: AbstractObjective: To investigate the sample selection, result correction and clinical application value of multi nucleotide polymorphism chimerism detection method based on Next-generation sequencing. METHODS: The chimerism samples from November 2018 to June 2020 were collected, and Pearson correlation coefficient (r) was used to analyze the consistency of bone marrow and peripheral blood results detected by MNPseq; according to the different information integrity before transplantation, the calibration model was constructed to analyze the correction value of the micro chimerism results in each model; the clinical results were retrospectively analyzed to verify the reliability and practicability of chimerism results correction and the clinical value of MNPseq method. RESULTS: The results of bone marrow and peripheral blood chimerism detected by MNPseq method were consistent with each other and showed significant correlation (r=0.985, P<0.01). The three groups of calibration models were constructed according to different pre-transplant information. For the no donor and pre-transplant patients information group, the correction value was 1%; while for the group with pre-transplant patients and without donor information, 0.61% of the chimerism rate and 13 heterotopic points were used as the correction value; 0.26% of the chimerism rate and 21.57% of the heterotopic points were used as the correction value for the group with pre-transplantation patients and donor information. After correction, the number of the patients with incomplete chimerism decreased from 276 (74.19%) to 141 (37.91%) (P<0.01). Among 18 (18/141, 12.77%) patients with incomplete chimerism, the results of MNPseq in the patients were 25-39 days earlier than those in STR and flow MRD, and the result showed statistical significance. CONCLUSION MNPseq method can be used to monitor chimerism with peripheral blood instead of bone marrow samples, and the results can be corrected to detect the changes of graft status in vivo in a more timely manner.
Chimerism ; Hematopoietic Stem Cell Transplantation ; Humans ; Nucleotides ; Reproducibility of Results ; Retrospective Studies ; Transplantation Chimera/genetics* ; Transplantation, Homologous

OBJECTIVE: To establish a mouse model of respiratory syncytial virus (RSV) infection after hematopoietic stem cell transplantation, so as to lay the foundation for future research on RSV infection and related complications after hematopoietic stem cell transplantation. METHODS: Bone marrow cells and spleen cells were transplanted to C57BL/6 mice after myeloablative treatment to establish a mouse model of allogeneic hematopoietic stem cell transplantation. The chimerism rate was detected by flow cytometry 3 and 7 weeks after transplantation. The transplanted mice were infected with RSV by nasal drops. The lung tissues were collected 5 days after infection for identification of infection, and lung tissues were analyzed for pathology 2 weeks and 2 months after infection. RESULTS: The chimerism rate was > 90% at 3 and 7 weeks after transplantation. Successful infection was detected 5 days after RSV infection, and there were severe and persistent pathological changes in the lung tissues of the mice 2 weeks and 2 months after infection. CONCLUSION RSV infection in stable chimeric mice after hematopoietic stem cell transplantation can cause significantly persistent lung disease, which lays foundation for the prevention and treatment of RSV infection and the mechanism of later bronchiolitis obliterans after hematopoietic stem cell transplantation.
Animals ; Chimerism ; Disease Models, Animal ; Hematopoietic Stem Cell Transplantation ; Mice ; Mice, Inbred C57BL ; Respiratory Syncytial Virus, Human

BACKGROUND: The impact of early peripheral blood chimerism on the outcome of allogeneic hematopoietic stem cell transplantation (allo-HSCT) is unclear. We aimed to determine whether day 14 peripheral blood chimerism after allo-HSCT predicts outcomes in patients with non-malignant diseases. METHODS: Data from 56 patients who received allo-HSCT between April 2007 and March 2016 were retrospectively analyzed. Chimerism was evaluated using short-tandem repeat polymerase chain reaction, with mixed chimerism (MC) defined as greater than 1% recipient cells which was further categorized into low-level MC (> 1% and < 15% of recipient-derived cells) and high-level MC (≥ 15% of the recipient-derived cells). RESULTS: Thirty-six patients showed complete donor chimerism (CC), 14 low-level MC, and 6 high-level MC at day 14 post-transplant. The estimated 5-year event-free survival (EFS) was higher in the CC or low-level MC groups than in the high-level MC group (86.1% vs. 71.4% vs. 33.3%; P = 0.001). In BM or peripheral blood stem cell (BM/PBSC) transplants, the 5-year EFS was higher in the CC or low-level MC group than in the high-level MC group (93.1% vs. 66.7% vs. 0%; P < 0.001). However, in cord blood transplants, the 5-year OS and EFS according to the day 14 peripheral blood chimerism did not reach statistical significance. CONCLUSION: Although CC is not always necessary after allo-HSCT for non-malignant diseases, our data suggest that day 14 peripheral blood chimerism may predict outcomes in patients with non-malignant diseases who underwent BM/PBSC transplants.
Bone Transplantation ; Chimerism ; Disease-Free Survival ; Fetal Blood ; Hematopoietic Stem Cell Transplantation ; Hematopoietic Stem Cells ; Humans ; Polymerase Chain Reaction ; Retrospective Studies ; Stem Cells ; Tissue Donors ; Treatment Outcome

Objective: To investigate the safety and efficacy of allogeneic CAR-T cells in the treatment of relapsed/refractory multiple myeloma (RRMM) . Methods: CAR-T cells were prepared from peripheral blood lymphocytes of HLA mismatch healthy donors. Median age was 55 (48-60) . Allogeneic cells were derived from 3 HLA haploidentical donors and 1 HLA completely mismatch unrelated donor. Four patients with RRMM were conditioned with FC regimen followed by CAR-T cell transfusion. They were infused into CART-19 (1×10(7)/kg on day 0) and (4.0-6.8) ×10(7)/kg CART-BCMA cells as split-dose infusions (40% on day 1 and 60% on day 2) . The adverse reactions and clinical efficacy were observed during follow-up after infusion, and the amplification and duration of CAR-T cells in vivo were monitored by PCR technique. Results: CAR-T cells were successfully infused in 3 of the 4 RRMM patients according to the study plan, and the infusion in one patient was delayed by 1 day due to high fever and elevated creatinine levels on day 3. The side effects included hematological and non-hematological toxicity, grade 3 hematological toxicity in 2 patients, grade 3 CRS in 1 one, grade 1 CRES in 1 one, prolonged APTT in 3 ones, tumor lysis syndrome in 1 one, mixed chimerism detected STR and clinical GVHD manifestation in 1 one. According to the efficacy criterias of IMWG, 2 patients acquired PR, 1 MR, and 1 SD respectively. Progression-free survival was 4 (3-5) weeks and overall survival was 63 (3-81) weeks. CAR T cells were amplified 2.2 (2-14) times in the patients with a median survival time of 10 (8-36) days. Conclusions: Small sample studies suggested that GVHD may be present in the treatment of RRMM with allogeneic CAR-T cells. There were early clinical transient events after transfusion. Low amplification and short duration of CAR-T cells in vivo may be the main factors affecting the efficacy.
Chimerism ; Hematopoietic Stem Cell Transplantation ; Humans ; Immunotherapy, Adoptive ; Multiple Myeloma ; T-Lymphocytes

Objective: To investigate the relationship between donor chimerism and relapse after allogeneic hematopoietic stem cell transplantation (allo-HSCT) . Methods: The clinical data of 105 patients with acute myeloid leukemia (AML) who underwent allo-HSCT and recurrence-free survival>90 days from January 2010 to January 2019 were retrospectively analyzed. The bone marrow samples were collected at 15, 30, 60, 90, 180, 270, 360 days after transplantation. Donor chimerism was detected by single nucleotide polymorphism (SNP) -PCR. Results: Of the 105 patients, 43 cases were male and 62 cases were female, with a median age of 38 (16-60) years. Till April 2019, the median follow-up was 843 (94-3 261) days. Ninety days after transplantation, 18 cases relapsed, 33 cases died, and 72 cases survived. The 3-year overall survival (OS) rate was (66.8±5.1) %, and the recurrence-free survival (RFS) rate was (65.1±5.0) %. Pre-transplant disease status, pre-transplant minimal residual disease (MRD) , and 90 day post-transplantation chimerism were independent risk factors related to RFS. The risk of recurrence was significantly increased in patients with a donor chimerism rate ≤97.24% at 90 days after transplantation[HR=6.921 (95%CI 2.669-17.950) , P<0.001], which was considered as a sign of early relapse. Conclusion: SNP-PCR is an applicable method for detecting donor chimerism in patients after allo-HSCT. Chimerism rate equal or less than 97.24% at 90 days after transplantation predicts a higher risk of relapse.
Adolescent ; Adult ; Chimerism ; Female ; Hematopoietic Stem Cell Transplantation ; Humans ; Leukemia, Myeloid, Acute/therapy* ; Male ; Middle Aged ; Prognosis ; Retrospective Studies ; Transplantation, Homologous ; Young Adult

Erdheim-Chester disease (ECD) is a rare non-Langerhan's cell histiocytosis disorder characterized by replacement of normal tissue by lipid-laden histiocytes affecting various organs. A few pediatric cases have been reported worldwide. Here we present a child with leukemia who was diagnosed as ECD. A 2-year and 11-month old boy diagnosed with high risk acute lymphoblastic leukemia (ALL) at the age of 17 months, received allogeneic hematopoietic stem cell transplantation (HSCT) at the age of 2 years old. Six months after the transplantation, the patient was admitted to the hospital with palpable left calf nodules. Bone marrow study suggested ECD without leukemia with complete chimerism status. Excisional biopsy of the left calf nodule showed ‘aggregation of non-Langerhan's cell type epitheloid histiocytes’; clinically suggestive of ECD. The patient was started on vinblastine and corticosteroid treatment.
Biopsy ; Bone Marrow ; Child* ; Chimerism ; Erdheim-Chester Disease* ; Hematopoietic Stem Cell Transplantation ; Histiocytes ; Histiocytosis ; Humans ; Leukemia* ; Male ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; Vinblastine

OBJECTIVETo establish a transplantation system for a trace amount of adult mouse bone marrow hematopoietic stem cells (HSCs).

METHODSThe HSCs from bone marrow cells of GFP adult mouse were seperated by using marker combination ESLAM (CD45CD201CD150CD48) The goal cell population acquired by flow cytometry sorting were injected into lethally irradiated recipient mouse plus protective cells. And the peripheral blood cells from recipient mice tail veins at different time points were acquired to observe the reconstruction level and lineage differentiation. Then the receptor mouse was killed and the cells from thymus, spleen, marrow, and peripheral blood were acquired to measure tissue chimerism.

RESULTSThe results of peripheral blood of recipient mice after transplantation showed that the reconstructive efficiency was 100% after 4th week. The proportion of GFP cells at different time points in various lines (myeloid, erythroid, B, T and megakaryocytes) were different and the change tendency of reconstruction were different. From different tissues (peripheral blood, bone marrow, spleen, thymus) after 6 months, the intramedullary spleen and thymus chimerism can be seen and showed a high proportion of GFPcells in the peripheral blood erythroid and megakaryocytes and there were no GFPcells in the myeloid and lymphatic cells, but the myeloid cells in the bone marrow cells of the recipient mice contained a higher proportion of GFPcells. The B cells in the spleen had a higher proportion of GFP cells, and the T cells in the thymus contained a higher proportion of GFP cells.

CONCLUSIONThe ESLAM combination can be highly efficient one for the enrichment of HSCs with long-term reconstructive ability, and the results of peripheral blood 6 months after the transplantation suggests that it may have the inclination to erythroid and megakaryocyte differentiation.

BACKGROUND: Allogeneic hematopoietic stem cell transplantation (HSCT) is a curative therapy for β-thalassemia major (TM) and sickle cell disease (SCD) in children. Graft-versus-host disease (GVHD) and treatment-related mortality (TRM) remain significant challenges to improving survival after HSCT. Here, we analyzed the outcome of TM and SCD patients, who received allogeneic HSCT with myeloablative conditioning at our institution. METHODS: Twenty-two patients (15 TM, 7 SCD), with a median age of 9 years (range, 1.6–16.9), underwent allogeneic HSCT using busulfan, cyclophosphamide and rabbit anti-thymocyte globulin-based conditioning. Cells were derived from either the bone marrow (8 patients), or peripheral blood stem cells (14 patients). The majority of patients received HSCT from a matched sibling donor (N=18). GVHD prophylaxis included cyclosporine and short course methotrexate. RESULTS: All patients achieved donor engraftment. Two SCD patients died from TRM-related grade IV gut GVHD (N=1) or severe bronchiolitis obliterans (BO) (N=1). Cumulative incidence of acute and chronic GVHD was 36.4% and 32.7%, respectively. Veno-occlusive disease (VOD) occurred in 8 patients (36.4%), but resolved in all instances. Epstein-Barr virus (EBV)-related post-transplantation lymphoproliferative disease (PTLD) occurred in 1 patient. The overall survival (OS) was 90.9% (TM 100%, SCD 71.4%), with all patients achieving transfusion independence, while 8 achieved complete donor chimerism. CONCLUSION: Busulfan, cyclophosphamide, and ATG-based conditioning for HSCT of TM and SCD patients did not result in graft failure, although modifications may be required to reduce VOD incidence. Further changes to donor type and cell source prioritization are necessary to minimize TRM and morbidity caused by GVHD.
Anemia, Sickle Cell ; Antilymphocyte Serum* ; beta-Thalassemia ; Bone Marrow ; Bronchiolitis Obliterans ; Busulfan ; Child ; Chimerism ; Cyclophosphamide ; Cyclosporine ; Graft vs Host Disease ; Hematopoietic Stem Cell Transplantation* ; Hematopoietic Stem Cells* ; Hemoglobinopathies* ; Herpesvirus 4, Human ; Humans ; Incidence ; Methotrexate ; Mortality ; Siblings ; Stem Cells ; Tissue Donors ; Transplants

Objective: To evaluate the prognostic significance of early phase full donor chimerism (FDC) after myeloablative allogeneic peripheral blood stem cell transplantation (allo-PBSCT). Methods: The clinical data of 72 hematological patients received myeloablative allo-PBSCT from Feb. 2016 to Jul. 2017 were analyzed retrospectively. The median age was 36.5 years (range 4-59), 44 were males and 28 females. Of the donors, there were 35 HLA matched sibling donors, 27 haploidentical donors and 10 unrelated donors. Polymerase chain reaction amplification of short tandem repeat sequence (PCR-STR) was used to detect donor cell chimerism (DC) rate of recipient bone marrow at one, two and three months after transplantation. Results: The median follow-up was 462 d (range: 47-805 d), 55 cases were still alive, and 45 cases were disease-free survival (DFS) at the end of follow-up. The 2-year overall survival (OS) and DFS were (68.9±7.7)% and (59.5±6.3)%, respectively. A number of 16 cases underwent relapses, with 2-year cumulative incidence of (24.1±5.3)%. The median time of recurrence was 157(32-374) d. Forty cases (55.6%) developed acute graft-versus-host diseases (aGVHD), with median time of 35.5 (13-90) d. Chronic GVHD (cGVHD) occurred in 23 patients (31.9%), with median time of 169 (94-475) d. Univariate analysis found the following factors were not related to OS, DFS or relapse rate (RR), including age, sex, blood type and sex of donor-recipient, occurrence of aGVHD and cGVHD. The OS and DFS in cases reached FDC and no FDC at two months after transplantation were (85.2±6.9)% vs (66.1±7.7)% (P=0.051) and (76.7±7.7)% vs (48.9±8.1)% (P=0.021), respectively. The RR rate in FDC group was lower than that in no FDC group [(16.6±6.8)% vs (30.4±7.8)%, P=0.187, respectively]. Conclusion: The present study confirmed the important value for predicting the prognosis with whether or not the patients reached FDC at the early phase after allo-PBSCT. The OS and DFS in cases with FDC at two months after transplantation were significantly higher than those of no FDC patients.
Adolescent ; Adult ; Child ; Child, Preschool ; Chimerism ; Female ; Graft vs Host Disease ; Hematopoietic Stem Cell Transplantation ; Humans ; Male ; Middle Aged ; Peripheral Blood Stem Cell Transplantation ; Prognosis ; Retrospective Studies ; Young Adult

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening hyperinflammatory clinical syndrome of uncontrolled immune response which results in hypercytokinemia due to underlying primary or secondary immune defect. A number of genetic defects in transport, processing and function of cytotoxic granules which result in defective granule exocytosis and cytotoxicity of cytotoxic T lymphocytes (CTL) and natural killer (NK) cells have been well identified at the cellular and molecular level. Important advances have been made during the last 20 years in the diagnosis and treatment of HLH. The Histiocyte Society has proposed diagnostic guideline using both clinical and laboratory findings in HLH-2004 protocol, and this has been modified partly in 2009. HLH used to be a fatal disease, but the survival of HLH patients has improved to more than 60% with the use of chemoimmunotherapy combined with hematopoietic cell transplantation (HCT) over the past 2 decades. However, HCT is still the only curative option of treatment for primary HLH and refractory/relapsed HLH after proper chemoimmunotherapy. The outcome of HCT for HLH patients was also improved steadily during last decades, but HCT for HLH still carries significant mortality and morbidity. Moreover, there remain ongoing controversies in various aspects of HCT including indication of HCT, donor selection, timing of HCT, conditioning regimen, and mixed chimerism after HCT. This review summarized the important practical issues which were proven by previous studies on HCT for HLH, and tried to delineate the controversies among them.
Cell Transplantation* ; Chimerism ; Diagnosis ; Donor Selection ; Exocytosis ; Hematopoietic Stem Cell Transplantation ; Histiocytes ; Humans ; Lymphohistiocytosis, Hemophagocytic* ; Mortality ; T-Lymphocytes, Cytotoxic ; Transplants*