Session Type: Abstract Submissions (ACR)
Background/Purpose: Raynaud’s phenomenon (RP) is a vasospastic disorder and shows discoloration of the fingers, toes, and occasionally other areas. RP affects 3-9% of the general population, but more frequently of patients with connective tissue diseases. In particular, more than 90% of systemic sclerosis (SSc) patients suffer from RP. While a variety of stress including cold and emotional stress have been reported to influence both cellular and humoral immune function, the pathogenesis of the RP is not fully understood. The aim of study was to identify a novel autoantigen related to cold-induced RP.
Methods: Cold-induced surface proteome alterations in human normal dermal microvascular endothelial cells (dHMVECs) were identified by iTRAQ (isobaric tag for relative and absolute quantitation) analysis. Autoantigens were screened by serological proteome analysis (SERPA) using the sera from patients with SSc-associated RP.
Results: By proteomic analyses combining iTRAQ and SERPA approach, heterogeneous nuclear RNP-K (hnRNP-K) was identified as a candidate autoantigen for patients with SSc-associated RP. Cold-induced translocation of hnRNP-K to cell surface was verified by western blot (WB) and flow cytometric analysis. The presence of anti-hnRNP-K autoantibody in patients’ sera with SSc-associated RP was confirmed by WB. ELISA analysis revealed that the prevalence of anti-hnRNP-K autoantibody in patients with SSc-associated RP was 30.70% (35 of 114), which was significantly higher than that of SSc patients without RP (7.14%, 2 of 28, P = 0.0027) and healthy controls (0%, 0 of 27, P = 0.0001).
Conclusion: Autoantibody against hnRNP-K is a potential marker for detecting a subset of SSc-associated RP. Cold stimulation may exacerbate RP by revealing autoantigens including hnRNP-K and inducing autoimmune reaction in vascular endothelia.
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ACR Meeting Abstracts - https://acrabstracts.org/abstract/heterogeneous-nuclear-rnp-k-is-a-novel-cold-related-autoantigen-in-patients-with-raynauds-phenomenon/