Background/Purpose: Neonatal-onset multisystem inflammatory disease (NOMID) is an IL- 1 mediated autoinflammatory disease caused by a gain-of-function mutations in NLRP3that results in constitutive activation of IL-1b and specific organ/tissue inflammation and damage. To date no reliable serum biomarkers that identify IL-1 mediated systemic inflammation or inflammatory organ damage particulary CNS inflammation exist. We explore high-throughput proteomic profiling to screen for potential biomarkers.

Methods: Serum samples were obtained from healthy age-matched children (HC), n=8 and 12 NOMID patients(pts.) before and after a median of 42 months (range 3-96mo) after starting IL-1 blocking treatment with anakinra. All patients were in inflammatory remission at the time of blood draw. Using an aptamer-based proteomic assay (SOMAscan) we screened 1129 proteins. To identify biomarkers of exaggerated systemic and tissue specific IL-1-mediated inflammation, we selected proteins that significantly changed with anakinra treatment many were significantly increased or decreased in untreated NOMID vs HC. Mann-Whitney U test and Wilcoxon rank-sum analyses with FDR correction were used for statistical comparison. We determined RNA transcripton levels (RNAseq) of the protein targets in whole blood. RPKMs< 1 characterized low expression in blood cells and suggested that the protein origin might be from non-hematopoietic cells. We also determined protein function.

Results: In the SOMAscan Assay we identified 70 proteins that changed in the serum of NOMID pts. before and after treatment (n=12; q<0.05). Of these 15 (21%) were also significantly increased or decreased compared to controls at baseline. Protein levels of 30 proteins decreased and protein levels of 40 increased with treatment. Of these, 63% and 82% respectively had low or no gene expression in whole blood. Protein targets of the IL-1 pathway (IL-1β, soluble IL-1RI, IL-1 RAcP) significantly decreased. Of markers that decreased were those indicating systemic inflammation including complements (i.e CRP, SAA1, C3, C9, CFI) and markers that have been associated with tissue damage including CNS manifestaions (CFI TNFSD11A) and hypercoagualabitly (F9) as well as vascular endothelial markers associated with atherosclerosis (PLAUR, CST3). Of the markers that increase, most are associated with growth and tissue regeneration (including growth hormone receptor: GHR, IGFBP3 and -5, NOTCH3, TGFβ), p<0.05 for all.

Conclusion: Protein changes with anakinra treatment reveal markers of IL-1 pathway that are not reliabley detectable in ELISA assays and transcription assays. These markers need to be validated in other presumed IL-1 mediated diseases. Furthermore, markers of tissue inflammation particulary of CNS inflammation need to be validated in treatment studies to determine their utility in assessing appropriate treatment with IL-1 blocking therapies.

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ACR Meeting Abstracts - https://acrabstracts.org/abstract/high-throughput-proteomic-profiling-identifies-dysregulated-proteins-in-neonatal-onset-multisystem-inflammatory-disease-nomid-that-respond-to-il-1blocking-treatment/