Clinical characteristics, risk factors and prognosis of systemic lupus erythematosus complicated with digital gangrene: a study of 2684 cases

Abstract

Objective To study clinical manifestations, risk factors and prognosis of patients with systemic lupus erythematosus (SLE) complicated with digital gangrene. Methods Data of 2684 inpatients with SLE admired to Peking Union Medical College Hospital during December 1997 to August 2007, including demographic information, clinical features, laboratory findings, as well as therapeutic regimens, were retrospectively analyzed, and 18 of those complicated with digital gangrene were identified and followed up. Results Average age at onset in patients of SLE complicated with digital gangrene was(33±12)years, with an average duration of disease course of (99±60 ) months. Longer course duration ( ≥ 4 yrs), Raynaud's phenomenon, elevated serum C-reactive protein (CRP) and positive anti-SSA antibody all were associated with occurrence of digital gangrene in patients of SLE, with P values of 0.012, 0.004, 0.037 and 0.087 respectively, and odds ratios of 1.03 (95% CI 1.01～1.05 ), 39.05 (95% CI 3.31～460.13 ), 17.99 (95%(CI 1.19～271.29) and 7.01 (95% CI 0.75～65.12), respectively. Fifteen of 18 SLE patients complicated with digital gangrene started treatment with predisone ≥1 mg˙kg-1 ˙d-1, and eighteen all were treated with cyclophosphamide, though eight cases failed and ultimately received digital amputation. Prompt corticosteroid treatment (predisone ≥ 1 mg˙kg-1˙d-1 within three weeks after occurrence) could decrease risk for amputation, with P =0.081 and OR =0.135 (95% CI 0.01～1.28). Conclusions Longer duration of disease course, Raynaud's phenomenon, elevated serum CRP and positive anti-SSA antibody all are independent predictors of SLE complicated with digital gangrene. Early and aggressive treatment can prevent occurrence of gangrene from its progression and improve its prognosis. Key words: Lupus erythematosus,systemic; Fournier; Raynand disease; C-reactive protein