[Causes and characteristics of pre-engraftment mortality after allogeneic hematopoietic stem cell transplantation].

Objective: To analyze the causes and demographic characteristics of pre-engraftment mortality in patients who underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT) and investigate the risk factors and measures for preventing pre-engraftment mortality. Methods: A retrospective case analysis, involving a total of 7 427 patients who underwent allo-HSCT at Peking University People's Hospital between January 2016 and July 2023, was conducted. Results: Among the 7 427 patients who underwent allo-HSCT, 56 cases (0.75% ) experienced pre-engraftment mortality. The median time to death for these 56 patients was +7 (-3 to +38) days after stem cell infusion. The median times to death for patients with acute leukemia (AL), severe aplastic anemia (SAA), and myelodysplastic syndrome (MDS) were +11 (-1 to +38), +3 (-1 to +34), and +16 (-1 to +38) days, respectively (P=0.013). The main causes of pre-engraftment mortality were infection (39.3% ), cardiac toxicity (28.6% ), and intracranial hemorrhage (26.8% ). Infection was the most common cause of pre-engraftment mortality in patients with AL and MDS (55.0% and 60.0% ), whereas cardiac toxicity was predominantly observed in patients with SAA (71.4% ), with no cases in patients with AL and only one case in patients with MDS. Among patients who died from intracranial hemorrhage, 53.3% had severe infections. The median times to death for infection, cardiac toxicity, and intracranial hemorrhage was +11 (-1 to +38), +2.5 (-1 to +17), and +8 (-3 to +37) days, respectively (P<0.001) . Conclusions: Infection is the primary cause of pre-engraftment mortality in allo-HSCT, and severe cardiac toxicity leading to pre-engraftment mortality should be closely monitored in patients with SAA.

[Clinical characteristics of human parvovirus B19 infection after allogeneic stem cell transplantation].

Human parvovirus B19 (HPVB19) belongs to Parvoviridae, a genus of erythrovirus, and has been associated with various human diseases, and HPVB19 infection is one of the most important causes of refractory anemia after allogeneic hematopoietic stem cell transplantation (allo-HSCT). This study retrospectively analyzed 24 patients with HSCT combined with HPVB19 infection to collate and summarize the clinical presentation, treatment, and regression of patients with combined HPVB19 infection after allo-HSCT and provide experience in the management of HPVB19 infection after allo-HSCT. The median age of the patients with HPVB19 infection was 25 years, and the median time of infection occurrence was +107 days after transplantation, and 22 (91.7% ) had anemia with a median hemoglobin (HGB) level of 77.5 (46-149) g/L, and 13 (54.2% ) had new-onset anemia or persistent decline in HGB. The median length of hospital stay was 19 days. Among patients with new-onset anemia or persistent decline in HGB, the mean increase in HGB after treatment with intravenous immunoglobulin and/or antiviral therapy was 15.69 g/L, and treatment was effective in 10 (76.92% ) patients. HPVB19 infection should be alerted to the development of refractory anemia after HSCT; despite the lack of specific treatment, the overall prognosis of HPVB19-infected patients is good.

[The 507th case: hemolytic anemia, parvovirus B19, and multiple organ dysfunction].

A 19-year-old male patient with high-risk acute B-cell lymphoblastic leukemia received haploidentical stem cell transplantation. He developed anemia repeatedly and parvovirus B19 nucleic acid was positive in blood plasma. The patient was diagnosed with cold agglutinin syndrome and multiple organ dysfunction including respiratory failure and hepatitis. In the conflict between viral infection and the treatment of cold agglutinin syndrome, we provided supportive treatment, complement inhibitors to control hemolysis, and antiviral therapy. After timely glucocorticoid and immunosuppressant therapy, the patient had achieved a good response.

[Prevalence of Echinococcus infections in small rodents in Yushu City, Qinghai Province in 2023].

OBJECTIVE: To investigate the prevalence of Echinococcus infections in small rodents around human residential areas in Yushu City, Qinghai Province in 2023, so as to provide insights into precision echinococcosis control. METHODS: One or two quadrats, each measuring 50 m × 50 m, were randomly assigned in Shanglaxiu Township and Longbao Township, Yushu City, Qinghai Province on June 2023, respectively, and 300 plate-type mouse traps, each measuring 12.0 cm × 6.5 cm, were assigned in each quadrat. Small rodents were captured during the period between 10 : 00 and 18 : 00 each day for 4 days. Then, all captured small rodents were identified and dissected, and liver specimens with suspected Echinococcus infections were subjected to pathological examinations. The Echinococcus cytochrome c oxidase 1 (cox1) gene was amplified using PCR assay, and the sequence of the amplified product was aligned to that was recorded in the GenBank to characterize the parasite species. In addition, a phylogenetic tree of Echinococcus was generated based on the cox1 gene sequence using the neighbor-joining method. RESULTS: A total of 236 small rodents were captured in Shanglaxiu and Longbao townships, Yushu City, including 65 Qinghai voles and 51 plateau pikas in Shanglaxiu Township, and 62 Qinghai voles and 58 plateau pikas in Longbao Township, and there was no significant difference in the constituent ratio of small rodents between the two townships (χ2 = 0.294, P > 0.05). Seven plateau pikas and 12 Qinghai voles were suspected to be infected with Echinococcus by dissection, and pathological examinations showed unclear structure of hepatic lobules and disordered hepatocyte arrangement in livers of small rodents suspected of Echinococcus infections. PCR assay identified E. shiquicus DNA in 7 Qinghai voles, which were all captured from Shanglaxiu Township. Phylogenetic analysis showed that the cox1 gene sequence of Echinococcus in small rodents was highly homologous to the E. shiquicus cox1 gene sequence reported previously. CONCLUSIONS: Plateau pika and Qinghai vole were predominant small rodents around human residential areas in Yushu City, Qinghai Province in 2023, and E. shiquicus infection was detected in Qinghai voles.

[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.

[Dynamic observation on capillarization of liver sinusoidal endothelial cells induced by Echinococcus multilocularis infection].

OBJECTIVE: To investigate the capillarization of liver sinusoidal endothelial cells (LSECs) and its association with hepatic fibrosis during the development of alveolar echinococcosis, so as to provide the basis for unraveling the mechanisms underlying the role of LSEC in the development and prognosis of hepatic injuries and hepatic fibrosis caused by alveolar echinococcosis. METHODS: Forty C57BL/6 mice at ages of 6 to 8 weeks were randomly divided into a control group and 1-, 2- and 4-week infection groups, of 10 mice in each group. Each mouse in the infection groups was intraperitoneally injected with 2 000 Echinococcus multilocularis protoscoleces, while each mouse in the control group was given an equal volume of phosphate-buffered saline using the same method. All mice were sacrificed 1, 2 and 4 weeks post-infection and mouse livers were collected. The pathological changes of livers were observed using hematoxylin-eosin (HE) staining, and hepatic fibrosis was evaluated through semi-quantitative analysis of Masson's trichrome staining-positive areas. The activation of hepatic stellate cells (HSCs) and extracellular matrix (ECM) deposition were examined using immunohistochemical staining of α-smooth muscle actin (α-SMA) and collagen type I alpha 1 (COL1A1), and the fenestrations on the surface of LSECs were observed using scanning electron microscopy. Primary LSECs were isolated from mouse livers, and the mRNA expression of LSEC marker genes Stabilin-1, Stabilin-2, Ehd3, CD209b, GATA4 and Maf was quantified using real-time fluorescence quantitative PCR (qPCR) assay. RESULTS: Destruction of local liver lobular structure was observed in mice 2 weeks post-infection with E. multilocularis protoscoleces, and hydatid cysts, which were surrounded by granulomatous tissues, were found in mouse livers 4 weeks post-infection. Semi-quantitative analysis of Masson's trichrome staining showed a significant difference in the proportion of collagen fiber contents in mouse livers among the four groups (F = 26.060, P < 0.001), and a higher proportion of collagen fiber contents was detected in mouse livers in the 4-week infection group [(11.29 ± 2.58)%] than in the control group (P < 0.001). Immunohistochemical staining revealed activation of a few HSCs and ECM deposition in mouse livers 1 and 2 weeks post-infection, and abundant brown-yellow stained α-SMA and COL1A1 were deposited in the lesion areas in mouse livers 4 weeks post-infection, which spread to surrounding tissues. Semi-quantitative analysis revealed significant differences in α-SMA (F = 7.667, P < 0.05) and COL1A1 expression (F = 6.530, P < 0.05) in mouse levers among the four groups, with higher α-SMA [(7.13 ± 3.68)%] and COL1A1 expression [(13.18 ± 7.20)%] quantified in mouse livers in the 4-week infection group than in the control group (both P values < 0.05). Scanning electron microscopy revealed significant differences in the fenestration frequency (F = 37.730, P < 0.001) and porosity (F = 16.010, P < 0.001) on the surface of mouse LSECs among the four groups, and reduced fenestration frequency and porosity were observed in the 1-[(1.22 ± 0.48)/µm2 and [(3.05 ± 0.91)%] and 2-week infection groups [(3.47 ± 0.10)/µm2 and (7.57 ± 0.23)%] groups than in the control group (all P values < 0.001). There was a significant difference in the average fenestration diameter on the surface of mouse LSECs among the four groups (F = 15.330, P < 0.001), and larger average fenestration diameters were measured in the 1-[(180.80 ± 16.42) nm] and 2-week infection groups [(161.70 ± 3.85) nm] than in the control group (both P values < 0.05). In addition, there were significant differences among the four groups in terms of Stabilin-1 (F = 153.100, P < 0.001), Stabilin-2 (F = 57.010, P < 0.001), Ehd3 (F = 31.700, P < 0.001), CD209b (F = 177.400, P < 0.001), GATA4 (F = 17.740, P < 0.001), and Maf mRNA expression (F = 72.710, P < 0.001), and reduced mRNA expression of Stabilin-1, Stabilin-2, Ehd3, CD209b, GATA4 and Maf genes was quantified in three infection groups than in the control group (all P values < 0.001). CONCLUSIONS: E. multilocularis infections may induce capillarization of LSECs in mice, and result in a reduction in the expression of functional and phenotypic marker genes of LSECs, and capillarization of LSECs occurs earlier than activation of HSC and development of hepatic fibrosis.

[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 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.

[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.