PT - JOURNAL ARTICLE AU - Thitima Benjachat Suttichet AU - Wonngarm Kittanamongkolchai AU - Chutipha Phromjeen AU - Sirirat Anutrakulchai AU - Thanachai Panaput AU - Atiporn Ingsathit AU - Nanticha Kamanamool AU - Vuddhidej Ophascharoensuk AU - Vasant Sumethakul AU - Yingyos Avihingsanon ED - , TI - Urine TWEAK level as a biomarker for early response to treatment in active lupus nephritis: a prospective multicentre study AID - 10.1136/lupus-2018-000298 DP - 2019 Apr 01 TA - Lupus Science & Medicine PG - e000298 VI - 6 IP - 1 4099 - http://lupus.bmj.com/content/6/1/e000298.short 4100 - http://lupus.bmj.com/content/6/1/e000298.full SO - Lupus Sci & Med2019 Apr 01; 6 AB - Background TNF-like weak inducer of apoptosis (TWEAK) is a proinflammatory molecule that plays a key role in active inflammation of lupus nephritis (LN). Urine TWEAK (uTWEAK) levels were found to be associated with renal disease activity among patients with LN. Here, we determined whether serial measurements of uTWEAK during induction therapy could predict treatment response or not.Methods Spot urine samples were collected from patients with biopsy-proven active LN at time of flare, and 3 and 6 months after flare to assess the uTWEAK levels. All patients received standard immunosuppressive therapy and treatment response was evaluated at 6 months. The performance of uTWEAK as a predictor for treatment response was compared with clinically used biomarkers for patients with LN.Results Among 110 patients with LN, there were 29% complete responders (CR), 34% partial responders (PR) and 37% non-responders (NR). On average, uTWEAK level was consistently low in CR, trended down by 3 months in PR and persistently elevated in NR. uTWEAK levels at month 3 were able to predict complete response at month 6 (OR adjusted for age, sex and creatinine=0.34 [95% CI 0.15 to 0.80], the area under the receiver operating characteristic curve [ROC-AUC]=0.68, p=0.02). The optimal threshold for uTWEAK level at month 3 was 0.46 pg/mgCr, discriminating complete response with 70% sensitivity and 63% specificity. Combining uTWEAK and urine protein at month 3 improved predictive performance for complete response at 6 months (ROC-AUC 0.83, p<0.001).Conclusions In addition to urine protein, uTWEAK level at 3 months after flare can improve the accuracy in predicting complete response at 6 months of induction therapy.