Younger age at disease onset and, perhaps, both gastrointestinal manifestations and more severe kidney disease seem to characterize the clinical profile in children with MPA compared to those with GPA. Delay in diagnosis suggests that recognition of these systemic vasculitides is suboptimal. Compared with adults, initial treatment regimens in children were comparable, but the complete reversal of female-to-male disease prevalence ratios is a provocative finding.

These findings show substantial alterations in MAS features that may limit utility of defined criteria for diagnosis of systemic JIA patients treated with biologic agents.

No abstract

NLRP12-related autoinflammatory disease (NLRP12-AID) is an exceptionally rare autosomal dominant disorder caused by germline mutations in NLRP12 gene. Very few patients with NLRP12-AD have been identified worldwide; therefore, there is a scarcity of data on phenotypic presentation of this syndrome. Here we provide evidence that NLRP12-AID may have clinical manifestations characteristic for primary immune deficiencies (PID). 246 children with periodic fever (PF) of unknown origin were subjects to the next generation sequencing (NGS) analysis; 213 of these patients had signs of primary immunodeficiency (PID) manifested by recurrent infections, while 33 kids had isolated PF. The NGS panel was composed of 302 genes implicated in PID and/or AID. 15 patients (9 girls and 6 boys) with NLRP12-AID were identified. Median age of first AID-related fever episode was 12 months, ranging from 2 months to 13 years. Main clinical features of NLRP12-related AID were periodic fever (100%), abdominal pain and diarrhea (47%), arthralgia (20%), headache (20%) and failure to thrive (33%). Nine patients demonstrated increased susceptibility to infection and two children suffered from Crohn's disease. Administration of short courses of NSAID or corticosteroids resulted in resolution of the disease flare. In one severe case, canakinumab (anti-interleukin-1β antibody) was successfully used. Significant number of patients with genetically assigned diagnosis of NLPR12-AID has clinical features which close resemble primary immune deficiency. This phenotypic overlap may result in underdiagnosis of NLPR12-AID among patients with PID.

Objectives: Diagnostic between multisystem inflammatory syndrome associated with COVID-19 in children (MIS-C) and Kawasaki disease (KD) can make difficulties due to many similarities. Our study aimed to create a Kawasaki/MIS-C differentiation score (KMDscore) allowing discrimination of MIS-C and KD.Study design: The retrospective multicenter cohort study included clinical, laboratory, and instrumental information about MIS-C (n = 72) and KD (n = 147). The variables allowed to discriminate both conditions used to construct and validate the diagnostic score called the KMDscore.Results: Patients with MIS-C were older, had earlier admission to the hospital, had a shorter time before fever resolution, two times frequently had signs of GI and CNS involvement observed, and had more impressive thrombocytopenia, higher level of CRP, ferritin, ALT, AST, LDH, creatinine, triglycerides, troponin, and D-dimer compared to KD patients. Respiratory signs in MIS-C were presented with pleuritis, acute respiratory distress syndrome, oxygen dependency, lung infiltration, and ground-glass opacities in CT. The heart involvement with fast progression of myocarditis provided the severity of MIS-C and ICU admission due to 12 times higher arterial hypotension or shock and required cardiotonic. No differences in the frequency of CA lesions were seen in the majority of cases. Five criteria, CRP >11 mg/dl (18 points), D-dimer >607 ng/ml (27 points), age >5 years (30 points), thrombocytopenia (25 points), and GI involvement (28 points), were included in the KMDscore. The summa >55 points allowed to discriminate MIS-C from KD with a sensitivity of 87.5% and specificity of 89.1%.Conclusion: The KMDscore can be used to differentiate the diagnostic of MIS-C from KD.