OA11 Serum interferon alpha levels as a predictor of short-term mortality in patients of SLE with high disease activity

Abstract

Abstract Background/Aims Short-term mortality in patients with SLE and high disease activity approaches 30% as reported by various studies. Raised serum interferon-alpha levels are observed in patients with active SLE. In mice studies interferon alpha(IFNα) delivered through adenovirus vector to lupus prone mice, caused rapid development of glomerulonephritis and death within 18 weeks. The aim was to study the value of interferon alpha in predicting short-term mortality in patients of SLE with high disease activity. Methods Serum samples of consecutive SLE patients with high disease activity (SLEDAI>12) and age more than 18 years admitted in NIMS Rheumatology ward and acute medical care (AMC) were analyzed for interferon alpha levels with IFNα ELISA kit (ELAB science). Patients admitted for any other reason and having SLEDAI less than 12 were excluded. Demographic details and SLEDAI were recorded simultaneously. Patients who survived and discharged were considered as survivor group and those who succumbed during admission were considered as non-survivors. Between groups, difference in mean interferon alpha level was calculated using unpaired t test. Binomial logistic regression was applied to IFNα levels, dsDNA and SLEDAI as for predicting in-hospital mortality. Using ROC curve, area under curve was calculated for IFNα as a predictor of in-hospital mortality. Patients or legal guardian provided written informed consent for the study. Study was approved by the Institute ethics committee. Results Seventy patients with SLEDAI >12 were admitted to ward (n = 62) or AMC (n = 18) from November 2020 to August 2021.Those excluded were age<18 (n = 6), SLEDAI<12 (n = 10), overlap syndromes (n = 8), patients with infection (n = 11). Mean age of the patients was 27.6±8.9 years. Mean duration of hospitalization was 8±4 days. 12 patients died in hospital and 58 survived. Mean days to death was 5±1 days. Mean SLEDAI (23.6±6.1, 18±5.6 p = 0.05), mean dsDNA (3.1±2.1, 1.7±1.8 p = 0.05) and mean serum IFNα levels in pg/ml (318.8±190.1, 39.9±74.7 p = <0.001) was higher in non-survivors than survivors. On applying binomial logistic regression, serum interferon alpha predicted in-hospital mortality (p = <0.001) while dsDNA(p = 0.4) and SLEDAI (p = 0.5) did not. Area under curve for predicting death was 0.9 for IFNα,0.74 for SLEDAI and 0.7 for dsDNA. A serum interferon alpha level of 140 pg/ml was the best predictor of in-hospital mortality with sensitivity of 84 %and specificity of 94%. Conclusion In-hospital mortality in patients with high disease activity is 17%. dsDNA, SLEDAI and serum interferon levels are predictors of in-hospital mortality. Among these serum IFNα is the best predictor of in-hospital mortality. Disclosure K. yerram: None. P. Devarasetti: None. L. Rajasekhar: None.