Long-Term Safety of Rituximab (Risks of Viral and Opportunistic Infections)

Parasite and host immune factors that impact the development of a mucosal vaccine for Cryptosporidium

The parasite Cryptosporidium is a leading cause of diarrhea and death in malnourished children and immunocompromised individuals and an important enteric pathogen of livestock. A mucosal vaccine to mitigate clinical disease and decrease transmission would address the public health impact of this organism, but current options are limited. The development of a rational strategy for vaccination requires an appreciation of the parasite life cycle, how Cryptosporidium interacts with its host cell (the enterocyte), and the immune mechanisms that act locally to control this organism. Here we review current knowledge of the adaptive immune mechanisms that mediate resistance to Cryptosporidium, their relevance to vaccine design, and how recent advances in parasite genetics inform vaccine development.

Single-Agent and Associated Therapies with Monoclonal Antibodies: What About Follicular Lymphoma?

Monoclonal antibodies (mAbs) have become a cornerstone in the treatment of follicular lymphoma (FL), offering highly specific therapeutic targeting that enhances efficacy while minimizing systemic toxicity. Their mechanisms of action include antibody-dependent cellular cytotoxicity (ADCC), complement-dependent cytotoxicity (CDC), and direct apoptotic signaling, effectively mediating malignant B-cell depletion. Anti-CD20 mAbs, such as rituximab and obinutuzumab, have significantly improved progression-free survival (PFS) and overall survival (OS), establishing immunochemotherapy as the standard of care for FL. However, the emergence of treatment resistance, often characterized by CD20 antigen downregulation or immune escape, has prompted the development of next-generation mAbs with enhanced effector functions. Bispecific antibodies (BsAbs), which simultaneously engage CD20-expressing tumor cells and CD3-positive cytotoxic T cells, have emerged as a novel immunotherapeutic strategy, redirecting T-cell activity to eliminate malignant B cells independently of major histocompatibility complex (MHC) antigen presentation. Additionally, antibody-drug conjugates (ADCs) offer a targeted cytotoxic approach by delivering potent chemotherapeutic payloads directly to tumor cells while limiting off-target effects. The integration of mAbs with immune checkpoint inhibitors and immunomodulatory agents is further enhancing treatment outcomes by overcoming immunosuppressive mechanisms within the tumor microenvironment. Despite these advancements, challenges remain, including optimizing the treatment sequence, mitigating immune-related toxicities-particularly cytokine release syndrome (CRS)-and identifying predictive biomarkers to guide patient selection. As the role of monoclonal antibodies continues to expand, their integration into therapeutic regimens is transforming the management of FL, paving the way for chemotherapy-free treatment approaches and long-term disease control. This review provides an updated overview of mAbs therapies for FL, emphasizing the advances brought by BsAbs and ADCs toward more tailored and effective treatments.

The efficacy of apremilast in pemphigus: a systematic review of case reports

Pemphigus is a severe autoimmune blistering disorder that significantly affects patients' quality of life. While corticosteroids and immunosuppressive agents are commonly used, they have substantial side effects, highlighting the need for safer alternatives. Apremilast, an oral phosphodiesterase 4 (PDE4) inhibitor, has shown efficacy in treating other autoimmune diseases and may offer promise for pemphigus. This systematic review evaluated the clinical outcomes, safety, and potential role of apremilast in pemphigus treatment by synthesizing available case reports and series. A literature search was conducted across multiple databases (PubMed, EMBASE, Cochrane, Web of Science, ScienceDirect, and Google Scholar) for case reports and series involving apremilast in pemphigus. Inclusion criteria were a confirmed pemphigus diagnosis and apremilast treatment. Five studies (four case reports and one case series) involving seven patients were included. Apremilast led to significant clinical improvement in four patients, with reductions in disease activity, lesion severity, and symptom scores (Pemphigus Disease Area Index, Autoimmune Bullous Skin Disorder Intensity Score, Visual Analog Scale, and Numerical Rating Score). Increases in regulatory T cells and decreases in anti-desmoglein antibodies were observed. No serious adverse events were reported, although one study noted treatment failure, possibly due to short follow-up or concurrent infections. Apremilast appears to be a promising treatment for therapy-resistant or corticosteroid-intolerant pemphigus patients. Although the evidence is limited, it supports apremilast's efficacy and favorable safety profile. Further research with larger sample sizes and randomized controlled trials is necessary to confirm these findings.

Pulmonary Complications of Biological Therapies in Inflammatory and Autoimmune Diseases

Infective and noninfective pulmonary complications occur with biologic agents and targeted small molecule inhibitors used to treat immune-mediated inflammatory conditions. The most common lower respiratory tract infection is bacterial pneumonia. Opportunistic infections including tuberculosis can also occur at increased rates depending on the immunosuppressive agent, specific disease, and epidemiologic background of the patient. The most common noninfectious sequela is drug-induced interstitial lung disease.

The Incidence, Aetiology and Clinical Course of Serious Infections Complicating Biological and Targeted Synthetic Disease-Modifying Antirheumatic Drug Therapy in Patients with Rheumatoid Arthritis in Tropical Australia

Introduction: Patients receiving biological and targeted synthetic disease-modifying antirheumatic drugs (b/tsDMARDs) for rheumatological conditions are at an increased risk of serious, potentially life-threatening, infection. However, the incidence, aetiology, and clinical course of serious infection in patients receiving b/tsDMARDs in tropical settings are incompletely defined. Methods: We retrospectively reviewed all patients with rheumatoid arthritis receiving b/tsDMARDs between October 2012 and October 2021, at Cairns Hospital in tropical Australia. The incidence, aetiology, and clinical course of serious infections (those requiring admission to hospital or parenteral antibiotics) were determined. Results: 310 patients had 1468 patient years of b/tsDMARD therapy during the study period; 74/310 (24%) had 147 serious infections translating to an overall risk of 10.0 episodes of serious infection per 100 patient years. The respiratory tract (50/147, 34%) and skin (37/147, 25%) were the most frequently affected sites. A pathogen was identified in 59/147 (40%) episodes and was most commonly Staphylococcus aureus (24/147, 16%). Only 2/147 (1%) were confirmed "tropical infections": 1 case of Burkholderia pseudomallei and 1 case of mixed B. pseudomallei and community-acquired Acinetobacter baumannii infection. Overall, 13/147 (9%) episodes of serious infection required Intensive Care Unit admission (0.9 per 100-patient years of b/tsDMARD therapy) and 4/147 (3%) died from their infection (0.3 per 100-patient years of b/tsDMARD therapy). The burden of comorbidity and co-administration of prednisone were the strongest predictors of death or a requirement for ICU admission. Conclusions: The risk of serious infection in patients taking b/tsDMARDs in tropical Australia is higher than in temperate settings, but this is not explained by an increased incidence of traditional tropical pathogens.

Long-term use of rituximab increases T cell count in MS patients

Rituximab has been used to treat MS patients in Iceland for over a decade. However, long-term effect of rituximab on leukocyte populations has not yet been elucidated. By retrospective analysis of flow cytometric data from 349 patients visiting the neurological ward at The National University Hospital of Iceland from 2012 to 2023 for rituximab treatment, the long-term effect of rituximab and whether the effect was dose dependent (1000mg vs 500mg) was evaluated. No difference was detected in efficacy of B cell depletion in patients treated with 500mg as an initial dose of rituximab when compared to 1000mg. Long-term use of rituximab led to an increase in T cell count (p=0,0015) in patients receiving 3-8 doses of rituximab (1.5-8 years of treatment). The increase occurred in both CD4+ (p=0,0028) and CD8+ T cells (p=0,0015) and led to a decrease in the CD4/CD8 ratio (p=0,004). The most notable difference lies in reshaping the balance between näive and effector CD8+ T cells. The clinical implications of long-term treatment with rituximab and its effect on the T cell pool needs to be explored further. Since no difference in B cell depletion was detected between the two patient groups, 1000mg as an initial dose might be excessive, suggesting a personalized dosing regimen might have therapeutic and financial advantages.

Infection incidence, timing and dose dependency in rheumatoid arthritis patients treated with rituximab: a retrospective cohort study

OBJECTIVES

Rituximab (RTX) is a safe and effective treatment for RA. However, there are some concerns about infection risk and preliminary data suggest dose and time dependency. This study aims to determine the infection incidence in a large real-life population of RA patients using RTX, with special focus on (ultra-)low dosing and time since last infusion.

METHODS

RA patients treated with 1000, 500 or 200 mg RTX per cycle between 2012 and 2021 at the Sint Maartenskliniek were included in a retrospective cohort study. Patient-, disease-, treatment- and infection characteristics were retrieved from electronic health records. Infection incidence rates, dose and time relations with RTX infusion were analysed using mixed-effects Poisson regression.

RESULTS

Among 490 patients, we identified 819 infections in 1254 patient years. Most infections were mild and respiratory tract infections were most common. Infection incidence rates were 41, 54 and 71 per 100 patient years for doses of 200, 500 and 1000 mg. Incidence rate ratio (IRR) was significantly lower for 200 mg compared with 1000 mg (adjusted IRR 0.35, 95% CI 0.17, 0.72, P = 0.004). In patients receiving 1000 or 500 mg RTX, infections seemed to occur more frequently within the first two months after infusion compared with later on in the treatment cycle, suggesting an association with peak concentration.

CONCLUSION

Ultra-low dosing (200 mg) of RTX is associated with a lower risk of infections in RA. Future interventions focusing on ultra-low dosing and slow release of RTX (e.g. by subcutaneous administration) may lower infection risk.

Rituximab in the Management of Autoimmune Bullous Diseases: A Treatment-Resistant Case Series from a Single Central European Referral Center

Background and Objectives: Rituximab (RTX) has been the predominant treatment for autoimmune bullous diseases (AIBDs). The objective of this research was to assess the advantages and safety characteristics of RTX treatment in individuals with AIBD. This assessment focused on clinical remission and a reduction in glucocorticosteroid usage, its effect on the titers of autoantibodies targeting desmoglein-1 (DSG-1) and desmoglein-3 (DSG-3), and adverse occurrences during a 12-month follow-up period in a dermatology department within a Central European university context. Materials and Methods: Our case series involved eleven patients, including eight patients with pemphigus vulgaris, two with pemphigus foliaceus, and one with epidermolysis bullosa acquisita. They received a 1 g dose of rituximab, repeated over a two-week interval. Results: The reduction in a prednisone-equivalent dosage after 2, 6, and 12 months following the second RTX infusion was 65.05%, 73.99%, and 76.93%, in that order. The titers of antibodies against DSG-1 exhibited reductions of 43.29%, 75.86%, and 54.02% at 2, 6, and 12 months, respectively. By contrast, the antibody concentrations targeting DSG-3 displayed a decrease of 27.88%, 14.48%, and 5.09% at the corresponding time points. Over the course of the 12-month monitoring period, 18.18% of patients experienced disease relapse, while the remaining individuals achieved either complete or partial remission with minimal or no therapy. Adverse effects were noted in 36.36% of the patient population; they were mild, and no serious adverse effects were reported. Conclusions: RTX represents an efficacious and well-tolerated therapeutic option for the management of AIBD and merits consideration in cases of refractory AIBD. However, further research is imperative to delineate the most optimal dosage, dosing frequency, and total quantity of maintenance infusions required. Additionally, there is a compelling need for studies that explore the impact of RTX on individuals with AIBD who do not exhibit a significant reduction in anti-desmoglein autoantibody levels.

Identification of Covariates Modulating B-Cell Repopulation Kinetics in Subjects Receiving Rituximab Treatment

OBJECTIVE

B-cell depletion using the anti-CD20 monoclonal antibody rituximab is a cornerstone in the therapeutic concept of multiple autoimmune diseases. B-cell depletion is associated with a higher risk for severe infections, and the time span of B-cell repopulation differs greatly between individuals. Data on factors influencing B-cell repopulation kinetics are limited. This study aims to identify patient-specific and therapy-associated covariates that modulate B-cell repopulation.

METHODS

This single-center retrospective observational study presents data of 839 subjects receiving 2,017 courses of rituximab for autoimmune diseases. Assessed covariates are patient-specific factors (sex, age, kidney function, and underlying disease) and co-immunosuppression with common agents (azathioprine, cyclosporine A, cyclophosphamide, hydroxychloroquine, methotrexate, mycophenolate mofetil, tacrolimus, and corticosteroids). The primary end point is the time to B-cell repopulation (≥5/μl). The secondary end point is the time to B-cell reconstitution (≥50/μl). Multivariate time-to-event analysis and logistic regression models were applied to estimate the influence of covariates.

RESULTS

Age over 60 years (hazard ratio [HR] 0.71 for repopulation, P = 0.008), impaired kidney function (HR 0.72, P = 0.001), antineutrophil cytoplasmic antibody-associated vasculitis (HR 0.61, P < 0.001), solid organ transplantation (HR 0.4, P < 0.001), and co-immunosuppression with corticosteroids (HR 0.64, P < 0.001) or azathioprine (HR 0.49, P < 0.001) were associated with impaired B-cell repopulation and reconstitution. Effects of corticosteroids (P = 0.043) and azathioprine (P = 0.025) were dose dependent.

CONCLUSION

Prolonged rituximab dosing intervals may be effective to achieve B-cell depletion and reduce risk of infection in advanced age or patients with impaired kidney function. Co-medication with corticosteroids or azathioprine prolongs B-cell recovery, which may increase therapeutic effects but also the rate of adverse events.

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.

Escalation Versus Induction/High-Efficacy Treatment Strategies for Relapsing Multiple Sclerosis: Which is Best for Patients?

After more than 2 decades of recommending an escalating strategy for the treatment of most patients with multiple sclerosis, there has recently been considerable interest in the use of high-efficacy therapies in the early stage of the disease. Early intervention with induction/high-efficacy disease-modifying therapy may have the best risk-benefit profile for patients with relapsing-remitting multiple sclerosis who are young and have active disease, numerous focal T2 lesions on spinal and brain magnetic resonance imaging, and no irreversible disability. Although we have no curative treatment, at least seven classes of high-efficacy drugs are available, with two main strategies. The first strategy involves the use of high-efficacy drugs (e.g., natalizumab, sphingosine 1-phosphate receptor modulators, or anti-CD20 drugs) to achieve sustained immunosuppression. These can be used as a first-line therapy in many countries. The second strategy entails the use of one of the induction drugs (short-term use of mitoxantrone, alemtuzumab, cladribine, or autologous hematopoietic stem cell transplant) that are mainly recommended as a second-line or third-line treatment in patients with very active or aggressive multiple sclerosis disease. Early sustained immunosuppression exposes patients to heightened risks of infection and cancer proportionate to cumulative exposure, and induction drugs expose patients to similar risks during the initial post-treatment period, although these risks decrease over time. Their initial potential safety risks should now be revisited, taking account of long-term data and some major changes in their regimens: natalizumab with the long-term monitoring of John Cunningham virus; use of monthly courses of mitoxantrone with maximum cumulative doses of 36-72 mg/m2, followed by a safer disease-modifying drug; cladribine with only 2-weekly treatment courses required in years 1 and 2 and no systematic treatment for the following 2 years; alemtuzumab, whose safety and clinical impacts have now been documented for more than 6 years after the last infusion; and autologous haematopoietic stem cell transplant, which dramatically reduces transplantation-related mortality with a new regimen and guidelines. Escalation and induction/high-efficacy treatments need rigorous magnetic resonance imaging monitoring. Monitoring over the first few years, using the MAGNIMS score or American Academy of Neurology guidelines, considerably improves prediction accuracy and facilitates the selection of patients with relapsing-remitting multiple sclerosis requiring aggressive treatment.

Povetacicept, an Enhanced Dual APRIL/BAFF Antagonist That Modulates B Lymphocytes and Pathogenic Autoantibodies for the Treatment of Lupus and Other B Cell-Related Autoimmune Diseases

OBJECTIVE

Dysregulated APRIL/BAFF signaling is implicated in the pathogenesis of multiple autoimmune diseases, including systemic lupus erythematosus and lupus nephritis. We undertook this study to develop and evaluate a high-affinity APRIL/BAFF antagonist to overcome the clinical limitations of existing B cell inhibitors.

METHODS

A variant of TACI-Fc generated by directed evolution showed enhanced binding for both APRIL and BAFF and was designated povetacicept (ALPN-303). Povetacicept was compared to wild-type (WT) TACI-Fc and related molecules in vitro and in vivo.

RESULTS

Povetacicept inhibited APRIL and BAFF more effectively than all evaluated forms of WT TACI-Fc and selective APRIL and BAFF inhibitors in cell-based reporter assays and primary human B cell assays, mediating potent suppression of B cell proliferation, differentiation, and immunoglobulin (Ig) secretion. In mouse immunization models, povetacicept significantly reduced serum immunoglobulin titers and antibody-secreting cells more effectively than anti-CD20 monoclonal antibodies, WT TACI-Fc, or APRIL and BAFF inhibitors. In the NZB × NZW mouse lupus nephritis model, povetacicept significantly enhanced survival and suppressed proteinuria, anti-double-stranded DNA antibody titers, blood urea nitrogen, glomerulonephritis, and renal immunoglobulin deposition. In the bm12 mouse lupus model, povetacicept significantly reduced splenic plasmablasts, follicular helper T cells, and germinal center B cells. In non-human primates, povetacicept was well tolerated, exhibited high serum exposure, and significantly decreased serum IgM, IgA, and IgG levels after a single dose.

CONCLUSION

Enhanced APRIL and BAFF inhibition by povetacicept led to greater inhibition of B cell populations critical for autoantibody production compared to WT TACI-Fc and CD20-, APRIL-, or BAFF-selective inhibitors. Potent, dual inhibition by povetacicept has the potential to significantly improve clinical outcomes in autoantibody-related autoimmune diseases.

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.

A systematic review on efficacy, safety and treatment durability of intravenous immunoglobulin in autoimmune bullous dermatoses: Special focus on indication and combination therapy

Autoimmune bullous diseases (AIBDs) are a group of rare blistering dermatoses of the mucous membrane and/or skin. The efficacy, safety and treatment durability of intravenous immunoglobulin (IVIg) as an alternative treatment should be explored to systematically review the available literature regarding treatment outcomes with IVIg in AIBD patients. The predefined search strategy was incorporated into the following database, MEDLINE/PubMed, Embase, Scopus and Web of Science on 18 July 2022. Sixty studies were enrolled using Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. The use of IVIg alone or combined with rituximab was reported in 500 patients with pemphigus, 82 patients with bullous pemphigoid, 146 patients with mucous membranes pemphigoid and 19 patients with epidermolysis bullosa acquisita. Disease remission with IVIg therapy and RTX + IVIg combination therapy were recorded as 82.8% and 86.7% in pemphigus, 88.0% and 100% in bullous pemphigoid and 91.3% and 75.0% in mucous membrane pemphigoid, respectively. In epidermolysis bullosa acquisita, treatment with IVIg led to 78.6% disease remission; no data were available regarding the treatment with RTX + IVIg in this group of patients. Among all the included patients, 37.5% experienced at least one IVIg-related side effect; the most common ones were headaches, fever/chills and nausea/vomiting. The use of IVIg with or without rituximab had a favourable clinical response in patients with AIBDs. IVIg has no major influence on the normal immune system, which makes its utilization for patients with AIBDs reasonable.

Current evidence of rituximab in the treatment of multiple sclerosis

Multiple sclerosis (MS) is a chronic inflammatory demyelinating disorder of the central nervous system. The immunopathology of MS involves both T and B lymphocytes. Rituximab is one of the anti-CD20 monoclonal antibody therapies which deplete B-cells. Although some anti-CD20 therapies have been approved by the Food and Drug Administration for treatment of MS, rituximab is used off-label. Several studies have shown that rituximab has a good efficacy and safety in MS, including certain specific patient conditions such as treatment-naïve patients, treatment-switching patients, and the Asian population. However, there are still questions about the optimal dose and duration of rituximab in MS due to the different dosing regimens used in each study. Moreover, many biosimilars have become available at a lower cost with comparable physicochemical properties, pharmacokinetics, pharmacodynamics, efficacy, safety, and immunogenicity. Thus, rituximab may be considered as a potential therapeutic option for patients without access to standard treatment. This narrative review summarized the evidence of both original and biosimilars of rituximab in MS treatment including pharmacokinetics, pharmacodynamics, clinical efficacy, safety, and dosing regimen.

COVID-19 disease frequency, risk factors, and re-infection rates in patients with autoimmune rheumatic disease receiving rituximab

INTRODUCTION

Rituximab, which is used in autoimmune rheumatic diseases (ARD), can cause both an increased risk of development of COVID-19 disease and re-infection due to its potent and long-acting immunosuppression. So, we aimed to evaluate the frequency, risk factors and re-infection rates of COVID-19 in ARD patients receiving rituximab.

METHODS

A single-center retrospective study was performed with patients receiving rituximab for ARD in 12 months before the onset of COVID-19 in Turkey. The data regarding severe acute respiratory syndrome-coronavirus 2 reverse transcription polymerized chain reaction (RT-PCR) test, clinical, laboratory, and mortality data of all patients were collected from medical records. Logistic regression analysis was used for predictors of COVID-19 disease. COVID-19 re-infection was defined as RT-PCR positivity and recurrence of acute COVID-19 symptoms after at least 1 negative RT-PCR in patients with clinical improvement.

RESULTS

Ninety-eight ARD patients with rituximab were evaluated and 23 (23%) of them had COVID-19. The presence of hypogammaglobulinemia increased the risk of COVID-19 disease 8-fold. COVID-19 pneumonia occurred in 13 (57%) and these patients' age was higher than those without pneumonia (59.6 ± 11.8 vs 44.9 ± 14.2 years, P = 0.013). Mortality due to COVID-19 was 13% and COVID-19 re-infection was seen in 20% of survivors.

CONCLUSION

Regardless of the underlying rheumatic disease and organ involvements, hypogammaglobulinemia in ARD could be a risk factor for COVID-19 development, and advanced age could be for COVID-19 severity. Moreover, COVID-19 re-infection rates are high.

Evaluation of hepatitis serology and frequency of viral reactivation in patients with inflammatory arthritis receiving biologic agents: a multicenter observational study

To evaluate of hepatitis serology and reactivation frequency in patients with rheumatic disease receiving biologic agents. Our study included patients with inflammatory rheumatic diseases from 23 centers, who were followed up with biological therapy. Demographic and clinical characteristics of the patients, duration of drug use and hepatitis serology and the state of viral reactivation were analyzed. A total of 4060 patients, 2095 being males, were included in our study. Of the patients, 2463 had Ankylosing Spondylitis (AS), 1154 had Rheumatoid Arthritis (RA), 325 had Psoriatic Arthritis (PsA), and 118 had other inflammatory rheumatic diseases. When the viral serology of the patients was evaluated, 79 patients (2%) who were identified as HBs Ag positive, 486 (12%) patients who were HBs Ag negative and anti-HBc IgG positive and 20 patients (0.5%) who were anti-HCV positive. When evaluated on a disease-by-disease basis, the rate of HBsAg was found to be 2.5% in RA, 2% in AS and 0.9% in PsA. Viral reactivation was detected in 13 patients while receiving biologic agents. HBs Ag was positive in nine patients with reactivation and negative in four patients. Anti-HBc IgG, however, was positive. Six of these patients had AS, four had RA, and three had PsA. The development of hepatitis reactivation in 11.4% of HBs Ag positive patients and 0.82% of anti-HBc IgG positive patients due to the use of biologic agents is an important problem for this group of patients. Antiviral prophylaxis is recommended to be started especially in patients who are HBs Ag positive and who are using biologic agents due to viral reactivation. Therefore, it is important to carry out hepatitis screenings before biologic agent treatment and to carefully evaluate the vaccination and prophylaxis requirements.

Regulation of CD8 T cell by B-cells: A narrative review

Activation of CD4 T cells by B cells has been extensively studied, but B cell-regulated priming, proliferation, and survival of CD8 T cells remains controversial. B cells express high levels of MHC class I molecules and can potentially act as antigen-presenting cells (APCs) for CD8 T cells. Several in vivo studies in mice and humans demonstrate the role of B cells as modulators of CD8 T cell function in the context of viral infections, autoimmune diseases, cancer and allograft rejection. In addition, B-cell depletion therapies can lead to impaired CD8 T-cell responses. In this review, we attempt to answer 2 important questions: 1. the role of B cell antigen presentation and cytokine production in the regulation of CD8 T cell survival and cell fate determination, and 2. The role of B cells in the formation and maintenance of CD8 T cell memory.

A Review of Adverse Reactions to Biologics Used in Allergy-Immunology Practice

Biologic agents have become an integral therapeutic option for practicing allergists-immunologists for the management of asthma, atopic dermatitis, chronic rhinosinusitis with nasal polyps, and various immunologic conditions. As these agents vary considerably from traditional small-molecule drugs, various adverse reactions have been noted. A different approach must be used to classify these reactions beyond the classic Gell-Coombs classification system as it does not capture many of the adverse events seen with biologic therapy. This article addresses the available literature on proposed classification systems and diagnostic modalities for adverse events associated with biologics and reviews each approved agent used frequently in allergy-immunology practice.

Late Hepatitis B reactivation after treatment with rituximab

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Patients with past hepatitis B virus (HBV) infections that undergo immunosuppression are in risk of HBV reactivation.

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Antiviral prophylaxis in patient with previous contact with HBV treated with rituximab is recommended by current guidelines.

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The duration of antiviral prophylaxis in patients with hematologic malignancies treated with rituximab remains controversial.

There is a large reservoir of individuals with past hepatitis B virus (HBV) infection that are in risk for HBV reactivation when immunosuppressed. On the setting of hematologic malignancy, the malignancy itself and currently used treatments, especially anti-CD20 agents, have risk of HBV reactivation. Antiviral prophylaxis is recommended by some international societies. We present a case of HBV reactivation more than 12 months after stopping rituximab containing treatment and 6 months of antiviral prophylaxis with entecavir, in a patient with HBV functional cure. The patient was restarted on antivirals and again obtain functional cure. The antiviral was stopped 1 year after seroconversion and the patient followed for another year without evidence of new reactivation. Most literature supports the use of antiviral prophylaxis in patients treated with rituximab. However, there are still conflicting indications and no consensus regarding the duration of prophylaxis. This clinical case and review of the literature supports a longer prophylaxis duration (more than 18 months after finishing rituximab treatments) instead of standard 12 months prophylaxis.