Project description:Rituximab, a chimeric anti-CD20 monoclonal antibody originally licensed for lymphoma, is emerging as a novel steroid-sparing agent for idiopathic nephrotic syndrome in children. The potential use of anti-CD20 monoclonal antibodies in idiopathic nephrotic syndrome has contributed to shifting the view of podocytopathies from T cell-mediated to more complex immunomediated disorders that can benefit from targeting B cells and other mediators of the early immune response. Clinical data on the use of rituximab also have implications on disease management and classification. In this review, we present results of clinical studies that support rituximab as an effective steroid-sparing agent in steroid-dependent idiopathic nephrotic syndrome. Recent randomized controlled trials suggest that potential benefits of rituximab therapy in steroid-dependent forms of idiopathic nephrotic syndrome vary depending on whether children are dependent on steroids alone or on both steroids and calcineurin inhibitors, with greater probabilities to achieve drug-free remission in the former group. Multiple-drug dependence may identify a different disease state with different prognosis and treatment options. Insufficient data are available on optimal use of rituximab as a maintenance steroid-sparing agent in these steroid-sensitive forms of the disease, including how often and for how long rituximab infusions should be repeated to maximize expected benefits and minimize potential harms. Finally, one randomized controlled trial in children with steroid-resistant idiopathic nephrotic syndrome yielded negative results. New anti-CD20 antibodies are under study in this patient population.
Project description:BackgroundThe chimeric anti-CD20 monoclonal antibody rituximab is effective in steroid-dependent and calcineurin inhibitor-dependent forms of nephrotic syndrome, but many patients relapse at 1 year. Because ofatumumab, a fully human anti-CD20 monoclonal antibody, has a more extended binding site and higher affinity to CD20 compared with rituximab, it might offer superior efficacy in these patients.MethodsWe designed a single-center randomized clinical trial to compare the long-term efficacy of ofatumumab versus rituximab in children and young adults with nephrotic syndrome maintained in remission with prednisone and calcineurin inhibitors. We randomized 140 children and young adults (aged 2-24 years) to receive intravenous ofatumumab (1.50 mg/1.73 m2) or rituximab (375 mg/m2). After infusions, oral drugs were tapered and withdrawn within 60 days. The primary outcome was relapse at 1 year, which was analyzed following the intent-to-treat principle. The secondary endpoint was relapse within 24 months from infusion, on the basis of urine dipstick and confirmed by a urine protein-to-creatinine ratio <200.ResultsAt 12 months, 37 of 70 (53%) participants who received ofatumumab experienced relapse versus 36 of 70 (51%) who received rituximab (odds ratio [OR], 1.06; 95% confidence interval [95% CI], 0.55 to 2.06). At 24 months, 53 of 70 (76%) participants who received ofatumumab experienced relapse, versus 46 of 70 (66%) who received rituximab (OR, 1.6; 95% CI, 0.8 to 3.3). The two groups exhibited comparable B cell subpopulation reconstitution and did not differ in adverse events.ConclusionsA single dose of ofatumumab was not superior to a single dose of rituximab in maintaining remission in children with steroid-dependent and calcineurin inhibitor-dependent nephrotic syndrome.Clinical trial registration numbersClinicalTrials.gov (NCT02394119) and https://www.clinicaltrialsregister.eu/ctr-search/search (2015-000624-28).
Project description:Nephrotic proteinuria is the hallmark of several glomerulonephritis determined by different pathogenetic mechanisms, including autoimmune, degenerative and inflammatory. Some conditions such as Minimal Change Nephropathy (MCN) and Focal Segmental Glomerulosclerosis (FSGS) are of uncertain pathogenesis. Chimeric anti-CD20 monoclonal antibodies have been used with success in a part of proteinuric conditions while some are resistant. New human and humanized monoclonal anti-CD 20 antibodies offer some advantages based on stronger effects on CD20 cell subtypes and have been already administered in hematology and oncology areas as substitutes of chimeric molecules. Here, we revised the literature on the use of human and humanized anti-CD 20 monoclonal antibodies in different proteinuric conditions, resulting effective in those conditions resistant to rituximab. Literature on the use of human anti-CD 20 monoclonal antibodies in different proteinuric diseases is mainly limited to ofatumumab, with several protocols and doses. Studies already performed with ofatumumab given in standard doses of 1,500 mg 1.73m2 suggest no superiority compared to rituximab in children and young adults with steroid dependent nephrotic syndrome. Ofatumumab given in very high doses (300 mg/1.73m2 followed by five infusion 2,000 mg/1.73 m2) seems more effective in patients who are not responsive to common therapies. The question of dose remains unresolved and the literature is not concordant on positive effects of high dose ofatumumab in patients with FSGS prior and after renal transplantation. Obinutuzumab may offer some advantages. In the unique study performed in patients with multidrug dependent nephrotic syndrome reporting positive effects, obinutuzumab was associated with the anti-CD38 monoclonal antibody daratumumab proposing the unexplored frontier of combined therapies. Obinutuzumab represent an evolution also in the treatment of autoimmune glomerulonephritis, such as membranous nephrotahy and lupus nephritis. Results of randomized trials, now in progress, are awaited to add new possibilities in those cases that are resistant to other drugs. The aim of the present review is to open a discussion among nephrologists, with the hope to achieve shared approaches in terms of type of antibodies and doses in the different proteinuric renal conditions.
Project description:AimsAnti-CD20 antibodies are increasingly being used to treat idiopathic nephrotic syndrome (INS) in children. While they may allow steroid and calcineurin inhibitor withdrawal, repeated infusions of anti-CD20 antibodies are often required to maintain remission. Data on their potential toxicity in INS are needed, to consider repeated infusions.MethodsWe investigated the side effects associated with the use of rituximab (a chimeric antibody; 130 patients) and ofatumumab (a humanized antibody; 37 patients) in children with INS (steroid-dependent and steroid/calcineurin inhibitor-dependent disease) treated at a national referral centre over a 9-year period (400 treatments; follow-up 1-9 years).ResultsInfusion reactions were mainly absent in children with steroid-dependent disease. Rash, dyspnoea, fever, cough and itchy throat (5% and 18% following rituximab and ofatumumab infusion, respectively) were resolved by using premedication with salbutamol. Other short-term reactions (up to 3 months), including arthritis (2%) and lung injury (1%), were more common with rituximab. Infections were observed 3-9 months following infusion, were similarly common in the two groups and resolved with targeted therapies [antibiotic, fluconazole, immunoglobulins (Igs), etc.]. The number of circulating CD19/20 cells fell to 0 at month 1 and were reconstituted at month 3; circulating IgG antibodies remained within the normal range for 1 year. Tetanus and hepatitis B virus immunization was not modified by either treatment; Epstein-Barr virus and John Cunningham virus activation markers were occasionally observed.ConclusionOverall, the toxicity of anti-CD20 monoclonal antibodies was limited to post-infusion side effects in children with more complex disease. The relatively safe profile of anti-CD20 antibodies supports their use as steroid-sparing agents in children with INS.
Project description:Anti-CD20 therapy is effective in idiopathic nephrotic syndrome (INS). However, transient or sustained hypogammaglobulinemia predisposing to an increased risk of infectious diseases can follow treatment in some patients. We analyzed the long-term effects of anti-CD20 therapy on immunological memory in 27 frequently-relapsing/steroid-dependent INS pediatric patients after more than 4 years from the first and at least 2 years from the last anti-CD20 infusion. Twenty-one INS children, never treated with anti-CD20 and under an intense oral immunosuppression with prednisone, mycophenolate mofetil, and calcineurin inhibitors were also included as control group. Levels of circulating B-cell subpopulations, total serum immunoglobulins and IgG and memory B cells directed against hepatitis B virus (HBV) and tetanus were determined and correlated with clinical characteristics. Nine patients never relapsed after more than 2 years from the last anti-CD20 administration (5 after the first, 3 after the second, and 1 after the fifth infusion). At last follow-up, most patients showed a complete recovery and normalization of total (27/27), transitional (27/27), and mature-naïve B cells (25/27). However, a sustained and significant reduction of total memory (20/27) and switched memory (21/27) B cells was found in most patients. 11/27 patients showed hypogammaglobulinemia at last follow-up and, among these, four presented with a severe hypogammaglobulinemia (IgG < 160 mg/dl). In contrast, no patient in the control group developed a severe hypogammaglobulinemia. Age at the time of first anti-CD20 administration was positively associated with IgG levels at last follow-up (p = 0.008); accordingly, younger patients had an increased risk of hypogammaglobulinemia (p = 0.006). Furthermore, severe hypogammaglobulinemia and delayed switched memory B-cell reconstitution were more frequent in non-relapsing patients. Reduced IgG levels against HBV and tetanus were observed at baseline and further declined at last follow-up. Antigen-specific memory B-cells were induced by re-immunization, but specific IgG titers remained low. In conclusion, anti-CD20 therapy can be disease-modifying in some INS patients. However, a prolonged impairment of immunological memory occurs frequently, independently from the number of anti-CD20 infusions, particularly in younger patients. Re-immunization may be necessary in these patients.
Project description:BackgroundThe aim of the current PodoNet registry analysis was to evaluate the outcome of steroid-resistant nephrotic syndrome (SRNS) in children who were not treated with intensified immunosuppression (IIS), focusing on the potential for spontaneous remission and the role of angiotensin blockade on proteinuria reduction.MethodsNinety-five pediatric patients who did not receive any IIS were identified in the PodoNet Registry. Competing risk analyses were performed on 67 patients with nephrotic-range proteinuria at disease onset to explore the cumulative rates of complete or partial remission or progression to kidney failure, stratified by underlying etiology (genetic vs. non-genetic SRNS). In addition, Cox proportional hazard analysis was performed to identify factors predicting proteinuria remission.ResultsEighteen of 31 (58.1%) patients with non-genetic SRNS achieved complete remission without IIS, with a cumulative likelihood of 46.2% at 1 year and 57.7% at 2 years. Remission was sustained in 11 children, and only two progressed to kidney failure. In the genetic subgroup (n = 27), complete resolution of proteinuria occurred very rarely and was never sustained; 6 (21.7%) children progressed to kidney failure at 3 years. Almost all children (96.8%) received proteinuria-lowering renin-angiotensin-aldosterone system (RAAS) antagonist treatment. On antiproteinuric treatment, partial remission was achieved in 7 of 31 (22.6%) children with non-genetic SRNS and 9 of 27 children (33.3%) with genetic SRNS.ConclusionOur results demonstrate that spontaneous complete remission can occur in a substantial fraction of children with non-genetic SRNS and milder clinical phenotype. RAAS blockade increases the likelihood of partial remission of proteinuria in all forms of SRNS. A higher resolution version of the Graphical abstract is available as Supplementary information.
Project description:Multisystem Inflammatory Syndrome in Children (MIS-C) is a delayed-onset, COVID-19-related hyperinflammatory illness characterized by SARS-CoV-2 antigenemia, cytokine storm, and immune dysregulation. In severe COVID-19, neutrophil activation is central to hyperinflammatory complications, yet the role of neutrophils in MIS-C is undefined. Here, we collect blood from 152 children: 31 cases of MIS-C, 43 cases of acute pediatric COVID-19, and 78 pediatric controls. We find that MIS-C neutrophils display a granulocytic myeloid-derived suppressor cell (G-MDSC) signature with highly altered metabolism, distinct from the neutrophil interferon-stimulated gene (ISG) response we observe in pediatric COVID-19. Moreover, we observe extensive spontaneous neutrophil extracellular trap (NET) formation in MIS-C, and we identify neutrophil activation and degranulation signatures. Mechanistically, we determine that SARS-CoV-2 immune complexes are sufficient to trigger NETosis. Our findings suggest that the hyperinflammatory presentation during MIS-C could be mechanistically linked to persistent SARS-CoV-2 antigenemia, driven by uncontrolled neutrophil activation and NET release in the vasculature.
Project description:Although most autoimmune diseases are considered to be CD4 T cell- or antibody-mediated, many respond to CD20-depleting antibodies that have limited influence on CD4 and plasma cells. This includes rituximab, oblinutuzumab and ofatumumab that are used in cancer, rheumatoid arthritis and off-label in a large number of other autoimmunities and ocrelizumab in multiple sclerosis. Recently, the COVID-19 pandemic created concerns about immunosuppression in autoimmunity, leading to cessation or a delay in immunotherapy treatments. However, based on the known and emerging biology of autoimmunity and COVID-19, it was hypothesised that while B cell depletion should not necessarily expose people to severe SARS-CoV-2-related issues, it may inhibit protective immunity following infection and vaccination. As such, drug-induced B cell subset inhibition, that controls at least some autoimmunities, would not influence innate and CD8 T cell responses, which are central to SARS-CoV-2 elimination, nor the hypercoagulation and innate inflammation causing severe morbidity. This is supported clinically, as the majority of SARS-CoV-2-infected, CD20-depleted people with autoimmunity have recovered. However, protective neutralizing antibody and vaccination responses are predicted to be blunted until naive B cells repopulate, based on B cell repopulation kinetics and vaccination responses, from published rituximab and unpublished ocrelizumab (NCT00676715, NCT02545868) trial data, shown here. This suggests that it may be possible to undertake dose interruption to maintain inflammatory disease control, while allowing effective vaccination against SARS-CoV-29, if and when an effective vaccine is available.
Project description:Purpose: This study aims to characterize the early innate and adaptive responses induced by SARS-CoV-2 infection in children and adults over time up to 8 weeks post symptoms onset (POS). We report the gene signature of COVID-19 over the course of the disease in both age groups. The kinetic of infection was divided in 5-time intervals according to the calculated days POS: interval 1 (0-5), interval 2 (6-14), interval 3 (15-22), interval 4 (23-35), and interval 5 (36-81). Methods: RNA extraction was performed automatically via the PAXgene Blood miRNA Kit and the QIAcube instrument (Qiagen) following the manufacturer’s protocol. RNA concentration and quality were assessed by using the Qubit instrument (Invitrogen) and the Agilent 2100 Bioanalyzer, respectively. The Stranded Total RNA Ribo-Zero Plus kit from Illumina was used for the library preparation with 100 ng of total RNA as input. Library molarity and quality were assessed with the Qubit and Tapestation using a DNA High sensitivity chip (Agilent Technologies). Libraries were pooled at 2 nM for clustering and sequenced on an Illumina HiSeq 4000 sequencer for a minimum of 30 million single-end 100 reads per sample. Main results: (I) we observed an antiviral-IFN-signature and innate-cell-activation within the first 5 days post symptoms onset (POS), while genes associated with CD4 T-cell responses, plasma cells and immunoglobulin were upregulated in both age groups during the first two weeks POS, indicative of SARS-CoV-2-specific adaptive immune responses; (II) in adults, genes associated with IFN antiviral responses and activated dendritic cells were maintained during the second week of disease, and subsided only after 14 days. By contrast, those transcriptome changes subsided already after 5 days in children.