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.

[Clinical and prognostic values of TP53 mutation in patients with B-lineage acute lymphoblastic leukemia]

Objective: To investigate the survival and prognosis of B-lineage acute lymphoblastic leukemia (B-ALL) patients with TP53 mutation. Methods: The clinical data of 479 newly diagnosed B-ALL patients treated in the First Affiliated Hospital of Soochow University from January 2016 to December 2019 were retrospectively analyzed. Results: Among 479 B-ALL patients, 34 cases (7.1%) were positive for TP53 gene mutation, and a total of 36 TP53 mutations were detected, including 10 frameshift gene mutations (27.8%) , 23 missense mutations (63.9%) and 3 nonsense mutations (8.3%) . A total of 34 (94.4%) mutations were located in the DNA binding domain (exons 5-8) .The average number of mutated genes in patients with TP53 gene mutation (2.3) and the group without TP53 gene mutation (1.1) were statistically different (P<0.001) . The proportion of Ph positive and Ph-like positive patients in the TP53 gene mutation negative group was significantly higher than that of the TP53 mutation positive group, and the difference was statistically significant (P<0.001) . The 3-year OS and EFS rates of the TP53 gene mutation negative group were significantly higher than those of the TP53 gene mutation positive group. The differences in OS and EFS rates between the two groups were statistically significant (χ(2)= 4.694, P = 0.030; χ(2)= 5.080, P= 0.024) . In the multivariate analysis, failure to achieve remission (CR) after one course of induction chemotherapy was an independent adverse prognostic factor affecting OS.Of the 34 patients with TP53 mutation, 16 underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT) in the CR(1) state, and 2 patients with recurrence after transplantation obtained CR(2) after infusion of donor-derived anti-CD19 chimeric antigen receptor T (CAR-T) cells. Among the 11 patients with TP53 gene mutation who relapsed during consolidation chemotherapy, 6 received anti-CD19 CAR T cell therapy, 4 patients achieved remission and minimal residual disease (MRD) turned negative, followed by bridging allo-HSCT, and 2 of them sustained CR. Conclusion: Missense mutations are the most common in B-ALL patients with TP53 gene mutation, and the majority of mutations were located in the DNA binding domain. B-ALL patients with TP53 gene mutation should undergo allo-HSCT as soon as possible after CAR-T cell therapy has cleared the MRD after recurrence. B-ALL patients with TP53 gene mutation still have a higher recurrence rate after allo-HSCT, and the infusion of donor-derived CAR-T cells can achieve better sustained remission.