The safety of canakinumab in systemic juvenile idiopathic arthritis and autoinflammatory diseases in pediatric patients: a multicenter study.

OBJECTIVE: To evaluate the safety of canakinumab using real-world data in patients with systemic juvenile idiopathic arthritis (sJIA) and autoinflammatory diseases (AID). RESEARCH DESIGN AND METHODS: This was a cross-sectional observational, multicenter study. Patients diagnosed with AID and sJIA treated with canakinumab were included in the study. The participating 13 centers retrospectively collected their patients' data. RESULTS: A total of 335 patients were involved in the study. Among these patients, 280 were in the AID group and 55 were in the sJIA group. Canakinumab was administered at a median dose of 3 (2.5-4) mg/kg. The median total exposure time to canakinumab was 1.9 (0.8-3.2) years, corresponding to 759.5 patient-years. Seven hundred and seventy-nine total adverse events (AE) were identified. The total incidence of AE, and serious adverse events (SAE) throughout the study period was 1.02 per patient-years. The upper respiratory tract infection rate was 0.7 per patient-years, while the other infection rate was 0.13 per patient-years. While no death was observed in any patient, SAE were observed in 8 patients. Interstitial lung disease, anaphylaxis, or anaphylactoid reactions were not observed in any patient. CONCLUSIONS: Real-life data from a large cohort of patients suggests that canakinumab is as safe as claimed in clinical trials.

A possibly new autoinflammatory disease due to compound heterozygous phosphomevalonate kinase gene mutation.

BACKGROUND: Mevalonate kinase (MVK) plays a role in cholesterol and non-sterol isoprenoid biosynthesis and its deficiency-related diseases are caused by bi-allelic pathogenic mutations in the MVK gene, (MVK), which leads to rare hereditary autoinflammatory diseases. The disease may manifest different clinical phenotypes depending on the degree of the deficiency in the enzyme activity. The complete deficiency of the enzyme activity results in the severe metabolic disease called mevalonic aciduria, while a partial deficiency results in a broad spectrum of clinical presentations called hyper-immunoglobulin D syndrome (HIDS). Serum immunoglobulin (Ig) D and urine mevalonic acid levels may be increased during inflammatory attacks of HIDS. CASE PRESENTATION: Herein, for the first time in the literature, we present a 6-year-old male patient who suffered from recurrent episodes of fever, polyarthritis, skin rash, diarrhea, abdominal pain, and inflammatory bowel disease-like manifestations with elevated levels of serum IgD, and urine mevalonic acid. Eventually we detected compound heterozygous mutations in the phosphomevalonate kinase (PMVK) gene coding the second enzyme after mevalonate kinase in the mevalonate pathway. CONCLUSION: For patients presenting with HIDS-like findings, disease exacerbations and persistent chronic inflammation, and having high urinary mevalonic acid and serum IgD levels, raising suspicion in terms of MVK deficiency (MVKD), it is recommended to study all mevalonate pathway enzymes, even if there is no mutation in the MVK gene. It should be kept in mind that novel mutations might be seen such as PMVK gene.