[Role and progress of allogeneic hematopoietic stem cell transplantation in the treatment of refractory/relapsed diffuse large B-cell lymphoma].

Diffuse large B-cell lymphoma (DLBCL) is the most common type of non Hodgkin's lymphoma. The current treatment plan can significantly improve the prognosis of patients, but about 30%-40% of DLBCL patients still experience drug resistance and relapse after treatment. For patients with refractory/relapse DLBCL, clinical treatment remains difficult and their prognosis is poor. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) remains one of the most important curative methods for refractory/relapse DLBCL patients. This article will review the role and progress of allo-HSCT in the treatment of refractory/relapse DLBCL.

[The effect of glucose-6-phosphate dehydrogenase deficiency on allogeneic hematopoietic stem cell transplantation in patients with hematological disorders].

Objectives: To determine the effect of glucose-6-phosphate-dehydrogenase (G6PD) deficiency on patients' complications and prognosis following allogeneic stem cell hematopoietic transplantation (allo-HSCT) . Methods: 7 patients with G6PD deficiency (study group) who underwent allo-HSCT at Peking University People's Hospital from March 2015 to January 2021 were selected as the study group, and thirty-five patients who underwent allo-HSCT during the same period but did not have G6PD deficiency were randomly selected as the control group in a 1∶5 ratio. Gender, age, underlying diseases, and donors were balanced between the two groups. Collect clinical data from two patient groups and perform a retrospective nested case-control study. Results: The study group consisted of six male patients and one female patient, with a median age of 37 (range, 2-45) years old. The underlying hematologic diseases included acute myeloid leukemia (n=3), acute lymphocytic leukemia (n=2), and severe aplastic anemia (n=2). All 7 G6PD deficiency patients achieved engraftment of neutrophils within 28 days of allo-HSCT, while the engraftment rate of neutrophils was 94.5% in the control group. The median days of platelet engraftment were 21 (6-64) d and 14 (7-70) d (P=0.113). The incidence rates of secondary poor graft function in the study group and control group were 42.9% (3/7) and 8.6% (3/35), respectively (P=0.036). The CMV infection rates were 71.4% (5/7) and 31.4% (11/35), respectively (P=0.049). The incidence rates of hemorrhagic cystitis were 57.1% (4/7) and 8.6% (3/35), respectively (P=0.005), while the bacterial infection rates were 100% (7/7) and 77.1% (27/35), respectively (P=0.070). The infection rates of EBV were 14.3% (1/7) and 14.3% (5/35), respectively (P=1.000), while the incidence of fungal infection was 14.3% (1/7) and 25.7% (9/35), respectively (P=0.497). The rates of post-transplant lymphoproliferative disease (PTLD) were 0% and 5.7%, respectively (P=0.387) . Conclusions: The findings of this study indicate that blood disease patients with G6PD deficiency can tolerate conventional allo-HSCT pretreatment regimens, and granulocytes and platelets can be implanted successfully. However, after transplantation, patients should exercise caution to avoid viral infection, complications of hemorrhagic cystitis, and secondary poor graft function.

[Clinical features and risk factors for invasive fungal sinusitis after allogeneic hematopoietic stem cell transplantation].

Objective: To analyze the clinical characteristics and outcomes of patients with invasive fungal sinusitis (invasive fungal rhinosinusitis, IFR) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) and explored the risk factors for IFR after allo-HSCT. Methods: Nineteen patients with IFR after allo-HSCT at Peking University People's Hospital from January 2012 to December 2021 were selected as the study group, and 95 patients without IFR after allo-HSCT during this period were randomly selected as the control group (1:5 ratio) . Results: Nineteen patients, including 10 males and 9 females, had IFR after allo-HSCT. The median age was 36 (10-59) years. The median IFR onset time was 68 (9-880) days after allo-HSCT. There were seven patients with acute myeloid leukemia, five with acute lymphoblastic leukemia, two with myelodysplastic syndrome, two with chronic myeloid leukemia, one with acute mixed-cell leukemia, one with multiple myeloma, and one with T-lymphoblastic lymph node tumor. There were 13 confirmed cases and 6 clinically diagnosed cases. The responsible fungus was Mucor in two cases, Rhizopus in four, Aspergillus in four, and Candida in three. Five patients received combined treatment comprising amphotericin B and posaconazole, one patient received combined treatment comprising voriconazole and posaconazole, nine patients received voriconazole, and four patients received amphotericin B. In addition to antifungal treatment, 10 patients underwent surgery. After antifungal treatment and surgery, 15 patients achieved a response, including 13 patients with a complete response and 2 patients with a partial response. Multivariate analysis revealed that neutropenia before transplantation (P=0.021) , hemorrhagic cystitis after transplantation (P=0.012) , delayed platelet engraftment (P=0.008) , and lower transplant mononuclear cell count (P=0.012) were independent risk factors for IFR after allo-HSCT. The 5-year overall survival rates in the IFR and control groups after transplantation were 29.00%±0.12% and 91.00%±0.03%, respectively (P<0.01) . Conclusion: Although IFR is rare, it is associated with poor outcomes in patients undergoing allo-HSCT. The combination of antifungal treatment and surgery might be effective.

[Effect of sirolimus combined with anti-CD20 monoclonal antibody desensitization on the prognosis of patients underwent haploidentical stem cell transplantation].

Objective: To investigate the effects of sirolimus combined with anti-CD20 monoclonal antibody desensitization on the prognosis of patients with haploidentical stem cell transplantation (haplo-SCT). Methods: Fifteen consecutive patients who received haplo-SCT and pre-transplant donor specific anti-human leukocyte antigen (HLA) antibody (DSA) positive [mean fluorescence intensity (MFI)≥2 000] in the Institute of Hematological Diseases from November 2021 to March 2023 were retrospectively recruited into the desensitized group. There were 4 males and 11 females, with a median age [M(Q1, Q3)] of 48 (37, 59) years. All patients were desensitized with sirolimus combined with anti-CD20 monoclonal antibody. The non-desensitized group included 29 patients with haplo-SCT who had not received desensitization treatment from August 2012 to June 2016. There were 12 males and 17 females with a median age of 42 (26, 50) years. Up to October 1, 2023, the median follow-up time was 13 (9, 18) months in the study group and 23 (14, 29) months in the control group. The changes of MFI before and after desensitization treatment and the prognosis of patients in the desensitized group were compared, including the incidence of primary implantation failure (pGF), neutrophil implantation time, platelet implantation time, grade Ⅱ-Ⅳ acute graft-versus-host disease (GVHD) and chronic GVHD incidence, non-recurrence related mortality, event-free survival rate, disease-free survival rate and overall survival rate. The survival curve was drawn by Kaplan-Meier method, and the survival rate between groups was compared with Log-rank test. Results: After desensitization treatment, the level of DSA MFI in the desensitized group decreased from 8 879 (7 544, 11 495) to 3 781 (1 638, 4 165) after desensitization treatment (P<0.01). All of the patients achieved hematopoietic recovery, and the median time for neutrophil and platelet engraftment were 14 (11, 15) and 20 (18, 25) days, respectively. The incidence of pGF in the desensitized group was 0, which was lower than that in the non-desensitized group (34.5%, 10/29) (P=0.011). The expected 1-year disease-free survival rate and overall survival rate in the desensitized group were 100% (15/15) and 100% (15/15) respectively, while those in the non-desensitized group were 75.9% (22/29) and 75.9% (22/29) respectively, the difference was not statistically significant (both P>0.05). The one-year event-free survival rate in the desensitized group was expected to be 100% (15/15), which was higher than that in the non-desensitized group (51.3%, 15/29) (P=0.002). Conclusion: Sirolimus combined with anti-CD20 monoclonal antibody desensitization therapy can reduce the DSA level of haplo-SCT recipients, promote hematopoietic engraftment after transplantation, and avoid the occurrence of pGF after transplantation.

[Clinical significance of Epstein-Barr Virus detection in the cerebrospinal fluid of patients who underwent hematopoietic stem cell transplantation].

Objective: To analyze the detection rate, clinical significance, and prognosis of Epstein-Barr virus (EBV) in the cerebrospinal fluid (CSF) of patients following allogeneic hematopoietic stem cell transplantation. Methods: A retrospective analysis was performed on 1100 patients who underwent the CSF virus test after allogeneic hematopoietic stem cell transplantation in Peking University People's Hospital between January 2017 and June 2022. Among them, 19 patients were screened positive for EBV in their CSF, and their clinical characteristics, treatment, and prognosis were analyzed. Results: Among 19 patients with EBV-positive cerebrospinal fluid, 12 were male and 7 were female, with 5 patients aged <18 years and 12 aged ≥18 years, with a median age of 27 (5-58) years old. There were 7 cases of acute myeloid leukemia, 8 of acute lymphocytic leukemia, 2 of aplastic anemia, 1 of Hodgkin's lymphoma, and 1 of hemophagocytic syndrome. All 19 patients underwent haploid hematopoietic stem cell transplantation, including 1 secondary transplant. Nineteen patients had neurological symptoms (headache, dizziness, convulsions, or seizures), of which 13 had fever. Ten cases showed no abnormalities in cranial imaging examination. Among the 19 patients, 6 were diagnosed with EB virus-related central nervous system diseases, with a median diagnosis time of 50 (22-363) days after transplantation. In 9 (47.3%) patients, EBV was detected in their peripheral blood, and they were treated with intravenous infusion of rituximab (including two patients who underwent lumbar puncture and intrathecal injection of rituximab). After treatment, EBV was not detected in seven patients. Among the 19 patients, 2 died from EBV infection and 2 from other causes. Conclusion: In patients who exhibited central nervous system symptoms after allogeneic hematopoietic stem cell transplantation, EBV should be screened as a potential pathogen. EBV detected in the CSF may indicate an infection; however, it does not confirm the diagnosis.

[Safety and survival analysis of haplo-identical hematopoietic stem cell transplantation in patients with severe aplastic anemia who had previous failure to antithymoglobulin treatment].

Objective: To investigate the safety and efficacy of haplo-identical hematopoietic stem cell transplantation (haplo-HSCT) conditioning with the same dosage form of antithymoglobulin (ATG) in patients with severe aplastic anemia (SAA) failure to ATG. Methods: This was a retrospective cohort study. A total of 65 patients with SAA who failed ATG treatment and received haplo-HSCT conditioning with the same dosage of ATG at the Institute of Hematology, Peking University People's Hospital between July 2008 and October 2020 were included as the ATG treatment failure group. An additional 65 SAA patients who applied ATG for the first time during haplo-HSCT were randomly selected by stratified sampling as the first-line haplo-HSCT group. Baseline clinical data and follow-up data of the two groups were collected. Conditioning-related toxicity within 10 days after ATG application and long-term prognosis were analyzed. The Kaplan-Meier was used to calculate the overall survival rate, and the Log-rank test was applied to compare the rates of the two groups. Results: In the ATG treatment failure group, there were 36 males and 29 females, and the age at the time of transplantation [M (Q1, Q3)] was 16 (8, 25) years. In the first-line haplo-HSCT group, there were 35 males and 30 females, with a median age of 17 (7, 26) years. Within 10 days of ATG application, the incidence of noninfectious fever, noninfectious diarrhea, and liver injury in the ATG treatment failure group was 78% (51 cases), 45% (29 cases), and 28% (18 cases), respectively, and in the first-line haplo-HSCT group was 74% (48 cases), 54% (35 cases), and 25% (16 cases), respectively; the difference between the two groups was not statistically significant for any of these three parameters (all P>0.05). For graft-versus-host disease (GVHD), there was no significant difference between the ATG treatment failure group and the first-line haplo-HSCT group in the development of 100 day Ⅱ to Ⅳ acute GVHD (29.51%±0.35% vs. 25.42%±0.33%), Ⅲ to Ⅳ acute GVHD (6.56%±0.10% vs. 6.78%±0.11%), and 3-year chronic GVHD (26.73%±0.36% vs. 21.15%±0.30%) (all P>0.05). Three-year overall survival (79.6%±5.1% vs. 84.6%±4.5%) and 3-year failure-free survival (79.6%±5.1% vs. 81.5%±4.8%) were also comparable between these two groups (both P>0.05). Conclusions: Compared with no exposure to ATG before HSCT, similar early adverse effects and comparable survival outcomes were achieved in patients with SAA who failed previous ATG treatment and received haplo-HSCT conditioning with the same dosage form of ATG. This might indicate that previous failure of ATG treatment does not significantly impact the efficacy and safety of salvaging haplo-HSCT in patients with SAA.

[Erythrocytosis after hematopoietic stem cell transplantation: report of 3 cases and literature review].

This is a report of three cases of three male patients. One of the patients had myelodysplastic syndrome, and two had aplastic anemia; their ages were 28, 32, and 21 years old, respectively. Two patients underwent sibling allogeneic hematopoietic stem cell transplantation, and one underwent haploidentical hematopoietic stem cell transplantation. All the patients showed elevated hemoglobin and hematocrit at 6, 16, and 9 months after transplantation, with normal white blood cells and platelets and no splenomegaly. All causes of secondary polycythemia were ruled out. Bone marrow morphology showed no erythroid hyperplasia. The PCR result for BCR-ABL (P210, P230, P190, and variants) was negative, and there were no mutations at the amino acid site 617 of JAK2, exon 12 of JAK2, exon 9 of CALR, and amino acid site 515 of MPL. All three patients had hypertension. One patient was treated with amlodipine, and the other two patients were treated with angiotensin receptor blockers. The durations of erythrocytosis for these three patients were 6 years and 3 months, 4 years and 7 months, and 5 years and 3 months, respectively through December 2022. There was no tendency for spontaneous remission. Erythrocytosis after hematopoietic stem cell transplantation is a rare complication. Previous reports in the literature suggest that the mechanism of post-transplant erythrocytosis in recipients of allogeneic hematopoietic stem cell transplantation may be different from that of recipients of other transplants.

[Efficacy and safety of secondary allogeneic hematopoietic stem cell transplantation in 70 patients with recurrent hematologic malignancies after transplantation].

Objectives: To investigate the role of donor change in the second hematopoietic stem cell transplantation (HSCT2) for hematological relapse of malignant hematology after the first transplantation (HSCT1) . Methods: We retrospectively analyzed patients with relapsed hematological malignancies who received HSCT2 at our single center between Mar 1998 and Dec 2020. A total of 70 patients were enrolled[49 males and 21 females; median age, 31.5 (3-61) yr]. Results: Forty-nine male and 21 female patients were enrolled in the trial. At the time of HSCT2, the median age was 31.5 (3-61) years old. Thirty-one patients were diagnosed with acute myeloid leukemia, 23 patients with ALL, and 16 patients with MDS or other malignant hematology disease. Thirty patients had HSCT2 with donor change, and 40 patients underwent HSCT2 without donor change. The median relapse time after HSCT1 was 245.5 (26-2 905) days. After HSCT2, 70 patients had neutrophil engraftment, and 62 (88.6%) had platelet engraftment. The cumulative incidence of platelet engraftment was (93.1±4.7) % in patients with donor change and (86.0±5.7) % in patients without donor change (P=0.636). The cumulative incidence of CMV infection in patients with and without donor change was (64.0±10.3) % and (37.0±7.8) % (P=0.053), respectively. The cumulative incidence of grade Ⅱ-Ⅳ acute graft versus host disease was (19.4±7.9) % vs (31.3±7.5) %, respectively (P=0.227). The cumulative incidence of TRM 100-day post HSCT2 was (9.2±5.1) % vs (6.7±4.6) % (P=0.648), and the cumulative incidence of chronic graft versus host disease at 1-yr post-HSCT2 was (36.7±11.4) % versus (65.6±9.1) % (P=0.031). With a median follow-up of 767 (271-4 936) days, 38 patients had complete remission (CR), and three patients had persistent disease. The CR rate was 92.7%. The cumulative incidences of overall survival (OS) and disease-free survival (DFS) 2 yr after HSCT2 were 25.8% and 23.7%, respectively. The cumulative incidence of relapse, OS, and DFS was (52.6±11.6) % vs (62.4±11.3) % (P=0.423), (28.3±8.6) % vs (23.8±7.5) % (P=0.643), and (28.3±8.6) % vs (22.3±7.7) % (P=0.787), respectively, in patients with changed donor compared with patients with the original donor. Relapses within 6 months post-HSCT1 and with persistent disease before HSCT2 were risk factors for OS, DFS, and CIR. Disease status before HSCT2 and early relapse (within 6 months post-HSCT1) was an independent risk factor for OS, DFS, and CIR post-HSCT2. Conclusion: Our findings indicate that changing donors did not affect the clinical outcome of HSCT2.

[Clinical analysis of the usefulness of letermovir for prevention of cytomegalovirus infection after haploidentical hematopoietic stem cell transplantation].

Objective: To analyze the efficacy and safety of letermovir in primary prophylaxis of cytomegalovirus (CMV) reactivation in patients receiving haploidentical hematopoietic stem cell transplantation. Methods: This retrospective, cohort study was conducted using data of patients who underwent haploidentical transplantation at Peking University Institute of Hematology and received letermovir for primary prophylaxis between May 1, 2022 and August 30, 2022. The inclusion criteria of the letermovir group were as follows: letermovir initiation within 30 days after transplantation and continuation for≥90 days after transplantation. Patients who underwent haploidentical transplantation within the same time period but did not receive letermovir prophylaxis were selected in a 1∶4 ratio as controls. The main outcomes were the incidence of CMV infection and CMV disease after transplantation as well as the possible effects of letermovir on acute graft versus host disease (aGVHD), non-relapse mortality (NRM), and bone marrow suppression. Categorical variables were analyzed by chi-square test, and continuous variables were analyzed by Mann-Whitney U test. The Kaplan-Meier method was used for evaluating incidence differences. Results: Seventeen patients were included in the letermovir prophylaxis group. The median patient age in the letermovir group was significantly greater than that in the control group (43 yr vs. 15 yr; Z=-4.28, P<0.001). The two groups showed no significant difference in sex distribution and primary diseases, etc. (all P>0.05). The proportion of CMV-seronegative donors was significantly higher in the letermovir prophylaxis group in comparison with the control group (8/17 vs. 0/68, χ2=35.32, P<0.001). Three out of the 17 patients in the letermovir group experienced CMV reactivation, which was significantly lower than the incidence of CMV reactivation in the control group (3/17 vs. 40/68, χ2=9.23, P=0.002), and no CMV disease development observed in the letermovir group. Letermovir showed no significant effects on platelet engraftment (P=0.105), aGVHD (P=0.348), and 100-day NRM (P=0.474). Conclusions: Preliminary data suggest that letermovir may effectively reduce the incidence of CMV infection after haploidentical transplantation without influencing aGVHD, NRM, and bone marrow suppression. Prospective randomized controlled studies are required to further verify these findings.

[Dynamic monitoring of plasma Epstein-Barr Virus DNA load can predict the occurrence of lymphoproliferative disorders after haploidentical hematopoietic stem cell transplantation].

Objective: To determine the optimal cutoff value of Epstein-Barr virus (EBV) DNA load that can assist in the diagnosis of post-transplant lymphoproliferative disease (PTLD) after haploidentical hematopoietic stem cell transplantation (haplo-HSCT) . Methods: The data of patients with EBV infection after haplo-HSCT from January to December 2016 were retrospectively analyzed. Through constructing the receiver operating characteristic (ROC) curve and calculating the Youden index to determine the cutoff value of EBV-DNA load and its duration of diagnostic significance for PTLD. Results: A total of 94 patients were included, of whom 20 (21.3% ) developed PTLD, with a median onset time of 56 (40-309) d after transplantation. The median EBV value at the time of diagnosis of PTLD was 70,400 (1,710-1,370,000) copies/ml, and the median duration of EBV viremia was 23.5 (4-490) d. Binary logistic regression was used to analyze the peak EBV-DNA load (the EBV-DNA load at the time of diagnosis in the PTLD group) and duration of EBV viremia between the PTLD and non-PTLD groups. The results showed that the difference between the two groups was statistically significant (P=0.018 and P=0.001) . The ROC curve was constructed to calculate the Youden index, and it was concluded that the EBV-DNA load ≥ 41 850 copies/ml after allogeneic hematopoietic stem cell transplantation had diagnostic significance for PTLD (AUC=0.847) , and the sensitivity and specificity were 0.611 and 0.932, respectively. The duration of EBV viremia of ≥20.5 d had diagnostic significance for PTLD (AUC=0.833) , with a sensitivity and specificity of 0.778 and 0.795, respectively. Conclusion: Dynamic monitoring of EBV load in high-risk patients with PTLD after haplo-HSCT and attention to its duration have important clinical significance, which can help clinically predict the occurrence of PTLD in advance and take early intervention measures.

[Treatment responses, outcomes, and prognostic factors associated with them in patients with secondary acute myeloid leukemia].

Objective: To evaluate treatment responses, outcomes, and prognostic factors in adults with secondary acute myeloid leukemia (sAML) . Methods: Between January 2008 and February 2021, date of consecutive cases of younger than 65 years of adults with sAML were assessed retrospectively. Clinical characteristics at diagnosis, treatment responses, recurrence, and survival were evaluated. Logistic regression and Cox proportional hazards model were employed to determine significant prognostic indicators for treatment response and survival. Results: 155 patients were recruited, including 38, 46, 57, 14 patients belonging to t-AML, and AML with unexplained cytopenia, post-MDS-AML, and post-MPN-AML, respectively. In the 152 evaluable patients, the rate of MLFS after the initial induction regimen was 47.4%, 57.9%, 54.3%, 40.0%, and 23.1% in the four groups (P=0.076) . The total rate of MLFS after the induction regimen was 63.8%, 73.3%, 69.6%, 58.2%, and 38.5% (P=0.084) , respectively. Multivariate analysis demonstrated that male gender (OR=0.4, 95% CI 0.2-0.9, P=0.038 and OR=0.3, 95% CI 0.1-0.8, P=0.015) , SWOG cytogenetic classification into unfavorable or intermediate (OR=0.1, 95% CI 0.1-0.6, P=0.014 and OR=0.1, 95% CI 0.1-0.3, P=0.004) and receiving low-intensity regimen as induction regimen (OR=0.1, 95% CI 0.1-0.3, P=0.003 and OR=0.1, 95%CI 0.1-0.2, P=0.001) were typical adverse factors impacting the first CR and the final CR; PLT<45 × 10(9)/L (OR=0.4, 95%CI 0.2-0.9, P=0.038) and LDH ≥258 U/L (OR=0.3, 95%CI 0.1-0.7, P=0.005) were independent factors for CR. Among the 94 patients with achieving MLFS, 46 cases had allogeneic hematopoietic stem cell transplantation. With a median follow-up period of 18.6 months, the probabilities of relapse-free survival (RFS) and overall survival (OS) at 3 years were 25.4% and 37.3% in patients with transplantation, and in patients with chemotherapy, the probabilities of RFS and OS at 3-year were 58.2% and 64.3%, respectively. At the time of achieving MLFS, multivariate analysis revealed that age ≥46 years (HR=3.4, 95%CI 1.6-7.2, P=0.002 and HR=2.5, 95%CI 1.1-6.0, P=0.037) , peripheral blasts ≥17.5% at diagnosis (HR=2.5, 95%CI 1.2-4.9, P=0.010 and HR=4.1, 95%CI 1.7-9.7, P=0.002) , monosomal karyotypes (HR=4.9, 95%CI 1.2-19.9, P=0.027 and HR=28.3, 95%CI 4.2-189.5, P=0.001) were typical adverse factors influencing RFS and OS. Furthermore, CR after induction chemotherapy (HR=0.4, 95%CI 0.2-0.8, P=0.015) and transplantation (HR=0.4, 95%CI 0.2-0.9, P=0.028) were substantially linked to longer RFS. Conclusion: Post-MDS-AML and post-MPN-AML had lower response rates and poorer prognoses than t-AML and AML with unexplained cytopenia. In adults with male gender, low platelet count, high LDH, and SWOG cytogenetic classification into unfavorable or intermediate at diagnosis, and receiving low-intensity regimen as the induction regimen predicted a low response rate. Age ≥46 years, a higher proportion of peripheral blasts and monosomal karyotype had a negative effect on the overall outcome. Transplantation and CR after induction chemotherapy were greatly linked to longer RFS.

[Clinical characteristics of patients with human adenovirus infection undergoing allogeneic hematopoietic stem cell transplantation].

Objective: To investigate the clinical characteristics and prognosis of human adenovirus (HAdV) infection in patients with allogeneic hematopoietic stem cell transplantation (allo-HSCT). Methods: This is a retrospective case series study. Patients who received allo-HSCT and had symptoms of HAdV infection were tested in the Hematology Department at Perking University People's Hospital from August 2015 to October 2019. Real-time quantitative PCR was used to detect HAdV DNA from 2 728 patients with potential infection. HAdV DNA-positive patients were defined as having HAdV infection. The clinical features of these patients were analyzed, and a case-pair method was used to select patients without HAdV infection as the control group in a 1∶3 ratio. The clinical results of the two groups were compared using Kaplan-Meier and Log-rank testing. Results: A total of 7 119 samples were tested for HAdV, of which 99 samples from 36 patients were positive. Of these patients, 22 developed HAdV viremia, and 24 patients had concurrent infection with another virus. Nineteen patients had fever (53%), 25 had gastrointestinal symptoms (69%), 11 had respiratory symptoms (31%), nine had reduced liver function (25%), and six had nervous system symptoms (17%). Twenty-three patients developed acute graft-versus-host disease of grade 2 or higher. Of all the patients with HAdV infection, nine were treated with cidofovir, seven of whom became HAdV negative and two had invalid treatment. The median follow-up time was 496 (216, 940) d post-HSCT. The overall survival at 5 years post HSCT was 48.4%±9.2% vs. 91.3%±3.5% (χ2=65.03, P<0.001) in patients with and without HADV, respectively. The non-relapse mortality at 5 years post-HSCT was 40.8%±8.8% vs. 4.0%±2.0% (χ2=34.17, P<0.001) in patients with and without HADV, respectively. Conclusions: After allo-HSCT, HAdV-infected patients are dominated by gastrointestinal and respiratory symptoms and have an increased risk of combined acute graft-versus-host disease of >2 degrees. Patients with HAdV infection have poor overall survival and high non-relapse mortality.

[Impact of SARS-CoV-2 infection on graft composition and early transplant outcomes following allogeneic hematopoietic stem cell transplantation].

Objective: To assess the feasibility of using donors with novel coronavirus disease 2019 (COVID-19) for allogeneic hematopoietic stem cell transplantation (allo-HSCT) when there are no other available donors and allo-HSCT cannot be delayed or discontinued. Methods: Seventy-one patients with malignant hematological diseases undergoing allo-HSCT between December 8, 2022, and January 10, 2023, were included. Of these, 16 received grafts from donors with mild COVID-19 (D-COVID(+) group) and 55 received grafts from donors without COVID-19 (D-COVID(-) group). The graft compositions were compared between the two groups. Engraftment, acute graft-versus-host disease (aGVHD), overall survival (OS), and relapse were also evaluated. Results: There were no serious side effects or adverse events in the D-COVID(+) group. The mononuclear cell dose and CD34(+) cell dose were comparable between the two groups, and no additional apheresis was required. There were no significant differences in the lymphocyte, monocyte, and T-cell subset doses between the two groups. The median natural killer cell dose in the D-COVID(+) group was significantly higher than that in the D-COVID(-) group (0.69×10(8)/kg vs. 0.53×10(8)/kg, P=0.031). The median follow-up time was 72 (33-104) days. All patients achieved primary engraftment. The 60-day platelet engraftment rates in the D-COVID(+) and D-COVID(-) groups were 100% and (96.4±0.2) %, respectively (P=0.568). There were no significant differences in neutrophil (P=0.309) and platelet (P=0.544) engraftment times. The cumulative incidence of grade 2-4 aGVHD was (37.5±1.6) % vs. (16.4±0.3) % (P=0.062), and of grade 3-4 aGVHD was 25.0% ±1.3% vs. 9.1% ±0.2% (P=0.095) in the D-COVID(+) and D-COVID(-) groups, respectively. The probabilities of 60-day OS were 100% and 98.1% ±1.8% (P=0.522) in the D-COVID(+) and D-COVID(-) groups, respectively. There was no relapse of primary disease during the study period. Conclusion: When allo-HSCT cannot be delayed or discontinued and no other donor is available, a donor with mild COVID-19 should be considered if tolerable. Larger sample sizes and longer follow-up periods are required to validate these results.

[Relationship between treatment and prognosis in patients with late-onset severe pneumonia after allogeneic hematopoietic stem cell transplantation].

OBJECTIVE: To explore the relationship between drug treatment and outcomes in patients with late-onset severe pneumonia (LOSP) after allogeneic stem cell transplantation (allo-SCT). METHODS: We retrospectively analyzed the effects of the initiation time of treatment drugs, especially antiviral drugs and glucocorticoids on the clinical outcomes in 82 patients between January 2016 and August 2021 who developed LOSP after allo-SCT in Peking University People's Hospital. Univariate analysis was performed by Mann-Whitney U test and χ2 test, and multivariate analysis was performed by Logistic regression. When multiple groups (n>2) were involved in the χ2 test, Bonferroni correction was used for the level of significance test. RESULTS: Of all 82 patients in this study, the median onset time of LOSP was 220 d (93-813 d) after transplantation, and the 60-day survival rate was 58.5% (48/82). The median improvement time of the survival patients was 18 d (7-44 d), while the median death time of the died patients was 22 d (2-53 d). Multivariate analysis showed that the initiation time of antiviral drugs from the onset of LOSP (< 10 d vs. ≥10 d, P=0.012), and the initiation time of glucocorticoids from antiviral drugs (< 10 d vs. ≥10 d, P=0.027) were the factors affecting the final outcome of the patients with LOSP at the end of 60 d. According to the above results, LOSP patients were divided into four subgroups: group A (antiviral drugs < 10 d, glucocorticoids ≥10 d), group B (antiviral drugs < 10 d, glucocorticoids < 10 d), group C (antiviral drugs ≥10 d, glucocorticoids ≥10 d) and group D (antiviral drugs ≥10 d, glucocorticoids < 10 d), the 60-day survival rates were 91.7%, 56.8%, 50.0% and 21.4%, respectively. CONCLUSION: Our study demonstrated that in patients who developed LOSP after allo-SCT, the initiation time of antiviral drugs and glucocorticoids were associated with the prognosis of LOSP, and the survival rate was highest in patients who received antiviral drugs early and glucocorticoids later. It suggested that for patients with LOSP of unknown etiology should be highly suspicious of the possibility of a secondary hyperimmune response to viral infection.

[Application value of metagenomic next-generation sequencing for infectious pathogens in patients receiving allogeneic hematopoietic stem cell transplantation].

Objective: To investigate the application value of Metagenomic Next-Generation sequencing (mNGS) in infectious patients after allogeneic hematopoietic stem cell transplantation(allo-HSCT). Methods: Patients suspected with local or systemic infections were retrospectively included after allo-HSCT in our department from April 2019 to November 2020. Pathogenic microorganisms were tested by mNGS in samples from peripheral blood, cerebrospinal fluid, alveolar lavage Liquid, abscess, etc. Other diagnostic methods such as bacterial/fungal culture, viral PCR detection were simultaneously explored comparing with mNGS results. Results: A total of 112 samples in 83 patients were detected by mNGS, and 34 pathogenic microorganisms were determined. Among these positive samples, 11 strains of bacteria (17 times) with the most common Escherichia coli (4/17) were reported. There were 7 strains of fungi (10 times) detected with primary Candida albicans (7/29). Although arvovirus 30.2% (39/129) were predominantly detected, its diagnostic relevance with infections was not definite. Other pathogenic viruses including cytomegalovirus (CMV) 25.6% (33/129) and Epstein Barr virus (EBV) 14.0% (18/129)were of significance. Comparing with golden diagnostic criteria, the sensitivity of mNGS was 86.5%, and specificity was 45.0%. Regarding single pathogen infection, the consistency of mNGS and conventional methods was 82.9% (29/35), while it was 16/17 in combination infections. Conclusion: mNGS could be a potential method to determine pathogens in patients suspected with infections after allo-HSCT.

[A retrospective comparative study of haplotype hematopoietic stem cell transplantation and human leukocyte antigen-matched sibling donor hematopoietic stem cell transplantation in the treatment of acute B-lymphocyte leukemia].

Objective: To investigate whether haplotype hematopoietic stem cell transplantation (haplo-HSCT) is effective in the treatment of pre transplant minimal residual disease (Pre-MRD) positive acute B lymphoblastic leukemia (B-ALL) compared with HLA- matched sibling donor transplantation (MSDT) . Methods: A total of 998 patients with B-ALL in complete remission pre-HSCT who either received haplo-HSCT (n=788) or underwent MSDT (n=210) were retrospectively analyzed. The pre-transplantation leukemia burden was evaluated according to Pre-MRD determinedusing multiparameter flow cytometry (MFC) . Results: Of these patients, 997 (99.9% ) achieved sustained, full donor chimerism. The 100-day cumulative incidences of neutrophil engraftment, platelet engraftment, and grades Ⅱ-Ⅳ acute graft-versus-host disease (GVHD) were 99.9% (997/998) , 95.3% (951/998) , and 26.6% (95% CI 23.8% -29.4% ) , respectively. The 3-year cumulative incidence of total chronic GVHD was 49.1% (95% CI 45.7% -52.4% ) . The 3-year cumulative incidence of relapse (CIR) and non-relapse mortality (NRM) of the 998 cases were 17.3% (95% CI 15.0% -19.7% ) and 13.8% (95% CI 11.6% -16.0% ) , respectively. The 3-year probabilities of leukemia-free survival (LFS) and overall survival (OS) were 69.1% (95% CI 66.1% -72.1% ) and 73.0% (95% CI 70.2% -75.8% ) , respectively. In the total patient group, cases with positive Pre-MRD (n=282) experienced significantly higher CIR than that of subjects with negative Pre-MRD [n=716, 31.6% (95% CI 25.8% -37.5% ) vs 14.3% (95% CI 11.4% -17.2% ) , P<0.001]. For patients in the positive Pre-MRD subgroup, cases treated with haplo-HSCT (n=219) had a lower 3-year CIR than that of cases who underwent MSDT [n=63, 27.2% (95% CI 21.0% -33.4% ) vs 47.0% (95% CI 33.8% -60.2% ) , P=0.002]. The total 998 cases were classified as five subgroups, including cases with negative Pre-MRD group (n=716) , cases with Pre-MRD<0.01% group (n=46) , cases with Pre-MRD 0.01% -<0.1% group (n=117) , cases with Pre-MRD 0.1% -<1% group (n=87) , and cases with Pre-MRD≥1% group (n=32) . For subjects in the Pre-MRD<0.01% group, haplo-HSCT (n=40) had a lower CIR than that of MSDT [n=6, 10.0% (95% CI 0.4% -19.6% ) vs 32.3% (95% CI 0% -69.9% ) , P=0.017]. For patients in the Pre-MRD 0.01% -<0.1% group, haplo-HSCT (n=81) also had a lower 3-year CIR than that of MSDT [n=36, 20.4% (95% CI 10.4% -30.4% ) vs 47.0% (95% CI 29.2% -64.8% ) , P=0.004]. In the other three subgroups, the 3-year CIR was comparable between patients who underwent haplo-HSCT and those received MSDT. A subgroup analysis of patients with Pre-MRD<0.1% (n=163) was performed, the results showed that cases received haplo-HSCT (n=121) experienced lower 3-year CIR [16.0% (95% CI 9.4% -22.7% ) vs 40.5% (95% CI 25.2% -55.8% ) , P<0.001], better 3-year LFS [78.2% (95% CI 70.6% -85.8% ) vs 47.6% (95% CI 32.2% -63.0% ) , P<0.001] and OS [80.5% (95% CI 73.1% -87.9% ) vs 54.6% (95% CI 39.2% -70.0% ) , P<0.001] than those of MSDT (n=42) , but comparable in 3-year NRM [5.8% (95% CI 1.6% -10.0% ) vs 11.9% (95% CI 2.0% -21.8% ) , P=0.188]. Multivariate analysis showed that haplo-HSCT was associated with lower CIR (HR=0.248, 95% CI 0.131-0.472, P<0.001) , and superior LFS (HR=0.275, 95% CI 0.157-0.483, P<0.001) and OS (HR=0.286, 95% CI 0.159-0.513, P<0.001) . Conclusion: Haplo HSCT has a survival advantage over MSDT in the treatment of B-ALL patients with pre MRD<0.1% .

[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].

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/m2) 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.