Allogeneic Hematopoietic Transplant Recipients Research Articles

Features of cytomegalovirus DNAemia and virus-specific T-cell responses in allogeneic hematopoietic stem-cell transplant recipients during prophylaxis with letermovir.

There is scarce information on the natural kinetics of cytomegalovirus (CMV) DNAemia and dynamics of CMV-specific T-cell reconstitution in allogeneic hematopoietic transplant recipients (allo-HSCT) undergoing letermovir (LMV) prophylaxis. Twelve adult CMV-seropositive high-risk recipients (median age, 53 years; 9 males/3 females) undergoing LMV prophylaxis and 13 non-LMV allo-HSCT controls (median age, 58 years; 7 males/6 females) were included. CMV DNAemia in plasma was monitored by real-time polymerase chain reaction. Preemptive antiviral therapy (PET) was administered upon detection of ≥1500IU/ml. CMV-specific interferon-gamma (IFN-γ)-producing CD8+ and CD4+ T cells were enumerated by flow cytometry around days +30, +60, and +90 after allo-HSCT. Ex vivo experiments assessing of the potential effect of LMV on CMV-specific T-cell expansion in a single CMV-seropositive donor were also conducted. Five LMV patients (41.6%) developed CMV DNAemia that cleared spontaneously. Four patients (33.3%) developed CMV DNAemia after LMV cessation, of which two required PET. Nine non-LMV patients (69.2%) developed CMV DNAemia (five required PET). The percentage of LMV and non-LMV patients exhibiting detectable CMV-specific T-cell responses was comparable (7/10 vs. 10/13; p=.71). Nevertheless, median CMV-specific CD4+ and CD8+ T-cell counts were lower in LMV patients by days +60 (p=.006 and .02, respectively) and +90 (p=.08 and .02). Ex vivo, CMV-specific CD8+ T cells expanded to the same level either in the presence (19.8%) or in the absence of LMV (20.6%). In our series, episodes of CMV DNAemia in LMV patients cleared spontaneously. A diminished degree of CMV-specific T-cell reconstitution in LMV patients compared to non-LMV patients was observed.

Acute Kidney Injury in Allogeneic Hematopoietic Transplant Recipients

<h3>Background</h3> The reported incidence of acute kidney injury (AKI) after allogeneic hematopoietic cell transplantation (allo-HCT) varies from 10 to 73%. The association between GVHD, calcineurin inhibitors (CNIs) and risk for kidney injury remains controversial. We sought to describe the incidence of AKI and identify modifiable risk factors in large cohort of patients undergoing allo-HCT in our institution. <h3>Methods</h3> All consecutive patients undergoing allo-HCT from 2014 to 2017 in our institution were included. Pre-HCT variables including patient and graft characteristics, as well as post-HCT variables, including nephrotoxic medication exposure, ICU admission, and CNI levels were analyzed in association with AKI. AKI was defined using KDIGO criteria, grades 1, 2 and 3, through post-transplant day 100. Severe AKI was defined as grades 2 or 3. Differences across groups were assessed using either Wilcoxon rank-sum tests or Fisher's exact tests. AKI risk factors were estimated using cause-specific Cox proportional hazards regression. <h3>Results</h3> A total of 616 patients underwent allo-HCT during the study period. Median age was 58 (19-79) years, 59% male, 83% Caucasian. Indication for HCT was leukemia in 49%, myelodysplastic syndrome in 16%, and lymphoma in 17%. Median baseline creatinine was 0.8 (0.3-2.7) mg/dL. Median age-adjusted HCT-comorbidity index was 3 (range 0-9). Median baseline albumin was 3.5 (IQR 3.3-3.8) mg/dL and BMI 27.2 (IQR 23.8-30.8). Incidence of acute GVHD was 47%, and 60 patients had severe (grades 3-4) GVHD. Bacteremia occurred in 19% of patients. Amphotericin preceded max-grade AKI in 3.1%, cidofovir in 0.8%, and Foscarnet in 4.4% of patients. Median tacrolimus level preceding AKI was 7.88 (range 4.2-23.2) mg/dL. By day 100 post-HCT, 403 (65.4%) had any AKI, 220 (35.7%) patients had grade 1 AKI, 119 (19.3%) grade 2 AKI, and 64 (10.4%) grade 3 AKI; 19 (3.1%) required hemodialysis. Median time to AKI was 17 (IQR 8-35) days, and median time to max-grade AKI was 31 (IQR 13-53) days. Ex vivo CD34-selected HCT patients had a lower risk for AKI, hazard ratio 0.46 (0.35-0.62), p<0.001 (Table 1). <h3>Conclusion</h3> AKI in patients undergoing allo-HCT remains a major concern, affecting 65.4% of patients, with grade 2 and 3 AKI occurring in 19.3% and 10.4%, respectively. Patients receiving CNIs including tacrolimus have a significantly higher risk for AKI, whereas patients undergoing CD34-selected allo-HCT have a lower risk of AKI. The effect of AKI after HCT on long-term kidney function requires further prospective study.

T-cells immune response controls the high incidence of adenovirus infection in adult allogenic hematopoietic transplantation recipients

T-cells immune response controls the high incidence of adenovirus infection in adult allogenic hematopoietic transplantation recipients

Thioredoxin-1 confines T cell alloresponse and pathogenicity in graft-versus-host disease.

Oxidative stress is elevated in the recipients of allogeneic hematopoietic transplantation (allo-HCT) and likely contributes to the development of graft-versus-host disease (GVHD). GVHD is characterized by activation, expansion, cytokine production and migration of alloreactive donor T cells, and remains a major cause of morbidity and mortality after allo-HCT. Hence, strategies to limit oxidative stress in GVHD are highly desirable. Thioredoxin1 (Trx1) counteracts oxidative stress by scavenging reactive oxygen species (ROS) and regulating other enzymes that metabolize H2O2. The present study sought to elucidate the role of Trx1 in the pathophysiology of GVHD. Using murine and xenograft models of allogeneic bone marrow transplantation (allo-BMT) and genetic (human Trx1-transgenic, Trx1-Tg) as well as pharmacologic (human recombinant Trx1, RTrx1) strategies; we found that Trx1-Tg donor T cells or administration of the recipients with RTrx1 significantly reduced GVHD severity. Mechanistically, we observed RTrx1 reduced ROS accumulation and cytokine production of mouse and human T cells in response to alloantigen stimulation in vitro. In allo-BMT settings, we found that Trx1-Tg or RTrx1 decreased downstream signaling molecules including NFκB activation and T-bet expression, and reduced proliferation, IFN-γ production and ROS accumulation in donor T cells within GVHD target organs. More importantly, administration of RTrx1 did not impair the graft-versus-leukemia (GVL) effect. Taken together, the current work provides a strong rationale and demonstrates feasibility to target the ROS pathway, which can be readily translated into clinic.

Aspergillus vaccines: Hardly worth studying or worthy of hard study?

Vaccines rank among the greatest advances in the history of public health. Yet, despite the need, there are no licensed vaccines to protect humans against fungal diseases, including aspergillosis. In this focused review, some of the major scientific and logistical challenges to developing vaccines to protect at-risk individuals against aspergillosis are discussed. Approaches that have shown promise in animal models include vaccines that protect against multiple fungal genera and those that are specifically directed to Aspergillus Advances in proteomics and glycomics have facilitated identification of candidate antigens for use in subunit vaccines. Novel adjuvants and delivery systems are becoming available that can skew vaccine responses toward those associated with protection. Immunotherapy consisting of adoptive transfer of Aspergillus-specific T cells to allogeneic hematopoietic transplant recipients has advanced to human testing but is technically difficult and of unproven benefit. While progress has been impressive, much work still needs to be done if vaccines against aspergillosis are to become a reality.

Cystatin C level as a marker of renal function in allogeneic hematopoietic stem cell transplantation

We retrospectively reviewed the medical records of 75 allogeneic hematopoietic transplant recipients and evaluated cystatin C as a potential marker of subsequent renal dysfunction. Acute kidney injury developed in 31 of 75 patients after a median of 46 days post-transplantation (range 1-502 days), while worsening of chronic kidney disease (CKD) was observed in 21 patients during the observational period. Cystatin C level was significantly elevated after allogeneic transplantation (P < 0.001). Multivariate analysis revealed the use of calcineurin inhibitors as a major cause of cystatin C elevation (odds ratio 7.26, P = 0.04). A strong inverse correlation was also noted between cystatin C and estimated glomerular filtration rate (r = -0.682, P < 0.001). Cystatin C measurement could provide a useful clinical tool to identify hematopoietic stem cell transplantation recipients at an increased risk for CKD.

Transfusion of leukoreduced cellular blood components from cytomegalovirus-unscreened donors in allogeneic hematopoietic transplant recipients: analysis of 72 recipients

Leukoreduction of blood components has been considered a safe alternative to screening donors for CMV. The objective of this study is to analyze the effectiveness of bedside leukoreduction in preventing CMV transmission. We retrospectively studied 72 transplant recipients and donors who were CMV-seronegative pairs. All patients were transfused with CMV-unscreened cellular blood products leukoreduced at the bedside using leukoreduction filters. Quality control measures performed monthly in our leukoreduced blood components consistently demonstrated that at least 95% of the units sampled meet the leukoreduction criterion established by the American Association of Blood Banks standards. The CMV status of the recipients and donors was determined before transplantation by the latex agglutination assay. Recipients were observed for at least 100 days after transplantation. CMV cultures of urine, buffy coat, bone marrow, and bronchial washings were done weekly when indicated. CMV antigenemia testing was performed twice weekly: 11 transplant recipients seroconverted after transplantation. One patient was positive for CMV antigenemia 4 months after transplantation, but did not have CMV infection. Two of 61 patients who were not seroconverted were CMV antigenemia positive and did not have CMV infection: leukoreduction of cellular blood products is an efficient method of preventing CMV infection.