Monogenic lupus: Tracing the therapeutic implications from single gene mutations.

Monogenic lupus, a distinctive variant of systemic lupus erythematosus (SLE), is characterized by early onset, family-centric clustering, and heightened disease severity. So far, over thirty genetic variations have been identified as single-gene etiology of SLE and lupus-like phenotypes. The critical role of these gene mutations in disrupting various immune pathways is increasingly recognized. In particular, single gene mutation-driven dysfunction within the innate immunity, notably deficiencies in the complement system, impedes the degradation of free nucleic acid and immune complexes, thereby promoting activation of innate immune cells. The accumulation of these components in various tissues and organs creates a pro-inflammatory microenvironment, characterized by a surge in pro-inflammatory cytokines, chemokines, reactive oxygen species, and type I interferons. Concurrently, single gene mutation-associated defects in the adaptive immune system give rise to the emergence of autoreactive T cells, hyperactivated B cells and plasma cells. The ensuing spectrum of cytokines and autoimmune antibodies drives systemic disease manifestations, primarily including kidney, skin and central nervous system-related phenotypes. This review provides a thorough overview of the single gene mutations and potential consequent immune dysregulations in monogenic lupus, elucidating the pathogenic mechanisms of monogenic lupus. Furthermore, it discusses the recent advances made in the therapeutic interventions for monogenic lupus.