Long-term maintenance rituximab for ANCA-associated vasculitis: relapse and infection prediction models

Clinical prediction models for medication adverse events in patients with rheumatic and musculoskeletal conditions: A systematic literature review

OBJECTIVES

This systematic review aims to identify, summarize, and evaluate the methodological quality of existing clinical prediction models (CPMs) that predict adverse events (AEs) associated with medications prescribed for rheumatic and musculoskeletal diseases (RMDs).

METHODS

We searched PubMed, Embase, and Medline databases up to March 2024. Studies were included if they developed multivariable CPM predicting AEs in adult patients using RMD medications. Data extraction and quality assessment were conducted using the Critical Appraisal and Data Extraction for Systematic Reviews of Prediction Modelling Studies (CHARMS) and Prediction model Risk Of Bias Assessment Tool (PROBAST) checklists to ensure consistent reporting and assess the risk of bias (ROB).

RESULTS

Of 2406 studies identified, 1734 titles/abstracts were screened, and 38 were reviewed in full. Twelve studies reporting 17 CPMs met eligibility criteria. Most CPMs (76.4 %) focused on rheumatoid arthritis and disease modifying anti-rheumatic drugs (DMARDs) such as methotrexate (69.2 %) and biologic drugs (15.3 %). Cox proportional hazards or logistic regression models were commonly used. Twelve models (70.5 %) had high overall ROB due to inappropriate variable selection methods and sample size.

CONCLUSIONS

This is the first systematic review summarising CPMs for AEs associated with RMD medications. It highlights that existing CPMs are affected by methodological pitfalls, including inappropriate variable selection and lack of clear sample size justification. Future models could consider a broader range of RMDs and medications. Emerging methods such as machine learning with the ability to model complex interactions, and multi-outcome CPMs to predict several AEs to one class of drug may improve predictions.

Trimethoprim sulfamethoxazole prophylaxis and serious infections in granulomatosis with polyangiitis treated with rituximab

OBJECTIVE

To assess the association of trimethoprim sulfamethoxazole (TMP-SMX) prophylaxis with serious infections in rituximab-treated patients with granulomatosis with polyangiitis (GPA).

METHODS

This retrospective cohort study included adults with GPA (2011-2020) within the United States Merative™ Marketscan® Research Databases with ≥6 months' enrolment prior to first (index) rituximab treatment. We defined TMP-SMX prophylaxis as a ≥28-day prescription dispensed after or overlapping the index date. Serious infection was a hospital primary diagnosis for infection (excluding viral or mycobacterial codes). Secondary outcomes were outpatient infection, Pneumocystis jirovecii pneumonia (PJP) and adverse events potentially attributable to TMP-SMX. Cox proportional hazards regression assessed the association of time-varying TMP-SMX with outcomes of interest, adjusting for potential confounders. Individuals were followed until the outcome of interest, end of database enrolment or 31 Decamber 2020.

RESULTS

Among 919 rituximab-treated individuals (53% female), mean (s.d.) age was 52.1 (16) years and 281 (31%) were dispensed TMP-SMX within 30 days of index date. Over a median of 496 (interquartile range 138-979) days, 130 serious infections occurred among 104 individuals (incidence 6.1 [95% CI: 5.0, 7.4] per 100 person-years). Time-varying TMP-SMX was negatively associated with serious infection (adjusted hazard ratio [aHR] 0.5; 95% CI: 0.3, 0.9). The aHR for outpatient infections was 0.8 (95% CI: 0.6, 1.1). The estimate for PJP was imprecise (13 events, unadjusted HR 0.2; 95% CI: 0.03-1.8). TMP-SMX was potentially associated with adverse events (aHR 1.3; 95% CI: 0.9, 1.9).

CONCLUSIONS

TMP-SMX prophylaxis was associated with reduced serious infections in rituximab-treated GPA, but may increase adverse events, warranting further study of optimal prophylaxis strategies.

Relapses and serious adverse events during rituximab maintenance therapy in ANCA-associated vasculitis: a multicentre retrospective study

OBJECTIVES

There are limited real-life data regarding the efficacy and safety of rituximab (RTX) as a remission maintenance agent in microscopic polyangiitis (MPA) and granulomatosis-with-polyangiitis (GPA). We aimed to estimate the incidence and risk factors for relapses, as well for serious adverse events (SAEs) in MPA/GPA patients during RTX maintenance.

METHODS

A retrospective cohort of newly diagnosed/relapsing GPA/MPA patients who received RTX maintenance (≥1 RTX cycle, ≥6 months follow-up) following complete remission (BVAS version-3 = 0 plus prednisolone ≤7.5 mg/day) with induction regimens. SAEs included serious infections, COronaVIrus-Disease 2019 (COVID-19)-associated hospitalizations, deaths, cardiovascular events, malignancies and hypogammaglobulinemia. The incidence rates (IRs) and relapse-free survival were estimated through Kaplan-Meier plots. Cox regression was conducted to investigate factors associated with the time-to-relapse.

RESULTS

A total of 101 patients were included: 48% females, 69% GPA, 53% newly diagnosed, median age 63 years. During follow-up (294.5 patient-years, median: 3 RTX cycles), 30 relapses (57% major) occurred among 24 patients (24%, IR 10.2/100 patient-years). Kidney involvement (adjusted hazard ratio/aHR: 0.20; 95% CI: 0.06-0.74, P = 0.016), prior induction with RTX plus CYC (vs RTX monotherapy: aHR = 0.02; 95% CI: 0.001-0.43, P = 0.012) and shorter time interval until complete remission (aHR = 1.07; 95% CI: 1.01-1.14, P = 0.023) were associated with decreased relapse risk. We recorded 17 serious infections (IR 5.8/100 patient-years), 11 COVID-19-associated hospitalizations (IR 3.7/100 patient-years), 4 malignancies (IR 1.4/100 patient-years), 6 cardiovascular events (IR 2/100 patient-years) and 10 deaths (IR 3.4/100 patient-years).

CONCLUSION

In this real-world study, relapses during RTX maintenance occurred in approximately 1 out of 4 patients. Kidney involvement, induction with RTX plus CYC, and earlier achievement of complete remission were associated with lower relapse risk. The serious infections rate was consistent with previous reports, whereas an increased rate of COVID-19-associated hospitalizations was observed.

Emerging targeted therapies in ANCA-associated vasculitis

Drug development in ANCA-associated vasculitis has aimed to improve on the success of the B cell depleting monoclonal antibody rituximab and exploit better understanding of inflammatory pathways. More potent B cell depletion strategies are being tested as are B cell cytokine inhibitors. The involvement of the complement system in pathogenesis is more complicated than previously thought and extends beyond C5a dysregulation and its inhibition with avacopan, broader complement inhibitors and complement regulatory agonists are potential newer therapies. Other approaches have aimed to directly control neutrophil activation and to try to modulate tissue repair and fibrosis that occurs following vasculitis inflammation.

Characteristics and risk factors for infection in patients with ANCA-associated vasculitis: A systematic review and meta-analysis

OBJECTIVE

To summarize the characteristics and risk factors for infection in patients with anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV).

METHODS

PubMed, Embase, and Cochrane Library databases were searched for relevant articles from database inception to November 2023. The prevalence, odds ratio (OR), and mean difference (MD) with 95 % confidence intervals (CIs) were pooled using a random-effects model. Sensitivity and subgroup analysis were also performed.

RESULTS

Forty-one studies with 5343 patients with AAV were included, of whom 2890 patients experienced an infection. The pooled prevalence was 54.6 % (95 % CI, 48.4 % to 61.1 %) for all infections and 35.8 % (95 % CI, 31.0 % to 40.8 %) for severe infections; and prevalence of Pneumocystis jirovecii pneumonia, aspergillosis, candidiasis, cryptococcosis, herpes zoster, cytomegalovirus, and specific bacterial infections were pooled. The respiratory system was the most common infection site, followed by blood, urinary tract, skin and soft tissue, and digestive infections. Risk factors for infection included older age, end-stage renal disease, dialysis, diabetes, smoking, kidney and lung involvement, leukopenia; higher Birmingham Vasculitis Activity Score, and serum creatinine and C-reactive protein levels; and lower hemoglobin levels, and platelet and CD4 counts. In addition, use of cyclophosphamide, steroid pulse therapy, plasma exchange, and higher initial glucocorticoid dose were associated with significantly increased risk of infection.

CONCLUSION

In patients with AAV, therapy should take risk factors for infection into account. Risk factors should be modified wherever possible. Physicians should be familiar with the common infection sites and pathogens, and consider empiric therapy covering common pathogens for life-threatening infections.

Two Decades Rituximab Therapy in Anti-Neutrophil Cytoplasmic Antibody Associated Vasculitis

Remission failure and relapse numerate as one of the main problems in patients with antineutrophil cytoplasmic antibody-associated vasculitis (AAVs). The need for new agents that provide effective and safe induction accompanied by sustained remission seems to be urgent in clinical care. The efficacy and safety of rituximab (RTX) for AAVs therapy has been reported in various studies. RTX therapy offers several advantages to treating AAVs patients compared to other therapeutic approaches including reduction of Glucocorticoids (GCs) and conventional Immunosuppressive therapy (IST) usage during both the induction of remission and maintenance phases. This reduction can lead to a lower rate of serious complications making RTX therapy a safer option. It seems that RTX may provide improved clinical outcomes in these patients mediated via B-lymphocyte depletion, Proteinase 3-antineutrophilic cytoplasmic antibody (PR3-ANCA), and myeloperoxidase-antineutrophilic cytoplasmic antibody (MPO-ANCA) titers reduction. In this regard, some uncertainties have been reported to validate the association between such depletion and clinical improvement, as suggested by other sources of autoreactive B cells that did not target with RTX. Due to the prolonged B cell depletion, fixed intervals and adjusted dosage of RTX may be required in patients with AAVs. In this narrative review, we aimed to insight better understand regarding the efficacy of RTX for effective induction and sustained remission in patients with AAVs. It seems that discovering new biomarkers predicting relapse in AAVs patients can lead to future targeted therapy.

Recommendations for the diagnosis and treatment of anti-neutrophil cytoplasmic autoantibody associated vasculitis

Anti-neutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis is characterised by small vessel necrotising inflammatory vasculitis. Prior to immunosupressant therapy availability it usually led to a fatal outcome. Current treatment has changed ANCA-associated vasculitis into a condition with a significant response rate, although with a not negligible relapse occurrence and cumulative organ lesions, mostly due to drug-related toxicities. The use of glucocorticoids, cyclophosphamide and other immunosupressants (such as azathioprine, mychophenolate and methotrexate) was optimised in a series of clinical trials that established the treatment of reference. In recent years, a better knowledge of B lymphocyte function and the role of complement inhibition has transformed the course of this disease while minimising treatment-related adverse effects. This multidisciplinary document of recommendations is based on the consensus of three scientific societies (Internal Medicine, Nephrology and Rheumatology) and on the best available evidence on diagnosis, treatment and follow-up of patients with ANCA-associated vasculitis, including some special situations. The aim of this document is to provide updated information and well-grounded clinical recommendations to practising physicians as to how to improve the diagnosis and treatment outcome of our patients.

An update on risk factors for relapse in antineutrophil cytoplasmic antibody-associated vasculitis

Ongoing therapeutic advances in antineutrophil cytoplasmic antibody-associated vasculitis (AAV) have significantly reduced the risk of death in AAV, but 30%-50% of patients still relapse. Relapse is a major problem in these diseases, leading to increased morbidity and mortality. It is, therefore, necessary to find predictors of relapse at the end of the remission induction and maintenance phases in order to personalize treatment.

Treatment goals in ANCA-associated vasculitis: defining success in a new era

Health-related quality of life is a key contributor to overall well-being, and this is becoming an increasingly prominent factor when making therapeutic choices in the management of ANCA-associated vasculitis (AAV). Progress in available therapeutic strategies for AAV has resulted in this historically acute disease with a potentially fatal short-term outcome, becoming a relapsing-remitting chronic disorder. This new perspective on AAV means that patient survival should no longer be considered as the only major treatment target. Additional outcomes in this context that should be portrayed in order to consider a therapeutic approach as successful include patient quality of life, as well as the burden of treatment-induced morbidity. Comorbidities and impaired quality of life in patients with AAV, as with many other autoimmune diseases, may be a consequence of the disease itself as well as a result of the therapy employed. The AAV disease process may induce organ damage, including kidney failure and structural lung damage, and increase the risk of cardiovascular disease. On top of this, treatments employed to manage the disease may contribute further to the overall comorbidities burden. Furthermore, pre-existing comorbidities can increase AAV severity and may also be contraindications that limit potential therapeutic options. Quality of life is another central topic that can have a huge impact on patient wellbeing as well as adherence to treatment. Ongoing monitoring of comorbidity risk and of quality of life is thus key for successful AAV management. This process, however, may be complicated; the identification of the correct parameters on which to focus is not always straightforward and, more importantly, it is sometimes the symptoms that may appear trivial to physicians that are most detrimental to a patient's quality of life. With these shifts in treatment capabilities and understanding of patient burden, it is necessary to adjust the treatment paradigm accordingly. Treatment success is no longer defined solely by the control of disease activity; treatment success requires holistic improvement determined through the assessment of all aspects of the disease, ranging from disease control to comorbidity risk through to the assessment of health-related quality of life. This review explores the burden of AAV itself as well as treatment-related side effects with a special focus on the tools available to measure outcomes. The management of AAV has entered a new era with a strong focus on both the management and prevention of comorbidities as well as patient-reported outcomes, both of which are now considered key factors in defining treatment success.

Rituximab as maintenance therapy for ANCA-associated vasculitides: pooled analysis and long-term outcome of 277 patients included in the MAINRITSAN trials

OBJECTIVE

To compare the long-term efficacy and safety of azathioprine (AZA), 18-month fixed-schedule rituximab (RTX), 18-month tailored RTX and 36-month RTX in preventing relapses in patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis who achieved a complete remission after induction therapy. Patients treated with 36-month RTX received either a fixed or a tailored regimen for the first 18 months and a fixed regimen for the last 18 months (36-month fixed/fixed RTX and 36-month tailored/fixed RTX, respectively).

METHODS

The Maintenance of Remission using Rituximab in Systemic ANCA-associated Vasculitis (MAINRITSAN) trials sequentially compared: 18-month fixed-schedule RTX versus AZA (MAINRITSAN); 18-month fixed-schedule RTX versus 18-month tailored-RTX (MAINRITSAN2); and extended therapy to 36 months with four additional RTX infusions after MAINRITSAN2 versus placebo (MAINRITSAN3). Patients were then followed prospectively through month 84 and their data were pooled to analyse relapses and adverse events. The primary endpoint was relapse-free survival at month 84.

RESULTS

277 patients were enrolled and divided in 5 groups: AZA (n=58), 18-month fixed-schedule RTX (n=97), 18-month tailored-RTX (n=40), 36-month tailored/fixed RTX (n=42), 36-month fixed/fixed RTX (n=41). After adjustment for prognostic factors, 18-month fixed-schedule RTX was superior to AZA in preventing major relapses at month 84 (HR 0.38, 95% CI 0.20 to 0.71). The 18-month tailored-RTX regimen was associated with an increased risk of major relapse compared with fixed-schedule regimen (HR 2.92, 95% CI 1.43 to 5.96). The risk of major relapse was similar between 36-month fixed/fixed and 18-month fixed-RTX (HR 0.69, 95% CI 0.38 to 1.25).

CONCLUSIONS

According to these results, it appears that the 84-month remission rate is higher with an 18-month fixed RTX regimen compared with AZA and 18-month tailored RTX. Also, extending RTX to 36 months does not appear to reduce the long-term relapse rate compared with the 18-month fixed RTX regimen. However, as this study was underpowered to make this comparison, further prospective studies are needed to determine the potential long-term benefits of extending treatment in these patients.

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.

Rituximab versus azathioprine for maintenance of remission for patients with ANCA-associated vasculitis and relapsing disease: an international randomised controlled trial

OBJECTIVE

Following induction of remission with rituximab in anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV) relapse rates are high, especially in patients with history of relapse. Relapses are associated with increased exposure to immunosuppressive medications, the accrual of damage and increased morbidity and mortality. The RITAZAREM trial compared the efficacy of repeat-dose rituximab to daily oral azathioprine for prevention of relapse in patients with relapsing AAV in whom remission was reinduced with rituximab.

METHODS

RITAZAREM was an international randomised controlled, open-label, superiority trial that recruited 188 patients at the time of an AAV relapse from 29 centres in seven countries between April 2013 and November 2016. All patients received rituximab and glucocorticoids to reinduce remission. Patients achieving remission by 4 months were randomised to receive rituximab intravenously (1000 mg every 4 months, through month 20) (85 patients) or azathioprine (2 mg/kg/day, tapered after month 24) (85 patients) and followed for a minimum of 36 months. The primary outcome was time to disease relapse (either major or minor relapse).

RESULTS

Rituximab was superior to azathioprine in preventing relapse: HR 0.41; 95% CI 0.27 to 0.61, p<0.001. 19/85 (22%) patients in the rituximab group and 31/85 (36%) in the azathioprine group experienced at least one serious adverse event during the treatment period. There were no differences in rates of hypogammaglobulinaemia or infection between groups.

CONCLUSIONS

Following induction of remission with rituximab, fixed-interval, repeat-dose rituximab was superior to azathioprine for preventing disease relapse in patients with AAV with a prior history of relapse.

TRIAL REGISTRATION NUMBER

NCT01697267; ClinicalTrials.gov identifier.

Advances in the maintenance of ANCA vasculitis remission

The maintenance treatment of ANCA-associated vasculitides (AAVs) has benefited from the results of several prospective clinical trials focusing on the evaluation of new drugs, therapeutic strategies, and adjuvant treatments. They also showed that rituximab was the most effective agent to maintain remission. However, because treatments can induce adverse events, including facilitating infections, therapeutic strategies should be adapted to find the optimal dose(s) and their administration duration(s) and to make them commensurate to the expected severity of relapse. That task is not easy to achieve because we have not yet been able to identify the clinical or biological parameters that can predict when a relapse will occur and its severity. Among AAVs, eosinophilic granulomatosis with polyangiitis (EGPA) has pathogenic and clinical specificities, and new drugs directly address those features. If rituximab could have a place such as in other AAVs, anti-IL5 biotherapies could also be prescribed successfully for maintenance. Another aim of vasculitis maintenance therapy is to control the disease with less prednisone than in the past. Herein, we emphasize the importance of individually devising a maintenance regimen adapted to the objectives of keeping the patient in remission without the adverse events related to the prescribed treatment(s).

Score to assess the probability of relapse in granulomatosis with polyangiitis and microscopic polyangiitis

OBJECTIVE

To develop a score assessing the probability of relapse in granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA).

METHODS

Long-term follow-up data from GPA and MPA patients included in five consecutive randomised controlled trials were pooled. Patient characteristics at diagnosis were entered into a competing-risks model, with relapse as the event of interest and death the competing event. Univariate and multivariate analyses were computed to identify variables associated with relapse and build a score, which was then validated in an independent cohort of GPA or MPA patients.

RESULTS

Data collected from 427 patients (203 GPA, 224 MPA) at diagnosis were included. Mean±SD follow-up was 80.6±51.3 months; 207 (48.5%) patients experienced ≥1 relapse. Relapse risk was associated with proteinase 3 (PR3) positivity (HR=1.81 (95% CI 1.28 to 2.57); p<0.001), age ≤75 years (HR=1.89 (95% CI 1.15 to 3.13); p=0.012) and estimated glomerular filtration rate (eGFR) ≥30 mL/min/1.73 m² (HR=1.67 (95% CI 1.18 to 2.33); p=0.004) at diagnosis. A score, the French Vasculitis Study Group Relapse Score (FRS), from 0 to 3 points was modelised: 1 point each for PR3-antineutrophil cytoplasmic antibody positivity, eGFR ≥30 mL/min/1.73 m² and age ≤75 years. In the validation cohort of 209 patients, the 5-year relapse risk was 8% for a FRS of 0, 30% for 1, 48% for 2 and 76% for 3.

CONCLUSION

The FRS can be used at diagnosis to assess the relapse risk in patients with GPA or MPA. Its value for tailoring the duration of maintenance therapy should be evaluated in future prospective trials.

Diagnosing and treating ANCA-associated vasculitis: an updated review for clinical practice

ANCA-associated vasculitides (AAV) are a group of rare, primary, systemic necrotizing small-vessel vasculitides. Granulomatosis with polyangiitis and microscopic polyangiitis account for ∼80–90% of all AAV. Exposure to silica dust, farming and chronic nasal Staphylococcus aureus carriage are associated with increased risk of developing AAV. When a diagnosis of AAV is suspected, as in patients with multisystem organ dysfunction or those with features such as chronic recurrent rhinosinusitis, cavitated lung nodules, palpable purpura or acute kidney injury, then appropriate further investigations are needed, including ANCA testing. In this scenario, a structured clinical assessment should be conducted, evaluating all the organs possibly involved, and tissue biopsy may be necessary for confirmation of the diagnosis. Therapeutic algorithms vary based on the severity of AAV, the clinical diagnosis/ANCA specificity, and the patient’s age, weight, comorbidities and prognosis. Recent data favour rituximab as a preferable option for both induction and maintenance of remission. In addition, regimens with less glucocorticoids are equally effective and safer in inducing remission compared with conventional regimens, and avacopan is an effective glucocorticoid-sparing option. In contrast, there is not compelling evidence to support the routine use of plasma exchange in addition to standard remission-induction therapy in AAV. ANCA and other biomarkers can be helpful in association with clinical assessment to guide diagnosis and treatment decisions. Patients should be frequently evaluated during follow-up for possible disease relapses or treatment-related morbidity, and for monitoring damage accrual, especially metabolic and cardiovascular damage.

A Personalized Rituximab Retreatment Approach Based on Clinical and B-Cell Biomarkers in ANCA-Associated Vasculitis

Background

Time to relapse after rituximab for the treatment of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is variable, and optimal retreatment strategy has remained unclear. In AAV following rituximab induction, the study objective was to evaluate clinical and B-cell predictors of relapse in order to develop a retreatment algorithm.

Methods

A retrospective observational study was conducted in 70 rituximab-treated ANCA-associated vasculitis patients followed up for over 10 years. Complete response (CR) was defined as Birmingham Vasculitis Activity Score v3.0 = 0. Retreatment was given on clinical relapse, defined as new features or worsening of persistent disease (not by biomarker status). Peripheral B-cell subsets were measured using highly sensitive flow cytometry. Predictors were tested using multivariable Cox regression.

Results

Median time to retreatment for cycles 1–5 were 84, 73, 67, 60, and 73 weeks. Over 467 patient-years follow-up, 158 relapses occurred in 60 patients; 16 (in 15 patients) were major (renal = 7, neurological = 4, ENT = 3, and respiratory = 2). The major-relapse rate was 3.4/100 patient-years. In multivariable analysis, concomitant immunosuppressant [HR, 0.48 (95% CI, 0.24–0.94)], achieving CR [0.24 (0.12–0.50)], and naïve B-cell repopulation at 6 months [0.43 (0.22–0.84)] were associated with longer time to relapse. Personalized retreatment using these three predictors in this cohort would have avoided an unnecessary fixed retreatment in 24% of patients. Area under the receiver operating characteristic for prediction of time to relapse was greater if guided by naïve B-cell repopulation than if previously evaluated ANCA and/or CD19⁺ cells return at 6 months had been used, 0.82 and 0.53, respectively.

Conclusion

Our findings suggest that all patients should be coprescribed oral immunosuppressant. Those with incomplete response or with absent naïve B cells should be retreated at 6 months. Patients with complete response and naïve repopulation should not receive fixed retreatment. This algorithm could reduce unnecessary retreatment and warrant investigation in clinical trials.

Pulmonary involvement of ANCA-associated vasculitis in adult Chinese patients

Objective

The aim of this study was to clarify the clinical characteristics and long-term outcomes of ANCA-associated vasculitis (AAV) patients with pulmonary involvement from a single Chinese cohort.

Methods

Newly diagnosed AAV patients with pulmonary involvement, as defined by CT, were recruited from January 2010 to June 2020. Clinical data and CT images were collected retrospectively. Baseline CTs were evaluated and re-classified into four categories: interstitial lung disease (ILD), airway involvement (AI), alveolar hemorrhage (AH), and pulmonary granuloma (PG).

Results

A total of 719 patients were newly diagnosed with AAV, 366 (50.9%) of whom combined with pulmonary involvement at baseline. Among the AAV cases with pulmonary involvement, 55.7% (204/366) had ILD, 16.7% (61/366) had AI alone, 14.8% (54/366) had PG, and 12.8% (47/366) had AH alone. During follow-up of a median duration of 42.0 months, 66/366 (18.0%) patients died, mainly died from infections. Survival, relapse, and infection were all significantly different based on the radiological features. Specifically, the ILD group tends to have a poor long-term prognosis, the PG group is prone to relapse, and the AI group is apt to infection. The AH group has a high risk of both early infection and relapse, thus a poor short-term prognosis.

Conclusion

AAV patients with diverse radiological features have different clinical characteristics and outcomes. Therefore, the intensity of immunosuppressive therapy must be carefully valued by considering the baseline CT findings among AAV patients with pulmonary involvement.

Rituximab Induction and Maintenance in ANCA-Associated Vasculitis: State of the Art and Future Perspectives

Antineutrophil cytoplasmatic antibody (ANCA)-associated vasculitis (AAV) is a group of rare autoimmune diseases characterized by inflammation of the vascular wall. The pathogenesis of AAV is strongly associated with B cell-derived ANCAs; thus, Rituximab (RTX) has become a promising drug in the induction and maintenance treatment of AAV. The purpose of this review is to describe the efficacy and safety of RTX in the induction of remission and maintenance therapy of AAV. Herein, we summarize the randomized controlled trials that have contributed to the refinement of the use of RTX in AAV in the past decades. RTX has been proven to be effective both in new-onset disease and in relapsing disease. Although the optimal duration of AAV maintenance therapy remains unknown, the ANCAs and the B-cell repopulation may offer support for the administration of further RTX cycles (or not). The safety of RTX is comparable with cyclophosphamide, with the advantage of a low risk of malignancy and no concern for fertility. In conclusion, RTX now plays an important role in the induction and maintenance therapy of AAV. Optimizing RTX-based treatment strategies in AAV is one of the main goals of the current research in AAV.