Hypogammaglobulinemia after rituximab for rheumatoid arthritis is not rare and is related with good response: 13 years real-life experience

Hypogammaglobulinaemia during rituximab treatment in multiple sclerosis: A Swedish cohort study

BACKGROUND AND PURPOSE

Mechanisms behind hypogammaglobulinaemia during rituximab treatment are poorly understood.

METHODS

In this register-based multi-centre retrospective cohort study of multiple sclerosis (MS) patients in Sweden, 2745 patients from six participating Swedish MS centres were identified via the Swedish MS registry and included between 14 March 2008 and 25 January 2021. The exposure was treatment with at least one dose of rituximab for MS or clinically isolated syndrome, including data on treatment duration and doses. The degree of yearly decrease in immunoglobulin G (IgG) and immunoglobulin M (IgM) levels was evaluated.

RESULTS

The mean decrease in IgG was 0.27 (95% confidence interval 0.17-0.36) g/L per year on rituximab treatment, slightly less in older patients, and without significant difference between sexes. IgG or IgM below the lower limit of normal (<6.7 or <0.27 g/L) was observed in 8.8% and 8.3% of patients, respectively, as nadir measurements. Six out of 2745 patients (0.2%) developed severe hypogammaglobulinaemia (IgG below 4.0 g/L) during the study period. Time on rituximab and accumulated dose were the main predictors for IgG decrease. Previous treatment with fingolimod and natalizumab, but not teriflunomide, dimethyl fumarate, interferons or glatiramer acetate, were significantly associated with lower baseline IgG levels by 0.80-1.03 g/L, compared with treatment-naïve patients. Switching from dimethyl fumarate or interferons was associated with an additional IgG decline of 0.14-0.19 g/L per year, compared to untreated.

CONCLUSIONS

Accumulated dose and time on rituximab treatment are associated with a modest but significant decline in immunoglobulin levels. Previous MS therapies may influence additional IgG decline.

Association between hypogammaglobulinaemia and severe infections during induction therapy in ANCA-associated vasculitis: from J-CANVAS study

OBJECTIVES

To investigate the association between decreased serum IgG levels caused by remission-induction immunosuppressive therapy of antineutrophil cytoplasmic antibody-associated vasculitis (AAV) and the development of severe infections.

METHODS

We conducted a retrospective cohort study of patients with new-onset or severe relapsing AAV enrolled in the J-CANVAS registry, which was established at 24 referral sites in Japan. The minimum serum IgG levels up to 24 weeks and the incidence of severe infection up to 48 weeks after treatment initiation were evaluated. After multiple imputations for all explanatory variables, we performed the multivariate analysis using a Fine-Gray model to assess the association between low IgG (the minimum IgG levels <500 mg/dl) and severe infections. In addition, the association was expressed as a restricted cubic spline (RCS) and analysed by treatment subgroups.

RESULTS

Of 657 included patients (microscopic polyangiitis, 392; granulomatosis with polyangiitis, 139; eosinophilic granulomatosis with polyangiitis, 126), 111 (16.9%) developed severe infections. The minimum serum IgG levels were measured in 510 patients, of whom 77 (15.1%) had low IgG. After multiple imputations, the confounder-adjusted hazard ratio of low IgG for the incidence of severe infections was 1.75 (95% confidence interval: 1.03-3.00). The RCS revealed a U-shaped association between serum IgG levels and the incidence of severe infection with serum IgG 946 mg/dl as the lowest point. Subgroup analysis showed no obvious heterogeneity between treatment regimens.

CONCLUSION

Regardless of treatment regimens, low IgG after remission-induction treatment was associated with the development of severe infections up to 48 weeks after treatment initiation.

Corticosteroid-induced low immunoglobulin levels in multiple sclerosis - A confounding factor

BACKGROUND

Changes in immunoglobulin (Ig) levels may occur in association with various drugs targeting immunity, including those used to treat multiple sclerosis (MS). However, influence of high-dose corticosteroids (CS) is poorly described.

OBJECTIVE

To describe influence of disease-modifying drugs (DMD) and CS on the Ig levels.

METHODS

Monocentric retrospective study examining changes in Ig levels in relation with CS intake in a series of 304 consecutive MS patients (and 1204 samples) followed or hospitalized for 7 years in a single centre. Ig levels are routinely collected in MS patients followed in our centre.

RESULTS

IgG levels were significantly lower in MS patients exposed to CS infusion during the last 24 months. IgG levels were also lower in DMD-treated patients exposed to CS. DMD-specific decrease of IgM levels was confirmed in interaction with CS.

CONCLUSION

Stratification by CS exposure suggested that a decrease in Ig levels occurring during DMD treatment was strongly associated with CS infusion. The strong and persistent effect of CS on Ig levels could be a hidden variable and should be considered in further studies targeting Ig levels.

Infection Risk, Mortality, and Hypogammaglobulinemia Prevalence and Associated Factors in Adults Treated with Rituximab: A Tertiary Care Center Experience

BACKGROUND

Rituximab is a human monoclonal antibody directed against the B-cell transmembrane protein CD20. Although well-tolerated, given its mechanism of action, rituximab can induce a state of severe immunosuppression, increasing the risk of opportunistic and fulminant infection and mortality.

AIM

To evaluate the risk of infection, mortality, and hypogammaglobulinemia and their associated factors among rituximab receivers.

METHOD

This was a single-center retrospective cohort study of adults treated with rituximab for various indications. Hypogammaglobulinemia was defined by a cut-off value below the normal limit (an IgG level of <7.51 g/L, an IgM level of <0.46 g/L, and/or an IgA level of <0.82 g/L). Patients who met the definition of hypogammaglobinemia solely based on IgA were excluded. Severe infection was defined as any infection that required intensive care unit admission.

RESULTS

A total of 137 adults with a mean age of 47.69 ± 18.86 years and an average BMI of 28.57 ± 6.55 kg/m2 were included. Hematological malignancies and connective tissue diseases were the most common primary diagnoses for which rituximab was used. More than half of the patients received the 375 mg/m2 dose. Rituximab's mean cumulative dose was 3216 ± 2282 mg, and the overall mortality rate was 22.6%. Hypogammaglobulinemia was diagnosed in 43.8% of the patients, and it was significantly more prevalent among males and the 375 mg/m2 and 500 mg doses. Hematological malignancy was the only predictor for infection. Patients with blood type AB or B, hematological malignancies, and corticosteroids had a significantly higher mortality rate. Receiving the 1000 mg dose and having a low CD19 were associated with a significantly lower risk of infection and mortality, respectively.

CONCLUSIONS

Hypogammaglobulinemia was diagnosed in 43.8% of the patients, and it was significantly more common among males and the 375 mg/m2 and 500 mg doses. Hematological malignancies were significantly associated with higher infection and mortality rates, while corticosteroids were significantly associated with a higher mortality. Since the culprit of mortality was infection, these findings highlight the critical need for more frequent immunological monitoring during rituximab treatment period to mitigate the burden of infection and identify candidates for immunoglobulin replacement.

Assessing Sustained B-Cell Depletion and Disease Activity in a French Multiple Sclerosis Cohort Treated by Long-Term IV Anti-CD20 Antibody Therapy

Few studies have investigated sustained B-cell depletion after long-term intravenous (IV) anti-CD20 B-cell depleting therapy (BCDT) in multiple sclerosis (MS) with respect to strict and/or minimal disease activity. The main objective of this study was to investigate how sustained B-cell depletion after BCDT influences clinical and radiological stability as defined by "no evidence of disease activity" (NEDA-3) and "minimal evidence of disease activity" (MEDA) status in MS patients at 12 and 18 months. Furthermore, we assessed the frequency of serious adverse events (SAE), and the influence of prior lymphocytopenia-inducing treatment (LIT) on lymphocyte subset counts and gammaglobulins in MS patients receiving long-term BCDT. We performed a retrospective, prospectively collected, study in a cohort of 192 MS patients of all clinical phenotypes treated by BCDT between January 2014 and September 2021. Overall, 84.2% and 96.9% of patients attained NEDA-3 and MEDA status at 18 months, respectively. Sustained CD19+ depletion was observed in 85.8% of patients at 18 months. No significant difference was observed when comparing patients achieving either NEDA-3 or MEDA at 18 months and sustained B-cell depletion. Compared to baseline levels, IgM and IgG levels on BCDT significantly decreased at 6 months and 30 months, respectively. Patients receiving LIT prior to BCDT showed significant CD4+ lymphocytopenia and lower IgG levels compared to non-LIT patients. Grade 3 or above SAEs were rare. As nearly all patients achieved MEDA at 18 months, we suggest tailoring IV BCDT after 18 months given the occurrence of lymphocytopenia, hypogammaglobulinemia, and SAE after this time point.

Hypogammaglobulinemia, late-onset neutropenia, and infections following rituximab

Rituximab is a chimeric anti-CD20 monoclonal antibody that targets CD20-expressing B lymphocytes, has a well-defined efficacy and safety profile, and is broadly used to treat a wide array of diseases. In this review, we cover the mechanism of action of rituximab and focus on hypogammaglobulinemia and late-onset neutropenia-2 immune effects secondary to rituximab-and subsequent infection. We review risk factors and highlight key considerations for immunologic monitoring and clinical management of rituximab-induced secondary immune deficiencies. In patients treated with rituximab, monitoring for hypogammaglobulinemia and infections may help to identify the subset of patients at high risk for developing poor B cell reconstitution, subsequent infections, and adverse complications. These patients may benefit from early interventions such as vaccination, antibacterial prophylaxis, and immunoglobulin replacement therapy. Systematic evaluation of immunoglobulin levels and peripheral B cell counts by flow cytometry, both at baseline and periodically after therapy, is recommended for monitoring. In addition, in those patients with prolonged hypogammaglobulinemia and increased infections after rituximab use, immunologic evaluation for inborn errors of immunity may be warranted to further risk stratification, increase monitoring, and assist in therapeutic decision-making. As the immunologic effects of rituximab are further elucidated, personalized approaches to minimize the risk of adverse reactions while maximizing benefit will allow for improved care of patients with decreased morbidity and mortality.

Long-term Outcomes After Rituximab Treatment for Patients With Systemic Sclerosis: Follow-up of the DESIRES Trial With a Focus on Serum Immunoglobulin Levels

Importance

Rituximab is emerging as a promising therapeutic option for systemic sclerosis (SSc), but its long-term outcomes and response markers are unknown.

Objective

To evaluate the long-term outcomes after rituximab treatment for SSc and identify potential response markers.

Design, Setting, and Participants

In this single-center cohort study, patients with SSc who continued to receive rituximab after the DESIRES trial were analyzed with a median follow-up of 96 weeks. Among the 43 patients who completed the DESIRES trial, 31 continued to receive rituximab, of which 29 with complete data were included in this study.

Exposures

Rituximab treatment.

Main Outcomes and Measures

A post hoc analysis of the clinical and laboratory data.

Results

In 29 patients with SSc (27 female [93%]; median [IQR] age, 48 [35-45] years), significant improvement in modified Rodnan skin score (MRSS) and percentage of predicted forced vital capacity (FVC%) were observed after 1 (median [IQR] change in MRSS, -7 [-8.5 to -4]; P < .001) and 3 (median [IQR] change in FVC% predicted, 1.85 [0.13-5.68]; P < .001) courses of rituximab, respectively, both of which were sustained during follow-up. High responders (MRSS improvement of ≥9; n = 16) experienced a greater decrease in serum levels of IgG (median [IQR] change in IgG, -125 [-207 to -83] vs 7 [-120 to 43]; P = .008) and IgA (median [IQR] change in IgA, -45 [-96 to -32] vs -11 [-20 to 3]; P < .001) compared with low responders (MRSS improvement of ≤8; n = 13). In particular, decrease in serum IgA levels significantly correlated with the improvement in MRSS (r = 0.64; P < .001). At the last follow-up, low IgM, low IgA, and low IgG was observed in 7, 1, and 1 patient, respectively, of which low IgM was associated with greater improvement in FVC% predicted (median [IQR] change in FVC% predicted, 7.2 [3.8-8.9] vs 3.6 [1.4-6.2]; P = .003).

Conclusions and Relevance

In this cohort study, rituximab treatment was associated with significantly improved skin and lung fibrosis in SSc in a long-term follow-up. Decrease in serum immunoglobulins was associated with greater clinical response.

Acquired B-cell deficiency secondary to B-cell-depleting therapies

The advantage of the newer biological therapies is that the immunosuppressive effect is targeted, in contrast, to the standard, traditional immunomodulatory agents, which have a more global effect. However, there are unintended targets and consequences, even to these "precise" therapeutics, leading to acquired or secondary immunodeficiencies. Besides depleting specific cellular immune subsets, these biological agents, which include monoclonal antibodies against biologically relevant molecules, often have broader functional immune consequences, which become apparent over time. This review focuses on acquired B-cell immunodeficiency, secondary to the use of B-cell depleting therapeutic agents. Among the many adverse consequences of B-cell depletion is the risk of hypogammaglobulinemia, failure of B-cell recovery, impaired B-cell differentiation, and risk of infections. Factors, which modulate the outcomes of B-cell depleting therapies, include the intrinsic nature of the underlying disease, the concomitant use of other immunomodulatory agents, and the clinical status of the patient and other co-existing morbidities. This article seeks to explore the mechanism of action of B-cell depleting agents, the clinical utility and adverse effects of these therapies, and the relevance of systematic and serial laboratory immune monitoring in identifying patients at risk for developing immunological complications, and who may benefit from early intervention to mitigate the secondary consequences. Though these biological drugs are gaining widespread use, a harmonized approach to immune evaluation pre-and post-treatment has not yet gained traction across multiple clinical specialties, because of which, the true prevalence of these adverse events cannot be determined in the treated population, and a systematic and evidence-based dosing schedule cannot be developed. The aim of this review is to bring these issues into focus, and initiate a multi-specialty, data-driven approach to immune monitoring.

Rituximab-Induced Hypogammaglobulinemia and Risk of Infection in Neuromyelitis Optica Spectrum Disorders

Background and Objectives

To investigate the frequency and predictors of hypogammaglobulinemia during long-term rituximab (RTX) treatment in patients with neuromyelitis optica spectrum disorder (NMOSD) and its association with infections.

Methods

We retrospectively reviewed the data of patients with NMOSD who received RTX through the maintenance regimen based on memory B-cell detection for at least 1 year from 2006 to 2021 at an institutional referral center for NMOSD.

Results

A total of 169 patients received a median of 10 courses (range 1–27) of RTX reinfusion after induction over a median of 8 (range, 1–15) years. Their mean serum immunoglobulin (Ig)G level began to decline significantly after 2 years of treatment, steadily declined at a rate of 2%–8% per year for the following 8 years, and then plateaued after 10 years. The proportion of patients with hypo-IgG (<6 g/L) increased from 1.2% after 1 year of treatment to 41% after 14 years of treatment. While being treated with RTX, 58 (34%) patients had 114 infections, of whom 14 (8%) patients had 15 severe infections. Multivariable logistic regression analyses identified duration of RTX treatment in years (odds ratio [OR] 1.234, 95% confidence interval [CI] 1.015–1.502), mean annual RTX dose (OR 0.063, 95% CI 0.009–0.434), history of mitoxantrone (OR 3.318, 95% CI 1.109–9.93), hypo-IgG at baseline (OR 40.552, 95% CI 3.024–543.786), and body mass index >25 kg/m² (OR 4.798, 95% CI 1.468–15.678) as independent predictors of hypo-IgG. The risk of infection during RTX treatment was independently associated with high Expanded Disability Status Scale scores (OR 1.427, 95% CI 1.2–1.697) and relapses during RTX treatment (OR 1.665, 95% CI 1.112–2.492), but not with hypogammaglobulinemia.

Discussion

Over 14 years of long-term RTX treatment, IgG levels gradually decreased, and the frequency of hypo-IgG increased to 41% of the patients. Patients with prolonged memory B-cell depletion after RTX, previous mitoxantrone history, hypo-IgG at baseline, or obesity were at risk of developing RTX-induced hypogammaglobulinemia. Nevertheless, infection rates remained low during treatment, and reduced immunoglobulin levels were not associated with an increased incidence of infections.

Hematologic side effects of biologics and kinase inhibitors used in rheumatologic diseases: a review of the current evidence

Treatment options for various rheumatologic diseases have been limited until the introduction of biologic agents and kinase inhibitor therapy in recent decades. Since their arrival, they have steadily been integrated into routine management. Given their wide use and overall successful outcomes, it becomes increasingly pertinent for clinicians to readily identify their side effects. Their effects can involve multiple organ systems, including hematologic. This review aims to identify and classify the range of hematologic effects associated with individual biologics and kinase inhibitors used for treatment of rheumatologic diseases.

Use of rituximab in the treatment of mucous membrane pemphigoid: An analytic review

Mucous Membrane Pemphigoid (MMP) is a potentially fatal mucocutaneous autoimmune blistering disease. Autoantibodies are produced against various components of the dermo-epidermal or mucosal-submucosal junction are referred to as basement membrane zone (BMZ). The hallmark is deposition of of Ig and C3 on the perilesional tissues and in some patients detection of anti-BMZ autoantibodies. A unique characteristic of MMP is that as the blisters or erosions heal, they leave irreversible scarring. This scarring results in serious and catastrophic sequelae that affect the quality of life. Conventional therapy consists of anti-inflammatory and immunosuppressive agents (ISA). In patients who fail conventional therapy or develop significant side effects to them, rituximab (RTX) has been used off label. In this review, the clinical outcomes of patients with MMP treated with RTX were studied. 124 patients were identified, 47.58% being male. 72 patients were treated by the Lymphoma Protocol and 51 by Rheumatoid Arthritis (RA) protocol. Follow up for the entire cohort was 36 months (range 0.5-72). On follow-up 64 patients (51.61%) achieved complete clinical remission (CR) off therapy, 25 patients (20.16%) were in CR on therapy, 5 patients (4.03%) were non-responders, and 9 patients (7.25%) were failures. 52 patients (41.93%) experienced a relapse, after 36 months follow-up. Duration between last RTX infusion and relapse was 10.5 months (range 1-30). Most patients with relapses were treated with additional RTX. A statistically significant better outcome was observed in patients treated with RTX as monotherapy compared to those who received RTX with ISA. Clinical outcomes in patients treated with Lymphoma protocol were better than RA protocol at a statistically significant level. Data on CD20+ B cell depletion and repopulation was limited. Interestingly relapses were seen in patients with CD20+ B cell depletion and after repopulation. In the final analysis, 89 patients (71.77%) were in complete remission. Data in this review indicated that RTX was a useful agent to treat MMP. While a randomized control trial may not be practically possible, better and disease specific protocols need to be developed. When publishing, authors should attempt to provide complete and detailed information. In doing so, they will benefit their colleagues and the patients with MMP they treat with RTX.

Long-term Safety of Rituximab in Primary Sjögren Syndrome: The Experience of a Single Center

OBJECTIVE

This work aims to evaluate the long-term safety of rituximab (RTX) in primary Sjögren syndrome (pSS) and to determine the safety and the efficacy of long-term treatment with B cell depleting therapy in pSS patients with active systemic disease.

METHODS

A historical cohort study, enrolling 35 patients with pSS treated with RTX between 2008 and 2019 in a single rheumatologic unit, was performed. When patients experienced adverse events, the treatment was suspended and patients' data were recorded.

RESULTS

The included patients were mainly female (91%), with a mean age of 54 years. During the time of observation, 13 patients (37.1%) suspended RTX treatment (10 cases per 100 patient-years, 95% CI 0.06-0.17). Baseline demographics, disease characteristics, European Alliance of Associations for Rheumatology (EULAR) Sjögren's Syndrome Disease Activity Index (ESSDAI) values, and treatment were comparable across RTX-suspended and nonsuspended groups. Patients exposed to RTX had been followed for 35.82 ± 32.56 months, and the time of observation varied from 6 to 96 months. All the patients except one experienced a significant and persisting meaningful improvement of their ESSDAI (≥ 3 points) during the long-term follow-up. For the duration of the follow-up, 13 (37%) patients discontinued RTX treatment. Four out of 13 (30.8%) discontinued the treatment after the first administration due to infusion-related reactions. During subsequent RTX courses, the main cause of withdrawal was hypogammaglobulinemia onset (7 patients). In 2 patients, hypogammaglobulinemia was associated with severe infections.

CONCLUSION

Long-term RTX administration was shown to be a safe, well tolerated, and effective treatment in patients with active systemic disease, significantly reducing ESSDAI and controlling disease activity.

Ocrelizumab for the Treatment of Multiple Sclerosis: Safety, Efficacy, and Pharmacology

The success of selective B-cells depleting therapies, as the anti-CD20 antibodies, in patients with multiple sclerosis (MS) has confirmed that B-cells are critical in the immune pathogenesis of the disease. Ocrelizumab, a humanized monoclonal antibody that selectively targets CD20+ B-cells, profoundly suppresses acute inflammatory disease activity, representing a highly effective therapy for relapsing-remitting multiple sclerosis (RRMS). It is also the first proven therapy able to slow disability progression in primary progressive multiple sclerosis (PPMS), particularly in patients with signs of acute radiological activity before being enrolled. Effectiveness has widely been demonstrated in randomized clinical trials (RCTs), and recently confirmed in open-label extension trials. Here, we review the role of B-cells in MS, the mechanism of action of ocrelizumab, its pharmacokinetics and pharmacodynamics, and the clinical data supporting its use, as well as safety data. We focus on issues related to the maintenance of immunocompetence, essential to ensure an immune response to either a primary infection or a vaccination. Lastly, we discuss about the possible role of ocrelizumab as an exit strategy from natalizumab-treated patients at risk of developing multifocal progressive leukoencephalopathy. In view of using ocrelizumab chronically, collecting long-term safety data and finding strategies to minimize adverse events will be extremely relevant.

Increased rate of hospitalisation for COVID-19 among rituximab-treated multiple sclerosis patients: A study of the Swedish multiple sclerosis registry

BACKGROUND

The primary objective of this study was to analyse the association between multiple sclerosis (MS) disease-modifying therapy (DMT) exposure and hospitalisation in patients infected with COVID-19.

METHODS

Associations between MS DMT exposure and COVID-19 hospitalisation were analysed using univariable and multi-variable-clustered propensity score weighted logistic regression, where the models were clustered on the individual patients to control for patients contributing multiple COVID-19 episodes.

FINDINGS

As of 18 January 2021, a total of 476 reported COVID-19 cases had been recorded in MS patients in the Swedish MS registry. Of these, 292 (61.3%) had confirmed COVID-19. The mean value (standard deviation (SD)) age at infection was 44.0 years (11.6). Of the 292 confirmed infections, 68 (23.2%) required hospitalisation. A total of 49 of the 164 confirmed COVID-19 patients on rituximab at baseline (29.9%) required hospitalisation, compared to a rate of 12.7% for all other DMTs combined. Rituximab in confirmed COVID-19 patients was associated with 2.95 times the odds of hospitalisation relative to any other DMT combined (odds ratio = 2.95; 95% confidence interval (CI) = 1.48-5.87).

INTERPRETATION

Rituximab treatment, known to increase the risk of severe infections in general, also confers such a risk for MS patients with COVID-19, in comparison with other MS DMTs.