159 Plasma Elafin as a biomarker for Skin Graft Versus Host Disease

Abstract

Skin is the most common organ involved in GVHD following hematopoietic stem cell transplant (HSCT). It is often difficult to clinically distinguish a GVHD rash from skin rash due to drugs, infection or engraftment. Plasma elafin has been found to be a diagnostic and prognostic biomarker of skin GVHD. We performed a prospective study to evaluate the role of plasma elafin as a biomarker. Consecutive allogeneic HSCT recipients over a 2 year period were recruited. Heparinised blood samples were collected at baseline and at first episode of skin rash after HSCT. Skin biopsies were obtained on day of rash. Patients were categorised into 3 groups: Patients with GVHD rash (group 1), non GVHD rash (Group 2) and Controls (group 3). Control samples were collected on Day 28 from 25 patients with no skin rash. Two hundred and sixty one patients with a median age of 16 years (1-61) and a male predominance (175:86) underwent HSCT. There were 56 patients in group 1, 49 in group 2 and 156 in group 3. Median baseline elafin value for the entire cohort was 16915 pg/ml (1205-158586). Elafin values at onset of rash between GVHD and non-GVHD were no different [34549 vs. 32077pg/ml;p=0.11]. Median rise =in elafin values [(value at rash–baseline value)/baseline value] were similar between group 1 (1.03) and group 2 (0.818; p+0.497) except at the highest quartile of elafin levels >61545 [p = 0.030]. Baseline elafin values >33329 were associated with lower overall survival [52.3% vs. 71.4%] [p=0.005] while elafin values >30248 at the time of onset of skin rash was associated with poorer outcomes [62.4 vs. 79.6%] [p=0.011]. Plasma elafin increased at the time of GVHD rash but could distinguish between GVHD and non-GVHD rash only at higher levels. There is a significant correlation between elafin levels at the time of onset of skin GVHD and overall survival. We conclude that plasma elafin can be a good prognostic marker.