C-terminal variants in CDC42 drive type I interferon-dependent autoinflammation in NOCARH syndrome reversible by ruxolitinib

Clin Immunol. 2023 Nov:256:109777. doi: 10.1016/j.clim.2023.109777. Epub 2023 Sep 22.

Abstract

C-terminal variants in CDC42 encoding cell division control protein 42 homolog underlie neonatal-onset cytopenia, autoinflammation, rash, and hemophagocytic lymphohistiocytosis (NOCARH). Pyrin inflammasome hyperactivation has been shown to contribute to disease pathophysiology. However, mortality of NOCARH patients remains high despite inflammasome-focused treatments. Here, we demonstrate in four NOCARH patients from three families that cell-intrinsic activation of type I interferon (IFN) is a previously unrecognized driver of autoinflammation in NOCARH. Our data show that aberrant innate immune activation is caused by sensing of cytosolic nucleic acids released from mitochondria, which exhibit disturbances in integrity and dynamics due to CDC42 dysfunction. In one of our patients, treatment with the Janus kinase inhibitor ruxolitinib led to complete remission, indicating that inhibition of type I IFN signaling may have an important role in the management of autoinflammation in patients with NOCARH.

Keywords: Autoinflammation; CDC42; JAK inhibition; NOCARH; Ruxolitinib; Type I interferonopathy.

Publication types

  • Case Reports
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Humans
  • Infant, Newborn
  • Inflammasomes / genetics
  • Interferon Type I*
  • Lymphohistiocytosis, Hemophagocytic* / etiology
  • Nitriles
  • Syndrome
  • cdc42 GTP-Binding Protein

Substances

  • cdc42 GTP-Binding Protein
  • Inflammasomes
  • Interferon Type I
  • Nitriles
  • ruxolitinib
  • CDC42 protein, human