Association of Immunoglobulin Levels, Infectious Risk, and Mortality With Rituximab and Hypogammaglobulinemia

Bruton tyrosine kinase inhibitors in multiple sclerosis: evidence and expectations

PURPOSE OF REVIEW

Despite availability of high-efficacy therapies for multiple sclerosis (MS), many patients experience significant disability worsening due to limited effects of currently available drugs on central nervous system (CNS)-compartmentalized inflammation. Bruton tyrosine kinase (BTK) is an intracellular signaling molecule involved in regulation of maturation, survival, migration, and activation of B cells and microglia, which are central players in the immunopathogenesis of progressive MS. Therefore, CNS-penetrant BTK inhibitors may better prevent disease progression by targeting immune cells on both sides of the blood-brain barrier. This review gives an overview on the preliminary results of clinical trials.

RECENT FINDINGS

Currently, the efficacy and safety of six BTK inhibitors are being evaluated in clinical trials in patients with relapsing and progressive MS. Evobrutinib, tolebrutinib and fenebrutinib have shown efficacy and safety in relapsing MS in phase 2 studies, and evobrutinib and tolebrutinib in their extension studies up to 3-5 years. However, evobrutinib failed to distinguish itself from the comparator drug teriflunomide in reduction of relapse rate (primary end point) in two phase 3 studies in relapsing MS.

SUMMARY

Inhibition of BTK has emerged as a promising therapeutic approach to target the CNS-compartmentalized inflammation. Results from phase 3 clinical trials will shed light on differences in efficacy and safety of BTK inhibitors and its potential role in the future MS landscape.

Effect of pre-emptive rituximab on EBV DNA levels and prevention of post-transplant lymphoproliferative disorder in pediatric kidney transplant recipients: A case series from the pediatric nephrology research consortium

BACKGROUND

There are scant data on the effect of rituximab on EBV DNA levels and prevention of post-transplant lymphoproliferative disorder (PTLD) in pediatric kidney transplant recipients with EBV DNAemia.

METHODS

Kidney transplant recipients with EBV DNAemia treated with rituximab to prevent PTLD between 7/1999 and 7/2019 at five pediatric centers were included. Those with confirmed PTLD at the onset of rituximab were excluded. Primary outcomes included percentage change in EBV DNAemia and occurrence of PTLD post rituximab.

RESULTS

Twenty-six pediatric kidney transplant recipients were included. Median age at transplant was 4 years (IQR 2.1-10.3). EBV DNA load monitoring by qPCR was performed at 1-3 month intervals. EBV DNAemia onset occurred at a median of 73 days post-transplant (IQR 52-307), followed by DNAemia peak at a median of 268 days (IQR 112-536). Rituximab was administered at a median of 9 days post peak (IQR 0-118). Rituximab regimens varied; median dose 375 mg/m2 (IQR 375-439) weekly for 1-4 doses per course. Following rituximab, EBV DNA load decreased to <10% of baseline at 120 days in 20/26 patients; however, only 30% achieved complete resolution at last follow-up (median 2094 days post-transplant [IQR 1538-3463]). Two (7%) developed PTLD at 915 and 1713 days post rituximab. All recipients had functioning grafts. One death occurred in a child with PTLD following remission due to unrelated reasons.

CONCLUSIONS

In the largest pediatric kidney transplant recipient case series with EBV DNAemia given rituximab to prevent PTLD, rituximab achieved a short-term reduction in DNA load; however, recurrent DNAemia is common.

Hypogammaglobulinemia and infections in patients with multiple sclerosis treated with anti-CD20 treatments: a systematic review and meta-analysis of 19,139 multiple sclerosis patients

Background

Recent years have seen the emergence of disease-modifying therapies in multiple sclerosis (MS), such as anti-cluster of differentiation 20 (anti-CD20) monoclonal antibodies, aiming to modulate the immune response and effectively manage MS. However, the relationship between anti-CD20 treatments and immunoglobulin G (IgG) levels, particularly the development of hypogammaglobulinemia and subsequent infection risks, remains a subject of scientific interest and variability. We aimed to investigate the intricate connection between anti-CD20 MS treatments, changes in IgG levels, and the associated risk of hypogammaglobulinemia and subsequent infections.

Method

PubMed, Scopus, Embase, Cochrane, and Web of Science databases have been searched for relevant studies. The "R" software utilized to analyze the occurrence of hypogammaglobulinemia, infections and mean differences in IgG levels pre- and post-treatment. The subgrouping analyses were done based on drug type and treatment duration. The assessment of heterogeneity utilized the I2 and chi-squared tests, applying the random effect model.

Results

Thirty-nine articles fulfilled our inclusion criteria and were included in our review which included a total of 20,501 MS patients. The overall prevalence rate of hypogammaglobulinemia was found to be 11% (95% CI: 0.08 to 0.15). Subgroup analysis based on drug type revealed varying prevalence rates, with rituximab showing the highest at 18%. Subgroup analysis based on drug usage duration revealed that the highest proportion of hypogammaglobulinemia occurred in individuals taking the drugs for 1 year or less (19%). The prevalence of infections in MS patients with a focus on different infection types stratified by the MS drug used revealed that pulmonary infections were the most prevalent (9%) followed by urinary tract infections (6%), gastrointestinal infections (2%), and skin and mucous membrane infections (2%). Additionally, a significant decrease in mean IgG levels after treatment compared to before treatment, with a mean difference of 0.57 (95% CI: 0.22 to 0.93).

Conclusion

This study provides a comprehensive analysis of the impact of anti-CD20 drugs on serum IgG levels in MS patients, exploring the prevalence of hypogammaglobulinemia, based on different drug types, treatment durations, and infection patterns. The identified rates and patterns offer a foundation for clinicians to consider in their risk-benefit.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=518239, CRD42024518239.

Efficacy and safety of ocrelizumab in patients with relapsing multiple sclerosis: Real-world experience of two Swiss multiple sclerosis centers

BACKGROUND

Ocrelizumab (OCR) is a humanized monoclonal antibody directed against CD-20 positive lymphocytes, mainly B-lymphocytes. OCR is approved for treatment of primary progressive (PPMS) and relapsing multiple sclerosis (RMS). This study aims to provide real-world safety and efficacy data of people with RMS treated with OCR in two Swiss Multiple Sclerosis (MS) centers.

METHODS

We have conducted a retrospective data analysis using the patient cohorts from the Cantonal Hospital Aarau and Bern University Hospital (RMS: n = 235). Statistical analyses were performed with Mann-Whitney U-Test, Chi-squared test and Spearman-Rho-Correlation. Adjustment for multiple testing was performed by Bonferroni procedure.

RESULTS

After initiation of OCR, there was a decrease in disease activity in RMS patients. In our study, 152/190 (80.0 %) RMS patients fulfilled the criteria for NEDA-3 12 months and 88/104 (84.6 %) showed NEDA-3 24 months after OCR initiation. The most frequent adverse events (AEs) in our study were infections, taking place in 78/235 (33.2 %) RMS patients. COVID-19 was the most common infection, followed by urinary infections and other respiratory infections and infectious adverse events occurred significantly more frequent in patients with reduced IgG serum concentration.

CONCLUSIONS

Our real-world study showed OCR being associated with low rates of any type of MS disease activity as indicated by NEDA-3. The adverse event profile is comparable to the known events especially infections and an association between infections and reduced IgG serum concentration was found.

Clinicopathological characteristics and predictors of outcome of rapidly progressive glomerulonephritis: a retrospective study

BACKGROUND

Globally, there are regional and time-based variations in the prevalence, etiology, and prognosis of rapidly progressive glomerulonephritis (RPGN). Prognosis of RPGN is poor, with a higher risk of death and end stage renal disease (ESRD) even with immunosuppressive medications. In the Middle East and North Africa, the studies on this disease are very limited. Therefore, we determined the predictors of outcome of RPGN.

METHODS

We retrospectively assessed 101 adult patients over age of 18, diagnosed with RPGN based on renal biopsy illustrating crescents in ≥ 50% of the glomeruli. Patients who had crescents in their renal biopsies that were < 50% and those who refused to consent to a renal biopsy were excluded. We categorized the patients into 3 groups based on immunohistochemistry; type I, type II and type III. Then, depending on renal loss, we divided them into ESRD and non-ESRD groups. The clinical history and physical examination were retrieved. Additionally, 24-hour urine protein, urine analysis, renal function tests, serum albumin, complete blood count, antinuclear antibodies, anti-double stranded DNA antibodies, ANCA antibodies and serum complement levels were checked. Each patient underwent a kidney biopsy for immunohistochemistry and light microscopy. The percentage of crescentic glomeruli, number of sclerosed glomeruli, tertiary lymphoid organ (TLO), neutrophil infiltration, endocapillary or mesangial hypercellularity, interstitial fibrosis with tubular atrophy (IFTA) were analyzed. Primary outcomes (remission, ESRD and mortality) and secondary outcomes were assessed.

RESULTS

Type II was the most frequent cause of RPGN (47.5%), followed by type III (32.7%) and type I (19.8%). 32 patients (31.7%) died during follow up, whereas 60 patients (59.4%) developed ESRD. In 41 patients (40.6%), remission occurred. Oliguria, serum creatinine, and need for HD at presentation were significantly increased in ESRD group compared to non-ESRD group (P < 0.001 for each). Mesangial proliferation, IFTA, TLO formation, sclerotic glomeruli and fibrous crescents were also significantly increased in ESRD group in comparison to non-ESRD group (P < 0.001 for each). Glomerulosclerosis (P = 0.036), and IFTA (P = 0.008) were predictors of ESRD. Infections (P = 0.02), respiratory failure (P < 0.001), and heart failure (P = 0.004) were mortality risk factors.

CONCLUSION

Type II RPGN was the most common. Infection was the most frequent secondary outcome. Oliguria, glomerulosclerosis, the requirement for hemodialysis at presentation, IFTA and TLO formation were predictors of ESRD. Respiratory failure, heart failure and infections were significant predictors of mortality.

Effect of rituximab on immune status in children with aggressive mature B-cell lymphoma/leukemia-a prospective study from CCCG-BNHL-2015

Background

Limited research has been conducted on the impact of rituximab on immune function and the incidence of side effects in children undergoing combination chemotherapy for aggressive mature B-cell lymphoma/leukemia.

Methods

Clinical data from 85 patients with primary pediatric aggressive mature B-cell lymphoma/leukemia, treated according to the Chinese Children's Cancer Group (CCCG)-mature B-cell non-Hodgkin lymphoma (BNHL)-2015 protocol from June 1, 2015, to December 1, 2022, were collected from three tertiary medical centers in China. Patients with pre-existing malignancies or primary immune deficiencies (PIDs) were excluded.

Results

Between June 1, 2015, and December 1, 2022, 85 patients (65 [76.5%] boys and 20[23.5%] girls; mean age, 6.95 years) were enrolled, and immune data at baseline during follow-up were analyzed. At the end of chemotherapy, a higher proportion of patients in the R4 group exhibited a decrease in peripheral blood CD3- CD19+ B cells (20[100%] of 20 vs 13[47.8%] of 18, p = 0.04), CD3+ T cells (21[91.3%] of 23 vs 14[60.9%] of 23, p = 0.016), and serum IgM (14[60.9%] of 23 vs 4[17.4%] of 23, p = 0.003) compared to the R3 group. However, these differences were no longer statistically significant six months after chemotherapy administration. The combination of rituximab with AA was associated with a higher incidence of significant thrombocytopenia (49[81.7%] of 60 vs 29[52.7%] of 55, p = 0.001) and infection (35[58.3%] of 60 vs 17[30.9%] of 55, p = 0.003) compared to AA alone. Furthermore, the combination of rituximab with BB was linked to a higher incidence of significant thrombocytopenia (32[52.5%] of 61 vs 31[31.0%] of 100, p = 0.007) compared to BB alone.

Conclusions

While the effects of rituximab in combination with intense chemotherapy for childhood aggressive mature B-cell lymphoma/leukemia on children's immune function generally recovers within six months it may still prolong the recovery from immunoglobulinemia, posing a risk of secondary infections. Further studies are required to identify children with potential primary immunodeficiencies.

Infections in the era of immunobiologicals

Immunobiologicals represent an innovative therapeutic option in dermatology. They are indicated in severe and refractory cases of different diseases when there is contraindication, intolerance, or failure of conventional systemic therapy and in cases with significant impairment of patient quality of life. The main immunobiologicals used in dermatology basically include inhibitors of tumor necrosis factor-alpha (anti-TNF), inhibitors of interleukin-12 and -23 (anti-IL12/23), inhibitors of interleukin-17 and its receptor (anti-IL17), inhibitors of interleukin-23 (anti-IL23), rituximab (anti-CD20 antibody), dupilumab (anti-IL4/IL13) and intravenous immunoglobulin. Their immunomodulatory action may be associated with an increase in the risk of infections in the short and long term, and each case must be assessed individually, according to the risk inherent to the drug, the patient general condition, and the need for precautions. This article will discuss the main risks of infection associated with the use of immunobiologicals, addressing the risk in immunocompetent and immunosuppressed patients, vaccination, fungal infections, tuberculosis, leprosy, and viral hepatitis, and how to manage the patient in the most diverse scenarios.

Secondary hypogammaglobulinemia in adults-A large retrospective cohort study

BACKGROUND AND OBJECTIVE

IgG replacement therapy (IgG-RT) has radically changed the clinical evolution of primary immunodeficiencies, yet the information regarding secondary hypogammaglobulinemia (SHG) is insufficient or conflicting. We aim to describe clinical features, evolution and treatment of SHG patients in our center.

METHODS

Dynamic retrospective cohort between January 2001 and July 2021 of adults with gamma globulin fraction <0.6g/dL in a serum protein electrophoresis and a coincident decrease of IgG levels - with a disease-related SHG or treatment that reduces serum immunoglobulins.

RESULTS

We included 1012 patients with SHG with a median follow-up of 5 years (IQR 2-8). Hematological diseases were identified in 95% of the patients and 61% received drugs related to SHG. Sixty five percent had more than one etiological factor associated with SHG. Infectious diseases were present in 69% of the patients, 48% had respiratory infections and 17% had severe infections. There was statistical association between respiratory and severe infections with multiple myeloma (MM), lymphoma and rituximab. MGUS had less infections and death compared with other etiologies. IgG-RT was indicated in 18.7% of the patients and 4.6% received it for more than 6 months with variable intervals. Among the latter group, there was a significant reduction of all-type infections and respiratory infections with IgG-RT (p<0.001), and it was consistent with similar findings in lymphoma, MM and all IgG levels subgroups.

CONCLUSION

SHG was associated with more than one etiological factor and a high frequency of infections. IgG-RT indication was irregular yet still effective. It is relevant to consider IgG levels screening, monitoring and accurate indication of IgG-RT.

Efficacy and safety of rituximab in multiple sclerosis and neuromyelitis optica spectrum disorder

In Thailand, resource limitations lead many multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD) patients to use off-label immunosuppressants. This study assesses the efficacy and safety of rituximab (RTX) with a CD19-based reinfusion regimen among Thai MS and NMOSD patients. A retrospective review of patients at the Faculty of Medicine Siriraj Hospital from January 1994 to April 2023 was conducted. The primary outcome assessed was the change in annualized relapse rate (ARR) for patients using RTX for over a year. Secondary outcomes included changes in the Expanded Disability Status Scale (EDSS) scores, time to the first relapse after RTX initiation for patients using RTX for over a year, and an evaluation of the safety of RTX. The study encompassed 36 MS and 39 NMOSD patients. A majority of patients (91.7% of MS and 79.5% of NMOSD) experienced no relapses during a median follow-up of 30 months (Interquartile range [IQR] 20-46) and 31 months (IQR 23-41), respectively. The median ARR significantly decreased in both MS (from 0.77 [IQR 0.42-1.83] to 0 [IQR 0-0], p < 0.001) and NMOSD (from 0.92 [IQR 0.68-1.78] to 0 [IQR 0-0.17], p < 0.001) patients after switching to RTX, with no difference between those following a fixed 6-month time point regimen and a CD19-based reinfusion regimen. Median EDSS scores improved significantly at the last follow-up visit in both groups. The mean time to the first subsequent relapse was 8.3 ± 3.0 months in MS and 6.8 ± 1.7 months in NMOSD. Mild adverse drug reactions occurred in 44% of patients. RTX effectively prevents relapses in Thai MS and NMOSD patients, with no observed serious adverse drug reactions.

Hypogammaglobulinemia and Infection Risk in an Ocrelizumab-treated Multiple Sclerosis Cohort

BACKGROUND

Ocrelizumab is an effective anti-CD20 therapy approved for Relapsing Remitting (RRMS) and Primary Progressive Multiple Sclerosis (PPMS). In clinical trials, a proportion of patients developed hypogammaglobulinemia which could contribute to infection risk. This study aimed to identify hypogammaglobulinemia and its risk factors and evaluate potentially associated serious infection risk in a real-world cohort of patients.

METHODS

All MS patients treated with ocrelizumab in a Quebec City MS clinic from January 2017 to August 2021 were included and detailed patient characteristics were collected by chart review. Levels of immunoglobulins (IgM, IgA and IgG) were assessed prior to each treatment. Serious infection was defined as an infection requiring hospitalization or emergency room treatment. Association between hypogammaglobulinemia and serious infection was analyzed.

RESULTS

A total of 266 patients (average follow-up 2.05 years) were included (87% RRMS). After 6 infusions, 32.8%, 3.5% and 4.2% of patients had at least one IgM, IgA and IgG hypogammaglobulinemia event respectively. Aside from pre-treatment hypogammaglobulinemia, there were no variables associated with on-treatment hypogammaglobulinemia. There was a total of 21 serious infections (3.36 and 12.33 per 100-person-years in RRMS and PPMS). Developing hypogammaglobulinemia during treatment was not associated with serious infection. A regression analysis did not show associations between serious infection and key disease characteristics.

CONCLUSION

Similar to ocrelizumab extension studies, our cohort demonstrated a significant rate of hypogammaglobulinemia over time, mostly with IgM. No association was found between hypogammaglobulinemia and serious infection.

Clinical outcomes and immunological features of COVID-19 patients receiving B-cell depletion therapy during the Omicron era

Background: The clinical outcomes and immunological features of coronavirus disease 2019 (COVID-19) patients receiving B-cell depletion therapy (BCDT), especially in Omicron variant era, have not been fully elucidated. We aimed to investigate the outcomes and immune responses of COVID-19 patients receiving BCDT during the Omicron period.Methods: We retrospectively compared clinical outcomes between COVID-19 patients treated with BCDT (the BCDT group) and those with the same underlying diseases not treated with BCDT (the non-BCDT group). For immunological analyses, we prospectively enrolled COVID-19 patients receiving BCDT and immunocompetent COVID-19 patients as controls. We measured humoral and cellular immune responses using the enzyme-linked immunosorbent assay and flow cytometry.Results: Severe to critical COVID-19 was more frequent in the BCDT group than in the non-BCDT group (41.9% vs. 28.3%, p = .030). BCDT was an independent risk factor for severe to critical COVID-19 (adjusted odds ratio [aOR] 2.21, 95% confidence interval [CI] 1.21-4.04, p = .010) as well as for COVID-19-related mortality (aOR 4.03, 95% CI 1.17-13.86, p = .027). Immunological analyses revealed that patients receiving BCDT had lower anti-S1 IgG titres and a tendency to higher proportions of activated CD4+ T-cells than the controls.Conclusions: BCDT was associated with worse COVID-19 outcomes in the Omicron period. Humoral immune response impairment and T-cell hyperactivation were the main immunological features of COVID-19 patients treated with BCDT, which may have contributed to the worse outcomes of COVID-19 in this population.

Treatment of neuromyelitis optica spectrum disorder: revisiting the complement system and other aspects of pathogenesis

Neuromyelitis optica spectrum disorder (NMOSD) represents a rare neuroimmunological disease causing recurrent attacks and accumulation of permanent disability in affected patients. The discovery of the pathogenic IgG‑1 antibody targeting a water channel expressed in astrocytes, aquaporin 4, constitutes a milestone achievement. Subsequently, multiple pathophysiological aspects of this distinct disease entity have been investigated. Demyelinating lesions and axonal damage ensue from autoantibodies targeting an astroglial epitope. This conundrum has been addressed in the current disease model, where activation of the complement system as well as B cells and interleukin 6 (IL-6) emerged as key contributors. It is the aim of this review to address these factors in light of novel treatment compounds which reflect these pathophysiological concepts in aiming for attack prevention, thus reducing disease burden in patients with NMOSD.

Role of B Cells in Relapsing-Remitting and Progressive Multiple Sclerosis and Long-Term Effects of B Cell Depletion

Depletion of circulating B lymphocytes using anti-CD20 monoclonal antibodies (mAbs) greatly reduces inflammatory activity in relapsing multiple sclerosis (RMS); it reduces progression to a lesser extent in nonrelapsing progressive MS. Mechanisms whereby anti-CD20 mAbs reduce MRI and clinical relapse activity in people with RMS are still being elucidated. Anti-CD20 agents do not fully protect from nonrelapsing disease progression, possibly due to their inability to cross the blood-brain barrier and inability to ameliorate the full extent of biology of MS progression. Anti-CD20 mAbs have a relatively favorable safety profile, at least in the short-term. Long-term safety studies are still needed.

The IPTA Nashville consensus conference on Post-Transplant lymphoproliferative disorders after solid organ transplantation in children: II-consensus guidelines for prevention

The International Pediatric Transplant Association (IPTA) convened an expert consensus conference to assess current evidence and develop recommendations for various aspects of care relating to post-transplant lymphoproliferative disorder after solid organ transplantation in children. In this report from the Prevention Working Group, we reviewed the existing literature regarding immunoprophylaxis and chemoprophylaxis, and pre-emptive strategies. While the group made a strong recommendation for pre-emptive reduction of immunosuppression at the time of EBV DNAemia (low to moderate evidence), no recommendations for use could be made for any prophylactic strategy or alternate pre-emptive strategy, largely due to insufficient or conflicting evidence. Current gaps and future research priorities are highlighted.

Paradoxical disease flare, skin infection and hypogammaglobulinaemia in patients with pemphigus vulgaris treated with rituximab

Patients with pemphigus vulgaris can develop hypogammaglobulinaemia after an infusion of rituximab, which manifests clinically as a paradoxical disease flare accompanying skin lesion infection.

NK Cell Levels Correlate with Disease Activity in Patients with Multiple Sclerosis on Ocrelizumab/Rituximab Therapy

BACKGROUND

Recently, research on the pathogenesis of multiple sclerosis (MS) has focused on the role of B lymphocytes and the possibility of using specific drugs, such as Ocrelizumab and Rituximab, directed toward these cells to reduce inflammation and to slow disease progression.

OBJECTIVE

We aimed to evaluate the effect of Ocrelizumab/Rituximab on laboratory immune parameters and identify the predictors of treatment responses.

METHODS

A retrospective single-center study was conducted among patients who received infusion therapy with an anti-CD20 drug to treat MS.

RESULTS

A total of 64 patients met the inclusion criteria, with 277 total cycles of therapy studied. Compared with the baseline values, anti-CD20 infusions resulted in absolute-value and percentage decreases in B lymphocyte levels and increased the absolute and percentage levels of NK cells 3 and 5 months after therapy (p < 0.001). After multivariate logistic regression analysis, a reduced percentage level of NK cells 3 months after infusion could predict disease activity 6 months after Ocrelizumab/Rituximab administration (p = 0.041).

CONCLUSIONS

Lower percentage levels of NK cells 3 months after anti-CD20 infusion correlate with the presence of disease activity 6 months after therapy, confirming a possible protective role of NK cells in MS.

COVID-19 and reported mortality cases among rheumatic disease patients in Kuwait: Data from the Global Rheumatology Alliance registry

Mycophenolate mofetil and rituximab have been shown to be considerably associated with poorer outcomes following SARS-CoV-2 infection. Such agents were associated with longer hospital stay as well as severe COVID-19 outcomes (infection-related complications, intensive care unit admission, and mortality). Using the data of the COVID-19 Global Rheumatology Alliance (GRA) registry of inflammatory rheumatic disease (IRD) patients in Kuwait, who had COVID-19 from March 2020 to March 2021, revealed 4 mortality cases (3 cases used CD-20 inhibitors as monotherapy and 1 case used mycophenolate mofetil/mycophenolic acid as monotherapy). This article describes the characteristics and course of disease among 4 patients with IRD who died following COVID-19 infection at Jaber Al Ahmed Hospital, Kuwait. The current series raises the intriguing prospect that IRD patients may have a varying risk of unfavorable clinical outcomes depending on the type of biological agents they were given. Rituximab and mycophenolate mofetil should be used with caution in IRD patients, particularly if they have concomitant comorbidities that put them at a high likelihood of developing severe COVID-19 outcomes.

Biologics in peripheral ulcerative keratitis

Over the past two decades biologic therapies have seen a rapid uptake in the management of ocular inflammation. Peripheral ulcerative keratitis (PUK), once a harbinger of blindness and mortality in refractory rheumatological disease, is now increasingly being treated with these agents. We conducted a review to evaluate the evidence base for this application and to provide a road map for their clinical usage in PUK, including dosage and adverse effects. A literature search across Medline, Embase and Cochrane Database of Systematic Reviews was undertaken to identify all patients with PUK that were treated with a biologic in a peer viewed article. Overall, whilst the evidence base for biologic use in PUK was poor, reported cases demonstrate an increasingly powerful and effective role for biologics in refractory PUK. This was particularly the case for rituximab in PUK secondary to granulomatous with polyangiitis.

Hypogammaglobulinemia after front-line immunochemotherapy in patients with follicular lymphoma

INTRODUCTION

Hypogammaglobulinemia after front-line immunochemotherapy for follicular lymphoma is a poorly studied adverse event that could be related to the appearance of severe and/or recurrent non-neutropenic infections which could affect the quality of life of the patients, even motivating a need of long-term replacement therapy with human immunoglobulins.

METHODS

Observational, retrospective study aiming to estimate the incidence of hypogammaglobulinemia, as well as its severity and clinical consequences, and to explore possible predictive factors for its development. Specific immunoglobulin deficiencies were also studied.

RESULTS

76.5% of patients had hypogammaglobulinemia during or after front-line treatment, mostly grade 1-2; with 38.8% patients who developed clinically relevant infections and 20% patients requiring human immunoglobulins replacement therapy. A high-risk FLIPI score was identified as a risk factor for hypogammaglobulinemia (ods ratio: 4.51; 95% confidence interval: 1.29-15.68; p < 0.001) and basal gamma globulin level as a protective factor (odds ratio: 0.92; 95% confidence interval: 0.988-0.996; p  =  0.018). Any type of immunochemotherapy regimen was associated with different risks of hypogammaglobulinemia in our study.

CONCLUSIONS

Hypogammaglobulinemia appears in a high percentage of patients with follicular lymphoma in a real-world population, identifying a high-risk FLIPI score as a risk factor for its development and basal gamma globulins as a protective factor.

CAR T-cell therapy in autoimmune diseases

Despite the tremendous progress in the clinical management of autoimmune diseases, many patients do not respond to the currently used treatments. Autoreactive B cells play a key role in the pathogenesis of autoimmune diseases, such as systemic lupus erythematosus, rheumatoid arthritis, and multiple sclerosis. B-cell-depleting monoclonal antibodies, such as rituximab, have poor therapeutic efficacy in autoimmune diseases, mainly due to the persistence of autoreactive B cells in lymphatic organs and inflamed tissues. The adoptive transfer of T cells engineered to target tumour cells via chimeric antigen receptors (CARs) has emerged as an effective treatment modality in B-cell malignancies. In the last 2 years treatment with autologous CAR T cells directed against the CD19 antigen has been introduced in therapy of autoimmune disease. CD19 CAR T cells induced a rapid and sustained depletion of circulating B cells, as well as in a complete clinical and serological remission of refractory systemic lupus erythematosus and dermatomyositis. In this paper, we discuss the evolving strategies for targeting autoreactive B cells via CAR T cells, which might be used for targeted therapy in autoimmune diseases.

IVIg Use Associated with Ten-Fold Reduction of Serious Infections in Multiple Myeloma Patients Treated with Anti-BCMA Bispecific Antibodies

BCMA-targeted bispecific antibodies (BiAb) are efficacious in relapsed/refractory multiple myeloma; however, serious infections have emerged as important toxicities. In this retrospective study, we characterized all infections and their risk factors, and evaluated the impact of infection prophylaxis in patients treated with BCMA-targeted BiAbs. Among 37 patients, 15 (41%) experienced a grade 3-5 infection, with two infection-related deaths during deep remissions. Most (84%) infections occurred during disease remissions. The cumulative probability of grade 3-5 infection increased over time with no plateau. Among responders (n = 26), profound hypogammaglobulinemia occurred in 100% and continued throughout the entire duration of treatment. During periods when patients were receiving intravenous immunoglobulin (IVIg), the rate of grade 3-5 infections was 90% lower than during observation (incidence rate ratio, 0.10; 95% confidence interval, 0.01-0.80; P = 0.0307). No other risk factors for infection were identified. This study demonstrates that profound hypogammaglobulinemia is universal with BCMA-targeted BiAbs, with intravenous immunoglobulin potentially abrogating most of the infection risk.

SIGNIFICANCE

To the best of our knowledge, this is the first study to comprehensively analyze risk factors and mitigation strategies to prevent infections in myeloma patients receiving anti-BCMA bispecific antibodies. Profound and prolonged hypogammaglobulinemia was universal among responders, while immunoglobulin replacement was associated with 90% lower rates of grade 3-5 infections. See related commentary by Garfall and Stadtmauer, p. 427 . This article is featured in Selected Articles from This Issue, p. 419.

Secondary hypogammaglobulinemia in patients with multiple sclerosis on anti-CD20 therapy: Pathogenesis, risk of infection, and disease management

Hypogammaglobulinemia is characterized by reduced serum immunoglobulin levels. Secondary hypogammaglobulinemia is of considerable interest to the practicing physician because it is a potential complication of some medications and may predispose patients to serious infections. Patients with multiple sclerosis (MS) treated with B-cell-depleting anti-CD20 therapies are particularly at risk of developing hypogammaglobulinemia. Among these patients, hypogammaglobulinemia has been associated with an increased risk of infections. The mechanism by which hypogammaglobulinemia arises with anti-CD20 therapies (ocrelizumab, ofatumumab, ublituximab, rituximab) remains unclear and does not appear to be simply due to the reduction in circulating B-cell levels. Further, despite the association between anti-CD20 therapies, hypogammaglobulinemia, and infections, there is currently no generally accepted monitoring and treatment approach among clinicians treating patients with MS. Here, we review the literature and discuss possible mechanisms of secondary hypogammaglobulinemia in patients with MS, hypogammaglobulinemia results in MS anti-CD20 therapy clinical trials, the risk of infection for patients with hypogammaglobulinemia, and possible strategies for disease management. We also include a suggested best-practice approach to specifically address secondary hypogammaglobulinemia in patients with MS treated with anti-CD20 therapies.

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.

Associations between Antiepileptic Use and Hypogammaglobulinaemia: Findings from a Population-Based Case-Control Study Using Data Linkage

BACKGROUND AND OBJECTIVES

Increased mortality in epilepsy due to infections (other than pneumonia) has been demonstrated. Small case series of people on antiepileptic drugs (AEDs) have described hypogammaglobulinaemia, which may predispose to infections. It is unclear whether hypogammaglobulinaemia is more frequent in people on AEDs, what AEDs it is associated with, or what clinical impact it has. In this population-based study, we aimed to determine whether AEDs were associated with hypogammaglobulinaemia, which AEDs were associated, and whether the associations may be causal.

METHODS

We conducted an unmatched case-control study using data linkage of routinely collected biochemistry, prescribing, and morbidity datasets in North-East Scotland from 2009-2021. Cases were participants with immunoglobulin levels less than the reference range. Controls were those with normal/high immunoglobulin levels. Logistic regression was used to investigate associations between AED exposure and any hypogammaglobulinaemia, adjusting for age, sex, and comorbidity. We also analysed low IgA, IgM, and IgG separately. We analysed "any AED" exposure and common individual drugs separately. Cumulative exposure data were used to determine whether an exposure-response relationship was present.

RESULTS

18,666 cases and 127,157 controls were identified. Use of any AED was associated with increased risk of hypogammaglobulinaemia (adjusted odds ratio [aOR] 1.20 [95% CI: 1.15-1.25]). Phenytoin use was strongly associated with low IgA (aOR 5.90 [95% CI: 3.04, 10.43]). Carbamazepine and lamotrigine were also associated with low IgA. Apart from topiramate, which was associated with a non-significant decrease in odds of hypogammaglobulinaemia, there was a consistent increase in odds of hypogammaglobulinaemia across most AEDs studied. Panhypogammaglobulinaemia was associated with any AED use, carbamazepine, lamotrigine, gabapentin, and multiple AED use. There was evidence of an exposure-response relationship between any AED use and any hypogammaglobulinaemia, low IgA, and low IgG. Carbamazepine and probably lamotrigine also had an exposure-response relationship with any hypogammaglobulinaemia.

DISCUSSION

AEDs may increase hypogammaglobulinaemia risk. Specific classes of immunoglobulins are differentially affected, and the exposure-response analysis suggests this may be causal. Further work should investigate the clinical impact of these findings. Clinicians should check immunoglobulin levels if unusual or recurrent infections occur in patients treated with AEDs.

Increased LPS-Induced Fever and Sickness Behavior in Adult Male and Female Rats Perinatally Exposed to Morphine

As a result of the current opioid crisis, the rate of children born exposed to opioids has skyrocketed. Later in life, these children have an increased risk for hospitalization and infection, raising concerns about potential immunocompromise, as is common with chronic opioid use. Opioids can act directly on immune cells or indirectly via the central nervous system to decrease immune system activity, leading to increased susceptibility, morbidity, and mortality to infection. However, it is currently unknown how perinatal opioid exposure (POE) alters immune function. Using a clinically relevant and translatable model of POE, we have investigated how baseline immune function and the reaction to an immune stimulator, lipopolysaccharide, is influenced by in utero opioid exposure in adult male and female rats. We report here that POE potentiates the febrile and neuroinflammatory response to lipopolysaccharide, likely as a consequence of suppressed immune function at baseline (including reduced antibody production). This suggests that POE increases susceptibility to infection by manipulating immune system development, consistent with the clinical literature. Investigation of the mechanisms whereby POE increases susceptibility to pathogens is critical for the development of potential interventions for immunosuppressed children exposed to opioids in utero.

Efficacy of Rituximab Outlasts B-Cell Repopulation in Multiple Sclerosis: Time to Rethink Dosing?

BACKGROUND AND OBJECTIVES

Patients with multiple sclerosis (PwMS) receiving extended dosing of rituximab (RTX) have exhibited no return of disease activity, which suggests that maintenance of deep depletion of circulating B cells is not necessary to maintain the efficacy of RTX in MS.

METHODS

This was a prospective monocentric observational study including all consecutive PwMS who started or continued RTX after 2019, when the medical staff decided to extend the dosing interval up to 24 months for all patients. Circulating B-cell subsets were monitored regularly and systematically in case of relapse. The first extended interval was analyzed.

RESULTS

We included 236 PwMS (81% with relapsing-remitting MS; mean [SD] age 43 [12] years; median [range] EDSS score 4 [0-8]; mean relapse rate during the year before RTX start 1.09 [0.99]; 41.5% with MRI activity). The median number of RTX infusions before extension was 4 (1-13). At the time of the analysis, the median delay in dosing was 17 months (8-39); the median proportion of circulating CD19+ B cells was 7% (0-25) of total lymphocytes and that of CD27+ memory B cells was 4% (0-16) of total B cells. The mean annual relapse rate did not differ before and after the extension: 0.03 (0.5) and 0.04 (0.15) (p = 0.51). Similarly, annual relapse rates did not differ before and after extension in patients with EDSS score ≤3 (n = 79) or disease duration ≤5 years (n = 71) at RTX onset. During the "extended dosing" period, MRI demonstrated no lesion accrual in 228 of the 236 patients (97%). Five patients experienced clinical relapse, which was confirmed by MRI. In these patients, the level of B-cell subset reconstitution at the time of the relapse did not differ from that for patients with the same extension window.

DISCUSSION

The efficacy of RTX outlasted substantial reconstitution of circulating B cells in PwMS, which suggests that renewal of the immune system underlies the prolonged effect of RTX in MS. These findings suggest that extended interval dosing of RTX that leads to a significant reconstitution of circulating B cells is safe in PwMS, could reduce the risk of infection, and could improve vaccine efficacy.

Rituximab-associated hypogammaglobulinemia in children with idiopathic nephrotic syndrome: results of an ESPN survey

BACKGROUND

There is paucity of information on rituximab-associated hypogammaglobulinemia (HGG) and its potential infectious consequences in children treated for idiopathic nephrotic syndrome (INS).

METHODS

A survey was distributed by the European Society Pediatric Nephrology to its members. It addressed the screening and management practices of pediatric nephrology units for recognizing and treating RTX-associated HGG and its morbidity and mortality. Eighty-four centers which had treated an overall 1328 INS children with RTX responded.

RESULTS

The majority of centers administered several courses of RTX and continued concomitant immunosuppressive therapy. Sixty-five percent of centers routinely screened children for HGG prior to RTX infusion, 59% during, and 52% following RTX treatment. Forty-seven percent had observed HGG prior to RTX administration, 61% during and 47% >9 months following treatment in 121, 210, and 128 subjects respectively. Thirty-three severe infections were reported among the cohort of 1328 RTX-treated subjects, of whom 3 children died. HGG had been recognized in 30/33 (80%) of them.

CONCLUSIONS

HGG in steroid-dependent/frequently relapsing nephrotic syndrome (SDNS/FRNS) children is probably multifactorial and can be observed prior to RTX administration in children with SDNS/FRNS. Persistent HGG lasting >9 months from RTX infusion is not uncommon and may increase the risk of severe infections in this cohort. We advocate for the obligatory screening for HGG in children with SDNS/FRNS prior to, during, and following RTX treatment. Further research is necessary to identify risk factors for developing both HGG and severe infections before recommendations are made for its optimal management. A higher resolution version of the Graphical abstract is available as Supplementary information.

A Systematic Review and Meta-analysis of Rituximab-Associated Infections Among Children and Adolescents With Glomerular Disease: Focus on the Risk of Infections

OBJECTIVE

This systematic review and meta-analysis aimed to explore rituximab (RTX) associated infectious complications in children with glomerular disease.

METHODS

We performed an electronic search of PubMed, International Scientific Information (ISI), Scopus, and EMBASE between January 2010 and July 2021. Infection rates and total drug-related adverse events were the outcomes. Statistical heterogeneity was evaluated by using the I2 statistic. When there was statistical evidence of heterogeneity (I2 > 50%, p > 0.1), a random-effect model was adopted. Data analysis was performed with Stata17.0 software.

RESULTS

A total of 7 studies with 668 patients (136 with lupus nephritis [LN] and 532 with nephrotic syndrome were included in the meta-analysis. The pooled risk ratio showed that the administration of RTX was significantly associated with lower risk of infectious complications in patients with LN and nephrotic syndrome (0.72 [95% CI 0.58, 0.85]) when compared with population data of patients without glomerular disease (p = 0.2). There was no significant difference between the LN and nephrotic syndrome groups in terms of total serious adverse events or the occurrence of infections. There was significant heterogeneity among the reported studies (Q = 42.39, p < 0.001, I2 = 81%).

CONCLUSION

Administration of RTX in children with glomerular disease is associated with a lower rate of infections when compared with population data of patients without LN or nephrotic syndrome. Additional high-quality randomized controlled trials with long-term follow-up are needed to identify the long-term potential complications. Trial registration PROPERO ID: CRD42021274869 (https://www.crd.york.ac/prospero/display_record.php?).

ALSUntangled #67: rituximab

ALSUntangled reviews alternative and off-label treatments on behalf of people with ALS who ask about them. Here we review rituximab, a drug which specifically depletes B lymphocytes. We show a current lack of evidence for a role of these cells in ALS progression. The one patient we found who described using Rituximab for their ALS found no benefit. Given all this, and the known serious risks of rituximab, we advise against its use as an ALS treatment.

Impact of aging on treatment considerations for multiple sclerosis patients

With a rapidly aging global population and improvement of outcomes with newer multiple sclerosis (MS)-specific disease-modifying therapies (DMTs), the epidemiology of MS has shifted to an older than previously described population, with a peak prevalence of the disease seen in the 55-65 years age group. Changes in the pathophysiology of MS appear to be age-dependent. Several studies have identified a consistent phase of disability worsening around the fifth decade of life. The latter appears to be independent of prior disease duration and inflammatory activity and concomitant to pathological changes from acute focal active demyelination to chronic smoldering plaques, slow-expanding lesions, and compartmentalized inflammation within the central nervous system (CNS). On the other hand, decreased CNS tissue reserve and poorer remyelinating capacity with aging lead to loss of relapse recovery potential. Aging with MS may imply longer exposure to DMTs, although treatment efficacy in patients >55 years has not been evaluated in pivotal randomized controlled trials and appears to decrease with age. Older individuals are more prone to adverse effects of DMTs, an important aspect of treatment individualization. Aging with MS also implies a higher global burden of comorbid illnesses that contribute to overall impairments and represent a crucial confounder in interpreting clinical worsening. Discontinuation of DMTs after age 55, when no evidence of clinical or radiological activity is detected, is currently under the spotlight. In this review, we will discuss the impact of aging on MS pathobiology, the effect of comorbidities and other confounders on clinical worsening, and focus on current therapeutic considerations in this age group.

The delicate balance of graft versus leukemia and graft versus host disease after allogeneic hematopoietic stem cell transplantation

INTRODUCTION

The curative basis of allogeneic hematopoietic stem cell transplantation (HSCT) relies in part upon the graft versus leukemia (GvL) effect, whereby donor immune cells recognize and eliminate recipient malignant cells. However, alloreactivity of donor cells against recipient tissues may also be deleterious. Chronic graft versus host disease (cGvHD) is an immunologic phenomenon wherein alloreactive donor T cells aberrantly react against host tissues, leading to damaging inflammatory symptoms.

AREAS COVERED

Here, we discuss biological insights into GvL and cGvHD and strategies to balance the prevention of GvHD with maintenance of GvL in modern HSCT.

EXPERT OPINION/COMMENTARY

Relapse remains the leading cause of mortality after HSCT with rates as high as 40% for some diseases. GvHD is a major cause of morbidity after HSCT, occurring in up to half of patients and responsible for 15-20% of deaths after HSCT. Intriguingly, the development of chronic GvHD may be linked to lower relapse rates after HSCT, suggesting that GvL and GvHD may be complementary sides of the immunologic foundation of HSCT. The ability to fine tune the balance of GvL and GvHD will lead to improvements in survival, relapse rates, and quality of life for patients undergoing HSCT.

Infectious risk when prescribing rituximab in patients with hypogammaglobulinemia acquired in the setting of autoimmune diseases

We conducted a single-centre retrospective cohort study in a French University Hospital between 2010 and 2018 to describe the risk of severe infectious event (SIE) within 2 years after the date of first rituximab infusion (T0) prescribed after the evidence of acquired hypogammaglobulinemia (gamma globulins [GG] ≤ 6 g/L) in the setting of autoimmune diseases (AID) other than rheumatoid arthritis. SIE occurred in 26 out of 121 included patients. Two years cumulative incidence rates were 12.7 % (95 % CI 5.1-23.9) in the multiple sclerosis/neuromyelitis optica spectrum disorder group (n = 48), 27.6 % (95 % CI 15.7-40.9) in the ANCA-associated vasculitis group (n = 48) and 30.6 % (95 % CI 13.1-50.3) in the 'other AID' group (n = 25). Median GG level at T0 was 5.3 g/l (IQR 4.1-5.6) in the 'SIE' group and 5.6 g/l (IQR 4.7-5.8) in the 'no SIE' group (p = 0.04). In regression analysis, risk of SIE increased with Charlson comorbidity index ≥ 3 (OR 2.77; 95 % CI 1.01-7.57), lung disease (OR 3.20; 95 % CI 1.27-7.99), GG < 4 g/L (OR 3.39; 95 % CI 1.02-11.19), concomitant corticosteroid therapy (OR 4.13; 95 % CI 1.63-10.44), previous cyclophosphamide exposure (OR 2.69; 95 % CI 1.10-6.61), a lymphocyte count < 1000 cells/µL (OR 2.86; 95 % CI 1.12-7.21) and absence of pneumococcal vaccination (OR 3.50; 95 % CI 1.41-8.70). These results may help to inform clinical decision when considering a treatment by rituximab in immunosuppressed AID patients with hypogammaglobulinemia.

Effect of rituximab on immune status in children with mature B-cell non-Hodgkin lymphoma: a prespecified secondary analysis of the Inter-B-NHL Ritux 2010 trial

BACKGROUND

Survival of children and adolescents with high-risk, mature B-cell non-Hodgkin lymphoma is improved by the addition of rituximab to chemotherapy. The effect of rituximab on immune reconstitution after therapy has not been well described. Herein, we evaluate the immune effects of the addition of rituximab to intensive chemotherapy, a prespecified secondary aim of the Inter-B-NHL Ritux 2010 trial.

METHODS

The Inter-B-NHL Ritux 2010 trial was an international, open-label, randomised, phase 3 trial in children (age 6 months to 18 years) with high-risk, mature B-cell non-Hodgkin lymphoma, comparing chemotherapy alone or chemotherapy with rituximab. Measures of immune status were completed at baseline, 1 month from the end of treatment, and 1 year from the start of therapy, and yearly thereafter until normalised. For this secondary analysis, we report on the proportions of patients with low lymphocyte counts and immunoglobulin concentrations at these timepoints with total lymphocyte count, B-cell count, and IgG concentration as the main endpoints. Other endpoints of interest included exposure to immunoglobulin replacement therapy and vaccine serologies. The population assessed for immune endpoints was the eligible per-protocol population with at least one immune parameter at one timepoint. Comparisons of immune status were made between the randomised treatment groups. Safety in the post-therapy period was assessed in the population eligible for the immunity study who were followed up at least 3 months after the end of treatment and without cancer-related events. The Inter-B-NHL Ritux 2010 study was registered with ClinicalTrials.gov, NCT01516580; status completed, with analyses of secondary aims ongoing.

FINDINGS

From Dec 19, 2011, to June 13, 2017, 421 patients (344 [82%] boys and 77 [18%] girls; mean age was 8·8 years [SD 4·1]) were enrolled and had immune data at baseline during follow-up, or both. The study population included randomly assigned patients (n=289) and a non-randomised cohort enrolled after the planned interim analysis (n=132). At baseline, 99 (34%) of 290 patients with available data (excluding patients with bone marrow disease with peripheral blast cells) had lymphopenia, and 178 (48%) of 368 had hypogammaglobulinemia. 1 month from the end of therapy, patients who received chemotherapy with rituximab were more likely than those who received chemotherapy alone to have lymphopenia (86 [81%] of 106 vs 53 (60%) of 89, odds ratio [OR] 2·92 [95% CI 1·53-5·57], p=0·0011), B-cell lymphopenia (72 [96%] of 75 vs 36 [64%] of 56, OR 13·33 [3·71-47·84], p<0·0001), and hypogammaglobulinemia (67 [71%] of 95 vs 37 [47%] of 79, OR 2·72 [1·45-5·07], p=0·0017). Differences remained at 1 year for hypogammaglobulinemia only (52 [55%] of 94 vs 16 [25%] of 63, OR 3·64 [1·81-7·31], p=0·0003). Patients in the chemotherapy with rituximab group were more likely than those in the chemotherapy group to receive immunoglobulin replacement (26 [16%] 164 vs nine [7%] of 158, hazard ratio [HR] 2·63 [95% CI 1·23-5·62], p=0·010), mainly due to low immunoglobulin concentration. In the combined treatment groups, including non-randomly assigned patients, the proportion of patients who had loss of protective serologies to a vaccine preventable infection varied from four (9%) of 47 for polio to 21 (42%) of 50 for Streptococcus pneumoniae (pneumococcus). One patient (chemotherapy with rituximab group) had a life-threatening infectious event of polymicrobial bacterial sepsis reported 2 months after the final chemotherapy administration.

INTERPRETATION

Children with high-risk mature B-cell non-Hodgkin lymphoma receiving chemotherapy with rituximab were at risk of prolonged hypogammaglobulinemia, although severe infections were rare. Strategies for immunoglobulin replacement and revaccination are needed.

FUNDING

Clinical Research Hospital Program of the French Ministry of Health, Cancer Research UK, National Institute for Health Research Clinical Research Network in England, Children's Cancer Foundation Hong Kong, US National Cancer Institute, F Hoffmann-La Roche.

B cell subsets reconstitution and immunoglobulin levels in children and adolescents with B non-Hodgkin lymphoma after treatment with single anti CD20 agent dose included in chemotherapeutic protocols: single center experience and review of the literature

BACKGROUND

RTX, an anti-CD20 monoclonal antibody, added to chemotherapy has proven to be effective in children and adolescents with high-grade, high-risk and matured non-Hodgkin lymphoma. RTX leads to prompt CD19+ B lymphocyte depletion. However, despite preserved immunoglobulin production by long-lived plasmablasts after treatment, patients remain at risk of prolonged hypogammaglobulinemia. Further, there are few general guidelines for immunology laboratories and clinical feature monitoring after B cell-targeted therapies. The aim of this paper is to describe B cell reconstitution and immunoglobulin levels after pediatric B-NHL protocols, that included a single RTX dose and to review the literature.

METHODS

A retrospective single-center study on the impact of a single RTX dose included in a chemotherapeutic pediatric B Non-Hodgkin Lymphoma (B-NHL) treatment protocols. Immunology laboratory and clinical features were evaluated over an eight hundred days follow-up (FU) period, after completing B-NHL treatment.

RESULTS

Nineteen patients (fifteen Burkitt lymphoma, three Diffuse large B cell lymphoma, and one Marginal zone B cell lymphoma) fulfilled the inclusion criteria. Initiation of B cell subset reconstitution occurred a median of three months after B-NHL treatment. Naïve and transitional B cells declined over the FU in contrast to the marginal zone and the switched memory B cell increase. The percentage of patients with IgG, IgA, and IgM hypogammaglobulinemia declined consistently over the FU. Prolonged IgG hypogammaglobulinemia was detectable in 9%, IgM in 13%, and IgA in 25%. All revaccinated patients responded to protein-based vaccines by specific IgG antibody production increase. Following antibiotic prophylaxes, none of the patients with hypogammaglobulinemia manifested with either a severe or opportunistic infection course.

CONCLUSION

The addition of a single RTX dose to the chemotherapeutic treatment protocols was not shown to increase the risk of developing secondary antibody deficiency in B-NHL pediatric patients. Observed prolonged hypogammaglobulinemia remained clinically silent. However interdisciplinary agreement on regular long-term immunology FU after anti-CD20 agent treatment is required.

Rituximab treatment of adults with primary focal segmental glomerulosclerosis

To evaluate the efficacy and safety of rituximab (RTX) in the treatment of primary focal segmental glomerulosclerosis (FSGS) in adults. The clinical data of patients with primary FSGS who received RTX treatment in the First Affiliated Hospital of Zhengzhou University were analyzed retrospectively. The selected patients received RTX twice or four times, with a single dose of 375 mg/m², and the interval between two times of administration of RTX was 2-4 weeks. The treatment target is to achieve the clearance of B cells (peripheral blood B cell count < 5/μl). The primary outcome measures were remission and recurrence of renal disease, and the secondary outcome measures were adverse events and renal outcomes. A total of 14 FSGS patients were included, including 12 males, 9 with glucocorticoid-dependent or frequently relapsing nephrotic syndrome, and 3 with newly diagnosed nephrotic syndrome. After RTX treatment, 7 patients with glucocorticoid-dependent/recurrent nephrotic syndrome were completely relieved. At 6 months of follow-up, glucocorticoids were discontinued in all patients except 1 patient. The other 5 patients achieved partial remission (PR), of which 1 patient relapsed after PR, and 1 initial patient achieved complete remission. One patient progressed to end-stage renal disease (ESRD) after 4 months of follow-up. RTX in the treatment of adult glucocorticoid-dependent/relapsing FSGS can reduce the risk of recurrence and help to decline or discontinue the use of glucocorticoid and immunosuppressants.

Hypogammaglobulinemia secondary to B-cell depleting therapies in neuroimmunology: Comparing management strategies

Background

Anti-CD20 agents are commonly used in MS, NMOSD, and MOGAD. Few studies have compared strategies to address hypogammaglobulinemia.

Objective

To compare strategies to manage secondary hypogammaglobulinemia in neuroimmunology patients, including reducing anti-CD20 dose and dosing frequency, IVIG/SCIG, anti-CD20 cessation, and DMT switches.

Methods

All MS, NMOSD, and MOGAD patients at our institution with hypogammaglobulinemia on anti-CD20 agents from 2001 to 2022 were analyzed. The median change in IgG, infection frequency, and infection severity before and after the treatment was calculated.

Results

In total, 257 patients were screened, and 30 had a treatment for hypogammaglobulinemia. IVIG/SCIG yielded the largest increase in IgG per year (674.0 mg/dL), followed by B-cell therapy cessation (34.7 mg/dL), and DMT switch (5.9 mg/dL). Dose reduction had the largest decrease in yearly infection frequency (2.7 fewer infections), followed by IVIG/SCIG (2.5 fewer), DMT switch (2 fewer), and reduced dosing frequency (0.5 fewer). Infection grade decreased by 1.9 for reduced dosing frequency (less severe infections), by 1.3 for IVIG/SCIG, and by 0.6 for DMT switch.

Conclusion

This data suggests that IVIG/SCIG may yield the greatest recovery in IgG while also reducing infection frequency and severity. Stopping anti-CD20 therapy and/or switching DMTs also increase IgG and may lower infection risk.

Use of Rituximab in Childhood Idiopathic Nephrotic Syndrome

Rituximab is an established therapy in children with idiopathic nephrotic syndrome to sustain short- to medium-term disease remission and avoid steroid toxicities. Recent trials focus on its use as a first-line agent among those with milder disease severity. Rituximab is used in multidrug refractory nephrotic syndrome and post-transplant disease recurrence, although the evidence is much less substantial. Available data suggest that the treatment response to rituximab depends on various patient factors, dosing regimen, and the concomitant use of maintenance immunosuppression. After repeated treatments, patients are found to have an improving response overall with a longer relapse-free period. The drug effect, however, is not permanent, and 80% of patients eventually relapse and many will require an additional course of rituximab. This underpins the importance of understanding the long-term safety profile on repeated treatments. Although rituximab appears to be generally safe, there are concerns about long-term hypogammaglobulinemia, especially in young children. Reliable immunophenotyping and biomarkers are yet to be discovered to predict treatment success, risk of both rare and severe side effects, e.g. , persistent hypogammaglobulinemia, and guiding of redosing strategy. In this review, we highlight recent advances in the use of rituximab for childhood nephrotic syndrome and how the therapeutic landscape is evolving.

Treatment of inflammatory complications in common variable immunodeficiency (CVID): current concepts and future perspectives

INTRODUCTION

Patients with Common variable immunodeficiency (CVID) have a high frequency of inflammatory complications like autoimmune cytopenias, interstitial lung disease and enteropathy. These patients have poor prognosis and effective, timely and safe treatment of inflammatory complications in CVID are essential, but guidelines and consensus on therapy are often lacking.

AREAS COVERED

This review will focus on current medical treatment of inflammatory complications in CVID and point out some future perspectives based on literature indexed in PubMed. There are a number of good observational studies and case reports on treatment of specific complications but randomized controlled trials are scarce.

EXPERT OPINION

In clinical practice, the most urgent issues that need to be addressed are the preferred treatment of GLILD, enteropathy and liver disease. Treating the underlying immune dysregulation and immune exhaustion in CVID is an alternative approach that potentially could alleviate these and other organ-specific inflammatory complications. Therapies of potential interest and wider use in CVID include mTOR-inhibitors like sirolimus, JAK-inhibitors like tofacitinib, the monoclonal IL-12/23 antibody ustekinumab, the anti-BAFF antibody belimumab and abatacept. For all inflammatory complications, there is a need for prospective therapeutic trials, preferably randomized controlled trials, and multi-center collaborations with larger cohorts of patients will be essential.

Low-dose immune tolerance induction therapy in severe hemophilia a children in China: Starting earlier resulted in better inhibitor eradication outcomes

BACKGROUND

Shorter interval-time from inhibitor detection to starting immune tolerance induction (ITI) might predict better ITI outcomes for severe Hemophilia A (SHA) patients with high-risk-inhibitors. However, the prediction-impact of interval-time for these patients on low-dose ITI strategy remained unclear.

OBJECTIVES

To explore the relationship between interval-time and low-dose ITI outcomes in Chinese SHA children with high-risk-inhibitors.

METHODS

This was a single-center, retrospective study on SHA children with high-risk-inhibitors (each with immediate pre-ITI inhibitor titer>10 Bethesda Units/mL) undergoing low-dose ITI strategy for ≥24 months. ITI outcomes and their predictive factors were evaluated at the 24th month treatment for each patient. The predictive ability of interval-time on ITI success was determined using receiver operating characteristic (ROC) curve.

RESULTS

Among 47 patients investigated, 34 (72.3 %) achieved success. Independent predictor for ITI-outcome on multivariate analysis included the interval-time (p = 0.007) and peak inhibitor-titer (p = 0.011). Shorter interval-time predicted ITI success [cut-off value = 22.3 months, area under ROC-curve (AUC) = 0.701] and early-ITI success within 12 month (cut-off value = 9.4 months AUC = 0.704). Linear regression analysis suggested each month interval-time delay delayed success by 0.1552 month. Unlike the interval-time, peak inhibitor-titer had no success-predictive value in high-peak inhibitor-titer patients on ITI with immunosuppressants.

CONCLUSIONS

Interval-time represented a strong predictive value for outcomes in our low-dose ITI strategy for SHA patients with high-risk-inhibitors. Shorter interval-time was associated with higher success rate and earlier success achievement. The respective interval-time cut-off values were 22.3 months for ITI success and 9.4 months for early-success.

Secondary immunodeficiencies and infectious considerations of biologic immunomodulatory therapies

Biologic immunomodulatory medications have rapidly expanded in the previous decades, providing new treatment options for individuals with a spectrum of oncologic, allergic, rheumatologic, and neurologic conditions. Biologic therapies alter immune function and can impair key host defense mechanisms, resulting in secondary immunodeficiency and increased infectious risks. Biologic medications can increase general risk for upper respiratory tract infections but can also be associated with unique infectious risks owing to distinct mechanisms of action. With the widespread use of these medications, providers in every area of medicine will likely care for individuals receiving biologic therapies and understanding their potential infectious complications can help mitigate these risks. This practical review discusses the infectious implications of biologics by class of medication and provides recommendations regarding the examination and screening both before therapy initiation and while the patient is receiving the medication. With this knowledge and background, providers can reduce risk whereas patients receive the treatment benefits of these biologic medications.

Targeting B Cells and Microglia in Multiple Sclerosis With Bruton Tyrosine Kinase Inhibitors: A Review

Importance

Currently, disease-modifying therapies for multiple sclerosis (MS) use 4 mechanisms of action: immune modulation, suppressing immune cell proliferation, inhibiting immune cell migration, or cellular depletion. Over the last decades, the repertoire substantially increased because of the conceptual progress that not only T cells but also B cells play an important pathogenic role in MS, fostered by the empirical success of B cell-depleting antibodies against the surface molecule CD20. Notwithstanding this advance, a continuous absence of B cells may harbor safety risks, such as a decline in the endogenous production of immunoglobulins. Accordingly, novel B cell-directed MS therapies are in development, such as inhibitors targeting Bruton tyrosine kinase (BTK).

Observations

BTK is centrally involved in the B cell receptor-mediated activation of B cells, one key requirement in the development of autoreactive B cells, but also in the activation of myeloid cells, such as macrophages and microglia. Various compounds in development differ in their binding mode, selectivity and specificity, relative inhibitory concentration, and potential to enter the central nervous system. The latter may be important in assessing whether BTK inhibition is a promising strategy to control inflammatory circuits within the brain, the key process that is assumed to drive MS progression. Accordingly, clinical trials using BTK inhibitors are currently conducted in patients with relapsing-remitting MS as well as progressive MS, so far generating encouraging data regarding efficacy and safety.

Conclusions and Relevance

While the novel approach of targeting BTK is highly promising, several questions remain unanswered, such as the long-term effects of using BTK inhibitors in the treatment of inflammatory CNS disease. Potential changes in circulating antibody levels should be evaluated and compared with B cell depletion. Also important is the potential of BTK inhibitors to enter the CNS, which depends on the given compound. Remaining questions involve where BTK inhibitors fit in the landscape of MS therapeutics. A comparative analysis of their distinct properties is necessary to identify which inhibitors may be used in relapsing vs progressive forms of MS as well as to clarify which agent may be most suitable for sequential use after anti-CD20 treatment.

Predictors of hospitalization due to infection in rituximab-treated MS patients

BACKGROUND

Rituximab is extensively used off-label to treat multiple sclerosis (MS), and long-term vigilance for adverse events is needed. This study was conducted to determine frequencies and predictors of hematological adverse events, including hypogammaglobulinemia, severe lymphopenia, neutropenia, and infections leading to hospitalization.

METHODS

This retrospective cohort study included all patients with MS initiating rituximab treatment at Haukeland University Hospital between January 1^st, 2017, and July 1^st, 2021. Patients were followed by clinical monitoring and repeated blood sampling every six months. Clinical outcomes and laboratory results were retrieved from the Norwegian MS Registry and Biobank and the patient administrative system at Haukeland University Hospital.

RESULTS

Five hundred and fifty-six patients were included, 515 with relapsing-remitting MS (RRMS) and 41 with progressive MS. Overall, 33 patients (5.9%) experienced 56 episodes of infections requiring hospital admission. Sixty patients (10.8%) had confirmed hypogammaglobulinemia, 17 (3.1%) had confirmed severe lymphopenia, and 10 (1.8%) had confirmed severe neutropenia. Predictors of infection requiring hospital admission were progressive MS (adjusted OR (aOR): 4.81; 95%CI: 1.25-18.48), duration of treatment with rituximab (aOR: 1.52; 95%CI: 1.11-2.09) and confirmed severe lymphopenia (aOR: 13.58; 95%CI: 3.41-54.06) and neutropenia (aOR: 13.40; 95%CI: 2.93-61.25). Of the hematological abnormalities, only hypogammaglobulinemia was associated with treatment duration (aOR: 1.35; 95%CI: 1.09-1.69).

CONCLUSION

The risk of hospitalization due to infection is associated with time on rituximab treatment, in patients with lympho- or neutropenia, and in patients with primary progressive MS. We observed a time-dependent decline in IgG values, in contrast to neutrophil and lymphocyte count, suggesting a cumulative dose-dependent response. These predictors can assist clinicians in assessing and monitoring MS patients receiving rituximab.

The association between hypogammaglobulinemia severity and infection risk in rituximab-treated patients with childhood-onset idiopathic nephrotic syndrome

BACKGROUND

Hypogammaglobulinemia is a major adverse effect from rituximab. However, the association between rituximab-induced hypogammaglobulinemia and infection frequency is unknown.

METHODS

Patients who received rituximab for complicated nephrotic syndrome between February 2006 and October 2020 were enrolled in this retrospective observational study. Infections requiring antibacterial or antiviral agents or hospitalization were identified, and the characteristics of infections were compared according to infection type.

RESULTS

One hundred and forty patients were enrolled. Fifty infection events were detected in 36 patients, 45 infection events in 32 patients required hospitalization, and 1 severe infection event required intensive care unit admission. In eight patients who developed severe hypogammaglobulinemia (serum IgG level < 200 mg/dL) for more than 1 year after rituximab treatment, eight infections occurred in six patients; six of these infections did not occur during the period of severe hypogammaglobulinemia. Febrile neutropenia accounted for 54.2% (13/24) of all infections among the patients with hypogammaglobulinemia. The incidence of infections was 0.028 (95% confidence interval = 0.017-0.448), 0.071 (95% [CI] = 0.041-0.114), and 0.096 (95% [CI] = 0.019-0.282) patient-years in patients with normal serum IgG levels and those with mild and severe hypogammaglobulinemia, respectively. Immunoglobulin replacement therapy was not administered to any patients except for the treatment of infection.

CONCLUSIONS

Our results showed no statistically significant association between hypogammaglobulinemia severity and infection rate. In addition, the frequency of infection was relatively low even in patients with severe hypogammaglobulinemia, suggesting that immunoglobulin replacement therapy may not be necessary for rituximab-treated patients with severe hypogammaglobulinemia. A higher resolution version of the Graphical abstract is available as Supplementary information.

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.

The effect of cladribine on immunoglobulin levels compared to B cell targeting therapies in multiple sclerosis

Background

Cladribine is a useful therapeutic option in RRMS with moderate to high disease activity. Its oral formulation and tolerability make it a useful alternative to infusion therapies. Cladribine is known to deplete CD19⁺ B lymphocytes, but its effect on immunoglobulin subsets is unclear.

Objective

To identify whether cladribine therapy in pwMS reduces immunoglobulin subset levels as a surrogate marker of infection risk.

Methods

A 'real-world' retrospective analysis of 341 pwMS presenting to a single tertiary centre between March 2017 and July 2021. Differences in immunoglobulin levels between cladribine, other disease-modifying therapies and no active treatment were assessed using a univariate ANOVA.

Results

Three hundred and forty-one patients had immunoglobulin levels assessed, with 29 patients treated with cladribine. The mean IgG, IgM and IgA levels on cladribine therapy were 10.44 ± 0.40, 0.99 ± 0.09 and 2.04 ± 0.18 g/L respectively. These were not significantly different from patients not on active treatment. There was a statistically significant reduction in IgG and IgM levels for patients treated with ocrelizumab (9.37 ± 0.19 and 0.68 ± 0.04 g/L) and natalizumab (8.72 ± 0.53 and 0.69 ± 0.12 g/L) compared to patients not on treatment.

Conclusion

Cladribine therapy for RRMS was not associated with immunoglobulin subset deficiencies. This is contrasted to ocrelizumab and natalizumab which demonstrate significant reductions in both IgG and IgM levels.

The impact of disease-modifying therapies on immunoglobulin blood levels in patients with multiple sclerosis: a retrospective cross-sectional study

Background

Although disease-modifying therapies (DMTs) in multiple sclerosis (MS) are known to target the immune system, mechanisms of action, efficacy, safety, and tolerability profiles differ. The long-term impact of DMTs on the immune system and its relation to infectious complications is still poorly understood.

Objectives

To analyze the effect of DMTs on serum immunoglobulin (Ig) levels under consideration of patient demographics and therapy duration.

Design

We included 483 patients on DMTs, 69 patients without DMTs, and 51 controls in this retrospective cross-sectional study.

Methods

IgG, IgM, and IgG subclass 1-4 levels of patients with MS under treatment with DMTs were compared with treatment naive MS patients and controls by multivariate linear regression. Further, Ig levels stratified by DMTs were analyzed regarding therapy duration.

Results

MS patients treated with fingolimod (FG), natalizumab, and B-cell depleting therapies (BCDT) demonstrated significantly lower IgG and IgM levels than healthy controls after a median treatment of 37, 31, and 23 months, respectively (p < 0.05). Treatment with dimethyl fumarate (DMF) and teriflunomide was associated with lower IgG, but not IgM levels. DMF and BCDT were also associated with lower IgG1 levels, while FG led to a reduction of IgG2. Treatment with interferon-beta (IFN) and glatiramer acetate (GA) had no impact on Ig levels. Analysis of subgroups by linear regression also showed a time-dependent decrease of Igs levels in patients treated with BCDT with a median annual reduction of IgG of 3.2% and IgM of 6.2%.

Conclusion

Treatment with DMTs, except GA and IFN, was associated with a decrease in Ig levels. DMTs differed in the extent of decreasing Ig levels but also in their differential effects on Ig subclasses. Monitoring of Ig levels should be considered in patients on long-term treatment with DMTs, particularly those on BCDT, to identify patients at risk of low immunoglobulin levels.

Management of Patients with Systemic Sclerosis-Associated Interstitial Lung Disease: A Focus on the Role of the Pharmacist

Interstitial lung disease (ILD) is a common manifestation of systemic sclerosis (SSc), which becomes fibrosing and progressive in some patients. Regular monitoring of patients with SSc-ILD is important to assess progression and inform treatment decisions. Therapy for SSc-ILD may include immunomodulatory and antifibrotic therapies. Therapeutic decisions should be made on a case-by-case basis, ideally following multidisciplinary discussion. Most patients with SSc-ILD have several organ manifestations of SSc or comorbidities and are taking a complex medication regimen. Patients with SSc are particularly susceptible to gastrointestinal side-effects of medications due to the gastrointestinal manifestations of the disease. Pharmacists play an important role in the management of patients with SSc-ILD by assisting patients with access to medications, optimizing medication regimens, and advising on alternative dosage forms. Pharmacists can also contribute to patient education to help patients better understand their treatment and how to prevent and manage potential side effects.