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.

Early anakinra treatment improves cardiac outcome of multisystem inflammatory syndrome in children, regardless of disease severity.

OBJECTIVE: The main aim of this study was to define the best treatment option for multisystem inflammatory syndrome in children (MIS-C) and to analyse the role of anakinra. METHODS: This is a multicentre retrospective cohort study. Patients were treated according to the attending physician's decision. The patients were divided into four groups on the basis of the first treatment at time of admittance: (i) IVIG, (ii) IVIG and methylprednisolone (≤2 mg/kg/day), (iii) IVIG with high-dose methylprednisolone (>2 mg/kg/day) and (iv) anakinra with or without IVIG and/or methylprednisolone. Primary outcomes were defined as the presence of at least one of the following features: death, the failure of initial treatment, meaning the need for additional treatment for clinical worsening and cardiac involvement at the end of follow-up. RESULTS: Two hundred thirty-nine patients were recruited. At univariate analysis, persistent heart involvement at discharge was more frequent in those not receiving anakinra as initial treatment (3/21 vs 66/189; P = 0.047). After comparisons between the four treatment regimens, adjusting for the propensity score, we observed that early treatment with anakinra was associated with a lower probability of developing persistent heart disease at the end of follow-up (odds ratio: 0.6; 95% CI: 0.4-1.0). CONCLUSION: We report that early treatment with anakinra is safe and very effective in patients with severe MIS-C. In addition, our study suggests that early treatment with anakinra is the most favourable option for patients with a higher risk of developing a severe disease outcome.

Uveitis as predictor of disease flare after the first anti-TNF withdrawal in oligoarticular and polyarticular juvenile idiopathic arthritis: a multicentric Italian experience.

OBJECTIVES: TNF inhibitors (TNFi) have dramatically changed the prognosis of juvenile idiopathic arthritis (JIA), but it is not clear how and when to stop therapy. We aim to describe a multicentric cohort of JIA treated with adalimumab or etanercept who discontinued the treatment for persistent inactivity and to identify factors associated with relapse. METHODS: In a multicentric Italian retrospective cohort study, medical records of patients with oligoarticular and polyarticular JIA were evaluated if they stopped therapy for persistent inactivity after the first TNFi. RESULTS: 136 patients were enrolled (102 female, median age at onset 3 years (range 1-15), of whom 55.9% had oligoarticular JIA, 40.4% uveitis and 72.8% ANA positivity. Adalimumab (59.3%) and etanercept (40.7%) were started at a median age of 6 years (range 1-16), TNFi were discontinued after a median time of 30 months (range 6-90), increasing the interval (76.5%), reducing the dose (18.4%) and abrupt discontinuation (16.9%). 79.4% of patients relapsed after a median time of 5 months (range 0.5-66). Patients with uveitis relapsed earlier (log rank χ² 16.4 p<0.0001), while patients who lengthened the interval of administration showed a later relapse (log rank χ² 6.95 p=0.008). Uveitis (HR 2.11 CI 1.34-3.31), age at onset (HR 0.909 CI 0.836-0.987), duration of tapering (HR 0.938 CI 0.893-0.985) and to have a persistent oligoarticular JIA (HR 0.597 CI 0.368-0.968) are significant predictors of disease relapse (Mantel-Cox χ² 34.23 p<0.001). CONCLUSIONS: Younger age at onset, uveitis, duration of tapering, and non-persistent oligoarticular JIA seem to be independent risk factors for earlier relapse after the first TNFi withdrawal.

Multisystem inflammatory syndrome in children: A review.

AIM: To comprehensively review the literature on multisystem inflammatory syndrome in children (MIS-C). METHODS: Narrative review of relevant studies published between April 2020 and January 2024. RESULTS: MIS-C is a SARS-CoV-2-related hyperinflammatory syndrome developing 2-6 weeks after COVID-19 in genetically susceptible individuals. Persisting fever, mucocutaneous manifestations, GI and cardiac involvement, together with lymphopenia and elevated inflammatory and cardiac markers are the main clinical features. It is believed to recognise some pathogenetic and clinical overlap with Kawasaki disease. New case definitions have been proposed after an assessment of the diagnostic performance of existing criteria; epidemiological criterion is however progressively losing its usefulness as the pandemic turns into an endemic and in the areas with the highest rates of COVID-19 vaccination. Current guidelines recommend both intravenous immunoglobulin and glucocorticoids in the first-line immunomodulatory treatment, mainly based on comparative retrospective cohorts; the actual role of biologics remains to be adequately established. Strict follow-up is mandatory, especially for those with severe cardiac involvement, as longitudinal studies evaluate the long-term evolution of cardiac damage. CONCLUSION: In this paper, we review the epidemiological, pathogenetic, clinical and prognostic features of MIS-C, and outline the main questions which still remain unanswered after more than 3 years of research.

Pediatric Recurrent Pericarditis: Appropriateness of the Standard of Care and Response to IL-1 Blockade.

OBJECTIVE: To analyze, in a cohort of pediatric patients with recurrent pericarditis undergoing anti-interleukin (IL)-1 treatment: the agent and dosing used as first-line treatment, the long-term efficacy of IL-1 blockers, the percentage of patients achieving a drug-free remission, and the presence of variables associated with drug-free remission. STUDY DESIGN: Data were collected from patients' charts. The annualized relapse rate (ARR) was used for evaluation of treatment efficacy, and bivariate logistic regression analysis was used for variables associated with drug-free remission. RESULTS: Fifty-eight patients, treated between 2008 and 2018, were included in the study (mean follow-up. 2.6 years). Of the 56 patients treated with first-line drugs, 14 not responsive patients were underdosed. Fifty-seven patients were treated with anakinra: the ARR before and during daily treatment was 3.05 and 0.28, respectively (P < .0001); an increase to 0.83 was observed after the reduction/withdrawal of treatment (P < .0001). The switch from anakinra to canakinumab (5 patients) was associated to an increase of the ARR (0.49 vs 1.46), but without statistical significance (P = .215). At last follow-up, only 9 of the 58 patients had withdrawn all treatments. With the limits of a retrospective study and the heterogeneity between the patients enrolled in the study, a shorter duration of treatment with anakinra was the only variable associated with drug-free remission. CONCLUSIONS: This study shows that most pediatric patients with recurrent pericarditis needing IL-1 blockade received an inadequate treatment with first-line agents. The effectiveness of anakinra is supported by this study, but few patients achieved drug-free remission. The different rate of response to anakinra and canakinumab may suggest a possible role of IL-1α in the pathogenesis of recurrent pericarditis.

Type I interferon signature as a possible new marker for stratification of patients with juvenile idiopathic arthritis.

OBJECTIVES: The interferon score (IS) quantifies the expression of interferon-stimulated genes in peripheral blood, providing an indirect estimate of interferon-mediated inflammation in rheumatological disorders. This study explores the clinical significance of IS among a cohort of patients affected by juvenile idiopathic arthritis (JIA) and its relevance to disease stratification and prognosis. METHODS: All patients referred to the Rheumatology Service of the Institute for Maternal and Child Health IRCCS Burlo Garofolo, Trieste, Italy, with a diagnosis of JIA (2001 ILAR criteria) were consecutively recruited. Systemic JIA was excluded. Demographic, clinical and laboratory data were collected for each patient in a structured database. Categorical variables were expressed as numbers (%) and compared by the χ2 test or Fisher's exact test. Principal Component Analysis (PCA) was performed with clinical and laboratory data. RESULTS: Forty-four patients were recruited (35 F, 9 M): 19 polyarticular, 13 oligoarticular, 6 oligoarticular-extended, 5 psoriatic and 1 enthesitis-related arthritis. Sixteen had a positive IS (≥3). Increased IS correlated with a higher number of involved joints ≥5 (p=0.013), increased erythrocyte sedimentation rate (ESR) (p=0.026) and hypergammaglobulinaemia (p=0.003). PCA highlighted a subgroup of patients who shared high levels of IS, ESR, C-reactive protein, hypergammaglobulinaemia, JADAS-27, polyarticular involvement and family history of autoimmunity. CONCLUSIONS: Although based on a small case series, our results may support the role of IS in better defining a subgroup of JIA subjects with stronger autoimmune features. The possible relevance of these results for therapeutic stratification remains to be explored.

High incidence of multisystem inflammatory syndrome and other autoimmune diseases after SARS-CoV-2 infection compared to COVID-19 vaccination in children and adolescents in south central Europe.

OBJECTIVES: To estimate the incidence and describe the spectrum of inflammatory and autoimmune diseases linked to SARS-CoV-2 infection and COVID-19 vaccination in children from two neighbouring south central European countries. METHODS: We performed a multi-centre prospective cohort study of children under 18 years diagnosed with inflammatory/autoimmune diseases linked to SARS-CoV-2 infection or COVID-19 vaccination, who were admitted to the paediatric tertiary care hospitals in Slovenia and Friuli Venezia Giulia, Italy, from January 1, 2020, to December 31, 2021. Disease incidence was calculated based on laboratory-confirmed cases only. RESULTS: Inflammatory and autoimmune diseases linked to SARS-CoV-2 were diagnosed in 192 children (127 laboratory-confirmed), of whom 112 had multisystem inflammatory syndrome (MIS-C), followed by vasculitis, neurological and cardiac diseases. Calculated risk of MIS-C was 1 in 860 children after SARS-CoV-2 infection and cumulative incidence of MIS-C was 18.3/100,000 of all children. Fifteen children had severe COVID-19. Two patients with MIS-C and a patient with myositis presented after COVID-19 vaccination. All 3 had at presentation also a serologically proven recent SARS-CoV-2 infection. After MIS-C, nine patients were vaccinated against COVID-19 and 25 patients had a SARS-CoV-2 reinfection, without recurrence of MIS-C. CONCLUSIONS: Autoimmune diseases following SARS-CoV-2 infection in children were 8.5 times as common as severe COVID-19. MIS-C was the most common manifestation and its incidence in this predominantly white population was higher than previously reported. MIS-C does not seem to recur after SARS-CoV-2 reinfection or COVID-19 vaccination. Autoimmune diseases were much more common after SARS-CoV-2 infection than after COVID-19 vaccination.

Cardiac MRI in midterm follow-up of MISC: a multicenter study.

In this multicenter retrospective study we aimed to evaluate the outcome of cardiac involvement in children affected by multisystem inflammatory syndrome (MIS-C), assessed through cardiac magnetic resonance (CMR). Children referring to three Italian tertiary pediatric centers between February 2020 and November 2021 with a diagnosis of MIS-C, who underwent CMR during a follow-up visit, were enrolled. Demographic, clinical, laboratory, treatment, and outcome data were collected. Twenty MIS-C patients (aged 9-17, median 12 years) were included in the study. Heart involvement at onset was testified by hypotension/shock (55%), laboratory evidence of myocardial involvement (100%), reduced LV ejection fraction (EF) on echocardiography (83%), and/or need for inotrope agents (40%); they all presented good clinical, laboratory, and echocardiographic response to treatment. CMR was performed after a median interval of 3 months from discharge. Pericardial effusion and myocardial edema were found in 5% of patients. Mild residual left ventricular (LV) dysfunction was found in 20% of patients, all showing normal echocardiographic LVEF at discharge. Minimal myocardial scars were found in 25% by late gadolinium enhancement (LGE). One patient was evaluated at two consecutive time points, showing partial resolution of a myocardial scar after 7 months from its first finding. CONCLUSION: Despite the severity of heart involvement in the acute MIS-C phase, the mid-term cardiac outcome is good. Direct cardiac tissue viral invasion may be involved in MIS-C pathogenesis. WHAT IS KNOWN: • Heart involvement is common in MIS-C, but conflicting findings have been shown regarding cardiac outcome when assessed through cardiac MRI. WHAT IS NEW: • Midterm cardiac MRI shows mild abnormalities in patients recovered from MIS-C with any grade of severity of cardiac involvement at presentation.

A toddler with an unusually severe polyarticular arthritis and a lung involvement: a case report.

BACKGROUND: COPA syndrome is a rare hereditary inflammatory disease caused by mutations in the gene encoding the coatomer protein subunit alpha, causing excessive production of type I interferon. This case is a reminder for the general paediatrician, highlighting the relevance of the association between arthritis and lung involvement in toddlers. CASE PRESENTATION: We report the case of a 2-year-old girl with intermittent limping and joint pain. Her family history was relevant for a Still disease with lung involvement in the mother. Physical examination showed moderate wrist swelling. Laboratory findings on admission showed an increase in inflammatory markers, positive rheumatoid factor, antibodies antinuclear antibody (ANA) and cyclic citrullinated peptide (anti-CCP). Wrists' ultrasound documented synovial thickening, and chest X-rays showed an unexpected severe interstitial pneumopathy. Genetic testing confirmed the diagnosis of a heterozygous mutation of the COPA gene in c.841C > T (p.R281W). Janus kinase treatment was started (baricitinib, 4 mg daily per os) with a remarkable improvement in limping and joint pain after two weeks. CONCLUSIONS: In cases of recurrent arthritis with family history and multiple involvement organs, a genetic disorder should be suspected and genetic testing should be performed. Furthermore, this case suggests that therapy with jak inhibitors may be effective and safe in interferonopathies.

Acute Acalculous Cholecystitis: Think of Hepatitis A Infection and Do Not Underestimate Pain.

ABSTRACT: A 14-year-old adolescent girl presented with severe abdominal pain, tenderness, and guarding in the right upper quadrant associated with nonbilious vomiting, scleral icterus, and fever. Laboratory tests were consistent with acute hepatitis A virus-related cholestatic hepatitis. A point-of-care ultrasound showed mild gallbladder wall thickening with increased color Doppler flow and pericholecystic fluid collection, in the absence of gallstones or biliary ducts dilatation, thus suggesting acute acalculous cholecystitis. Both the clinical symptoms and the point-of-care ultrasound findings completely resolved within 1 week after admission with conservative treatment.

A bullous rash.

A 3-year-old boy presented with a 5-day history of bullous skin lesions localised mainly in the upper and lower limbs and in the genital region (figure 1). Lesions were not pruritic nor painful and showed a central crust. There was no family history of skin disorders or autoimmune diseases. The child never had fever and his physical examination was otherwise unremarkable.

A toddler with a persisting limp after a minor trauma.

A 3-year-old toddler was admitted for a 5-day history of worsening painful limping on his left leg. History was remarkable only for a minor trauma 2 days before the onset of symptoms; the boy fell on his buttocks but was walking normally in the following days. No fever was reported. Pain was also present at night, with no response to oral ibuprofen.On physical examination, the patient refused to stand on his left leg, palpation of the left buttock evoked pain, and exorotation and abduction of the left hip were only moderately limited, without local signs of inflammation such as redness, swelling or skin warming. Blood tests showed elevated erythrocyte sedimentation rate (ESR) (98 mm/hour, normal value <20 mm/hour) with normal C reactive protein (CRP) level (0.5 mg/dL, normal value <0.5 mg/dL). His white cell count was 12 110 x 109/L, haemoglobin was 127 g/L and PLT was 430 x 109/L. Creatine kinase values were within the normal range.An X-ray of the pelvis was unremarkable. An ultrasound of the left hip showed a 2 mm articular effusion.

Cutaneous manifestations in mevalonate kinase deficient patients treated with canakinumab.

Canakinumab is a human monoclonal antibody anti-interleukin-1ß, it is the only biologic drug approved to treat mevalonate kinase deficiency (MKD). Canakinumab injection can trigger several local cutaneous reactions, but also chronic-relapsing skin infections and other manifestations. We report three cases of unusual cutaneous manifestations in patients treated with canakinumab.

Acute rheumatic fever prophylaxis in high-income countries: clinical observations from an Italian multicentre, retrospective study.

OBJECTIVES: The aim of the study is to evaluate the compliance rate to secondary prophylaxis and the presence of rheumatic heart disease (RHD) in a cohort of Italian patients with acute rheumatic fever (ARF). METHODS: This is a multicentre retrospective study. The patients were divided into two groups by the presence or absence at last follow-up of RHD. Clinical features, ARF recurrences and the rate of compliance to secondary prophylaxis were evaluated. RESULTS: Two-hundred and ninety patients were enrolled (137 females; 153 males). Carditis at onset was present in 244 patients (84.7%). At the end of follow-up, 173 patients manifested RHD. Adherence to secondary prophylaxis was low in 26% of patients. The presence of RHD at follow-up was associated with the presence of carditis and its severity at onset (p=0.001), but it was not related to secondary prophylaxis adherence (p=NS). No association between prophylaxis adherence and ARF recurrence was found (p=NS) nor between ARF recurrence and RHD at the end of follow-up (p=NS). CONCLUSIONS: Poor adherence to secondary prophylaxis does not seem to be associated with increased risk of RHD in developed countries. Further studies are needed to confirm our data in a larger population.

Prevalence of cranial involvement in a cohort of Italian patients with chronic non-bacterial osteomyelitis.

OBJECTIVES: Chronic non-bacterial osteomyelitis (CNO) is a non-infectious inflammatory disease characterised by uni- or multi-focal bone lytic lesions. CNO mainly affects metaphysis of long bones, pelvis and shoulder girdle. Neurocranium lesions are extremely rare. The objective of the study is to describe the prevalence and clinical manifestations of CNO patients with neurocranium involvement in an Italian cohort of CNO patients. METHODS: This is a retrospective study. Medical records of patients with CNO admitted to eight paediatric rheumatology centres were reviewed. RESULTS: Among 86 patients with CNO enrolled in the study, three of them were female and presented neurocranium involvement - multifocal lesions. Two out of the 3 patients were completely asymptomatic for cranial involvement, while one of the 3 complained of cranial bossing. Cranial involvement was detected with bone scintigraphy and then confirmed by magnetic resonance imaging and/or computed tomography. Two patients presented fever and two with skin manifestations. Laboratory inflammatory markers were increased in two of them. All patients underwent bone biopsy confirming the diagnosis. They all received NSAIDs. Two patients received corticosteroids and then methotrexate and achieved clinical remission, while one patient received pamidronate. CONCLUSIONS: This is the first report of neurocranium involvement in a cohort of patients affected by CNO. In our cohort no patient showed significant signs attributable to cranial involvement.

A Case of Uveitis in a Patient With Juvenile Myelomonocytic Leukemia Successfully Treated With Adalimumab.

Patients with juvenile myelomonocytic leukemia due to germline CBL mutation (10% to 15%) may have a subacute course occasionally associated with autoimmune disorders, which may resemble RAS-associated autoimmune lymphoproliferative disorder. In both conditions, prognosis and standard treatment for autoimmune phenomena remain poorly understood. We report the case of a 7-year-old boy with juvenile myelomonocytic leukemia with severe steroid-dependent uveitis, who did not respond to several therapeutic attempts with immunosuppressant agents, including sirolimus, and was finally successfully treated with adalimumab. This case offers further insight into the management of autoimmune disorders in the context of predisposing genetic conditions.

Preliminary data on prednisone effectiveness in children with Sydenham chorea.

The objective of the study is to evaluate the efficacy of corticosteroids in Sydenham chorea. This is a retrospective observational study. Clinical information of children with Sydenham chorea were collected. Outcome of Sydenham chorea was evaluated in consideration of presence or absence of corticosteroid therapy. Thirty patients were enrolled. A total of 15 were treated with prednisone, 15 received symptomatic drugs or no treatment. Patients who were treated with prednisone showed faster improvement (4 vs 16 days; p = 0.002) and shorter median time of remission (30 vs 135 days; p < 0.001).Conclusion: Our study showed that corticosteroid therapy is an effective treatment of Sydenham chorea.What is Known:• Steroid treatment in Sydenham chorea is widely used but it is not standardized.• Few manuscript report a beneficial use of steroids in Sydenham chorea if compared with no treatment.What is New:• Steroid treatment seems to be effective in both clinical remission and clinical improvement of symptoms among patients with Sydenham chorea.• Steroid treatment seems to be superior to conventional treatment.

Biological and Clinical Changes in a Pediatric Series Treated with Off-Label JAK Inhibitors.

Off-label use of medications is still a common practice in pediatric rheumatology. JAK inhibitors are authorized in adults in the treatment of rheumatoid arthritis, psoriatic arthritis and ulcerative colitis. Although their use is not authorized yet in children, JAK inhibitors, based on their mechanism of action and on clinical experiences in small series, have been suggested to be useful in the treatment of pediatric interferon-mediated inflammation. Accordingly, an increased interferon score may help to identify those patients who might benefit of JAK inhibitors. We describe the clinical experience with JAK inhibitors in seven children affected with severe inflammatory conditions and we discuss the correlation between clinical features and transcriptomic data. Clinical improvements were recorded in all cases. A reduction of interferon signaling was recorded in three out of seven subjects at last follow-up, irrespectively from clinical improvements. Other signal pathways with significant differences between patients and controls included upregulation of DNA repair pathway and downregulation of extracellular collagen homeostasis. Two patients developed drug-related adverse events, which were considered serious in one case. In conclusion, JAK inhibitors may offer a valuable option for children with severe interferon-mediated inflammatory disorders reducing the interferon score as well as influencing other signal pathways that deserve future studies.

Functional analysis of the third identified SLC25A19 mutation causative for the thiamine metabolism dysfunction syndrome 4.

Thiamine metabolism dysfunction syndrome-4 (THMD4) includes episodic encephalopathy, often associated with a febrile illness, causing transient neurologic dysfunction and a slowly progressive axonal polyneuropathy. Until now only two mutations (G125S and S194P) have been reported in the SLC25A19 gene as causative for this disease and a third mutation (G177A) as related to the Amish lethal microcephaly. In this work, we describe the clinical and molecular features of a patient carrying a novel mutation (c.576G>C; Q192H) on SLC25A19 gene. Functional studies on this mutation were performed explaining the pathogenetic role of c.576G>C in affecting the translational efficiency and/or stability of hMTPPT protein instead of the mRNA expression. These findings support the pathogenetic role of Q192H (c.576G>C) mutation on SLC25A19 gene. Moreover, despite in other patients the thiamine supplementation leaded to a substantial improvement of peripheral neuropathy, our patient did not show a clinical improvement.