[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.

[Comparison of the characteristics of NK cells after two different methods of expansion and observation of the clinical efficacy in patients who relapsed post allogeneic hematopoietic stem cell transplantation].

Objective: To explore the differences in the biological effects of different expansion systems on natural killer (NK) cells, as well as the safety and preliminary clinical efficacy in the treatment of patients with recurrence after allogeneic hematopoietic stem cell transplantation (allo-HSCT) . Methods: Peripheral blood cells from healthy donors were stimulated with either CD3 combined with CD52 or K562 feeder cells loaded with IL-21/4-1BB to induce NK cell expansion. Changes in the NK cell phenotype, cytokine secretion, and cytotoxicity before and after expansion were detected. We also evaluated the safety and clinical efficacy of two different expansion strategies for patients received NK infusion. Results: Compared with the CD3/CD52 monoclonal antibody amplification system, the feeder cell expansion group had a higher purity of NK cells and higher expression ratios of NK cell surface activation receptors such as DNAM-1 and NKp30, while inhibitory receptor CTLA-4 expression was low and NKG2D/CD25/CD69/ Trail/PD-1/TIM-3/TIGIT had no statistically significant differences between the groups. Further functional results showed that the expression level of KI67 in NK cells after expansion in the two groups increased significantly, especially in the feeder cell expansion group. Simultaneously, the perforin and granzyme B levels of NK cells in the feeder cell expansion group were significantly higher than in the CD3/CD52 expansion group. A retrospective analysis of eight patients who received monoclonal antibody-expanded NK cell reinfusion and nine patients with trophoblast cell-expanded NK cell reinfusion was done. The disease characteristics of the two groups were comparable, NK cell reinfusion was safe, and there were no obvious adverse reactions. Clinical prognostic results showed that in the CD3/CD52 monoclonal antibody amplification group, the MRD conversion rate was 50% (2/4) , and the feeder cell expansion group was 50% (3/6) . After 5 years of follow-up from allo-HSCT, three patients in the monoclonal antibody expansion group had long-term survival without leukemia, and the remaining five patients had died; two patients died in the feeder cell expansion group, and the other six patients had long-term survival. Six cases had GVHD before NK cell reinfusion, and GVHD did not aggravate or even relieved after NK cell reinfusion. Conclusions: Preliminary results show that the biological characteristics of NK cells with diverse expansion strategies are significantly different, which may affect the clinical prognosis of patients with recurrence or persistent minimal residual disease after HSCT. The two groups of patients treated with NK cells from different expansion strategies had no obvious adverse reactions after NK cell infusion, but efficacy still needs to be further confirmed.

[Scanning electron microscopic observation of the external morphology of Dermatophagoides farinae at different developmental stages].

OBJECTIVE: To investigate the morphological characteristics of Dermatophagoides farinae at different developmental stages. METHODS: The cultured D. farinae was isolated, and the external morphological features of mites at various developmental stages were observed using scanning electron microscopy (SEM), including egg, larva, nymph and adult stages. RESULTS: The D. farinae egg appeared a long oval shape, and the larval mites had three pairs of legs. The nymph had four pairs of legs and underdeveloped genital pores containing genital setae and anal setae, and adult mites appeared long and oval in shape, with decorative patterns on epidermis, and had four pairs of legs. In male adult mites, remarkable thickening of the leg I and thicker and longer leg III than the leg IV were seen, and ventral genital regions were found between the basal segments of legs III and IV; the anus was surrounded by a circular peri-anal ring, with a pair of anal suckers and anal setae within the ring. In the female adult mites, slender legs III and IV with an equal length were seen, and a "λ-shape" genital hole was observed on the ventral surface, with a crescent-like genital plate in the anterior part, and the anus appeared a longitudinal slit. CONCLUSIONS: An SEM observation of the external morphology of D. farinae provides understandings of the morphological characteristics of D. farinae, which is of great significance for the classification and identification.

[Short-term efficacy of venetoclax combined with azacitidine in acute myeloid leukemia: a single-institution experience].

Objective: To explore the safety and short-term efficacy of venetoclax combined with azacitidine (Ven+AZA) in previously untreated patients unfit for standard chemotherapy and patients with relapsed/refractory (R/R) acute myeloid leukemia (AML) in China. Methods: A retrospective study was conducted in 60 previously untreated patients unfit for standard chemotherapy and patients with R/R AML who received Ven+ AZA (venetoclax, 100 mg D1, 200 mg D2, 400 mg D3-28; azacitidine, 75 mg/m(2) D1- 7) at the Peking University Institute of Hematology from June 1, 2019 to May 31, 2021. The incidence of adverse events, complete remission (CR) /CR with incomplete hematological recovery (CRi) rate, objective remission rate (ORR) , and minimal residual disease (MRD) status in patients with different risk stratification and gene subtypes were analyzed. Results: The median age of the patients was 54 (18-77) years, 33 (55.0%) were males, and the median follow-up time was 4.8 (1.4-26.3) months. Among the 60 patients, 24 (40.0%) were previously untreated patients unfit for standard chemotherapy, and 36 (60.0%) were R/R patients. The median mumber cycles of Ven+AZA in the two groups were both 1 (1-5) . According to the prognostic risk stratification of the National Comprehensive Cancer Network, it was divided into 8 cases of favorable-risk, 2 cases of intermediate risk, and 14 cases of poor-risk. In previously untreated patients unfit for standard chemotherapy, after the first cycle of Ven+AZA, 17/24 (70.8%) cases achieved CR/CRi, 3/24 (12.5%) achieved partial remission (PR) , and the ORR was 83.3%. Among them, nine patients received a second cycle chemotherapy and two received a third cycle. Among CR/CRi patients, 8/17 (47.1%) achieved MRD negativity after two cycles of therapy. In the R/R group, after the first cycle of Ven+AZA, 21/36 (58.3%) cases achieved CR/CRi (7/21 achieved MRD negativity) , 3 achieved PR, and the ORR was 66.7%. Among R/R patients, 12 were treated for more than two cycles. There were no new CR/CRi patients after the second treatment cycle, and 14 cases (66.7%) achieved MRD negativity. According to the time from CR to hematological recurrence, the R/R group was divided into 12 cases in the favorable-risk group (CR to hematological recurrence ≥18 months) and 24 in the poor-risk group (CR to hematological recurrence<18 months, no remission after one cycle of therapy, and no remission after two or more cycles of therapy) . Eleven of 24 (45.8%) cases achieved CR/CRi after one cycle of Ven+AZA in the poor-risk R/R group, and 10 of 12 (83.3%) achieved CR/CRi in the favorable-risk R/R group, which was significantly superior to the poor-risk group (P=0.031) . After one cycle of treatment, 13 patients with IDH1/2 mutations and 4 that were TP53-positive all achieved CR/CRi. The CR/CRi rate of 18 patients with NPM1 mutations was 77.8%. Five patients with RUNX1-RUNX1T1 combined with KIT D816 mutation (two initial diagnoses and three recurrences) had no remission. Ven+ AZA was tolerable for AML patients. Conclusion: Ven+AZA has acceptable safety in previously untreated patients unfit for standard chemotherapy, patients with R/R AML can achieve a high response rate, and some patients can achieve MRD negativity. It is also effective in NPM1-, IDH1/IDH2-, and TP53-positive patients. The long-term efficacy remains to be observed.

[Safety of rabbit anti-human thymocyte immunoglobulin in second allogeneic hematopoietic stem cell transplantation for patients with hematological diseases].

Objective: To look into the security of a second allogeneic hematopoietic stem cell transplantation (allo-HSCT) using rabbit anti-human thymocyte immunoglobulin (rATG) . Methods: Twenty-seven patients who used rATG in the first and second allo-HSCT at the Institute of Hematology, Peking University were enrolled in the study. Experienced toxicities associated with the conditioning protocol within 10 days (-5 d to +3 d) following the beginning of the rATG application, including fever, diarrhea, arrhythmia, reduced blood pressure, liver damage, seizures, and other problems. Results: The overall incidence of conditioning regimen early adverse reactions during the first transplantation and the second allo-HSCT conditioning regimen was 96.3% and 77.8% (P=0.043) . Fever rates were 81.5% and 63.0% (P=0.129) , diarrhea rates were 59.3% and 25.9% (P=0.013) , liver damage rates were 22.2% and 25.9% (P=0.75) , and the rates of other events (cardiac arrhythmia, low blood pressure, and epilepsy) were 3.7% and 18.5% (P=0.083) . Adverse reactions that occurred during both the first and second course of rATG applications have been improved with symptomatic treatment, and no treatment interruptions occurred. Conclusion: Reusing rATG in a second transplant was risk-free and did not result in higher early toxicities.

[Outcomes of alternative donor allogeneic hematopoietic stem cell transplantation for Fanconi anemia: a five cases report].

Five patients with Fanconi anemia who received hematopoietic cell transplantation were retrospectively analyzed. The conditioning regimens included fludarabine, cyclophosphamide and anti-thymocyte globulin. Two patients received both bone marrow and peripheral blood stem cells as the source of stem cell grafts from haploidentical matched related donors, while the others received peripheral blood stem cells from unrelated donors. All patients tolerated well and reached hematopoietic reconstitution. One patient died of intracranial infection. During follow-up, 4 patients survived independent of transfusion with full donor chimerism.

Unmanipulated haploidentical transplantation conditioning with busulfan, cyclophosphamide and anti-thymoglobulin for adult severe aplastic anaemia.

We conducted a retrospective analysis to evaluate outcomes of haploidentical transplantation in adult severe aplastic anaemia (SAA) patients. Fifty-one adults received haploidentical transplantation between May 2011 and December 2016. Patients were administered busulfan (Bu), cyclophosphamide (Cy) and anti-thymoglobulin (ATG) as conditioning regimens, followed by bone marrow and peripheral blood transplantation. The patients' median age was 25 years. Forty-nine patients survived for more than 28 days and all achieved donor myeloid engraftment. The median time for myeloid engraftment and platelet recovery was 13 days (range, 10-21) and 17.5 (range, 7-101) days. The cumulative incidence (CI) of grade II-IV and III-IV acute GvHD) was 20.00±0.33% and 6.00±0.12%, respectively. The incidence of chronic GvHD was 14.00±0.36% and 25.90±0.71%, and that of moderate-severe chronic GvHD was 2.51±0.06% and 6.92±0.25% at 1 and 3 years, respectively. The 3-year estimated overall survival and failure-free survival were both 83.5±5.4% with a median follow-up of 21.1 months. Multivariate analysis showed hematopoietic cell transplantation-specific comorbidity index (HCT-CI) score of ⩾3 was significantly associated with worse outcome. Haploidentical transplantation conditioning including Bu/Cy/ATG was a safe and effective strategy for adult SAA patients, and HCT-CI might be an outcome predictor in these patients.

[Clinical value of PCR for viral detection of bronchoalveolar lavage fluid in the diagnosis and treatment of pneumonia after allogeneic hematopoietic stem cell transplantation].

Objective: To analyze the clinical value of real-time PCR for virus detection in the diagnosis and treatment of patients after allo-HSCT who had no infection evidence of pneumonia using routine pathogen detection panel. Methods: The clinical data of 71 episodes with acute lung injury from May 2015 to March 2017 after allo-HSCT in hematology department of Peking University People's Hospital (PKUPH) were retrospectively analyzed. PCR for virus detection and other routine pathogen detection tests were performed on bronchoalveolar lavage fluid (BALF) samples. Results: Among 71 episodes with acute lung injury, a total of 15 patients were diagnosed as lower respiratory tract disease merely associated with virus (detection rate of 21.13%) , 19 episodes were absent of lower respiratory tract infection. The median time from allo-HSCT to the occurrence of lung injury were 176 (49-1 376) d and 196 (57-457) d respectively (z=-0.191, P=0.864) . There were no statistical differences for baseline characteristics and clinical features between two groups. The 100-day attributable mortalities were 13.3% (2/15) and 26.3% (5/19) (χ(2)=0.864, P=0.426) . Patients with low-dose steroids treatment had favorable outcome than those with high-dose steroids treatment (the dose of methylprednisolone ≥250 mg/d as standard) [4.2% (1/24) vs 60.0% (6/10) ]. In patients with detectable virus in BALF, 2 patients died with early high-dose steroids treatment, while 11 patients survived with no steroids treatment or late application. Conclusions: Virus infection should be considered in post-HSCT pneumonia patient with negative result using routine pathogen detection panel. Expanding virus detection panel by PCR in BALF could increase diagnostic precision and might be instructive to treatment.

[Analysis of risk factors related to the prognosis in patients with late-onset severe pneumonia after allogeneic hematopoietic stem cell transplantation].

Objective: To investigate the prognostic factors of late-onset severe pneumonia (LOSP) in patients who underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT). Methods: From January 2009 to December 2015, 68 patients with LOSP after allo-HSCT at Peking University Institute of Hematology were enrolled. In this retrospective study, univariate and multivariate analysis were used to evaluate the prognostic factors for LOSP after allo-HSCT. Results: The median time from allo-HSCT to the development of LOSP was 213 (90-2 330) days. The overall survival rate was 42.6% (29/68). The median survival time from LOSP to death was 21 days. Early mortality was defined as death within 21 days after LOSP, as late death more than or equal to 21 days. The median oxygenation index was 199.15 (92.21-290.48) mmHg. LOSPs in thirty-two patients (36.8%) were caused by virus, bacteria, fungi or mixed pathogens. The median C-reactive protein (CRP) was 75.65 (0.94-451.00) mg/L. The median procalcitonin (PCT) was 0.66 (0.00-249.00) µg/L. The higher PCT value indicated an early higher mortality rate by the ROC curve (PCT: cut-off ≥0.94 µg/L). Furthermore, multivariate analysis suggested that PCT more than or equal to 0.94 µg/L was a risk factor for early death of LOSP (OR=5.77, 95%CI 1.66-20.11, P=0.006). LOSP occurred later or equal to 213 days after allo-HSCT was also a risk factor of early death in LOSP (OR=4.74, 95%CI 1.33-16.89, P=0.017). No previous history of chronic graft versus host disease (GVHD) (OR=4.50, 95%CI 1.58-12.83, P=0.005) and LOSP later or equal to 213 days (OR=4.40, 95%CI 1.61-11.99, P=0.004) were the risk factors of late death in LOSP. Conclusions: PCT more than or equal to 0.94 µg/L and LOSP later or equal to 213 days are the risk factors of early death in LOSP. No previous chronic GVHD and LOSP later or equal to 213 days are the risk factors of late death in LOSP.

[Surgical treatment of severe, refractory hemorrhagic cystitis following allogeneic hematopoietic stem cell transplantation: a report of 17 patients].

Objective: To investigate the clinical effect and safety of surgical treatment for severe, refractory hemorrhagic cystitis (HC) after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Methods: Patients with severe HC, who were admitted to Peking University Institute of Hematology from January 2010 to December 2015, were enrolled in this study.All patients were refractory to medical managements and received bladder surgery including mucous electrocoagulation and/or selective transcatheter arterial embolization. Results: A total of 17 patients with severe HC (grade Ⅲ, n=5; grade Ⅳ, n=12) received surgical treatment, including 11 embolization and 18 mucous electrocoagulation.The median time from allo-HSCT to surgery was 107 d (46-179 d) and 75 d after HC.Eight patients only received embolization.Four patients only received mucous electrocoagulation.Five patients were given combined embolization and electrocoagulation.HC was cured in 11 patients, improved in 1 patient, which corresponded to a response rate of 70.6% and complete remission rate of 64.7%.Five patients didn't respond to these methods.In patients with response, macroscopic hematuria disappeared 3 to 10 days after treatments whereas microscopic hematuria vanished after 25 to 32 days.Both procedures were well tolerated and no severe adverse effects were observed. Conclusion: Surgery of bladder mucous electrocoagulation and/or selective arterial embolization are safe and effective for severe HC.

Influence of two different doses of antithymocyte globulin in patients with standard-risk disease following haploidentical transplantation: a randomized trial.

To evaluate the effect of the different doses of antithymocyte globulin (ATG) on the incidence of acute GVHD among patients receiving hematopoietic SCT without ex vivo T-cell-depletion from haploidentical donors, 224 patients with standard-risk hematological malignancy were randomized in this study. One hundred and twelve patients received 6 mg/kg ATG, whereas the remaining patients received 10 mg/kg ATG. This study was registered at http://www.chictr.org as No. ChiCTR-TRC-11001761. The incidence of grade III-IV acute GVHD was higher in the ATG-6 group (16.1%, 95% confidence interval (CI), 9.1-23.1%) than in the ATG-10 group (4.5%, CI, 0.7-8.3%, P=0.005, 95% CI for the difference, -19.4% to -3.8%). EBV reactivation occurred more frequently in the ATG-10 group (25.3%, 17.1-33.5%) than in the ATG-6 group (9.6% (4.0-15.2%), P=0.001). The 1-year disease-free survival rates were 84.3% (77.3-91.3%) and 86.0% (79.2-92.8%) for the ATG-6 group and ATG-10 groups, respectively (P=0.88). In conclusion, although 6 mg/kg ATG applied in haploidentical transplantation decreased the risk of EBV reactivation compared with 10 mg/kg ATG, this treatment exposes patients to a higher risk for severe acute GVHD.