Monitoring of Adverse Events and Safety in Autoinflammatory Diseases: Real-Life Data from the Eurofever Registry.

OBJECTIVES: The study is aimed to evaluate the impact of safety events in the Eurofever registry for Autoinflammatory diseases. METHODS: This was a retrospective and longitudinal observational multicentre study. Data were retrieved from the international registry Eurofever, starting patients' enrolment since 2009. All moderate, severe, or very severe AEs reported by treating physician in Eurofever were analyzed regardless of a possible suspected causal relationship to any therapies and according to the latest release of the Medical Dictionary for Regulatory Activities. RESULTS: Complete information on safety were available in 2464 patients enrolled in the registry. In 1499 of them retrospective data encompassing the period from disease onset to enrolment were available, whereas 965 consecutive patients entered in the longitudinal part of the study. A total of 479 AEs have been reported in 275 patients. Eighty-two AEs were reported as serious and 99 were drug-related according to the physicians. Infections or infestations (94; 19.6%), gastrointestinal disorders (66; 13.8%), nervous system disorders (41; 8.6%) and systemic disorders or administration site reactions (35; 7.3%) were the most frequent reported events. The highest absolute number of drug-related AEs were related to biologic DMARDs (40/99 reports, 40,4%) and colchicine (31/99 reports, 31.3%). CONCLUSIONS: Present study shows the importance of a longitudinal and homogeneous registration of the AEs in rare conditions, with a particular focus on the safety profile of the treatments used in these conditions.

The HyperPed-COVID international registry: Impact of age of onset, disease presentation and geographical distribution on the final outcome of MIS-C.

OBJECTIVES: The aim of the study was to establish an international multicenter registry to collect data on patients with Multisystem Inflammatory Syndrome in Children (MIS-C), in order to highlight a relationship between clinical presentation, age of onset and geographical distribution on the clinical outcome. STUDY DESIGN: Multicenter retrospective study involving different international societies for rare immunological disorders.1009 patients diagnosed with MIS-C between March and September 2022, from 48 centers and 22 countries were collected. Five age groups (<1, 1-4, 5-11, 12-16, >16 years) and four geographic macro-areas, Western Europe, Central-Eastern Europe, Latin America, Asian-African resource-limited countries (LRC), were identified. RESULTS: Time to referral was significantly higher in LRC. Intensive anti-inflammatory treatment, including biologics, respiratory support and mechanic ventilation were more frequently used in older children and in European countries. The mortality rate was higher in very young children (<1 year), in older patients (>16 years of age) and in LRC. Multivariate analysis identified the residence in LRC, presence of severe cardiac involvement, renal hypertension, lymphopenia and non-use of heparin prophylaxis, as the factors most strongly associated with unfavorable outcomes. CONCLUSIONS: The stratification of patients by age and geographic macro-area provided insights into the clinical presentation, treatment and outcome of MIS-C. The mortality and sequelae rates exhibited a correlation with the age and geographical areas. Patients admitted and treated in LRC displayed more severe outcomes, possibly due to delays in hospital admission and limited access to biologic drugs and to intensive care facilities.

Similarities and differences between systemic juvenile idiopathic arthritis and adult-onset Still's disease: a multicenter Spanish study.

To describe the characteristics of systemic juvenile idiopathic arthritis (sJIA) and adult-onset Still's disease (AOSD), compare their presentation and evolution, and analyse possible complication predictors. Multicenter study. Data were retrieved from a hospital-based study of patients with a diagnosis or suspected diagnosis of sJIA or AOSD according to the responsible physician and followed-up for at least one year. Descriptive variables (classification criteria, clinical manifestations, complications, family, and personal history) were collected at disease onset and during follow-up. We present the clinical characteristics of 326 patients, 67% of whom had a diagnosis of sJIA and 33% of AOSD. Clinical manifestation frequencies were similar between the two groups, except for odynophagia, which was significantly more frequent in AOSD than in sJIA (78.4% vs. 25.5%; p < 0.0001). Among the complications, macrophage activation syndrome (MAS) was significantly more common in sJIA than in AOSD (24.4% vs. 9.5%; p = 0.002), to the extent that an sJIA diagnosis significantly increased the risk of MAS, together with serositis presence, and the need for biological therapy. Patients with sJIA and AOSD showed similar characteristics, supporting the idea that they are both part of Still's disease, but are expressed at different ages. Differences in manifestations and complications might be due to different management between diseases and immune response maturity.

TNFRSF1A-pR92Q variant identifies a subset of patients more similar to systemic undifferentiated recurrent fever than TNF receptor-associated periodic syndrome.

OBJECTIVES: To describe the clinical phenotype and response to treatment of autoinflammatory disease (AID) patients with the TNFRSF1A-pR92Q variant compared to patients with tumour necrosis factor receptor-associated periodic syndrome (TRAPS) due to pathogenic mutations in the same gene and patients diagnosed with other recurrent fever syndromes including periodic fever with aphthous stomatitis, pharyngitis, and adenitis (PFAPA) and syndrome of undefined recurrent fever (SURF). METHODS: Clinical data from pR92Q variant associated AID, classical TRAPS, PFAPA and SURF patients were obtained from the Eurofever registry, an international, multicentre registry enabling retrospective collection of data on AID patients. RESULTS: In this study, 361 patients were enrolled, including 77 pR92Q variant, 72 classical TRAPS, 152 PFAPA and 60 SURF patients. pR92Q carriers had an older age of disease onset than classical TRAPS and PFAPA patients. Compared to pR92Q variant patients, classical TRAPS patients had more relatives affected and were more likely to have migratory rash and AA-amyloidosis. Despite several differences in disease characteristics and symptoms between pR92Q variant and PFAPA patients, part of the pR92Q variant patients experienced PFAPA-like symptoms. pR92Q variant and SURF patients showed a comparable clinical phenotype. No major differences were observed in response to treatment between the four patient groups. Steroids were most often prescribed and effective in the majority of patients. CONCLUSIONS: Patients with AID carrying the TNFRSF1A-pR92Q variant behave more like SURF patients and differ from patients diagnosed with classical TRAPS and PFAPA in clinical phenotype. Hence, they should no longer be diagnosed as having TRAPS and management should differ accordingly.

Kawasaki disease in children younger than 6 months of age: characteristics of a Spanish cohort.

A retrospective study that compared children younger than 6 months versus older children of a Spanish cohort of patients diagnosed with Kawasaki disease between 2011 and 2016 (Kawa-Race study). From the 598 patients recruited, 42 patients were younger than 6 months (7%) and presented more frequently with an incomplete diagnosis of Kawasaki disease (52.4 vs 27.9%, p = 0.001). Cardiac abnormalities detected by echocardiography were more common in younger patients (52.4 vs 30%, p = 0.002). These younger patients presented with a higher proportion of coronary aneurysms as well (19 vs 8.6%, p < 0.001). Shock at diagnosis (9.5 vs 1.9%, p = 0.016) and admission to intensive care units (17.7 vs 4.1%, p = 0.003) were more frequent in patients younger than 6 months. There were no statistically significant differences in relation to infections, non-response to IVIG, or mid- or long-term outcomes.Conclusion: Data of the Spanish cohort are consistent with other American and Asian studies, although Spanish children younger than 6 months had a lower rate of non-response to IVIG and better clinical outcomes. A high index of suspicion should be considered for this population due to a higher risk of coronary abnormalities, presentation of shock, and admission to the intensive care unit. What is Known: •Children below 6 months of age with Kawasaki disease (KD) have different features compared to older. •Younger patients usually have an incomplete form of KD and coronary artery abnormalities. What is New: •Younger than 6 months with KD presented with shock and required admission to PICU more frequently compared to older. •Infections play a similar role in KD despite the age of the patients.

Giant coronary aneurysm in a 6-week-old infant, an unusual finding?

Kawasaki disease (KD) is a self-limited vasculitis with significant morbidity and even mortality if not treated early. The diagnosis and timely treatment in children younger than 3 months is challenging as most of them have an incomplete or atypical presentation. Coronary artery abnormalities are frequent in this type of patients. We present a 6-week-old female infant with KD who developed a giant coronary aneurysm. An early diagnosis and promptly treatment, as well as the echocardiographic and multimodality follow-up allowed us to improve our clinical approach and management.

Incidence, epidemiology and clinical features of Kawasaki disease in Catalonia, Spain.

OBJECTIVES: To assess the incidence, epidemiology and clinical features of Kawasaki disease (KD) in Catalonia (northeast region of Spain). METHODS: This was an observational population-based study including all Paediatric Units in Catalonia, under both public and private management. Retrospective data retrieval was performed for 10 years (2004-2013). A 12-month (March 2013 to March 2014) prospective collection of new cases of KD was carried out to determine the incidence of KD. RESULTS: Data from 399 patients over the 10-year study period was analysed, revealing that 233 (58.4%) had complete KD, 159 (39.8) incomplete KD and 7 (1.7%) were considered atypical KD. Mean annual incidence was 3.5/105 children <14 years old (yo) and 8/105 children <5 yo (mean age 37±33 months, range 1.3-191.3). KD was more frequent in boys (59.6%, p<0.001) and in rural areas (p<0.001). Patients with IVIG non-responsiveness, need of a 2(nd) IVIG dose, delay of treatment >10(th) day of illness, ages <1 yo and >8 yo and the presence of sterile piuria, aseptic meningitis, abdominal pain and uveitis at diagnosis were found to have higher risk of coronary aneurisms (CAA) (p<0.05). CONCLUSIONS: This is the first population-based study on the epidemiology of KD in the western Mediterranean area. Incidence, clinical features and treatment plans in our cohort are similar to those described in other European studies.

Role of the Egami score to predict immunoglobulin resistance in Kawasaki disease among a Western Mediterranean population.

Kawasaki disease is an acute self-limited systemic vasculitis common in childhood. Intravenous immunoglobulin (IVIG) is an effective treatment, and it reduces the incidence of cardiac complications. Egami score has been validated to identify IVIG non-responder patients in Japanese population, and it has shown high sensitivity and specificity to identify these non-responder patients. Although its effectiveness in Japan, Egami score has shown to be ineffective in non-Japanese populations. The aim of this study was to apply the Egami score in a Western Mediterranean population in Catalonia (Spain). Observational population-based study that includes patients from all Pediatric Units in 33 Catalan hospitals, both public and private management, between January 2004 and March 2014. Sensitivity and specificity for the Egami score was calculated, and a logistic regression analysis of predictors of overall response to IVIG was also developed. Predicting IVIG resistance with a cutoff for Egami score ≥3 obtained 26 % sensitivity and 82 % specificity. Negative predictive value was 85 % and positive predictive value 22 %. This low sensitivity implies that three out of four non-responders will not be identified by the Egami score. Besides, logistic regression models did not found significance for the use of the Egami score to predict IVIG resistance in Catalan population although having an area under the ROC curve of 0.618 (IC 95 % 0.538-0.698, p < 0.001). Although regression models found an area under the ROC curve >0.5 to predict IVIG resistance, the low sensitivity excludes the Egami score as a useful tool to predict IVIG resistance in Catalan population.

Efficacy and safety of TNF-alpha antagonists in children with juvenile idiopathic arthritis who started treatment under 4 years of age.

The aims of the study were to assess efficacy and safety of TNF-alpha antagonists (anti-TNF) in a cohort of patients with juvenile idiopathic arthritis (JIA) who began treatment under 4 years old and to assess relapse rate after methotrexate and/or anti-TNF withdrawal. We made a retrospective charts review of our non-systemic JIA patients treated with anti-TNF under 4 years of age between January 2006 and April 2013. Demographics, epidemiologic, clinical, laboratory data and rate of relapse after treatment withdrawal due to clinical remission were collected. Efficacy and safety end points included side effects (SE) and time to achieve clinical remission. We included 27 patients, 23 received etanercept and 4 adalimumab with a median age of 3.01 (range 0.88-3.97) years at anti-TNF beginning and 1.94 (range 0.18-5.44) and 2.39 (range 0.18-7.24) years of treatment and follow-up, respectively. All patients had previously received disease-modifying antirheumatic drugs at optimal dose. Nineteen patients reached clinical remission on treatment in a median time of 9.1 (range 6.23-21.17) months. Four of those relapsed during treatment. Six developed mild SE, mostly mild infections. No serious SE were described. Eleven patients who reached clinical remission relapsed after treatment withdrawal. None achieved clinical remission off treatment. Most patients reached clinical remission on anti-TNF. In our cohort of patients, etanercept and adalimumab were safe, with mostly mild infections and no serious SE. We observed a high relapse rate during treatment withdrawal.

Diagnosis and classification of Kawasaki disease.

Kawasaki disease is an acute systemic vasculitis of unknown etiology. Diagnosis is based on clinical criteria that include fever, exanthema, conjunctivitis, changes in the extremities, erythema of oral mucosa and lips and cervical lymphadenopathy. However, these criteria have low sensitivity and specificity and therefore, other clinical and laboratory features may be helpful in establishing the diagnosis, especially for cases of atypical or incomplete Kawasaki disease. Prognosis depends on the extent of cardiac involvement; coronary aneurysms develop in 20-25% of untreated patients and these may lead to myocardial infarction and sudden death. Treatment with high-dose intravenous immunoglobulin is effective in reducing the risk of coronary aneurysms in most cases and is the treatment of choice for initial Kawasaki disease.

Thrombotic manifestations in pediatric Behcet syndrome: A multicenter comparative study from the EUROFEVER registry.

INTRODUCTION: Vascular events account for a considerable burden of morbidity and mortality in Behçet syndrome (BS). Thrombosis occurs in 1.8-21 % pediatric BS patients, even if the real prevalence is still largely unknown. OBJECTIVES: To report clinical features and outcomes of pediatric BS patients with thrombosis and to compare the demographic and clinical characteristics of BS patients with and without thrombosis. METHODS: Retrospective data collection of BS patients with thrombosis (T+) included in the EUROFEVER registry. BS patients without thrombosis (T-), belonging to the same rheumatology units, were matched in a 2:1 ratio. RESULTS: 37 T+ were compared to 74 T- patients. At onset, ICBD criteria fulfillment was higher in the T- group (p = 0.015). Caucasian patients were more often T-, Turkish patients were more frequent in T+ group (p = 0.002). At onset, pustulosis was most frequently observed in the T- (p < 0.001) as well as gastrointestinal symptoms (p < 0.001) and ocular involvement (p = 0.022). Neurological symptoms were more often described in T+ (p = 0.034). As for T+, thrombosis was reported at BS presentation in 8/37 (21.6 %). For the T + e patients who developed thrombosis later, oral aphthosis (p = 0.003), genital aphthosis (p = 0.014) were more frequently observed at BS onset, while pustulosis (p = 0.005) and fever (p = 0.043) coexisted with thrombosis. Thrombosis was mainly venous (26/37,70.3 %), involving the cerebral sinuses (21/37, 56.8 %). After thrombosis, 35/37 (94.6 %) T+ patients received an immunomodulatory treatment compared with 16/29 (55.2 %) pre-thrombosis. A recurrence was reported in 6/31(19.4 %). CONCLUSION: Thrombosis was reported at BS presentation in one fifth of cases. Pustolosis and fever were more frequently concomitant to thrombosis. Sinus veins were the most frequent site.

Clinical characteristics and prognostic factor in juvenile dermatomyositis: data of the Spanish registry.

BACKGROUND: Juvenile Dermatomyositis (JDM) is the most common chronic idiopathic inflammatory myopathy in children. The diagnosis is clinical. Baseline laboratory and complementary studies trace the phenotype of these patients. The objective of this study was to describe epidemiological, clinical and laboratory characteristics at diagnosis of JDM patients included in the Spanish JDM registry, as well as to identify prognostic factors on these patients. METHODS: We retrospectively reviewed clinical features, laboratory tests, and complementary studies at diagnosis of JDM patients included on the Spanish JDM registry. These data were analyzed to assess whether there was a relationship with the development of complications and time to disease inactivity. RESULTS: One hundred and sixteen patients from 17 Spanish paediatric rheumatology centres were included, 76 girls (65%). Median age at diagnosis was 7.3 years (Interquartile range (IQR) 4.5-10.2). All patients had pathognomonic skin lesions at the beginning of the disease. Muscle weakness was present in 86.2%. Median Childhood Muscle Assessment Scale was 34 (IQR 22-47). Twelve patients (34%) had dysphagia and 3,5% dysphonia. Anti-p155 was the most frequently detected myositis specific antibody, followed by anti-MDA5. Twenty-nine patients developed calcinosis and 4 presented with macrophage activation syndrome. 70% reached inactivity in a median time of 8.9 months (IQR 4.5-34.8). 41% relapsed after a median time of 14.4 months (IQR 8.6-22.8) of inactivity. Shorter time to treatment was associated with better prognosis (Hazard ratio (HR) = 0.95 per month of evolution, p = 0.02). Heliotrope rash at diagnosis correlates with higher risk of development complications. CONCLUSIONS: We describe heliotrope rash as a risk factor for developing complications in our cohort of JDM patients, an easy-to-evaluate clinical sign that could help us to identify the group of patients we should monitor closely for this complication.

Real-World Health Care Outcomes and Costs Among Patients With Juvenile Idiopathic Arthritis in Spain.

Background: Juvenile idiopathic arthritis (JIA) is the most frequent chronic rheumatic disease in children. If inflammation is not adequately treated, joint damage, long-term disability, and active disease during adulthood can occur. Identifying and implementing early and adequate therapy are critical for improving clinical outcomes. The burden of JIA on affected children, their families, and the healthcare system in Spain has not been adequately assessed. The greatest contribution to direct costs is medication, but other expenses contribute to the consumption of resources, negatively impacting healthcare cost and the economic conditions of affected families. Objective: To assess the direct healthcare, indirect resource utilization, and associated cost of moderate-to-severe JIA in children in routine clinical practice in Spain. Methods: Children were enrolled in this 24-month observational, multicentric, cross-sectional, retrospective study (N = 107) if they had been treated with biologic disease-modifying anti-rheumatic drugs (bDMARDs), had participated in a previous study (ITACA), and continued to be followed up at pediatric rheumatology units at 3 tertiary Spanish hospitals. Direct costs included medication, specialist and primary care visits, hospitalizations, emergency visits or consultations, surgeries, physiotherapy, and tests. Indirect costs included hospital travel expenses and loss of caregiver working hours. Unitary costs were obtained from official sources (€, 2020). Results: Overall, children had inactive disease/low disease activity according to JADAS-71 score and very low functional disability as measured by Childhood Health Assessment Questionnaire score. Up to 94.4% of children received treatment, mainly with bDMARDs as monotherapy (84.5%). Among anti-TNFα treatments, adalimumab (47.4%) and etanercept (40.2%) were used in similar proportions. Annual mean (SD) total JIA cost was €7516.40 (€5627.30). Average cost of pharmacological treatment was €3021.80 (€3956.20), mainly due to biologic therapy €2789.00 (€3399.80). Direct annual cost (excluding treatments) was €3654.60 (€3899.00). Indirect JIA cost per family was €747.20 (€1452.80). Conclusion: JIA causes significant costs to the Spanish healthcare system and affected families. Public costs are partly due to the high cost of biologic treatments, which nevertheless remain an effective long-term treatment, maintaining inactive disease/low disease activity state; a very low functional disability score; and a good quality of life.

Characterization of the nasopharyngeal microbiome in patients with Kawasaki disease.

INTRODUCTION: The aetiology of Kawasaki disease (KD) remains unknown. Several studies have linked the human microbiome with some diseases. However, there are limited studies on the role of the respiratory microbiome in KD. The aim of our study was to make a more thorough analysis of the causes and processes that increase the susceptibility to KD. METHODS: Case-control study comparing the respiratory microbiome of KD patients with that of healthy children. The V3-V4 region of the 16S rRNA bacterial gene and 16 respiratory viruses were analysed by real-time polimerase-chain reaction. We used the Ribosomal Database Project (RDP) version 11.5 (taxonomic assignment). RESULTS: The initial sample included 11 cases and 11 controls matched for age, sex and seasonality. One of the cases was excluded to poor sample quality. The final analysis included 10 cases and 10 controls. In the case group, the analysis detected Haemophilus, Moraxella, Streptococcus and Corynebacterium species (27.62%, 19.71%, 25.28%, 11.86%, respectively). In the control group, it found Haemophilus, Streptococcus, Moraxella, and Dolosigranulum species (38.59%, 23.71%, 16.08, 8.93%, respectively). We found a higher relative abundance of Corynebacterium in patients with KD (11.86% vs. 1.55%; P = 0.004). CONCLUSIONS: To our knowledge, this is the first study that has found differences in the composition of the respiratory microbiome between patients with KD and healthy controls. The relative abundance of Corynebacterium spp. was greater in the KD group. This study shows differences in the microbiome between cases and controls, which suggests that the microbiome may play a role in facilitating the development of KD.

Risk scores for Kawasaki disease, a management tool developed by the KAWA-RACE cohort.

INTRODUCTION/OBJECTIVES: Asian scores developed to predict unresponsiveness to intravenous immunoglobulin (IVIG) or development of coronary artery aneurysms (CAA) in patients with Kawasaki disease (KD) are not appropriate in Western populations. The purpose of this study is to develop 2 scores, to predict unresponsiveness to IVIG and development of CAA, appropriate for Spanish population. METHOD: Data of 625 Spanish children with KD collected retrospectively (2011-2016) were used to identify variables to develop the 2 scores of interest: unresponsiveness to IVIG and development of CAA. A statistical model selected best variables to create the scores, and scores were validated with data from 98 patients collected prospectively. RESULTS: From 625 patients of the retrospective cohort, final analysis was performed in 439 subjects: 37 developed CAA, and 212 were unresponsive to IVIG. For the score to predict CAA, a cutoff ≥ 8 was considered for high risk, considering a score system with a different weight for each of the eight variables. External validation showed a sensitivity of 22% and a specificity of 75%. The score to predict unresponsiveness to IVIG established a cutoff ≥ 8 for high risk, considering a score system with a different weight for each of the nine variables. External validation showed a sensitivity of 78% and a specificity of 50%. CONCLUSIONS: Two risk scores for KD were developed from Spanish population, to predict development of CAA and unresponsiveness to IVIG; validation in other cohorts could help to implement these tools in the management of KD in other Western populations.

Similarities and differences between the immunopathogenesis of COVID-19-related pediatric multisystem inflammatory syndrome and Kawasaki disease.

Multisystem inflammatory syndrome associated with the SARS-CoV-2 pandemic has recently been described in children (MIS-C), partially overlapping with Kawasaki disease (KD). We hypothesized that (a) MIS-C and prepandemic KD cytokine profiles may be unique and justify the clinical differences observed, and (b) SARS-CoV-2-specific immune complexes (ICs) may explain the immunopathology of MIS-C. Seventy-four children were included: 14 with MIS-C, 9 patients positive for SARS-CoV-2 by PCR without MIS-C (COVID), 14 with prepandemic KD, and 37 healthy controls (HCs). Thirty-four circulating cytokines were quantified in pretreatment serum or plasma samples and the presence of circulating SARS-CoV-2 ICs was evaluated in MIS-C patients. Compared with HCs, the MIS-C and KD groups showed most cytokines to be significantly elevated, with IFN-γ-induced response markers (including IFN-γ, IL-18, and IP-10) and inflammatory monocyte activation markers (including MCP-1, IL-1α, and IL-1RA) being the main triggers of inflammation. In linear discriminant analysis, MIS-C and KD profiles overlapped; however, a subgroup of MIS-C patients (MIS-Cplus) differentiated from the remaining MIS-C patients in IFN-γ, IL-18, GM-CSF, RANTES, IP-10, IL-1α, and SDF-1 and incipient signs of macrophage activation syndrome. Circulating SARS-CoV-2 ICs were not detected in MIS-C patients. Our findings suggest a major role for IFN-γ in the pathogenesis of MIS-C, which may be relevant for therapeutic management.

Prevalence and Clinical Characteristics of SARS-CoV-2 Confirmed and Negative Kawasaki Disease Patients During the Pandemic in Spain.

Introduction: COVID-19 has a less severe course in children. In April 2020, some children presented with signs of multisystem inflammation with clinical signs overlapping with Kawasaki disease (KD), most of them requiring admission to the pediatric intensive care unit (PICU). This study aimed to describe the prevalence and clinical characteristics of KD SARS-CoV-2 confirmed and negative patients during the pandemic in Spain. Material and Methods: Medical data of KD patients from January 1, 2018 until May 30, 2020 was collected from the KAWA-RACE study group. We compared the KD cases diagnosed during the COVID-19 period (March 1-May 30, 2020) that were either SARS-CoV-2 confirmed (CoV+) or negative (CoV-) to those from the same period during 2018 and 2019 (PreCoV). Results: One hundred and twenty-four cases were collected. There was a significant increase in cases and PICU admissions in 2020 (P-trend = 0.001 and 0.0004, respectively). CoV+ patients were significantly older (7.5 vs. 2.5 yr) and mainly non-Caucasian (64 vs. 29%), had incomplete KD presentation (73 vs. 32%), lower leucocyte (9.5 vs. 15.5 × 109) and platelet count (174 vs. 423 × 109/L), higher inflammatory markers (C-Reactive Protein 18.5vs. 10.9 mg/dl) and terminal segment of the natriuretic atrial peptide (4,766 vs. 505 pg/ml), less aneurysm development (3.8 vs. 11.1%), and more myocardial dysfunction (30.8 vs. 1.6%) than PreCoV patients. Respiratory symptoms were not increased during the COVID-19 period. Conclusion: The KD CoV+ patients mostly meet pediatric inflammatory multisystem syndrome temporally associated with COVID-19/multisystem inflammatory syndrome in children criteria. Whether this is a novel entity or the same disease on different ends of the spectrum is yet to be clarified.

Canakinumab for the treatment of hyperimmunoglobulin D syndrome.

INTRODUCTION: Mevalonate Kinase Deficiency (MKD) is a rare monogenic autoinflammatory disorder (AID) with autosomal recessive inheritance caused by mutations in the MVK gene. It includes hyperimmunoglobulinemia D syndrome (HIDS) and mevalonic aciduria (a severe form). Patients have recurrent inflammatory attacks with high fever, gastrointestinal symptoms, lymphadenopathy, splenomegaly, arthralgia, rash, pharyngitis, aphtosis and constitutional complaints. Heightened understanding of molecular mechanisms in monogenic autoinflammatory disorders has provided tools for targeted treatment. HIDS is an extrinsic inflammasomopathy and is responsive to anti-IL-1 therapies, such as the recombinant IL-1-receptor antagonist anakinra, the monoclonal antibody against IL-1b canakinumab (CAN), and the recombinant IL-1R fusion protein rilonacept. Areas covered: CAN is a human monoclonal anti-IL-1ß antibody that binds with high affinity and neutralizes the activity of IL-1 ß. Both observational registries and some case reports have seemed promising in the efficacy of CAN in the HIDS treatment. Two clinical trials have corroborated CAN as an effective and safe drug. Expert commentary: CAN is effective and safe for the treatment of HIDS patients. Some data suggest these patients may need higher dosage or shorter dosing interval than other AIDs, to achieve and maintain complete clinical and laboratory response. Reported adverse events were mild, most often non-complicated infections.