Research advances on haploidentical hematopoietic stem cell transplantation in the treatment of severe aplastic anemia in children / 中国当代儿科杂志

Haploidentical hematopoietic stem cell transplantation is a recommended alternative therapy for children with severe aplastic anemia who lack a human leukocyte antigen (HLA)-identical sibling donor and do not respond well to immunosuppressive therapy; however, due to non-identical HLA, the patients may have donor-specific anti-HLA antibody, which may lead to a relatively high incidence rate of poor graft function. Compared with HLA-identical transplantation, conditioning regimen for haploidentical transplantation still needs to be explored. This article reviews the detection and treatment of donor-specific anti-HLA antibody, the selection of conditioning regimen, and the mechanism and treatment of poor graft function in haploidentical hematopoietic stem cell transplantation.

Negative effects of donor specific anti-HLA antibody on poor hematopoietic recovery in patients with hematological diseases receiving haploidentical stem cell transplantation and rituximab for desensitization / 中华内科杂志

Objective:To investigate the incidences and risk factors of poor hematopoietic reconstitution (PHR) in patients with hematological diseases who underwent haploidentical allograft and were treated with rituximab for desensitization.Methods:Eight-three donor specific anti-HLA antibody (DSA, 2000 ≤MFI<10 000) positive patients who underwent haploidentical allograft were prospectively enrolled. Rituximab (375 mg/m 2) was used for desensitization day-3 of conditioning regimen. Incidence and factors associated with PHR, including primary poor graft function and prolonged thrombocytopenia, were investigated. Results:There were 22 males and 61 females with a median age of 39(range: 1-65) years. Kaplan-Meier analysis showed that the 100 day cumulative incidences of neutrophil and platelet engraftment were 93.0% and 90.7%, respectively. The incidences of PHR were 14.7%. The 3-year relapse rate, non-relapse mortality (NRM) rate, event-free survival (EFS), leukemia-free survival (DFS) and overall survival (OS) were 6.5%, 15.1%, 70.8%, 79.4% and 79.4%, respectively. Patients with DSA MFI<5 000 (group A, n=46) experienced lower PHR (4.4% vs. 27.5%, P=0.003), and higher 3-year EFS (79.5% vs. 59.8%, P=0.020) compared to those with DSA MFI≥5 000 (group B, n=37). Multivariate analysis showed that DSA MFI≥5 000 was correlated with PHR ( HR=6.101, P=0.021). PHR was associated with higher NRM ( HR=4.110, P=0.026), lower DFS ( HR=3.656, P=0.019) and OS ( HR=3.656, P=0.019). Conclusion:Our data suggest that high pre-transplant DSA level is a risk factor for PHR in patients with hematological diseases receiving haploidentical allograft and rituximab for desensitization.

Clinical Impact of Pre-transplant Antibodies Against Angiotensin II Type I Receptor and Major Histocompatibility Complex Class I-Related Chain A in Kidney Transplant Patients

BACKGROUND: Evidence of antibody-mediated injury in the absence of donor-specific HLA antibodies (HLA-DSA) has recently emerged, suggesting a role of antibodies in targeting non-HLA antigens expressed on renal allograft tissue. However, the clinical significance of pre-transplant non-HLA antibodies remains unclear. We compared the histological and clinical impact of pre-transplant HLA-DSA and non-HLA antibodies, especially angiotensin II type I receptor (anti-AT1R) and MHC class I-related chain A (anti-MICA), in kidney transplant patients. METHODS: Pre-transplant HLA-DSA, anti-AT1R, and anti-MICA were retrospectively examined in 359 kidney transplant patients to determine the effect of each antibody on allograft survival and clinical characteristics. RESULTS: Pre-transplant HLA-DSA, anti-AT1R, and anti-MICA were detected in 37 (10.3%), 174 (48.5%), and 50 patients (13.9%), respectively. Post-transplant antibody-mediated rejection was associated with a pre-transplant HLA-DSA (+) status only. The development of microvascular inflammation (MVI) was associated with pre-transplant HLA-DSA (P=0.001) and anti-AT1R (P=0.036). Anti-AT1R (+) patients had significantly lower allograft survival compared with anti-AT1R (−) patients (P=0.042). Only pre-transplant anti-AT1R positivity was an independent risk factor for allograft failure (hazard ratio 4.824, confidence interval 1.017–24.888; P=0.038). MVI was the most common histological feature of allograft failure in patients with pre-transplant anti-AT1R. CONCLUSIONS: Pre-transplant anti-AT1R is an important risk factor for allograft failure, which may be mediated by MVI induction in the allograft tissue.