The impact of pre-transplant anti-HLA antibodies in transplants from HLA-identical sibling donors: A multicenter study

Few studies have performed comparative analysis of the outcome of hematopoietic stem cell transplantation from HLA-identical sibling donors (ISD-HSCT) in patients with or without anti-HLA Abs. In this study we retrospectively collected data from a multicenter study to analyze the distribution and impact of the pre-existing anti-HLA Abs in ISD-HSCT. Among 402 recipients, 111 were positive for anti-HLA Abs. Gender, time from diagnosis to transplantation and distribution of primary disease might be risk factors for the occurrence of anti-HLA Abs. We found that patients with anti-HLA Abs had delayed neutrophil engraftment and were more vulnerable to experience Cytomegalovirus (CMV) reactivation. The presence of anti-HLA Abs was proved to be an independent risk factor for neutrophil engraftment (HR 1.42 95% CI 1.13-1.80, p = 0.003) and CMV reactivation (HR 2.03 95% CI 1.19-3.46, p = 0.009). We found that anti-HLA Abs have a negative impact on the prognosis in the early period after transplantation from sibling donors and anti-HLA Abs was also an independent risk factor for the overall survival (OS) at 180 days (HR 2.32, 95% CI 1.03-5.27, p = 0.042) among female recipients. In conclusion, anti-HLA Abs have a negative impact on the prognosis early after ISD-HSCT.