Hematopoietic cell transplant outcomes after myeloablative conditioning with fludarabine,busulfan, low-dose total body irradiation,and rabbit antithymocyte globulin

Optimal conditioning and graft-vs-host disease (GVHD) prophylaxis for hematopoietic cell transplantation (HCT) are unknown. Here, we report on outcomes after low toxicity, myeloablative conditioning consisting of fludarabine, busulfan, and 4 Gy total body irradiation, in combination with thymoglobulin and post-transplant methotrexate and cyclosporine. We retrospectively studied 700 patients with hematologic malignancies who received blood stem cells from 7 to 8/8 HLA-matched unrelated or related donors. Median follow-up of surviving patients was 5 years. At 5 years, overall survival (OS), relapse-free survival (RFS), and chronic GVHD/relapse-free survival (cGRFS) were 58%, 55%, and 40%. Risk factors for poor OS, RFS, and cGRFS were (1). high to very high disease risk index (DRI), (2). high recipient age, and (3). cytomegalovirus (CMV)-seropositive recipient with seronegative donor (D−R+). The latter risk factor applied particularly to patients with lymphoid malignancies. Neither donor other than HLA-matched sibling (7-8/8 unrelated) nor one HLA allele mismatch was risk factors for poor OS, RFS, or cGRFS. In conclusion, the above regimen results in excellent long-term outcomes. The outcomes are negatively impacted by older age, high or very high DRI, and CMV D−R+ serostatus, but not by donor unrelatedness or one HLA allele mismatch.     

Post-transplant cyclophosphamide and early mixed donor Chimerism in myeloid malignancies; a single-center experience

BackgroundAllogeneic hematopoietic stem cell transplantation (allo-HSCT) remains the only curative option for high-risk myeloid malignancies. Post-transplant cyclophosphamide (PT-Cy) has proven to be effective for graft versus host disease (GVHD) prophylaxis. Given that graft-versus-tumor (GVT) effect plays a major role in reducing the risk of disease relapse, the application of PT-Cy must balance the risk of relapse. Mixed chimerism (MC) refers to a state of concurrent presence of recipient and donor cells post allo-HSCT which may precede relapse disease.ObjectiveWe investigated the impact of PT-Cy on early MC (EMC) and disease relapse in patients with a myeloid malignancy post allo-HSCT.Study designThis retrospective single-center study included patients that underwent allo-HSCT between 2015 and 2021. Patient and disease characteristics were collected from the electronic health records. EMC was defined as <95% donor cells at day 90–120 post allo-HSCT.ResultsA total of 144 patient that received an allo-HSCT were included in the study. One hundred and eight (75%) patients received PT-Cy as part of the GVHD prophylaxis regimen. The majority underwent allo-HSCT for acute myeloid leukemia (62%) or myelodysplastic syndrome (31%). Sixty-five percent received allo-HSCT from a matched unrelated donor transplant and 65% received a myeloablative conditioning regimen. A lower rate of chronic GVHD (p = 0.03) and a higher rate of EMC (p = 0.04) were observed in patients that received PT-Cy. PT-Cy was not associated with overall survival (OS) and relapse-free survival (RFS). Multivariable analysis identified measurable residual disease status (p = 0.003), hematopoietic cell transplantation-specific comorbidity index (p = 0.012) and chronic GVHD (p = 0.006) as independent prognostic variables for OS. AML-adverse risk (p = 0.004) and EMC (p = 0.018) were independently prognostic for RFS. While EMC overall was not significantly associated with higher risk of relapse, EMC was associated with shorter RFS within adverse-risk AML patients.ConclusionOur study shows that PT-Cy was associated with an increased risk of EMC. The predictive value of EMC for relapse remains unclear and may depend on the underlying disease, which should be validated in a larger cohort.     

Ruxolitinib on acute graft-versus-host disease prophylaxis after modified donor lymphocyte infusion

ObjectiveTo evaluate the effectiveness of ruxolitinib on acute graft-versus-host disease (aGVHD) prophylaxis and its impact on graft-versus-leukemia (GVL) effect in patients after modified donor lymphocyte infusion (mDLI).MethodsWe retrospectively included patients with relapsed leukemia after allogeneic hematopoietic stem cell transplantation (allo-HSCT) who received ruxolitinib prophylaxis between October 2018 and April 2020. The incidence of aGVHD, disease-free survival (DFS), overall survival (OS), and treatment safety were evaluated.ResultsSeventeen patients were followed up for a median time of 8 months (range: 1–26 months). The incidence of aGVHD on Day 30 after mDLI was 41.2% and ranged from Grade 1 to 4; ten of 17 patients (58.8%) achieved a complete response (CR), and two (11.8%) had a partial response (PR). Cytomegalovirus (CMV) reactivation rate was 23.5%, and the median time from mDLI to CMV reactivation was 48.5 days. The mean DFS and OS after mDLI were 1.0 (95% CI 0.0–3.5) and 9.0 (95% CI 1.2–16.8) months, respectively. The causes of death for 10 patients were leukemia relapse (n = 5), aGVHD and septic shock (n = 3), intracranial lesion (n = 1), and COVID-19 (n = 1).ConclusionsWe reported encouraging results of ruxolitinib monotherapy in the prevention of aGVHD and maintenance of GVL for post-transplantation relapsed patients, even though being at high risk with poor initial prognosis.     

Outcomes of patients with detectable CMV DNA at randomization in the phase III trial of letermovir for the prevention of CMV infection in allogeneic hematopoietic cell transplantation

Letermovir, a cytomegalovirus (CMV) terminase‐complex inhibitor, is indicated for prophylaxis of CMV infection and disease in adult CMV‐seropositive recipients of allogeneic hematopoietic cell transplantation (HCT). In a phase III, double‐blind, randomized trial, letermovir significantly reduced the risk of clinically significant CMV infection (CS‐CMVi) vs placebo through Week 24 post‐HCT. This analysis investigated outcomes in participants with detectable CMV DNA at randomization, who were excluded from the primary efficacy analysis. In total, 70 of 565 randomized participants had detectable CMV DNA at randomization (letermovir 48; placebo 22). Study treatment completion rates were greater in letermovir‐treated participants compared with placebo (52.1% vs 9.1%). The incidence of CS‐CMVi or imputed primary endpoint events through Week 24 were 64.6% and 90.9% in the letermovir and placebo groups, respectively (treatment difference ?26.1%; P = .010). Kaplan‐Meier event rates for CS‐CMVi onset through Week 14 (end‐of‐treatment period) were 33.1% for letermovir and 86.6% for placebo (P < .001). Median viral loads at the CS‐CMVi events was similar in both treatment arms. All‐cause mortality through Week 24 posttransplant was 15.0% for letermovir and 18.2% for placebo; through Week 48, mortality rates were 26.5% and 40.9%, respectively (P = .268). Overall, clinical outcomes were similar to those reported for participants with undetectable CMV DNA at randomization.     

Letermovir in lung transplant recipients with cytomegalovirus infection: A retrospective observational study

Letermovir is a new antiviral drug approved for the prophylaxis of CMV infection in allogeneic stem cell transplants. The aim of the study was to assess the therapeutic efficacy of letermovir in difficult to treat CMV infections in lung transplant recipients. All lung transplant recipients between March 2018 and August 2020, who have been treated with letermovir for ganciclovir-resistant or refractory CMV infection were included in the study and analysed retrospectively. In total, 28 patients were identified. CMV disease was present in 15 patients (53.6%). In 23 patients (82.1%), rapid response was noticed, and CMV-viral load could be significantly decreased (>1 log₁₀) after a median of 17 [14–27] days and cleared subsequently in all of these patients. Five patients (17.9%) were classified as non-responder. Thereof, development of a mutation of the CMV UL56 terminase (UL-56-Gen: C325Y) conferring letermovir resistance could be observed in three patients (60%). Common side effects were mild and mostly of gastrointestinal nature. Mild adjustments of the immunosuppressive drugs were mandatory upon treatment initiation with letermovir. In addition to other interventions, letermovir was effective in difficult to treat CMV infections in lung transplant recipients. However, in patients with treatment failure mutation conferring letermovir, resistance should be taken into account.     

Delayed vs initial cytomegalovirus prophylaxis after kidney transplantation

It is recommended to start cytomegalovirus (CMV) prophylaxis within 10 days of solid organ transplant, if indicated. Our center underwent a cost-savings initiative to delay CMV prophylaxis initiation from postoperative day zero to postoperative day 7 or upon discharge, hypothesizing this would not affect clinical outcomes but could impact costs. The purpose of this retrospective study was to determine the effects of early vs delayed (<72 vs >72 hours after transplant) CMV prophylaxis in kidney and kidney/pancreas transplant recipients transplanted between June 2014 and January 2017. The primary endpoint was incidence of CMV infection within 1 year. Secondary endpoints included CMV disease, CMV testing, and valganciclovir cost during index hospitalization. A total of 173 patients (114 early, 59 delayed) were included. CMV infection occurred in 61% vs 54% in the early vs delayed group (P = .5). Excluding low-level DNAemia (QNAT < 200 IU/mL), infection occurred in 30% vs 22% in the early vs late group (P = .4). The median days to starting prophylaxis were 0 and 6 in the early and delayed group (P < .05), which led to a median cost savings of $497.00 per patient during index hospitalization (P < .05). Delaying prophylaxis initiation did not impact CMV outcomes in this cohort and decreased costs.     

Risk factors for cytomegalovirus reactivation after CD6+ T-cell-depleted allogeneic bone marrow transplantation

BACKGROUND: Cytomegalovirus (CMV) infection is a significant cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation (HSCT). Recipients of T-cell-depleted (TCD) transplants may be more susceptible to CMV infection as a result of the reduction in transferred T cell immunity. We sought to determine the effect of prior donor and patient CMV exposure on the incidence of CMV infection after TCD allogeneic HSCT. METHODS: We retrospectively examined CMV antigen testing results in all patients who had undergone CD6+ TCD related and unrelated donor allogeneic HSCT at our institution from 1996 to 1999. All 124 patients who had documented donor and recipient CMV serologies pretransplant and had undergone CMV antigen testing before day +100 posttransplant were included in the analysis. RESULTS: Forty-one percent of seropositive recipients and 1% of seronegative recipients developed evidence of CMV reactivation (odds ratio 54.1, 95% confidence interval [CI] 6.9-424.1, P<0.001). Prior donor CMV exposure did not place seronegative recipients at increased risk of CMV conversion. Multivariable analysis indicated that prior donor CMV exposure significantly reduced the risk of CMV reactivation in seropositive recipients by 81% (odds ratio 0.19, 95% CI 0.04-0.91, P=0.04). Grades II to IV acute graft-versus-host disease (GVHD) was associated with CMV conversion (P=0.04) when seropositive recipients underwent HSCT from CMV-negative donors, but not when the donor was CMV-seropositive (P=0.54). CONCLUSIONS: The CMV serology status of the recipient, rather than the donor, was the primary determinant of risk for CMV conversion after TCD allogeneic HSCT. Despite CD6+ T-cell depletion, immunity against CMV seemed to be transferred with the donor graft and protected seropositive HSCT recipients from CMV reactivation.     

Epstein–Barr virus reactivation in allogeneic stem cell transplantation is highly related to cytomegalovirus reactivation

Monitoring of Epstein–Barr virus (EBV) load and pre‐emptive rituximab is an appropriate approach to prevent post‐transplant lymphoproliferative disease (PTLD) occurring after hematopoietic stem cell transplantation (HSCT). This pre‐emptive approach, based on EBV‐DNA monitoring through a quantitative polymerase chain reaction, was applied to 101 consecutive patients who underwent allo HSCT at our Institute (median age 50). A single infusion of rituximab was administered to 11 of 16 patients who were at high risk for progression to PTLD, defined as a DNA value >10 000 copies/mL. All patients cleared EBV DNAemia, without any recurrences. Main factors significantly associated with high risk for PTLD were as follows: (i) unrelated vs. sibling (26% vs. 7%; p = 0.011); (ii) T‐cell depletion (29% vs. 6%; p = 0.001); (iii) graft versus host disease (GVHD; 30% vs. 7%; p = 0.002); and (iv) cytomegalovirus (CMV) reactivation (29% vs. 4%; p = 0.001). Multivariate analysis showed that CMV reactivation was the only independent variable associated with EBV reactivation. We conclude that: (i) a single infusion of rituximab is able to prevent the risk of progression into EBV‐related PTLD; and (ii) CMV reactivation is strongly associated with EBV reactivation; therefore, an intensive EBV monitoring strategy could be advisable only in case of CMV reactivation.     

Minimum-Dose,Short-Term Methotrexate With Tacrolimus for Graft-vs-Host Disease Prophylaxis Following Unrelated Cord Blood Transplantation in Adults: A Retrospective Analysis at a Single Institution

BackgroundMethotrexate (MTX) or mycophenolate mofetil with tacrolimus (TAC) is used for graft-vs-host disease (GVHD) prophylaxis in unrelated cord blood transplantation (CBT). However, there is no consensus regimen for GVHD prophylaxis in CBT. We aimed to assess the efficacy and feasibility of minimum-dose, short-term MTX (MS-MTX) for GVHD prophylaxis in CBT.MethodsWe retrospectively evaluated 35 consecutive adult patients who underwent CBT and received MS-MTX (6 mg/m² day 1; 3 mg/m² days 3 and 6, intravenously) with TAC for GVHD prophylaxis in our hospital between 2015 and 2019. Transplantation outcomes with respect to time to hematopoietic recovery, engraftment, incidence and severity of GVHD, adverse events, relapse, nonrelapse mortality (NRM), and overall survival were evaluated.ResultsThe median time to neutrophil, platelet, and reticulocyte recovery was 22, 38, and 32 days, respectively. Cumulative neutrophil engraftment was 91.4%. After a median 3.2-year follow-up, the 2-year overall survival was 64.3%. The 2-year cumulative incidence of relapse and NRM was 20.4% and 14.9%, respectively. The 100-day cumulative incidence of grade II-IV acute GVHD and 2-year cumulative incidence of chronic GVHD were 28.6% and 36.6%, respectively. No grade IV acute GVHD was observed. Sixteen patients experienced oral mucositis and/or pharyngeal pain (46%; grades 1-2, n = 15; grade 3 pharyngeal pain, n = 1). No patients suffered from human herpesvirus 6 encephalitis/myelitis.ConclusionsMS-MTX with TAC is feasible and safe and yields lower rates of severe oropharyngeal mucositis and human herpesvirus 6 encephalitis/myelitis without increasing GVHD, graft failure, relapse, or NRM.     

Cytomegalovirus prophylaxis with intravenous polyvalent immunoglobulin in high-risk renal transplant recipients

Cytomegalovirus (CMV) seronegative renal allograft recipients (R-), particularly those with a graft from a CMV-seropositive donor (D+), are at high risk for primary CMV infection. CMV resistance to antiviral oral therapy is an emerging problem in renal transplantation, prompting development of new prophylactic strategies. We retrospectively studied the 1-year posttransplantation incidence of CMV infection in high-risk renal transplant recipients, in whom polyvalent intravenous immunoglobulins (IVIg) were used as prophylaxis. Forty R- patients received immunoprophylaxis by polyvalent IVIg (0.25 g/kg weekly for 8 weeks, starting on the operative day). CMV serological tests remained negative in eight patients (20%). Eight patients (20%) had asymptomatic CMV infection while 24 (60%) developed CMV syndrome and were treated with gancyclovir (10 mg/kg/day intravenously for 3 weeks). None had CMV disease or opportunistic infection. Six patients (15%) had biopsy-proven acute rejection, which followed CMV syndrome in three cases. One-year renal allograft and patient survivals were 95% and 97.5%, respectively. Mean serum creatinine level was 124 +/- 33 micromol/L at 1 year. Clinical tolerance of IVIg was excellent, without any episode of acute renal failure. Polyvalent IVIg provides effective prophylaxis in renal transplant recipients at high risk for CMV infection and is associated with excellent 1-year allograft survival. Because of their immunomodulatory functions, IVIg may have a beneficial effect on the incidence of acute and chronic rejection and allograft survival. A randomized prospective study is required to evaluate long-term effects of CMV prophylaxis with polyvalent IVIg compared to antiviral agents in renal transplant recipients.     

Modified donor lymphocyte infusion‐associated acute graft‐versus‐host disease after haploidentical T‐cell‐replete hematopoietic stem cell transplantation: incidence and risk factors

We performed a study to investigate the profile of donor lymphocyte infusion (DLI)‐associated acute graft‐versus‐host disease (GVHD) in haploidentical T‐cell‐replete hematopoietic stem cell transplantation (HSCT). A total of 124 patients receiving modified DLI after haploidentical T‐cell‐replete HSCT were enrolled. The cumulative incidence of DLI‐associated acute GVHD was 53.2% for grades II–IV and 28.4% for grades III–IV. The duration of GVHD prophylaxis after DLI was the only risk factor for DLI‐associated grades III–IV acute GVHD (p < 0.05). The cumulative incidence of grades III–IV acute GVHD in patients with prophylaxis more than six, four to six, two to four, and <2 wk were 9.3%, 14.4%, 31.6%, and 49.5%, respectively (p = 0.018). Furthermore, DLI‐associated grades III–IV acute GVHD was the only risk factor for overall survival (p = 0.038, OR   = 2.869) and transplant‐related mortality (p = 0.018, OR = 3.296) but not a risk factor for relapse after DLI (p = 0.840). This study confirms for the first time that the duration of GVHD prophylaxis after DLI is the only risk factor for the development of grades III–IV acute GVHD. Donor lymphocyte infusion with prophylaxis more than six wk was associated with a lower incidence of grades III–IV acute GVHD.     

Immunoglobulin prophylaxis against cytomegalovirus infection in patients at high risk of infection following allogeneic hematopoietic cell transplantation

Reports on the efficacy of intravenous immunoglobulin (IVIG) prophylaxis against cytomegalovirus (CMV) infection after allogeneic hematopoietic cell transplantation (HCT) have often sparked controversy. In addition, we are not aware of any study that has examined whether prophylaxis with IVIG affects the incidence of CMV infection in high-risk patients—those who are elderly or have received human leukocyte antigen (HLA) mismatched HCT. In the present open-label, phase II study, we addressed this question. We enrolled 106 patients in the study. The cumulative incidences of CMV infection at 100 days after HCT were similar in the intervention and the control groups (68% and 64%, P = .89; 89% and 87%, P = .79, respectively, for patients 55 years or older and those who received HLA-mismatched HCT). In those who received HLA-mismatched HCT, 1-year overall survival after HCT was 46% in the intervention group and 40% in the control group (P = .31); for age ≥ 55 years, the corresponding values were 46% and 40% (P = .27). Our data showed that prophylaxis with regular polyvalent IVIG did not affect the incidence of CMV infections or survival among older patients or those who receive HLA-mismatched HCT.     

Mycophenolate mofetil use after unrelated hematopoietic stem cell transplantation for prophylaxis and treatment of graft‐vs.‐host disease in adult patients in Japan

Our previous study of 301 patients who received hematopoietic stem cell transplantation (HSCT) from related donors demonstrated the efficacy of mycophenolate mofetil (MMF) for prophylaxis and treatment of graft‐vs.‐host disease (GVHD). In this study, we investigated the safety and efficacy of MMF in 716 adult patients who received unrelated HSCT. The incidences of Grade II–IV and III–IV acute GVHD in the prophylactic administration group were 38.3% and 14.3%, respectively. These rates were not statistically significant when evaluating the MMF dosage and graft source. The incidences of limited and extensive chronic GVHD were 16.6% and 11.1%, respectively. In the therapeutic administration group, 69.1% of the subjective symptoms for both acute and chronic GVHD improved. With respect to the adverse events, 75 infections and 50 cases of diarrhea were observed, and the frequency of these events increased with increasing MMF dose. The overall survival rate was 36.4% after a median follow‐up period of three yr. This study shows that MMF is safe and effective for the prevention and treatment of GVHD in patients who have received HSCT from unrelated donors.     

Delay of CMV infection in high-risk CMV mismatch lung transplant recipients due to prophylaxis with oral ganciclovir

Cytomegalovirus (CMV) is a common opportunistic infection in lung transplant recipients. Despite the use of early post-operative intravenous ganciclovir, most high-risk patients develop CMV infection. We conducted this retrospective study to determine the efficacy of extended CMV prophylaxis with oral ganciclovir in high-risk, donor-positive-recipient-negative, lung recipients. All patients initially received 3 months of intravenous ganciclovir and CMV hyperimmune globulin. Clinical outcomes in all CMV mismatch patients undergoing lung transplant surviving at least 3 months were included (n = 42). Since 1998, 14 patients received no oral ganciclovir prophylaxis (group 1) and 28 patients received indefinite oral ganciclovir after completion of intravenous therapy (group 2). In those patients receiving oral ganciclovir, the prevalence of post-transplant CMV infection was significantly reduced over the first 180 d post-transplant (50% in group 1 vs. 4% in group 2; p < 0.001). Although some CMV events were observed with additional follow-up in group 2, there remained a significantly greater freedom from CMV infection by Kaplan-Meier analysis in group 2 as compared with group 1, with over 30 months follow-up time in each group (log-rank, p = 0.02). A moderate rate of drug discontinuation was observed in group 2, and no severe drug-related events occurred. In high-risk lung transplant recipients, CMV prophylaxis with intravenous ganciclovir, followed by indefinite oral ganciclovir, significantly delays and reduces post-transplant CMV infections. A larger prospective randomized study is needed to confirm the benefits of oral ganciclovir on CMV prevention.     

Prospective validation of the L-index reflecting both the intensity and duration of lymphopenia and its detailed evaluation using a lymphocyte subset analysis after allogeneic hematopoietic stem cell transplantation

We prospectively validated the previously reported L-index, which reflects both the intensity and duration of lymphopenia, and further evaluated it using a lymphocyte subset analysis after allogeneic hematopoietic stem cell transplantation (HSCT) (n = 30). The L-index was defined as the area over the lymphocyte curve during lymphopenia (<700/μl), and calculated from the start of conditioning to day30 (L-index(30)) and day100 (L-index(100)). The lymphocyte subset including CD3, CD4, CD8, CD19 and CD56 was analyzed before and at 14, 21, 28, 42, 56, 70, and 84 days after HSCT. Cytomegalovirus (CMV) antigenemia was detected as >3 cells/2 slides by the C10/11 method in 21 cases (CMV-AG ≥3 group) at a median of 34 days. L-index(30) was significantly higher in the CMV-AG ≥3 group than in the CMV-AG <3 group (median 20,358 vs 17,235, P = .028). Recovery of the CD4+ and CD56+ cell counts between days 14 and 28 after HSCT was impaired in the CMV-AG ≥3 group. Regarding graft-versus-host disease (GVHD), grade II-IV acute GVHD was identified in 14 patients (GVHD group) at a median of 31 days. L-index(30) was significantly lower in the GVHD group (median 19,048 vs 22,256, P = .043). Recovery of CD3+ cells including both CD4+ and CD8+ cells between days 14 and 28 tended to be better in the GVHD group. In conclusion, L-index(30) was significantly associated with CMV reactivation and grade II-IV acute GVHD, but its clinical significance seemed to differ according to the results of a lymphocyte subset analysis.     

Risk factors and impact of cytomegalovirus disease in simultaneous pancreas-kidney transplantation.

BACKGROUND: The relevance of cytomegalovirus (CMV) in simultaneous pancreas kidney (SPK) transplant recipients in the modern era of immunosuppression and antiviral therapeutics is largely unquantified. We sought to determine the risk factors of CMV disease and its impact on SPK transplant outcomes in recipients all receiving a consistent regime of maintenance immunosuppression and CMV prophylaxis. METHODS: This is a retrospective, single center study of 100 consecutive SPK transplant recipients. All received maintenance immunosuppression with mycophenolate mofetil, tacrolimus, and prednisone. CMV prophylaxis consisted of a short course of parenteral gancyclovir followed by oral gancyclovir. Recipients at high-risk (D+/R-) for CMV also received CMV hyperimmune globulin. Multivariate analysis of risk factors for CMV disease and risk factors for adverse outcomes in SPK transplantation were determined. The effect of duration of prophylaxis on timing and severity of CMV disease in high-risk (D+/R-) SPK transplant recipients was also evaluated. RESULTS: The actual 1-year rate of CMV disease was 17.0% (12.0% noninvasive, 5.0% tissue invasive); and according to donor and recipient CMV serological status was: D-/R+: 0%; D-/R-: 2.8%; D+/R+: 25.6%; and D+/R-: 40.6%. Multivariate analysis showed transplantation of organs from a donor with positive CMV serology to be predictive of CMV disease with a relative risk of 63.37 (P=0.0052). In the high-risk (D+/R-) subgroup, the duration of prophylactic therapy delayed onset of CMV disease, but had minimal effect on severity. Invasive CMV disease was an independent predictor of mortality but did not decrease kidney or pancreas allograft survival. CONCLUSIONS: Outcomes of SPK transplantation have improved in the current era of modern immunosuppression, yet CMV remains an important pathogen. The serological status of the organ donor and the duration of CMV prophylaxis are predictive of who and when CMV disease may occur. Nevertheless, new strategies that reduce risk and severity of CMV disease are still needed.     

A high antithymocyte globulin dose increases the risk of relapse after reduced intensity conditioning HSCT with unrelated donors

The study included 110 consecutive patients with hematological malignancies receiving fludarabine‐based reduced intensity conditioning (RIC) and hematopoietic stem cell transplantation (HSCT) from matched unrelated donors. The median age was 55 yr (range 11–68) and all but 15 patients received peripheral blood stem cell grafts. Antithymocyte globulin (ATG) (Thymoglobulin, Genzyme) at a total dose of 6 mg/kg (n = 66) or 8 mg/kg (n = 44) was given to all patients according to protocol. The ATG dose did not affect time‐to‐neutrophil or platelet engraftment. The incidences of acute GVHD grades II–IV were 34% and 18% (p = 0.11) and of chronic GVHD were 40% and 26% (p = 0.46) in patients receiving 6 and 8 mg/kg of ATG, respectively. The five‐yr relapse‐free survival (RFS) was 61% and 36% (p = 0.14) in patients, given low and high ATG dose, respectively. In patients given low‐dose ATG, the incidence of relapse was lower compared to those given high‐dose ATG, 19% vs. 41% (p = 0.04). In multivariate analysis, age >50 yr (p < 0.001), absence of acute (p < 0.001) and chronic GVHD (p = 0.001) were correlated to relapse, and low‐dose ATG was associated with improved RFS (p < 0.05). A high dose (8 mg/kg) of ATG in RIC HSCT with unrelated donors increased the risk for relapse and reduced the RFS.     

Two decades of stem cell transplantation in patients with Fanconi anemia: Analysis of factors affecting transplant outcomes

Allogeneic hematopoietic stem cell transplantation (HSCT) is currently the only curative treatment for the hematological complications of patients with Fanconi anemia (FA). Over the last two decades, HSCT outcomes have improved dramatically following the development of regimens tailored for FA patients. In this study, we analyzed genetic, clinical, and transplant data of 41 patients with FA who underwent HSCT at Hadassah Medical Center between November 1996 and September 2020. Overall survival (OS) was 82.9% with a median follow-up time of 2.11-years (95% CI, .48–16.56). Thirteen patients (31.7%) developed acute graft-versus-host disease (GVHD), three of them with grades 3-4. Nine patients developed chronic GVHD, five had extensive disease. Twelve patients (29.3%) developed stable mixed-chimerism with complete resolution of bone marrow failure (BMF); none of them had acute nor chronic GVHD. Significantly higher GVHD rates were observed in transplants from peripheral blood stem cell grafts as compared to other stem cell sources (p = .002 for acute and p = .004 for chronic GVHD). Outcome parameters were comparable between HSCT from matched-sibling (n = 20) to other donors (n = 21), including survival rates (p = .1), time to engraftment (p = .69 and p = .14 for neutrophil and platelet engraftment time, respectively), chimerism status (p = .36 and p = .83 for full-donor and mixed chimerism, respectively), and GVHD prevalence (p = 1). Our results demonstrate the vast improvements in HSCT outcomes of patients with FA, narrowing the gap between matched-sibling versus alternative donor transplantations. Our data identifies factors that may significantly affect transplant outcomes such as graft source and chimerism status.     

Preemptive treatment of Cytomegalovirus infection in kidney transplant recipients with letermovir: results of a Phase 2a study

Cytomegalovirus (CMV) infection remains a significant cause of morbidity and mortality in transplant recipients. Letermovir (AIC246), is a novel anti‐HCMV drug in development, acting via a novel mechanism of action. In this proof‐of‐concept trial with first administration of letermovir to patients, 27 transplant recipients with active CMV replication were randomly assigned to a 14‐day oral treatment regimen of either letermovir 40 mg twice a day, letermovir 80 mg once a day, or local standard of care (SOC) in a multicenter, open‐label trial. Efficacy, safety, and limited pharmacokinetic parameters were assessed. All groups had a statistically significant decrease in CMV‐DNA copy number from baseline (40 mg BID: P = 0.031; 80 mg QD: P = 0.018; SOC: P = 0.001), and comparison of viral load reduction between treatment groups showed no statistically significant differences. Viral clearance was achieved for 6 of 12 patients (50%) in the letermovir groups versus two of seven SOC patients (28.6%). Letermovir treatment was generally well tolerated, no patient developed CMV disease during the trial. Both letermovir treatment regimens resulted in equally high trough level plasma concentrations. The efficacy, safety, and pharmacokinetics observed in these viremic transplant recipients indicate that letermovir is a promising new anti‐CMV drug.     

The use of donor and recipient screening for toxoplasma in the era of universal trimethoprim sulfamethoxazole prophylaxis

BACKGROUND: Toxoplasmosis is a serious complication of solid organ transplantation. The highest risk of infection and disease occurs in heart recipients with primary infection transmitted by a seropositive donor to a seronegative recipient (donor-recipient mismatch). Toxoplasmosis has been reported to occur in noncardiac transplant recipients; however, no large studies examining the frequency of such events or the need for serologic screening exist. METHODS: A retrospective cohort study of 1,006 solid organ transplant recipients transplanted in our center between 1984 and 1997 was performed to examine the incidence of Toxoplasma seroconversion, reactivation, and clinical toxoplasmosis and to evaluate the impact of trimethoprim sulfamethoxazole (TMP/SMX) prophylaxis on these outcomes. RESULTS: Pretransplant Toxoplasma seroprevalence was 13.4% in donors and 17.8% in recipients. The incidence of Toxoplasma donor-recipient mismatch was 9.5% during the 14-year study period, and only 39.1% of mismatched recipients received TMP/SMX prophylaxis. Only four patients seroconverted, of whom two had received prophylaxis. There were no cases of clinical disease; either primary or reactivation. CONCLUSIONS: We therefore conclude that in transplant centers with low Toxoplasma seroprevalence, routine screening for Toxoplasma in solid organ donors and recipients is not necessary, particularly in the era of routine TMP/SMX prophylaxis.