NLRC4 inflammasomopathies

The purpose of the review is to highlight developments in autoinflammatory diseases associated with gain-of-function mutations in the gene encoding NLR-family CARD-containing protein 4 (NLRC4), the NLRC4-inflammasomopathies.

Three years since the identification of the first autoinflammation with infantile enterocolitis (AIFEC) patients, there is an improved understanding of how the NLRC4 inflammasome and interleukin 18 (IL-18) contribute to gut inflammation in myeloid and also intestinal epithelial cells. This information has opened new therapeutic avenues to treat AIFEC patients with targeted agents like recombinant IL-18 binding protein and antiinterferon-γ antibodies. Additional phenotypes traditionally associated with NLRP3 mutations like familial cold autoinflammatory syndrome and neonatal onset multisystem inflammatory disease (NOMID), have now also been associated with gain-of-function NLRC4 mutations. Finally, NLRC4 somatic mosaicism has now been identified in a NOMID and an AIFEC patient, a finding emphasizing nontraditional modes of inheritance in autoinflammatory diseases.

The NLRC4 inflammasomopathies constitute a growing autoinflammatory disease category that spans a broad clinical spectrum from cold urticaria to NOMID and the often fatal disease AIFEC. Rapid case identification with biomarkers like elevated serum IL-18 concentrations and early intervention with targeted immunomodulatory therapies are key strategies to improving outcomes for AIFEC patients.