The Role of Pre-existing Anti-HLA Antibodies in Severe Aplastic Anemia Patients Undergoing Allogenic Hematopoietic Stem Cell Transplantation.

The objective is to underscore the significance of pre-existing anti-HLA Abs in the context of allogeneic hematopoietic stem cell transplantation (allo-HSCT) for SAA. A retrospective analysis was conducted using data from 244 SAA patients who underwent allo-HSCT between January 2016 and October 2022. The patient cohort was divided into 2 groups based on the presence of pre-existing anti-HLA Abs. Out of 244 SAA patients, 82 were tested positive for anti-HLA Abs. Seventeen patients were tested with DSA in haplo-HSCT. We found that the presence of pre-existing anti-HLA Abs did not influence neutrophil engraftment (P = .600); however, it resulted in delayed platelet recovery (P = .006). Comparatively, patients with anti-HLA Abs demonstrated lower overall survival (OS) compared to their counter parts without anti-HLA Abs (P = .001), with a correspondingly elevated transplant-related mortality (TRM) in the former group (P = .002). Multivariate analysis established pre-existing anti-HLA Abs as an independent risk factor for impaired platelet recovery (HR 1.67, 95% CI 1.16 to 2.44, P = .006) and OS (HR 2.19, 95% CI 1.03 to 4.67, P = .043). However, there were no differences between DSA and non-DSA patients after desensitization in haplo-HSCT. In summary, the presence of pre-existing anti-HLA Abs in SAA patients undergoing allo-HSCT appears to detrimentally affect platelet recovery and overall prognosis.

The impact of pre-transplant anti-HLA antibodies in transplants from HLA-identical sibling donors: A multicenter study.

Few studies have performed comparative analysis of the outcome of hematopoietic stem cell transplantation from HLA-identical sibling donors (ISD-HSCT) in patients with or without anti-HLA Abs. In this study we retrospectively collected data from a multicenter study to analyze the distribution and impact of the pre-existing anti-HLA Abs in ISD-HSCT. Among 402 recipients, 111 were positive for anti-HLA Abs. Gender, time from diagnosis to transplantation and distribution of primary disease might be risk factors for the occurrence of anti-HLA Abs. We found that patients with anti-HLA Abs had delayed neutrophil engraftment and were more vulnerable to experience Cytomegalovirus (CMV) reactivation. The presence of anti-HLA Abs was proved to be an independent risk factor for neutrophil engraftment (HR 1.42 95% CI 1.13-1.80, p = 0.003) and CMV reactivation (HR 2.03 95% CI 1.19-3.46, p = 0.009). We found that anti-HLA Abs have a negative impact on the prognosis in the early period after transplantation from sibling donors and anti-HLA Abs was also an independent risk factor for the overall survival (OS) at 180 days (HR 2.32, 95% CI 1.03-5.27, p = 0.042) among female recipients. In conclusion, anti-HLA Abs have a negative impact on the prognosis early after ISD-HSCT.

Risk Factors for Carbapenem-Resistant Enterobacteriaceae Colonization and the Effect on Clinical Outcomes and Prognosis in Allogeneic Hematopoietic Stem Cell Transplanted Patients.

Purpose: The current study assesses which are the main risk factors, clinical outcome and prognosis following the colonization of CRE in patients that underwent allo-HSCT. Patients and Methods: A total of 343 patients subjected to allo-HSCT in the period comprised between June 2021 and June 2022 were enrolled in this retrospective study. The CRE colonization was diagnosed by clinical history and routine microbial culture of perirectal swab. In this regard, a clinical prediction model was designed based on independent risk factors underlying the pre-transplantation CRE colonization using a backward stepwise logistic regression, followed by the evaluation of its discrimination and calibration efficacies, along with clinical usefulness. Furthermore, univariate and multivariate Cox regression analyses were then conducted to assess the risk factors for post-transplantation clinical outcomes. Results: Out of 343 patients enrolled in this study, 135 (39.3%) reported CRE colonization. The independent risk factor variables for CRE colonization were incorporated into the nomogram to build a prediction model, which showed an area under the curve of 0.767 (95% CI: 0.716-0.818), and well-fitted calibration curves (χ2 = 1.737, P = 0.9788). The patients with CRE colonization reported a significantly lower platelet engraftment rate with a higher risk of post-transplantation BSI when compared with the non-CRE colonization group (P = 0.02 and P < 0.001; respectively). The non-relapse mortality (NRM) value was higher in the CRE patients (P < 0.05), consistently with a survival probability that was thus significantly lower for the same timeframe (P < 0.05). Conclusion: A reliable clinical prediction model for pre-transplantation CRE colonization was developed that demonstrated that the CRE colonization negatively affects platelet engraftment and survival outcomes following allo-HSCT.

The impact of Rituximab administered before transplantation in patients undergoing allogeneic hematopoietic stem cell transplantation: A real-world study.

Rituximab is used to eliminate B cells as a chimeric monoclonal antibody directed against CD20, a B-cell antigen expressed on B cells. To explore the impact of rituximab administered before transplantation, we implemented a retrospective, monocentric study and utilized real-world data collected at our center between January 2018 and December 2020, and then followed until December 2021. Based on whether a dose of 375mg/m2 rituximab was used at least once within two weeks before transplantation, patients undergoing allo-HSCT were classified into two groups: rituximab (N=176) and non-rituximab (N=344) group. Amongst all the patients, the application of rituximab decreased EBV reactivation (P<0.01) and rituximab was an independent factor in the prevention of EBV reactivation by both univariate and multivariate analyses (HR 0.56, 95%CI 0.33-0.97, P=0.04). In AML patients, there were significant differences in the cumulative incidence of aGVHD between the two groups (P=0.04). Our data showed that rituximab was association with a decreased incidence of aGVHD in AML patients according to both univariate and multivariate analyses. There was no difference between the two groups in other sets of populations. Thus, our study indicated that rituximab administered before transplantation may help prevent EBV reactivation in all allo-HSCT patients, as well as prevent aGVHD in AML patients after allo-HSCT.

Fucosylation Promotes Cytolytic Function and Accumulation of NK Cells in B Cell Lymphoma.

Natural killer (NK) cells have been demonstrated as a promising cellular therapy as they exert potent anti-tumor immune responses. However, applications of NK cells to tumor immunotherapy, especially in the treatment of advanced hematopoietic and solid malignancies, are still limited due to the compromised survival and short persistence of the transferred NK cells in vivo. Here, we observed that fucosyltransferase (FUT) 7 and 8 were highly expressed on NK cells, and the expression of CLA was positively correlated with the accumulation of NK cells in clinical B cell lymphoma development. Via enzyme-mediated ex vivo cell-surface fucosylation, the cytolytic effect of NK cells against B cell lymphoma was significantly augmented. Fucosylation also promoted NK cell accumulation in B cell lymphoma-targeted tissues by enhancing their binding to E-selectin. Moreover, fucosylation of NK cells also facilitated stronger T cell anti-tumor immune responses. These findings suggest that ex vivo fucosylation contributes to enhancing the effector functions of NK cells and may serve as a novel strategy for tumor immunotherapy.

Relationship of Oropharyngeal Colonization Microorganisms to Clinical Outcomes within 100 Days after Allogeneic Hematopoietic Stem Cell Transplantation.

Little is known about oropharyngeal colonization microorganisms in patients during allogeneic hematopoietic stem cell transplantation (allo-HSCT), and updated epidemiologic investigations are advisable. This study aimed to characterize oropharyngeal colonization microorganisms in patients during allo-HSCT and confirm whether they were related to clinical outcomes. This retrospective, matched case-control study included 1267 consecutive patients undergoing allo-HSCT between January 2018 and December 2020 at our institution. Patients with oropharyngeal colonization microorganisms were those with a positive throat swab before or on the day of transplantation without the occurrence of any symptoms of infection. Propensity score matching was used. Characteristics of oropharyngeal colonization microorganisms were evaluated among patients in the transplant medicine wards and compared with clinical outcomes within 100 days in positive and negative colonization groups. A total of 127 patients had oropharyngeal colonization microorganisms before or on the day of transplantation. Using propensity score matching, we matched the 127 patients in the positive colonization group with 508 patients in the negative colonization group at a 1:4 ratio (total of 635 cases). None of the differences in clinical traits between the 2 groups remained significant. Among the 127 patients with oropharyngeal colonization microorganisms, 90 patients suffered from the documented infection subsequently, and the others were asymptomatic. A total of 82 single gram-negative bacteria were identified in 127 isolates. There were no differences between the positive and negative colonization groups in the occurrence of oral mucositis, Epstein-Barr virus, or acute graft-versus-host disease and relapse within 100 days. However, the rate of neutrophil or platelet recovery was significantly lower in the positive colonization group compared with the negative colonization group (hazard ratio [HR], .71; 95% confidence interval [CI], .59 to .84; P < .001; HR .69; 95% CI, .58 to .83; P = .003; separately). The risk of bloodstream infection was higher in the positive colonization group compared with the negative colonization group (HR, 6.09; 95% CI, 3.16 to 11.75; P < .001). The continency rate between the bacteria isolated from the blood samples and oropharyngeal colonization microorganisms among the patients with positive results was 73.3%. Patients in the positive colonization group were more vulnerable to cytomegalovirus infection compared with the negative colonization group (HR, 1.41; 95% CI, 1.00 to 1.99; P = .049). The nonrelapse mortality at day +100 was higher in the positive colonization group (HR, 3.46; 95% CI, 1.69 to 7.08; P < .001). The survival probability within 100 days was significantly lower in the positive colonization group (HR, 3.38; 95% CI, 1.78 to 6.41; P < .001). Our data show that the presence of oropharyngeal colonization microorganisms is related to clinical outcomes, and that oropharyngeal microorganism monitoring may be useful during allo-HSCT.