Interleukin-1 receptor antagonist (IL-1Ra), encoded by the IL1RN gene, is a naturally occurring protein that competitively inhibits pro-inflammatory cytokines IL-1α and IL-1β by binding to the IL-1 receptor (IL-1R) without activating downstream signaling. This regulatory mechanism is critical in balancing inflammatory responses, as dysregulated IL-1 signaling is implicated in autoimmune diseases, sepsis, and chronic inflammatory conditions.
IL1RN antibodies are tools designed to detect, quantify, or modulate IL-1Ra activity. In research, they are used to study IL-1Ra expression in diseases like rheumatoid arthritis, type 2 diabetes, or inflammatory skin disorders. Therapeutically, recombinant IL-1Ra (e.g., anakinra) and monoclonal antibodies targeting IL-1 pathways have been developed to treat conditions such as cryopyrin-associated periodic syndromes (CAPS) or cytokine storm syndromes.
Notably, genetic IL1RN deficiencies cause severe autoinflammatory disorders like deficiency of IL-1Ra (DIRA), highlighting IL-1Ra's role in immune homeostasis. IL1RN antibodies also serve diagnostic purposes, measuring IL-1Ra levels in patient sera to assess disease severity or therapeutic response. Challenges include ensuring antibody specificity due to structural similarities among IL-1 family members. Ongoing studies explore IL-1Ra modulation in cancer and metabolic diseases, expanding its clinical relevance.