Sequential rituximab therapy sustains remission of nephrotic syndrome but carries high risk of adverse effects.

BACKGROUND: Sequential rituximab (RTX) administration has emerged as an important strategy to sustain remission of disease in patients with difficult-to-treat nephrotic syndrome. METHODS: We report the efficacy and safety of sequential therapy with two or more courses of intravenous RTX in 250 patients with difficult-to-treat steroid dependence (n = 127) and calcineurin inhibitor (CNI)-dependent or CNI-refractory steroid resistance (n = 123) managed at one center during 2015-2021. Subsets of patients were cross-sectionally tested for hypogammaglobulinemia, seroprotection against and hyporesponsiveness to vaccines for hepatitis B and tetanus, BK/JC viruria and human antichimeric antibodies (HACAs). RESULTS: Sequential RTX therapy, initiated at a median of 10 years [interquartile range (IQR) 7.3-14.4], was administered for 1.8 courses/person-year [95% confidence interval (CI) 1.7-2.0] over 2.0 years (95% CI 1.2-3.0). Therapy was associated with postponement of relapses by a median of 3 years in patients with steroid-sensitive disease and 2 years in those with steroid resistance. Relapses were reduced by a mean of 2.0 relapses/person-year (95% CI 1.8-2.2), enabling a reduction in prednisolone dose to 0.04 mg/kg/day (95% CI 0.01-0.11) and withdrawal of additional immunosuppression in 154 (62%) patients. RTX-associated adverse events, occurring at 0.20 events/person-year (95% CI 0.17-0.23), were chiefly comprised of infusion reactions (n = 108) and infections (n = 46); serious adverse events were observed in 10.8% patients, at 0.03 events/person-year (95% CI 0.02-0.05). Hypogammaglobulinemia was observed in 35% of 177 patients and was moderate to severe in 8.5% of cases. Rates of seroprotection at baseline and response following vaccination were lower for hepatitis B [1.9% and 29.4% (n = 52)] than tetanus [65.5% and 34.5% (n = 58)]. BK/JC viruria, without viremia, was observed in 7.3% of 109 cases. A total of 19 of 107 patients (17.8%) had HACAs, which were associated with B cell nondepletion and serum sickness. Age at therapy of <9-10 years was associated with a risk of early relapse, treatment failure and hypogammaglobulinemia following RTX therapy. CONCLUSIONS: Sequential therapy with RTX effectively reduces relapses in patients with difficult-to-treat steroid- and/or CNI-dependent or CNI-refractory nephrotic syndrome. Therapy is associated with high rates of hypogammaglobulinemia and infusion reactions.

Rituximab-treated rheumatic patients: B-cells predict seroconversion after COVID-19 boost or revaccination in initial vaccine non-responders.

OBJECTIVES: To investigate the effect of either a booster vaccine (one dose) or revaccination (two doses three weeks apart) on the antibody response to the COVID-19 mRNA vaccines in patients with rheumatic disease (RD) treated with Rituximab (RTX), who had not produced vaccine-reactive antibodies after the initial two vaccine doses. Further, to examine if B cell levels in peripheral blood predicted seroconversion. METHODS: We included 91 RTX-treated RD patients previously vaccinated against COVID-19. Patients were offered revaccination or a single booster vaccination with an mRNA vaccine. Serum total antibodies against SARS-CoV-2 spike protein were measured before and six weeks after the last vaccine dose. B-cells (CD19+CD45+) were measured by flow cytometry at inclusion. RESULTS: Of RD patients with undetectable SARS-CoV-2 antibody levels before inclusion, seroconversion was seen in 38% six weeks after the booster dose and 32% after revaccination. Patients receiving revaccination had significantly higher antibody levels than patients receiving a booster dose (p< 0.001). In both univariate and multivariate logistic regression analysis, only B-cells higher than 10/µL before boost or revaccination were associated with seroconversion (p= 0.009 and p= 0.01, respectively). Seroconversion was independent of age, gender, diagnosis, cumulative RTX dose, RTX treatment time, and time since last RTX treatment. CONCLUSION: Continuously impaired humoral response to mRNA vaccines was found in most RTX treated patients after a booster dose or revaccination. Seroconversion was observed in approximately one-third of the patients. Measurable B-cells before boosting or revaccination was the strongest predictor of antibody response after boost or revaccination.

Humoral and cellular immunity in convalescent and vaccinated COVID-19 people with multiple sclerosis: Effects of disease modifying therapies.

OBJECTIVES: To determine anti-SARS-Cov2 antibodies and T-cell immunity in convalescent people with multiple sclerosis (pwMS) and/or pwMS vaccinated against Covid-19, depending on the disease modifying therapy, and in comparison to healthy controls (HC). METHODS: 75 participants were enrolled: Group 1-29 (38.7%) COVID-19 convalescent participants; Group 2-34 (45.3%) COVID-19 vaccinated; Group 3-12 (16.0%) COVID-19 convalescent participants who were later vaccinated against COVID-19. Cellular immunity was evaluated by determination of number of CD4+ and CD8+ cells secreting TNFα, IFNγ, and IL2 after stimulation with SARS-CoV-2 peptides. RESULTS: pwMS treated with ocrelizumab were less likely to develop humoral immunity after COVID-19 recovery or vaccination. No difference was observed in the cellular immunity in all studied parameters between pwMS treated with ocrelizumab compared to HC or pwMS who were treatment naïve or on first line therapies. These findings were consistent in convalescent, vaccinated, and convalescent+vaccinated participants. COVID-19 vaccinated convalescent pwMS on ocrelizumab compared to COVID-19 convalescent HC who were vaccinated did not show statistically difference in the rate of seroconversion nor titers of SARS-CoV-2 antibodies. CONCLUSION: Presence of cellular immunity in pwMS on B-cell depleting therapies is reassuring, as at least partial protection from more severe COVID-19 outcomes can be expected.

Persistent SARS-CoV-2 infection in patients with secondary antibody deficiency: successful clearance following combination casirivimab and imdevimab (REGN-COV2) monoclonal antibody therapy.

BACKGROUND: There is growing evidence that antibody responses play a role in the resolution of SARS-CoV-2 infection. Patients with primary or secondary antibody deficiency are at increased risk of persistent infection. This challenging clinical scenario is associated with adverse patient outcome and potentially creates an ecological niche for the evolution of novel SARS-CoV-2 variants with immune evasion capacity. Case reports and/or series have implied a therapeutic role for convalescent plasma (CP) to secure virological clearance, although concerns have been raised about the effectiveness of CP and its potential to drive viral evolution, and it has largely been withdrawn from clinical use in the UK. CASE PRESENTATION: We report two cases in which persistent SARS-CoV-2 infection was cleared following administration of the monoclonal antibody combination casirivimab and imdevimab (REGN-COV2, Ronapreve). A 55-year-old male with follicular lymphoma, treated with B cell depleting therapy, developed SARS-CoV-2 infection in September 2020 which then persisted for over 200 days. He was hospitalised on four occasions with COVID-19 and suffered debilitating fatigue and malaise throughout. There was no clinical response to antiviral therapy with remdesivir or CP, and SARS-CoV-2 was consistently detected in nasopharyngeal swabs. Intrahost evolution of several spike variants of uncertain significance was identified by viral sequence analysis. Delivery of REGN-COV2, in combination with remdesivir, was associated with clinical improvement and viral clearance within 6 days, which was sustained for over 150 days despite immunotherapy for relapsed follicular lymphoma. The second case, a 68-year-old female with chronic lymphocytic leukaemia on ibrutinib, also developed persistent SARS-CoV-2 infection. Despite a lack of response to remdesivir, infection promptly cleared following REGN-COV2 in combination with remdesivir, accompanied by resolution of inflammation and full clinical recovery that has been maintained for over 290 days. CONCLUSIONS: These cases highlight the potential benefit of REGN-COV2 as therapy for persistent SARS-CoV-2 infection in antibody deficient individuals, including after failure of CP treatment. Formal clinical studies are warranted to assess the effectiveness of REGN-COV2 in antibody-deficient patients, especially in light of the emergence of variants of concern, such as Omicron, that appear to evade REGN-COV2 neutralisation.

Recovery from COVID-19 in a B-cell-depleted multiple sclerosis patient.

Approximately 200,000 multiple sclerosis (MS) patients worldwide receive B-cell-depleting immunotherapy with rituximab (anti-CD20), which eliminates the ability to generate an antibody response to new infections. As severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific antibodies might help viral clearance, these patients could be at risk of severe complications if infected. Here, we report on an MS patient who had received rituximab for ~3 years. The patient was examined 5 days before the onset of coronavirus disease 2019 (COVID-19) symptoms and was admitted to the hospital 2 days after. She recovered 14 days after symptom onset despite having a 0% B lymphocyte count and not developing SARS-CoV-2 immunoglobulin G (IgG) antibodies.