Systemic lupus erythematosus (SLE) is a common and potentially fatal autoimmune disease characterized by autoantibodies associated with multiorgan injury， including the renal， cardiovascular， neural， musculoskeletal， and cutaneous systems .
Forty patients with active SLE were enrolled from 4 clinical centers in China. Allogenic UCMSCs were infused intravenously on days 0 and 7. Primary endpoints were safety profiles.Second endpoints included major clinical response (MCR)， partial clinical response (PCR)and relapse. Clinical index including SLEDAI score， BILAG score， renal functional indices were also determined.
The overall survival rate was 92.5% (37/40). UC-MSCT was well tolerated， and no transplantation-related adverse event was observed. Thirteen and eleven patients achieved MCR (13/40， 32.5%) and PCR (11/40， 27.5%) during 12 months follow-up， respectively. Then three and four patients experienced disease relapse at 9 (12.5%) and 12 (16.7%) months follow-up， after a prior clinical response. SLEDAI score significantly decreased at 3， 6， 9 and 12 months follow-up.
Total BILAG score markedly decreased at 3 months and continued to decrease at subsequent follow-up visits. BILAG scores for renal， hematopoietic and cutaneous systems significantly improved. For those with lupus nephritis， 24-hour proteinuria declined after transplantation， with statistical differences at 9 and 12 months. Serum creatinine and urea nitrogen decreased to the lowest level at 6 months， while these values slightly increased at 9 and 12 months as a result of 7 relapsed cases. In addition， serum levels of albumin and complement 3 increased after MSCT， peaked at 6 months and then slightly declined at 9 and 12 months follow-up. Serum antinuclear antibody and anti-double-strand DNA antibody decreased after MSCT， with statistical differences at 3 months follow-up.
UC-MSCT results in satisfactory clinical response in SLE patients. However， several cases experienced disease relapse after 6 months， indicating the necessity to repeat MSCT after 6 months.