The impact of environmental factors on aetiopathogenesis and clinical manifestations of Behçet's syndrome.

Behçet's syndrome (BS) is a rare multisystem vasculitis involving blood vessels of any size. BS aetiology is still unclear to date, and the heterogeneity of clinical expression among ethnics and genders make early diagnosis challenging. However, so far, considerable efforts have been made toward the understanding of BS, leading researchers to agree that the coexistence of some environmental triggers and a genetical susceptibility both underlie BS aetiopathogenesis. In particular, viral agents, oral microbial flora, and mucosal microbiota have been widely explored in this regard, but still no specific microorganism has been definitely linked to the disease aetiology. Likewise, the concept that some environmental factors may play a role in BS clinical presentation has emerged based on the growing evidence that disease severity is usually higher in male patients, and that diet and fatigue may be involved in disease recurrence, especially in mucocutaneous manifestations. Moreover, smoke cessation is acknowledged as a risk factor for oral ulcerations, although the underlying mechanism is still not clear. All those environmental factors play their effects through epigenetic mechanisms. The aim of this review is to discuss the evidence on the role of environmental factors in BS aetiopathogenesis and clinical course.

Validation of the Italian version of the ANCA-associated vasculitis patient-reported outcome (AAV-PRO) questionnaire.

Objectives: The primary objective of this study was the translation and validation of the ANCA-associated vasculitis patient-reported outcome (AAV-PRO) questionnaire into Italian, denoted as AAV-PRO_ita. The secondary objective was to evaluate the impact of ANCA-associated vasculitis (AAV) on quality of life (QoL) and work impairment in a large cohort of Italian patients. Methods: The study design took a prospective cohort study approach. First, the AAV-PRO was translated into Italian following the step guidelines for translations. The new AAV-PRO_ita questionnaire covered three disease domains: organ-specific and systemic symptoms and signs; physical function; and social and emotional impact. Second, Italian-speaking AAV patients were recruited from 17 Italian centres belonging to the Italian Vasculitis Study Group. Participants completed the AAV-PRO_ita questionnaire at three time points. Participants were also requested to complete the work productivity and activity impairment: general health questionnaire. Results: A total of 276 AAV patients (56.5% women) completed the questionnaires. The AAV-PRO_ita questionnaire demonstrated a good internal consistency and test-retest reliability. Female AAV patients scored higher (i.e. worse) in all thee domains, especially in the social and emotional impact domain (P < 0.001). Patients on glucocorticoid therapy (n = 199) had higher scores in all domains, especially in the physical function domain (P < 0.001), compared with patients not on glucocorticoid therapy (n = 77). Furthermore, patients who had at least one relapse of disease (n = 114) had higher scores compared with those who had never had one (n = 161) in any domain (P < 0.05). Finally, nearly 30% of the patients reported work impairment. Conclusion: The AAV-PRO_ita questionnaire is a new 29-item, disease-specific patient-reported outcome measuring tool that can be used in AAV research in the Italian language. Sex, glucocorticoids and relapsing disease showed the greatest impact on QoL.

Long-term outcome of a cohort of Italian patients affected with alpha-Mannosidosis.

Alpha-mannosidosis (MIM #248500) is an ultra-rare autosomal recessive lysosomal storage disease with multi-system involvement and a wide phenotypic spectrum. Information on long-term outcomes remains poor. We present the long-term outcomes (median, 19 years) of nine patients with alpha-mannosidosis, three females and six males, followed at a single center. The findings of the nine patients were collected from medical records and reported as mean ± SD or median, and range. The age of onset of the first symptoms ranged from 0-1 to 10 years. The diagnostic delay ranged from 2 to 22 years (median= 11 years). Coarse face, hearing, heart valves, joints, gait, language, dysarthria, psychiatric symptoms, I.Q., MRI, walking disabilities, orthopedic disturbances and surgeries showed a slow worsening over the decades. Our patients showed a slowly worsening progressive outcome over the decades. Psychiatric symptoms were present in 100% of our population and improved with the appropriate pharmacological intervention. This aspect requires attention when following up on these patients. Our description of the long-term evolution of alpha-mannosidosis patients may provide basic knowledge for understanding the effects of specific treatments.

Dupilumab for relapsing or refractory sinonasal and/or asthma manifestations in eosinophilic granulomatosis with polyangiitis: a European retrospective study.

BACKGROUND: Eosinophilic granulomatosis with polyangiitis (EGPA) is often associated with glucocorticoid-dependent asthma and/or ear, nose and throat (ENT) manifestations. When immunosuppressants and/or mepolizumab are ineffective, dupilumab could be an option. We describe the safety and efficacy of off-label use of dupilumab in relapsing and/or refractory EGPA. PATIENTS AND METHODS: We conducted an observational multicentre study of EGPA patients treated with dupilumab. Complete response was defined by Birmingham Vasculitis Activity Score (BVAS)=0 and prednisone dose ≤4 mg/day, and partial response by BVAS=0 and prednisone dose >4 mg/day. Eosinophilia was defined as an eosinophil count >500/mm3. RESULTS: Fifty-one patients were included. The primary indication for dupilumab was disabling ENT symptoms in 92%. After a median follow-up of 13.1 months, 18 patients (35%) reported adverse events (AEs), including two serious AEs. Eosinophilia was reported in 34 patients (67%), with a peak of 2195/mm3 (IQR 1268-4501) occurring at 13 weeks (IQR 4-36) and was associated with relapse in 41%. Twenty-one patients (41%) achieved a complete response and 12 (24%) a partial response. Sixteen (31%) patients experienced an EGPA relapse while on dupilumab, which was associated with blood eosinophilia in 14/16 (88%) patients. The median eosinophil count at the start of dupilumab was significantly lower in relapsers than in non-relapsers, as was the median time between stopping anti-IL-5/IL-5R and switching to dupilumab. CONCLUSION: These results suggest that dupilumab may be effective in treating patients with EGPA-related ENT manifestations. However, EGPA flares occurred in one-third of patients and were preceded by eosinophilia in 88%, suggesting that caution is required.

Early and Late Response and Glucocorticoid-Sparing Effect of Belimumab in Patients with Systemic Lupus Erythematosus with Joint and Skin Manifestations: Results from the Belimumab in Real Life Setting Study-Joint and Skin (BeRLiSS-JS).

AIM: To assess the efficacy of belimumab in joint and skin manifestations in a nationwide cohort of patients with SLE. METHODS: All patients with skin and joint involvement enrolled in the BeRLiSS cohort were considered. Belimumab (intravenous, 10 mg/kg) effectiveness in joint and skin manifestations was assessed by DAS28 and CLASI, respectively. Attainment and predictors of DAS28 remission (<2.6) and LDA (≥2.6, ≤3.2), CLASI = 0, 1, and improvement in DAS28 and CLASI indices ≥20%, ≥50%, and ≥70% were evaluated at 6, 12, 24, and 36 months. RESULTS: DAS28 < 2.6 was achieved by 46%, 57%, and 71% of patients at 6, 12, and 24 months, respectively. CLASI = 0 was achieved by 36%, 48%, and 62% of patients at 6, 12, and 24 months, respectively. Belimumab showed a glucocorticoid-sparing effect, being glucocorticoid-free at 8.5%, 15.4%, 25.6%, and 31.6% of patients at 6, 12, 24, and 36 months, respectively. Patients achieving DAS-LDA and CLASI-50 at 6 months had a higher probability of remission at 12 months compared with those who did not (p = 0.034 and p = 0.028, respectively). CONCLUSIONS: Belimumab led to clinical improvement in a significant proportion of patients with joint or skin involvement in a real-life setting and was associated with a glucocorticoid-sparing effect. A significant proportion of patients with a partial response at 6 months achieved remission later on during follow-up.

Prevalence and clinical associations of ultrasound-confirmed enthesitis in systemic lupus erythematosus.

OBJECTIVES: To assess the prevalence of US-confirmed enthesitis in a cohort of patients with SLE and to analyse the clinical associations to enthesitis during the course of SLE. METHODS: In a retrospective analysis of the SLE cohort of the Lupus Unit of the Careggi University Hospital, US examinations of SLE patients presenting with tender and/or swollen joints were retrieved to assess the presence of enthesitis. Patients with US-proven enthesitis were compared with SLE controls with tender and/or swollen joints who showed no US evidence of enthesitis. Clinical and laboratory features were compared at disease onset and during follow-up. RESULTS: A total of 400 patients fulfilling EULAR/ACR classification criteria for SLE were assessed. Of these, 106 underwent articular US examination. Evidence of enthesitis was found in 31/106 (29.2%) patients. Seventy-one patients without US-enthesitis were included as controls; four were excluded due to lack of follow-up data. Laboratory and clinical features were comparable between cases and controls at disease onset. Throughout a median follow-up of 10.0 (interquartile range [IQR] 8.3-23.3) years for cases and 12.4 (IQR 7.2-13.3) years for controls, patients with enthesitis were less likely to develop renal involvement (22.6% vs 46.5%, P = 0.028) and failed B cell depletion more frequently (75.0% vs 0%). CONCLUSION: In SLE patients with clinically active joints, US-proven enthesitis is a fairly common finding. Enthesitis in SLE could be the hallmark of a distinct disease phenotype with less renal involvement, more arthritis and low response to anti-CD 20 therapy, potentially requiring a tailored treatment.

Evidence of subclinical atherosclerosis in eosinophilic granulomatosis with polyangiitis.

OBJECTIVES: Patients affected by eosinophilic granulomatosis with polyangiitis (EGPA) display an increased risk of atherothrombotic events compared with the general population. An increased frequency of subclinical markers of atherosclerosis has been observed in other ANCA-associated vasculitis, but no specific study focused on EGPA. We therefore evaluated subclinical atherosclerosis in EGPA patients and in a control population. METHODS: Forty EGPA patients and 80 controls matched by age, sex and traditional cardiovascular risk factors underwent sonographic assessment of common carotid artery (CCA) intima-media thickness (IMT). The presence of plaques of the CCA was also investigated. The correlation between CCA-IMT and clinical and laboratory features was also assessed. RESULTS: Median CCA-IMT was significantly higher in EGPA patients compared with controls (P = 0.002). Also, the proportion of subjects with increased CCA-IMT and with presence of plaques was significantly higher among EGPA patients (P < 0.001 for both). Moreover, within the EGPA cohort, CCA-IMT tended to increase with disease duration (P = 0.034) and corticosteroid cumulative dose (P = 0.004). No significant associations were found between CCA-IMT, ANCA status, other clinical features and therapeutic regimens. Notably, the prevalence of traditional cardiovascular risk factors was comparable in patients with vs without an increased CCA-IMT. CONCLUSION: Ultrasound markers of subclinical atherosclerosis are increased in EGPA patients as compared with controls, independently of traditional cardiovascular risk factors.

SIRT1 and thrombosis.

Thrombosis is a major cause of morbidity and mortality worldwide, with a complex and multifactorial pathogenesis. Recent studies have shown that SIRT1, a member of the sirtuin family of NAD + -dependent deacetylases, plays a crucial role in regulating thrombosis, modulating key pathways including endothelial activation, platelet aggregation, and coagulation. Furthermore, SIRT1 displays anti-inflammatory activity both in vitro, in vivo and in clinical studies, particularly via the reduction of oxidative stress. On these bases, several studies have investigated the therapeutic potential of targeting SIRT1 for the prevention of thrombosis. This review provides a comprehensive and critical overview of the main preclinical and clinical studies and of the current understanding of the role of SIRT1 in thrombosis.

Benralizumab for eosinophilic granulomatosis with polyangiitis: a retrospective, multicentre, cohort study.

BACKGROUND: Interleukin-5 (IL-5) inhibitors represent novel therapies for eosinophilic granulomatosis with polyangiitis (EGPA). This study assessed the effectiveness and safety of the IL-5 receptor inhibitor benralizumab in a European cohort of patients with EGPA. METHODS: This retrospective cohort study included patients with EGPA from 28 European referral centres of the European EGPA Study Group across six countries (Italy, France, UK, Russia, Spain, and Switzerland) who received benralizumab as any line of treatment between Jan 1, 2019, and Sep 30, 2022. We assessed the rates of complete response, defined as no disease activity (Birmingham Vasculitis Activity Score [BVAS] of 0) and a prednisone dose of up to 4 mg/day, in contrast to partial response, defined as a BVAS of 0 and a prednisone dose greater than 4 mg/day. Active disease manifestations, pulmonary function, variation in glucocorticoid dose, and safety outcomes were also assessed over a 12-month follow-up. FINDINGS: 121 patients with relapsing-refractory EGPA treated with benralizumab at the dose approved for eosinophilic asthma were included (64 [53%] women and 57 [47%] men; median age at the time of beginning benralizumab treatment 54·1 years [IQR 44·2-62·2]). Complete response was reported in 15 (12·4%, 95% CI 7·1-19·6) of 121 patients at month 3, 25 (28·7%, 19·5-39·4) of 87 patients at month 6, and 32 (46·4%, 34·3-58·8) of 69 patients at month 12; partial response was observed in an additional 43 (35·5%, 27·0-44·8) patients at month 3, 23 (26·4%, 17·6-37·0) at month 6, and 13 (18·8%, 10·4-30·1) at month 12. BVAS dropped from 3·0 (IQR 2·0-8·0) at baseline to 0·0 (0·0-2·0) at months 3 and 6, and to 0·0 (0·0-1·0) at month 12. The proportion of patients with systemic manifestations, active peripheral neurological disease, ear, nose, and throat involvement, and pulmonary involvement decreased, with an improvement in lung function tests. Six patients relapsed after having a complete response. The oral prednisone (or equivalent) dose decreased from 10·0 mg/day (5·0-12·5) at baseline to 5·0 mg/day (3·6-8·5) at month 3 (p<0·01), to 5·0 mg/day (2·5-6·3) at month 6, and to 2·5 mg/day (0·0-5·0) at month 12 (p<0·0001). 19 (16%) of 121 patients had adverse events and 16 (13%) discontinued benralizumab. INTERPRETATION: These data suggest that benralizumab could be an effective treatment for EGPA in real-life clinical practice. Further clinical trials are required to confirm the efficacy of benralizumab in patients with a higher baseline disease activity. FUNDING: None.

Persistent Isolated C3 Hypocomplementemia as a Strong Predictor of End-Stage Kidney Disease in Lupus Nephritis.

Introduction: Proliferative lupus nephritis (LN) progresses to end-stage kidney disease (ESKD) in roughly 10% of the cases despite treatment. Other than achieving <0.8 g/24h proteinuria at 12 months after treatment, early biomarkers predicting ESKD or death are lacking. Recent studies encompassing not only LN have highlighted the central role of the alternative complement pathway (ACP), with or without histological evidence of thrombotic microangiopathy (TMA), as a key promotor of renal death. Methods: We assessed whether persistent isolated C3 hypocomplementemia (PI-LowC3), that is not accompanied by C4 hypocomplementemia, 6 months after kidney biopsy, is associated with an increased risk of death or ESKD in proliferative LN. Results: We retrospectively followed-up 197 patients with proliferative LN (51 with PI-LowC3) for a median of 4.5 years (interquartile-range: 1.9-9.0), 11 of whom died and 22 reached ESKD. After adjusting for age, gender, ethnicity, hypertension, mycophenolate, or cyclophosphamide use, PI-LowC3 was associated with a hazard ratio [HR] of the composite outcome ESKD or death of 2.46 (95% confidence interval [CI]: 1.22-4.99, P = 0.012). These results were confirmed even after controlling for time-varying estimated glomerular filtration rate (eGFR) measurements in joint longitudinal-survival multiple regression models. After accounting for the competing risk of death, PI-LowC3 patients showed a strikingly increased risk of ESKD (adjusted HR 3.41, 95% CI: 1.31-8.88, P = 0.012). Conclusion: Our findings support the use of PI-LowC3 as a low-cost readily available biomarker, allowing clinicians to modify treatment strategies early in the course of disease and offering a rationale for complement blockade trials in this particularly at-risk subgroup of LN patients.

Disease activity at conception predicts lupus flare up to two years after birth: A multicentre long term follow-up study.

OBJECTIVE: To assess predicting factors that might influence systemic lupus erythematosus (SLE) disease activity in women in an extended follow-up period of two years after giving birth with clinical assessments every three months. METHODS: The study was design as an international retrospective study, enrolling 119 women with a first birth and with a two years follow-up. RESULTS: Joint involvement was present in 80% of patients, acute cutaneous in 64%, haematological in 54%, renal in 41% and 75% of patients were positive for anti-dsDNA. The mean SLE disease activity index 2000 (SLEDAI-2K) at diagnosis was 13.5±6.8 and at first birth was 2.8±4.4. At follow-up, 51.3% of patients had at least one flare after a mean time after birth of 9±6.3 months (mean flare per patient 0.94±1.1). The most frequent flare manifestations were joint involvement (48%), renal (33%), cutaneous (28%) and haematologic (20%). Patients with remission of disease (SLEDAI-2K=0; no clinical or laboratory manifestations of SLE) at conception had significantly lower rates of flares (18/49-37% vs. 43/70-61%; p=0.008). Patients who experienced a flare during pregnancy (17 patients) had higher rates of flares during follow-up (76% vs. 47%; p=0.019), lower time for first flare (4.4±2.3 months vs. 10.3±6.5; p<0.001), lower rate of remission of disease at conception (12% vs. 46%; p<0.001), lower rates of SLEDAI-2K at conception (5.9±5.6 vs. 2.3±4; p<0.001) and lower rates of exclusive breastfeeding (24% vs. 57%: p=0.009). Results were confirmed after performing multivariate analysis. CONCLUSION: Remission at conception can influence SLE disease positively, even at long-term. Planned pregnancy counseling is fundamental when managing SLE patients.

The management of transitional care of patients affected by phenylketonuria in Italy: Review and expert opinion.

Phenylketonuria (PKU) is a metabolic inherited disorder in which transition from infancy to adult care is particularly difficult and not sufficiently regulated. According to the scientific literature, only few medical centers offer healthcare assistance for adult patients with PKU that are therefore still treated in pediatric settings. This generates psychological, emotional, and organizational discomfort among patients, leading them to discontinue the follow-up. European guidelines and national consensus documents underline this unmet need and the lack of practical recommendations for a structured transitional pathway in PKU. The aim of this review and expert opinion is to propose good practices for managing the transition period of PKU patients, based on the literature and the experience of a panel of Italian experts in PKU. The consensus of the experts was obtained through the administration of three rounds of surveys and one structured interview. The result is the first proposal of a pathway for an efficient transition of PKU patients. Key steps of the proposed pathway are the "a priori" planning involving the pediatric and adult teams, the acceptance of the patient and his/her family to the process, the preliminary definition of appropriate spaces in the structure, the organization of meetings with the joint team, and the appointment of a transition coordinator. For the first time, the involvement of decision makers and patient associations is proposed.

Validity of Machine Learning in Predicting Giant Cell Arteritis Flare After Glucocorticoids Tapering.

Background: Inferential statistical methods failed in identifying reliable biomarkers and risk factors for relapsing giant cell arteritis (GCA) after glucocorticoids (GCs) tapering. A ML approach allows to handle complex non-linear relationships between patient attributes that are hard to model with traditional statistical methods, merging them to output a forecast or a probability for a given outcome. Objective: The objective of the study was to assess whether ML algorithms can predict GCA relapse after GCs tapering. Methods: GCA patients who underwent GCs therapy and regular follow-up visits for at least 12 months, were retrospectively analyzed and used for implementing 3 ML algorithms, namely, Logistic Regression (LR), Decision Tree (DT), and Random Forest (RF). The outcome of interest was disease relapse within 3 months during GCs tapering. After a ML variable selection method, based on a XGBoost wrapper, an attribute core set was used to train and test each algorithm using 5-fold cross-validation. The performance of each algorithm in both phases was assessed in terms of accuracy and area under receiver operating characteristic curve (AUROC). Results: The dataset consisted of 107 GCA patients (73 women, 68.2%) with mean age ( ± SD) 74.1 ( ± 8.5) years at presentation. GCA flare occurred in 40/107 patients (37.4%) within 3 months after GCs tapering. As a result of ML wrapper, the attribute core set with the least number of variables used for algorithm training included presence/absence of diabetes mellitus and concomitant polymyalgia rheumatica as well as erythrocyte sedimentation rate level at GCs baseline. RF showed the best performance, being significantly superior to other algorithms in accuracy (RF 71.4% vs LR 70.4% vs DT 62.9%). Consistently, RF precision (72.1%) was significantly greater than those of LR (62.6%) and DT (50.8%). Conversely, LR was superior to RF and DT in recall (RF 60% vs LR 62.5% vs DT 47.5%). Moreover, RF AUROC (0.76) was more significant compared to LR (0.73) and DT (0.65). Conclusions: RF algorithm can predict GCA relapse after GCs tapering with sufficient accuracy. To date, this is one of the most accurate predictive modelings for such outcome. This ML method represents a reproducible tool, capable of supporting clinicians in GCA patient management.

Clinical Delphi on aPL Negativization: Report from the APS Study Group of the Italian Society for Rheumatology (SIR-APS).

BACKGROUND: The rate of antiphospholipid antibody (aPL) negativization in antiphospholipid syndrome (APS) patients is uncertain, but it is estimated to be as high as 8%. Currently, a consensus definition of aPL negativization is lacking, as well as international recommendations on how to approach treatment in patients with a persistent aPL-negative seroconversion. AIM: The aim of the Delphi survey was to evaluate the clinical approach and level of consensus among experts from the APS Study Group of the Italian Society for Rheumatology (SIR-APS) in different clinical scenarios. METHODS: Experts of SIR-APS were contacted using a survey methodology. RESULTS: A structured survey was circulated among 30 experts. Up to 90% of the interviewed experts agreed on defining aPL negativization as the presence of two negative determinations, 1 year apart (90%). Almost full consensus exists among experts in some clinical settings, including: (1) the role of aPL negativization in the management of a thrombotic event determined by concomitant presence of cardiovascular risk factors, both modifiable and not modifiable (90%); (2) approach to young patients with triple aPL positivity who experienced pulmonary arterial thrombotic events and tested negative for aPL detection after 5 years of vitamin K antagonist (VKA) treatment (90%); (3) the use of "extra criteria" aPL antibody testing before pondering VKA suspension (93%). CONCLUSION: A substantial agreement exists among experts on how to define aPL negativization. VKA suspension should be embraced with extreme caution, particularly in case of previous thrombotic events and/or triple aPL positivity. Nevertheless, VKA cessation might be considered when risk factors are carefully monitored/treated and the presence of "extra criteria" aPL is ruled out.

A unique circulating miRNA profile highlights thrombo-inflammation in Behçet's syndrome.

OBJECTIVES: Behçet's syndrome (BS) is a rare systemic vasculitis often complicated by thrombotic events. Given the lack of validated biomarkers, BS diagnosis relies on clinical criteria.In search of novel biomarkers for BS diagnosis, we determined the profile of plasmatic circulating microRNAs (ci-miRNAs) in patients with BS compared with healthy controls (HCs). METHODS: ci-miRNA profile was evaluated by microarray in a screening cohort (16 patients with BS and 18 HCs) and then validated by poly(T) adaptor PCR (PTA-PCR) in a validation cohort (30 patients with BS and 30 HCs). Two disease control groups (30 patients with systemic lupus erythematosus (SLE) and 30 patients with giant cell arteritis (GCA) were also analysed. RESULTS: From the microarray screening, 29 deregulated (differentially expressed (DE)) human ci-miRNAs emerged. A hierarchical cluster analysis indicated that DE ci-miRNAs clearly segregated patients from controls, independently of clinical features. PTA-PCR analysis on the validation cohort confirmed the deregulation of miR-224-5p, miR-206 and miR-653-5p. The combined receiver operating characteristic (ROC) curve analyses showed that such ci-miRNAs discriminate BS from HCs (and BS with active vs inactive disease), as well as BS from patients with SLE and GCA.The functional annotation analyses (FAAs) showed that the most enriched pathways affected by DE ci-miRNAs (ie, cell-matrix interaction, oxidative stress and blood coagulation) are related to thrombo-inflammatory mechanisms. Accordingly, the expression of the three ci-miRNAs from the validation cohort significantly correlated with leucocyte reactive oxygen species production and plasma lipid peroxidation. CONCLUSIONS: The ci-miRNA profile identified in this study may represent a novel, poorly invasive BS biomarker, while suggesting an epigenetic control of BS-related thrombo-inflammation.

Mepolizumab for Eosinophilic Granulomatosis With Polyangiitis: A European Multicenter Observational Study.

OBJECTIVE: Mepolizumab proved to be an efficacious treatment for eosinophilic granulomatosis with polyangiitis (EGPA) at a dose of 300 mg every 4 weeks in the randomized, controlled MIRRA trial. In a few recently reported studies, successful real-life experiences with the approved dose for treating severe eosinophilic asthma (100 mg every 4 weeks) were observed. We undertook this study to assess the effectiveness and safety of mepolizumab 100 mg every 4 weeks and 300 mg every 4 weeks in a large European EGPA cohort. METHODS: We included all patients with EGPA treated with mepolizumab at the recruiting centers in 2015-2020. Treatment response was evaluated from 3 months to 24 months after initiation of mepolizumab. Complete response to treatment was defined as no disease activity (Birmingham Vasculitis Activity Score [BVAS] = 0) and a prednisolone or prednisone dose (or equivalent) of ≤4 mg/day. Respiratory outcomes included asthma and ear, nose, and throat (ENT) exacerbations. RESULTS: Two hundred three patients, of whom 191 received a stable dose of mepolizumab (158 received 100 mg every 4 weeks and 33 received 300 mg every 4 weeks) were included. Twenty-five patients (12.3%) had a complete response to treatment at 3 months. Complete response rates increased to 30.4% and 35.7% at 12 months and 24 months, respectively, and rates were comparable between mepolizumab 100 mg every 4 weeks and 300 mg every 4 weeks. Mepolizumab led to a significant reduction in BVAS score, prednisone dose, and eosinophil counts from 3 months to 24 months, with no significant differences observed between 100 mg every 4 weeks and 300 mg every 4 weeks. Eighty-two patients (40.4%) experienced asthma exacerbations (57 of 158 [36%] who received 100 mg every 4 weeks; 17 of 33 [52%] who received 300 mg every 4 weeks), and 31 patients (15.3%) experienced ENT exacerbations. Forty-four patients (21.7%) experienced adverse events (AEs), most of which were nonserious AEs (38 of 44). CONCLUSION: Mepolizumab at both 100 mg every 4 weeks and 300 mg every 4 weeks is effective for the treatment of EGPA. The 2 doses should be compared in the setting of a controlled trial.

In vitro evaluation of the effect of mutations in primer binding sites on detection of SARS-CoV-2 by RT-qPCR.

A number of RT-qPCR assays for the detection of SARS-CoV-2 have been published and are listed by the WHO as recommended assays. Furthermore, numerous commercial assays with undisclosed primer and probe sequences are on the market. As the SARS-CoV-2 pandemic progresses, the virus accrues mutations, which in some cases - as seen with the B.1.1.7 variant - can outperform and push back other strains of SARS-CoV-2. If mutations occur in primer or probe binding sites, this can impact RT-qPCR results and impede SARS-CoV-2 diagnostics. Here we tested the effect of primer mismatches on RT-qPCR performance in vitro using synthetic mismatch in vitro transcripts. The effects of the mismatches ranged from a shift in ct values from -0.13 to +7.61. Crucially, we found that a mismatch in the forward primer has a more detrimental effect for PCR performance than a mismatch in the reverse primer. Furthermore, we compared the performance of the original Charité RdRP primer set, which has several ambiguities, with a primer version without ambiguities and found that without ambiguities the ct values are ca. 3 ct lower. Finally, we investigated the shift in ct values observed with the Seegene Allplex kit with the B.1.1.7 SARS-CoV-2 variant and found a three-nucleotide mismatch in the forward primer of the N target.