupus patients treated with BEL developed immune responses to SARS-CoV-2; this indicates retention of the immunogenicity of the COVID-19 vaccine.