Prognostic values of increased B7 family proteins in haploidentical hematopoietic stem cell transplantation patients with aGVHD

It has been reported that B7H1 and B7H3 play a role in graft-versus-host disease (GVHD), the major cause of treatment-related mortality (TRM) in haploidentical hematopoietic stem cell transplantation (haplo-HSCT) patients; however, the prognostic value of these factors has not been defined. We retrospectively collected 64 haplo-HSCT patients in our hospital from 2013 to 2014, as well as 38 HLA-matched-HSCT patients during the same period as the control group. We analyzed B7H1, B7H3, PD1, soluble CD25, ST2 and TNFR1 at 0day, +7days, +14days and +28days after HSCT. The +7days/+14days B7H1/B7H3 and +28days ST2 serum levels were higher in patients with aGVHD who underwent haplo-HSCT. Moreover, +7days B7H1/B7H3 serum levels were predictive of grade III-IV aGVHD (B7H1: AUC=0.830, P<0.001; B7H3: AUC=0.775, P=0.001). Haplo-HSCT patients with higher+7days B7H1/B7H3 or +28days ST2 serum levels had poor GVHD-related mortality (GRM) (B7H1: P<0.001; B7H3: P=0.002; ST2: P=0.047). Multivariate analysis revealed that the +7days B7H1 serum level (P=0.041), as well as viral infection (P=0.015) and donor age (P=0.012), could independently predict GRM. Collectively, we found that +7days B7H1/B7H3 serum levels can predict grade III-IV aGVHD, while only the +7days B7H1 serum level, together with viral infection and donor age, could independently predict GRM in patients with haplo-HSCT.