PERIODIC FEVER SYNDROME (MEVALONATE KINASE DEFICIENCY, HYPERIMMUNOGLOBULINEMIA D SYNDROME) IN CHILDREN

Mevalonate Kinase Deficiency (MKD) is a rare inborn disease belonging to the family of periodic fever syndromes. The MKD phenotype is characterized by systemic inflammation involving multiple organs, including the nervous system. Current anti-inflammatory approaches to MKD are only partially effective and do not act specifically on neural inflammation. According to the new emerging pharmacology trends, the repositioning of drugs from the indication for which they were originally intended to another one can make mechanistic-based medications easily available to treat rare diseases. According to this perspective, the squalene synthase inhibitor Lapaquistat (TAK-475), originally developed as a cholesterol-lowering drug, might find a new indication in MKD, by modulating the mevalonate cholesterol pathway, increasing the availability of anti-inflammatory isoprenoid intermediates. Using an in vitro model for MKD, we mimicked the blockade of the cholesterol pathway and evaluated the potential anti-inflammatory effect of Lapaquistat. The results obtained showed anti-inflammatory effects of Lapaquistat in association with a low blockade of the metabolic pathway, while this effect did not remain with a tighter blockade. On these bases, Lapaquistat could be configured as an effective treatment for MKD’s mild forms, in which the residual enzymatic activity is only reduced and not almost completely absent as in the severe forms.

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Validation of the new classification criteria for hereditary recurrent fever in an independent cohort: experience from the JIR Cohort Database

Rheumatology ◽

10.1093/rheumatology/keaa031 ◽

2020 ◽

Vol 59 (10) ◽

pp. 2947-2952

Author(s):

Glory Dingulu ◽

Sophie Georgin-Lavialle ◽

Isabelle Koné-Paut ◽

Pascal Pillet ◽

Anne Pagnier ◽

...

Keyword(s):

Periodic Fever ◽

Classification Criteria ◽

Recurrent Fever ◽

Mevalonate Kinase Deficiency ◽

Periodic Syndrome ◽

Mevalonate Kinase ◽

New Classification ◽

Clinical Criteria ◽

Clinical Variables ◽

Independent Cohort

Abstract Objective The new classification criteria for the hereditary recurrent fever (HRF) syndrome [cryopyrin-associated periodic syndrome (CAPS), TNF-α receptor-associated periodic syndrome (TRAPS), FMF and mevalonate kinase deficiency] have been published recently. These criteria define two core sets of criteria for each HRF: mixed criteria, including genetic and clinical variables, and clinical criteria, relying on clinical variables only. Our aim was to validate the criteria for HRF in an independent cohort, the JIR Cohort database, an international repository of systemic inflammatory diseases. Methods We enrolled patients with HRF, periodic fever, adenitis, pharyngitis and aphthous stomatitis syndrome (PFAPA) and syndrome of undefined recurrent fever (SURF). A score ranging from zero to two was attributed to their respective genotypes: zero (no mutation), one (non-confirmatory genotype) or two (confirmatory genotype). The criteria were applied to all patients based on genotype scoring. The treating physician’s diagnosis served as the gold standard for the determination of specificity. Results We included 455 patients. The classification criteria showed excellent specificity for CAPS and TRAPS (98% specificity each), fair specificity for FMF (88%), but poor specificity for mevalonate kinase deficiency (58%). Sub-analysis showed excellent accuracy of the mixed criteria for all four HRFs. Misclassification was mainly attributable to clinical criteria sets, with false-positive patients in all four HRF clinical criteria sets. Conclusion This study represents the final validation step of the HRF classification criteria as recommended by the ACR. Genetic data appear to be necessary to classify patients with HRF correctly.

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