Jiangying Gu

TCR spectratyping revealed T lymphocytes associated with graft-versus-host disease after allogeneic hematopoietic stem cell transplantation

Clonal expansion of T cells after allogeneic hematopoietic stem cell transplantation (allo-HSCT) has been observed, but their characteristics remain to be fully elucidated. We report here that CD8+ T cells were the dominant T lymphocytes seen and T-cell repertoire diversity decreased dramatically during the first 3 months after allo-HSCT. Patients with GVHD grade II – IV had significantly lower T-cell repertoire diversity compared with non-GVHD patients. TCR beta variable gene (TCRBV) subfamily 8, 5.1, 5.2, 4, and 13 were the five most frequently expanded subfamilies among these patients. Among the 49 over-expanded clones identified, clonotype “TCR3-5” and “TCR18-5” were isolated from four patients with HLA-A2 allele and skin GVHD. Their frequencies correlated well with skin symptoms (i.e. rash). Moreover, they were detected in donors but not detected in recipients before transplantation. Lastly, three common TCRBV CDR3 motifs shared by T cells related with GVHD were discovered: TGDS, GLAG, and GGG. These findings suggest that TCR spectratyping is helpful for revealing GVHD-related T cells and may have utility in early diagnosis.

An improved design of PCR primers for detection of human T cell receptor β chain repertoire

Analysis of T cell receptor β variable region (TCRBV) gene rearrangement is useful for clonal assessment of abnormal T cell proliferations in various diseases. However, most primer panels previously used can only amplify the third complementarity-determining region. Following IMGT database we established a panel of primers, which can amplify entire sequences of all functional TCRBV families. To confirm the usefulness of this panel of primers, we detected different TCRBV repertoires. In 15 healthy donors, most of the BV families were expressed and appeared as a Gaussian distribution. 13 acute myeloid leukemia patients showed monoclonal or oligoclonal changes of BV15 family, and some of them also had monoclonal or oligoclonal expansion of BV2, BV4, BV6 or BV13 families. In one patient after allo-hematopoietic stem cell transplantation, monoclonal proliferation of BV10 family occurred during graft-versus-host disease. In conclusion, this panel of primers improves our abilities to analyze TCRBV repertoire changes in related diseases.

Salvaged allogeneic hematopoietic stem cell transplantation for pediatric chemotherapy refractory acute leukemia

There is an ongoing debate concerning the performance of salvaged allogeneic hematopoietic stem cell transplantation (allo-HSCT) in pediatric patients with acute refractory leukemia, in whom the prognosis is quite dismal. Few studies have ever been conducted on this subject. This may be partly due to missed opportunities by majority of the patients in such situations. To investigate the feasibility, evaluate the efficiency, and identify the prognostic factors of allo-HSCT in this sub-setting, the authors performed a single institution-based retrospective analysis. A total of 44 patients, of whom 28 had acute myeloid leukemia (AML), 13 had acute lymphocytic leukemia (ALL), and 3 had mixed phenotype leukemia (MPL), were enrolled in this study. With a median follow-up of 19 months, the estimated 2-year overall survival (OS) and progression free survival (PFS) were 34.3% (95% CI, 17.9–51.4%) and 33.6% (95% CI, 18.0–50.1%), respectively. The estimated 2-year incidence rates of relapse and non-relapse mortality (NRM) were 43.8% (95% CI 26.4–60.0%) and 19.6% (95% CI 9.1–32.9%), respectively. The estimated 100-day cumulative incidence of acute graft versus host disease (aGvHD) was 43.6% (95% CI 28.7–57.5%), and the 1-year cumulative incidence of chronic GvHD (cGvHD) was 45.5% (95% CI 30.5–59.3%). Compared with the previous studies, the multivariate analysis in this study additionally identified that female donors and cGvHD were associated with lower relapse and better PFS and OS. Male recipients, age younger than 10 years, a diagnosis of ALL, and the intermediate-adverse cytogenetic risk group were associated with increased relapse. On the contrary, extramedullary disease (EMD) and aGvHD were only linked to worse PFS. These data suggested that although only one-third of the patients would obtain PFS over 2 years, salvaged allo-HSCT is still the most reliable and best therapeutic strategy for refractory pediatric acute leukemia. If probable, choosing a female donor, better management of aGvHD, and induction of cGvHD promotes patient survival.

Cord Haploidentical Non-In Vitro T Cell Depletion Allogeneic Hematopoietic Stem Cell Transplantation Reduces Relapse of Refractory Acute Leukemia

Whether a graft-versus-graft (GVG) response in patients undergoing allogeneic hematopoietic stem cell transplantation (HSCT) is associated with an enhanced graft-versus-leukemia (GVL) effect remains highly controversial. Furthermore, it is unknown if the GVG response overwhelms the impact of refractory acute leukemia. We aimed to compare the characteristics and therapeutic outcomes between patients undergoing a modified haploidentical cord blood (cord-haplo) HSCT protocol (n = 97) and those undergoing haploidentical HSCT (n = 42) for refractory acute leukemia. A reliable and stable predominant haploidentical donor chimerism was established. The 2-year relapse rate was more favorable in patients undergoing cord-haplo HSCT than in those undergoing haploidentical HSCT (25.9% versus 53.2%; P = .007), as was progression-free survival (PFS; 35.5% versus 17.9%; P = .049). Meanwhile, nonrelapse mortality at 2 years was not significantly different (38.0% versus 24.6%; P = .367). We also found that a higher number of mutual haploidentical donor-mismatched antigens, a concept similar to HLA mismatching, was associated with better disease control. Multivariate analysis identified cord-haplo HSCT as an independent significant predictor of reduced relapse (hazard ratio [HR], .44; P = .028) and improved PFS (HR, .58; P = .033), as was chronic graft-versus-host disease (GVHD) (relapse: HR, .42; P  = .013; PFS: HR, .63: P = .052). However, the incidences of neutrophil and platelet engraftment, GVHD, and virus reactivation were comparable in the 2 groups. This study demonstrates that cord-haplo HSCT significantly enhances the GVL effect and improves PFS, providing a reliable and efficient therapeutic platform for patients with refractory acute leukemia.