Targeting type I interferon in lupus panniculitis: a case-based systematic literature review.

Lupus panniculitis (LEP) is a rare form of cutaneous lupus (CLE) characterised by progressive, often disfiguring course and poor response to treatment. Type I interferon inhibition through anifrolumab (ANF) is effective in CLE but limited data are available for its use in LEP. To address this issue, we screened patients with CLE and/or systemic lupus erythematosus (SLE) for biopsy-proven diagnoses of LEP and treatment with ANF. Besides demographics, general clinical features, concomitant treatments before and after ANF and safety signals, we measured disease activity and damage with the SLE disease activity index 2000 (SLEDAI-2 K), the CLE Disease Area and Severity Index activity (CLASI-A) and damage scores and the SLE International collaborating clinics/American College of Rheumatology damage index. The same data were retrieved, when available, from existing cases extracted from systematic literature review. Sixteen cases were identified, including 3/421 newly described patients, with two receiving ANF as first-line immunosuppressant and one as an early treatment devoid of oral corticosteroids. All patients had a good response to treatment and most of them could taper or discontinue corticosteroids. CLASI-A scores were markedly reduced after ANF treatment [11.5 (7-29)] to 0 (0-2); p = 0.005]. The time to response was within five months in most cases. No significant adverse events were reported. Taken together, our data suggest that ANF might be effective in LEP and used as a first-line treatment to prevent LEP-related damage accrual.