Incidence, risk factors, and outcome of cytomegalovirus infection and disease in patients receiving prophylaxis with oral valganciclovir or intravenous ganciclovir after umbilical cord blood transplantation

Incidence of refractory CMV infection with or without antiviral resistance in Spain: A systematic literature review

INTRODUCTION

Solid organ transplantation (SOT) and hematopoietic stem cell transplantation (HSCT) recipients are susceptible to cytomegalovirus (CMV) infection. The incidence of refractoriness to antivirals, with or without resistance, is unclear. The purpose of this review was to describe the epidemiology of refractory CMV infection in Spain to understand the current unmet needs.

METHODS

PubMed, EMBASE, Cochrane and MEDES were searched systematically for relevant articles. We included randomized controlled trials and observational studies published during the period from January 1990 to June 2021.

RESULTS

From 212 screened records, we selected 19 papers including 1973 transplant recipients. Refractory infection ranged from 3 to 10% in studies with SOT recipients. The incidence of CMV resistance ranged from 1% to 36% in these patients. The incidence of CMV refractory infection in HSCT recipients ranged from 11 to 50%, while values for resistant infection ranged from 0% to 21%.

CONCLUSION

The wide range of definitions and values observed does not allow us to establish the true incidence of refractory CMV infection with or without resistances in SOT and HSCT patients in Spain. This review highlights the gap between clinical practice and clinical trials' definitions which needed to be updated to be easier followed in current clinical practice.

Extended-duration letermovir prophylaxis for cytomegalovirus infection after cord blood transplantation in adults

Cord blood transplantation (CBT) can be complicated by a high incidence of clinically significant cytomegalovirus infection (csCMVi). We have investigated the efficacy of extended letermovir prophylaxis in seropositive adult CBT recipients. The aim was to continue prophylaxis for ≥6 months (insurance permitting). By day 100, the incidence of csCMVi was 0% in 28 patients who received letermovir prophylaxis. Moreover, of 24 patients alive at day 100, none had csCMVi by day 180, having continued prophylaxis for all (n = 20) or part (n = 4) of that period. Overall, 20 patients stopped letermovir at a median of 354 days (range, 119-455 days) posttransplant, with only 5 requiring 1 (n = 4) or 2 (n = 1) courses of valganciclovir (median total duration, 58 days; range, 12-67 days) for postprophylaxis viremia, with no subsequent csCMVi. There were no toxicities attributable to letermovir. Of the 62 historic control subjects who received acyclovir only, 51 developed csCMVi (median onset, 34 days; range, 5-74 days), for a day 100 incidence of 82% (95% confidence interval, 73-92). Seven patients developed proven/probable CMV disease, and 6 died before day 100 (3 with proven/probable CMV pneumonia). Forty-five patients required extended therapy during the first 6 months for 1 (n = 10), 2 (n = 14), or 3/persistent (n = 21) csCMVi, with 43 (84%) of 51 developing significant treatment toxicities. Letermovir is a highly effective, well-tolerated prophylaxis that mitigates CMV infection, CMV-related mortality, and antiviral therapy toxicities in CBT recipients. Our data support prophylaxis duration of at least 6 months after CBT.

Coexistence of HLA and KIR ligand mismatches as a risk factor for viral infection early after cord blood transplantation

Viral infection is one of the lethal adverse events after cord blood transplantation (CBT). Human leukocyte antigen (HLA) and killer immunoglobulin-like receptor (KIR) ligand divergences can increase the risk of viral infection due to conflicting interactions between virus-infected cells and immune cells. However, the relationship between these disparities and the frequency of viral infection after CBT remains to be evaluated. Herein, we have conducted a retrospective multicenter study to assess the effect of HLA and KIR ligand mismatches on viral infections after CBT. The study included 429 patients, among which 126 viral infections occurred before day 100. Viral infection was significantly associated with poorer overall survival (OS; hazard ratio [HR] 1.74, p < 0.01). Patients harboring ≥3 mismatches in the HLA allele and inhibitory KIR ligand mismatches (HLA & KIR mismatches) had a significantly greater prevalence of viral infection (HR 1.66, p = 0.04). Thus, patients with HLA & KIR mismatches had poorer outcomes in terms of non-relapse mortality (HR 1.61, p = 0.05). Our study demonstrates the unfavorable impacts of HLA & KIR mismatches on viral infections and non-relapse mortality after CBT. Evaluating the viral infection risk and performance of an appropriate and early intervention in high-risk patients and optimizing the graft selection algorithm could improve the outcome of CBTs.

How I treat CMV reactivation after allogeneic hematopoietic stem cell transplantation

Cytomegalovirus (CMV) reactivation remains one of the most common and life-threatening infectious complications following allogeneic hematopoietic stem cell transplantation, despite novel diagnostic technologies, several novel prophylactic agents, and further improvements in preemptive therapy and treatment of established CMV disease. Treatment decisions for CMV reactivation are becoming increasingly difficult and must take into account whether the patient has received antiviral prophylaxis, the patient's individual risk profile for CMV disease, CMV-specific T-cell reconstitution, CMV viral load, and the potential drug resistance detected at the time of initiation of antiviral therapy. Thus, we increasingly use personalized treatment strategies for the recipient of an allograft with CMV reactivation based on prior use of anti-CMV prophylaxis, viral load, the assessment of CMV-specific T-cell immunity, and the molecular assessment of resistance to antiviral drugs.

Impact of HLA class I allele-level mismatch on viral infection within 100 days after cord blood transplantation

Viral infection is more frequently reported in cord blood transplantation (CBT) than in transplantation of other stem cell sources, but its precise mechanism related to antiviral host defenses has not been elucidated yet. To evaluate the effect of human leukocyte antigen (HLA) class I allele-level incompatibility on viral infection in CBT, we conducted a single-center retrospective study. Total 94 patients were included, and viral infections were detected in 32 patients (34%) within 100 days after CBT. HLA-C mismatches in graft-versus-host direction showed a significantly higher incidence of viral infection (hazard ratio (HR), 3.67; p = 0.01), while mismatches in HLA-A, -B, or -DRB1 were not significant. Overall HLA class I mismatch was also a significant risk factor and the predictor of post-CBT viral infection (≥ 3 mismatches, HR 2.38, p = 0.02), probably due to the insufficient cytotoxic T cell recognition and dendritic cell priming. Patients with viral infection had significantly worse overall survival (52.7% vs. 72.1%; p = 0.02), and higher non-relapse mortality (29.3% vs. 9.8%; p = 0.01) at 5 years. Our findings suggest that appropriate graft selection as well as prophylaxis and early intervention for viral infection in such high-risk patients with ≥ 3 HLA class I allele-level mismatches, including HLA-C, may improve CBT outcomes.

COVID-19 therapy: What weapons do we bring into battle?

Urgent treatments, in any modality, to fight SARS-CoV-2 infections are desired by society in general, by health professionals, by Estate-leaders and, mainly, by the scientific community, because one thing is certain amidst the numerous uncertainties regarding COVID-19: knowledge is the means to discover or to produce an effective treatment against this global disease. Scientists from several areas in the world are still committed to this mission, as shown by the accelerated scientific production in the first half of 2020 with over 25,000 published articles related to the new coronavirus. Three great lines of publications related to COVID-19 were identified for building this article: The first refers to knowledge production concerning the virus and pathophysiology of COVID-19; the second regards efforts to produce vaccines against SARS-CoV-2 at a speed without precedent in the history of science; the third comprehends the attempts to find a marketed drug that can be used to treat COVID-19 by drug repurposing. In this review, the drugs that have been repurposed so far are grouped according to their chemical class. Their structures will be presented to provide better understanding of their structural similarities and possible correlations with mechanisms of actions. This can help identifying anti-SARS-CoV-2 promising therapeutic agents.

Prospective Randomized Study Comparing Myeloablative Unrelated Umbilical Cord Blood Transplantation versus HLA-Haploidentical Related Stem Cell Transplantation for Adults with Hematologic Malignancies

In this prospective randomized study, we compared the outcomes of single-unit umbilical cord blood transplantation (UCBT) and unmanipulated haploidentical stem cell transplantation (haplo-SCT) with post-transplantation cyclophosphamide (PTCy) in adults with hematologic malignancies. All patients received a myeloablative conditioning (MAC) regimen consisting of thiotepa, busulfan, and fludarabine, with antithymocyte globulin (ATG) added for UCBT recipients. Nineteen patients were randomized to UCBT and the other 26 to haplo-HSCT. Four patients (15%) allocated to the haplo-HSCT arm lacked a suitable donor and were crossed over to the UCBT arm. Finally, 23 underwent UCBT and 22 underwent haplo-HSCT. The cumulative incidence of neutrophil recovery was 87% at a median of 19 days (range, 13 to 24 days) in the UCBT arm versus 100% at a median of 17 days (range, 13 to 25 days) in the haplo-SCT arm (P = .04). Platelet recovery was 70% at a median of 40 days (range, 18 to 129 days) in the UCBT arm versus 86% at a median of 24 days (range, 12 to 127 days) in the haplo-HCT arm (P = .02). Rates of acute graft-versus-host disease (GVHD) grade II-IV or grade III-IV, overall chronic GVHD, and extensive chronic GVHD in the UCBT and Haplo-SCT arms were 43% versus 36% (P = .8), 9% versus 9% (P = 1), 66% versus 43% (P = .04), and 41% versus 23% (P = .2), respectively. Two-year nonrelapse mortality and relapse in the 2 arms were 52% versus 23% (P = .06) and 17% versus 23% (P = .5), respectively. Two-year disease-free survival, overall survival, and GVHD/relapse-free survival in the 2 arms were 30% versus 54% (P = .2), 35% versus 59% (P = .1), and 17% versus 40% (P = .04), respectively. Our data show that in the context of an MAC regimen, haplo-SCT with PTCy provides improved outcomes compared with ATG-containing single-unit UCBT.

Partial T Cell-Depleted Peripheral Blood Stem Cell Transplantation from HLA-Identical Sibling Donors for Patients with Severe Aplastic Anemia

We analyzed the outcomes of 26 consecutive patients with acquired severe aplastic anemia (SAA) undergoing peripheral blood stem cell transplantation (PBSCT) with partial ex vivo T cell depletion with a targeted T cell dose from HLA-identical sibling donors. The median patient age was 37 years (range, 3 to 63 years). Four patients with uncontrolled pneumonia at the time of transplantation died, on days +1, +2, +21, and +26. All evaluable patients engrafted, with a median time to neutrophil recovery of 11 days (range, 10 to 14 days) and a median time to platelet recovery of 19 days (range, 8 to 53 days). Two patients had transient grade I acute graft-versus-host disease (GVHD) with skin involvement, but no patients developed grade II-IV acute GVHD. Two patients had mild skin chronic GVHD, and 1 patient had moderate chronic GVHD with ocular involvement. No relapse was observed after a median follow-up of 114 months (range, 4 to 233 months). The overall cumulative incidence of TRM at 10 years was 19%, whereas it was 5% for those with a Karnofsky Performance Status (KPS) score >60 at the time of transplantation. Disease-free survival, overall survival, and GVHD and relapse-free survival at 10 years were 81%, 81%, and 80%, respectively, for all patients and 95%, 95%, and 90%, respectively, for patients with a KPS score >60 at transplantation. Our data indicate that PBSCT with partial ex vivo T cell-depleted targeted cell dose grafts from an HLA-identical sibling donor is a feasible, safe, and effective approach to reduce GVHD and cure patients with SAA.

An update on the treatment of cytomegalovirus infection after allogeneic hematopoietic stem cell transplantation

Introduction: Human Cytomegalovirus (CMV) remains a major cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation. Standard treatment options have for long been limited to a small number of effective drugs with significant toxicities.Areas covered: In this manuscript, the authors update a previous review summarizing recent developments in the virology lab and their possible implications for treatment strategies at bedside. In particular, the authors focused on new antiviral drugs already available and under investigation in clinical trials and innovative immunotherapeutic approaches, including adoptive T-cell therapy and vaccines.Expert opinion: Broader knowledge of CMV biology and its relationship with the host immune system is greatly contributing to the development of novel therapeutic approaches. The availability of new drugs, the improved techniques for virological testing and the more accurate patient risk stratification allow to better individualize treatment, limiting toxicity while sparing antiviral effects. The role of immunotherapy is clearly emerging and will further expand our treatment armamentarium.

Guidelines for the management of cytomegalovirus infection in patients with haematological malignancies and after stem cell transplantation from the 2017 European Conference on Infections in Leukaemia (ECIL 7)

Cytomegalovirus is one of the most important infections to occur after allogeneic haematopoietic stem cell transplantation (HSCT), and an increasing number of reports indicate that cytomegalovirus is also a potentially important pathogen in patients treated with recently introduced drugs for hematological malignancies. Expert recommendations have been produced by the 2017 European Conference on Infections in Leukaemia (ECIL 7) after a review of the literature on the diagnosis and management of cytomegalovirus in patients after HSCT and in patients receiving other types of therapy for haematological malignancies. These recommendations cover diagnosis, preventive strategies such as prophylaxis and pre-emptive therapy, and management of cytomegalovirus disease. Antiviral drugs including maribavir and letermovir are in development and prospective clinical trials have recently been completed. However, management of patients with resistant or refractory cytomegalovirus infection or cytomegalovirus disease is a challenge. In this Review we summarise the reviewed literature and the recommendations of the ECIL 7 for management of cytomegalovirus in patients with haematological malignancies.

Validation of a multivariable prediction model for post-engraftment invasive fungal disease in 465 adult allogeneic hematopoietic stem cell transplant recipients

BACKGROUND

Recently, we reported a simple prognostic score for post-engraftment invasive fungal disease (IFD) obtained in 404 adult allogeneic hematopoietic stem cell transplant (alloSCT) (training cohort).

OBJECTIVES

We aim to validate this score in an external cohort assessing the 1-year cumulative incidence (CI) of post-engraftment IFD. Additionally, we analyse the type of IFD and incidence of IFD according to type of prophylaxis.

PATIENTS/METHODS

We included 465 consecutive adult recipients surviving >40 days who engrafted and were discharged without prior IFD (median age 45 years, range, 14-69).

RESULTS

Patients classified as low-risk, 139; intermediate-risk, 162; and high-risk, 164 (35% vs 27% in the training cohort, P = 0.03). The CI of probable/proven IFD in the validation cohort was 8% vs 11% in the training cohort (P = 0.006). The only voriconazole prophylaxis used in the training cohort was 100 mg/12 h, 65% vs 27% in the validation cohort, but 38% received 200 mg/12 h. Thus, the validation cohort showed a lower CI of IFD (P = 0.009). The post-engraftment IFD score was validated, showing a CI of IFD for low-, intermediate- and high-risk of 3%, 6% and 14%, respectively (P < 0.001).

CONCLUSION

To our knowledge, this is the first prognostic index to predict the occurrence of post-engraftment IFD after alloSCT that has been validated in an external cohort.

Pulmonary cytomegalovirus (CMV) DNA shedding in allogeneic hematopoietic stem cell transplant recipients: Implications for the diagnosis of CMV pneumonia

OBJECTIVES

To date no definitive cut-off value for cytomegalovirus (CMV) DNA load in bronchoalveolar lavage (BAL) fluid specimens has been established to discriminate between CMV pneumonia and pulmonary CMV DNA shedding in allogeneic hematopoietic stem cell transplant (allo-HSCT) recipients.

METHODS

The current retrospective study is aimed at assessing the range of CMV DNA loads quantified in BAL fluid specimens from allo-HSCT patients with pneumonia in which different microorganisms were causally involved.

RESULTS

A total of 144 BAL specimens from 123 patients were included. CMV DNA was detected in 56 out of 144 BAL fluid specimens and the median CMV DNA load from patients in whom CMV pneumonia was unlikely or could be tentatively ruled out was 1210 (31-68, 920) IU/ml. The frequency of CMV DNA detection and median CMV DNA loads were comparable, irrespective of the attributable cause of pneumonia. Detection of CMV DNA loads in BAL fluid specimens >500 IU/ml was independently associated with pneumonia-attributable mortality.

CONCLUSIONS

The current study highlights the difficulty in establishing universal CMV DNA load thresholds in BAL fluid specimens for distinguishing between CMV pneumonia and pulmonary CMV DNA shedding, and suggests that the presence of CMV DNA in BAL fluid specimens beyond a certain level may have a deleterious impact on patient outcome.

Infections in Allogeneic Stem Cell Transplantation

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) has become a widely used modality of therapy for a variety of malignant and nonmalignant diseases. Despite advances in pharmacotherapy and transplantation techniques, infection remains one of the most severe and frequently encountered complications of allo-HSCT.

This chapter will address the risk factors for development of infection following allo-HSCT, including those related to the host, the conditioning regimen, and the graft, as well as the timing of opportunistic infections after allo-HSCT. The most common bacterial, viral, fungal, and parasitic infections, as well as issues surrounding their diagnostics and treatment, will be discussed. Finally, this chapter will address vaccination and other preventative strategies to be utilized when caring for patients undergoing allo-HSCT.

Community-acquired respiratory virus lower respiratory tract disease in allogeneic stem cell transplantation recipient: Risk factors and mortality from pulmonary virus-bacterial mixed infections

Risk factors (RFs) and mortality data of community‐acquired respiratory virus (CARVs) lower respiratory tract disease (LRTD) with concurrent pulmonary co‐infections in the setting of allogeneic hematopoietic stem cell transplantation (allo‐HSCT) is scarce. From January 2011 to December 2017, we retrospectively compared the outcome of allo‐HSCT recipients diagnosed of CARVs LRTD mono‐infection (n = 52, group 1), to those with viral, bacterial, or fungal pulmonary CARVs LRTD co‐infections (n = 15, group 2; n = 20, group 3, and n = 11, group 4, respectively), and with those having bacterial pneumonia mono‐infection (n = 19, group 5). Overall survival (OS) at day 60 after bronchoalveolar lavage (BAL) was significantly higher in group 1, 2, and 4 compared to group 3 (77%, 67%, and 73% vs 35%, respectively, P = .012). Recipients of group 5 showed a trend to better OS compared to those of group 3 (62% vs 35%, P = .1). Multivariate analyses showed bacterial co‐infection as a RF for mortality (hazard ratio[HR] 2.65, 95% C.I. 1.2‐6.9, P = .017). We identified other 3 RFs for mortality: lymphocyte count <0.5 × 10⁹/L (HR 2.6, 95% 1.1‐6.2, P = .026), the occurrence of and CMV DNAemia requiring antiviral therapy (CMV‐DNAemia‐RAT) at the time of BAL (HR 2.32, 95% C.I. 1.1‐4.9, P = .03), and the need of oxygen support (HR 8.3, 95% C.I. 2.9‐35.3, P = .004). CARV LRTD co‐infections are frequent and may have a negative effect in the outcome, in particular in the context of bacterial co‐infections.

Infectious Complications after Umbilical Cord-Blood Transplantation from Unrelated Donors

Umbilical cord-blood (UCB) is a well-recognized alternative source of stem cells for unrelated donor hematopoietic stem cell transplantation (HSCT). As compared with other stem cell sources from adult donors, it has the advantages of immediate availability of cells, absence of risk to the donor and reduced risk of graft-versus-host disease despite donor-recipient HLA disparity. However, the use of UCB is limited by the delayed post-transplant hematologic recovery due, at least in part, to the reduced number of hematopoietic cells in the graft and the delayed or incomplete immune reconstitution. As a result, severe infectious complications continue to be a leading cause of morbidity and mortality following UCB transplantation (UCBT). We will address the complex differences in the immune properties of UCB and review the incidence, characteristics, risk factors, and severity of bacterial, fungal and viral infectious complications in patients undergoing UCBT.

Risk factors for cytomegalovirus DNAemia following haploidentical stem cell transplantation and its association with host hepatitis B virus serostatus

BACKGROUND

The risk factors associated with CMV DNAemia are not well known after haploidentical stem cell transplantation (SCT).

OBJECTIVES

This study investigated the risk factors and prognosis for CMV DNAemia among CMV seromatched donors and recipients (D+/R+).

STUDY DESIGN

A retrospective study of patients undergoing haploidentical stem cell transplantation (SCT) between January 2010 and January 2012 was conducted. Cox regression analysis was performed to identify the risk factors for CMV DNAemia. These possible factors included recipient/donor age, recipient/donor gender, gender disparity, recipient HBsAg serostatus, diagnosis, risk stratification, anti-thymocyte globulin (ATG) dose (6mg/kg,10mg/kg), early neutrophil engraftment (≤12 days, >12 days), absolute lymphocyte count on day 30 (ALC30) and the occurrence of acute GVHD before CMV DNAemia.

RESULTS

The total number of patients was 248 with median age of 31 years (range, 14-56). The cumulative incidence of CMV DNAemia (146/248) was 59.5%. CMV DNAemia was first detected after a median of +35 days (range,12-82). Seventeen patients (17/146, 11.6%) developed CMV disease. Multivariate analysis identified HBsAg seropositivity (P=0.002, hazard ratio (HR)=1.833; 95%CI=1.257-2.673) and the occurrence of acute GVHD before CMV DNAemia (P=0.014; HR=1.520; 95%CI=1.088-2.124) as risk factors for CMV DNAemia. CMV DNAemia was associated with subsequent II-IV acute graft-versus-host disease (GVHD) (P=0.014), III-IV aGVHD (P=0.013) and chronic GVHD (P=0.008). Totally, CMV DNAemia was found to be a poor prognostic factor in terms of non-relapse mortality (NRM) (P=0.003, HR=2.730; 95%CI=1.406-5.197), and overall survival (OS) (P=0.045, HR=1.654; 95%CI=1.012-2.701).

CONCLUSIONS

Our data showed HBsAg seropositivity was associated with an increased risk of cytomegalovirus DNAemia. Detection of CMV DNAemia proved to be a poor prognostic factor for haploidentical patients.

Incidence and risk factors of post-engraftment invasive fungal disease in adult allogeneic hematopoietic stem cell transplant recipients receiving oral azoles prophylaxis

Studies that analyze the epidemiology and risk factors for invasive fungal disease (IFD) after engraftment in alloSCT are few in number. This single-center retrospective study included 404 alloSCT adult recipients surviving >40 days who engrafted and were discharged without prior IFD. All patients who received ⩾20 mg/day of prednisone were assigned to primary oral prophylaxis (itraconazole or low-dose voriconazole). The primary end point was the cumulative incidence (CI) of probable/proven IFD using the European Organization for Research and Treatment of Cancer and Mycoses Study Group (EORTC/MSG) criteria. The independent prognostic factors after multivariate analyses were used to construct a post-engraftment IFD risk score. The 1-year CI of IFD was 11%. The non-relapse mortality was 40% in those developing IFD and 16% in those who did not. The intent-to-treat analysis showed that 17% of patients abandoned the assigned prophylaxis. Age >40 years, ⩾1 previous SCT, pre-engraftment neutropenia >15 days, extensive chronic GVHD and CMV reactivation were independent risk factors. The post-engraftment IFD score stratified patients into low risk (0-1 factor, CI 0.7%), intermediate risk (2 factors, CI 9.9%) and high risk (3-5 factors, CI 24.7%) (P<0.0001). The antifungal prophylaxis strategy failed to prevent post-engraftment IFD in 11% of alloSCT. Our risk score could be useful to implement risk-adapted strategies using antifungal prophylaxis after engraftment.

Cytomegalovirus infection in seropositive unrelated cord blood recipients: a study of 349 Korean patients

To gain insight into the natural history of cytomegalovirus (CMV) infection following unrelated cord blood transplantation (UCBT) in seropositive patients, we analyzed the data of 349 seropositive patients who received UCBT in Korea between 2000 and 2011. CMV reactivation occurred in 49 % (171/349) of the CMV-seropositive transplant recipients at a median of 31 days post UCBT. One hundred sixty-four out of 171 patients (96 %) received preemptive therapy. The median duration of CMV reactivation was 29 days. In multivariate analysis, weight >22 kg, use of total body irradiation, use of pre-transplant antithymocyte globulin, graft-versus-host disease (GVHD) prophylaxis with mycophenolate mofetil, and presence of grade II-IV acute GVHD were independent predictors of CMV reactivation. CMV reactivation did not impact transplantation-related mortality (TRM), leukemia relapse, or survival. CMV disease was diagnosed in 62 patients (17.8 %) at a median 55 days after UCBT. Longer duration of CMV reactivation was the only risk factor for progression to CMV disease (p = 0.01). CMV disease resulted in higher TRM (56.0 vs. 31.4 %, p < 0.01) and lower survival (36.1 vs. 55.1 %, p = 0.02).

EBV-associated post-transplant lymphoproliferative disorder after umbilical cord blood transplantation in adults with hematological diseases

We analyzed the incidence, clinicopathological features, risk factors and prognosis of patients with EBV-associated post-transplant lymphoproliferative disorder (EBV-PTLD) in 288 adults undergoing umbilical cord blood transplantation (UCBT) at a single institution. Twelve patients developed proven EBV-PTLD at a median time of 73 days (range, 36-812). Three-year cumulative incidence (CI) of EBV-PTLD was 4.3% (95% CI: 1.9-6.7). All patients presented with extranodal involvement. Most frequently affected sites were the liver, spleen, central nervous system (CNS), Waldeyer's ring and BM in 7, 6, 4, 3 and 3 patients, respectively. One patient had polymorphic and 11 had monomorphic EBV-PTLD (7 diffuse large B-cell lymphomas not otherwise specified, 4 plasmablastic lymphomas). We confirmed donor origin and EBV infection in all histological samples. EBV-PTLD was the cause of death in 11 patients at a median time of 23 days (range, 1-84). The 3-year CI of EBV-PTLD was 12.9% (95% CI: 3.2-22.5) and 2.6% (95% CI: 0.5-4.7) for patients receiving reduced-intensity conditioning (RIC) and myeloablative conditioning, respectively (P<0.0001). In conclusion, adults with EBV-PTLD after UCBT showed frequent visceral and CNS involvement. The prognosis was poor despite routine viral monitoring and early intervention. An increased risk of EBV-PTLD was noted among recipients of RIC regimens.

Myeloablative cord blood transplantation in adults with acute leukemia: comparison of two different transplant platforms

We compared the clinical outcomes of adults with acute leukemia that received single-unit umbilical cord blood transplantation (sUCBT) after conditioning with a busulfan/antithymocyte globulin (BU-ATG)-based regimen at University Hospital La Fe (n = 102) or double-unit UCBT (dUCBT) after conditioning with a total body irradiation (TBI)-based regimen at the University of Minnesota (n = 91). Nonrelapse mortality, relapse and disease-free survival were similar in the 2 groups. Multivariate analyses, showed more rapid neutrophil (hazard ratio [HR], .6; 95% confidence interval [CI], .45 to .80; P = .0006) and platelet recovery (HR, .59; 95% CI, .43 to.83; P = .002) after the BU-ATG-based conditioning and sUCBT. Although there was a lower risk of acute graft-versus-host disease (GVHD) grade II to IV (HR, 2.81; 95% CI, 1.75 to 4.35; P < .001) after BU-ATG and sUCBT, the incidences of grade III to IV acute and chronic GVHD were similar between the 2 groups. Regarding disease-specific outcomes, disease-free survival in both acute myeloid leukemia and acute lymphoblastic leukemia (ALL) patients were not significantly different; however, a significantly lower relapse rate was found in patients with ALL treated with TBI and dUCBT (HR, .3; 95% CI, .12 to .84; P = .02). In the context of these specific treatment platforms, our study demonstrates that sUCB and dUCBT offer similar outcomes.

Impact of graft-versus-host disease prophylaxis on outcomes after myeloablative single-unit umbilical cord blood transplantation

Myeloablative single-unit umbilical cord blood transplantation (sUCBT) using busulfan, thiotepa, fludarabine, and antithymocyte globulin (Grupo Español de Trasplante Hematopoyético [GETH]-2005 protocol) resulted in high rates of engraftment and high antitumor activity. We designed a new graft-versus-host disease prophylaxis, substituting long-term steroids with mycophenolate mofetil together with a slight reduction of antithymocyte globulin (GETH/Gruppo Italiano Trapianto Midollo Osseo [GITMO]-2008 protocol). The results in 145 consecutive patients were compared with those obtained in 88 patients from the previous GETH-2005 trial. The cumulative incidence (CI) of myeloid engraftment at 60 days for patients in the GETH-2005 and GETH/GITMO-2008 trials was 94% and 88%, respectively, at a median time to neutrophil recovery of 19 and 23 days, respectively (P < .0001). In the multivariable analyses, platelet engraftment, acute and chronic graft-versus-host disease, nonrelapse mortality, relapse, and event-free survival were not significantly different. The 3-year event-free survival rate in the GETH/GITMO-2008 trial was 66%, 31%, and 25% for patients transplanted in early, intermediate, and advanced stages of the disease, respectively (P < .0001). This study confirms that myeloablative sUCBT using busulfan-based conditioning is a valuable strategy for patients with hematological malignancies. The use of mycophenolate mofetil apparently had an adverse effect on myeloid engraftment, and therefore a cautious use of this agent is warranted in the UCBT setting.

Distinct clinical features of infectious complications in adult T cell leukemia/lymphoma patients after allogeneic hematopoietic stem cell transplantation: a retrospective analysis in the Nagasaki transplant group

Although allogeneic hematopoietic stem cell transplantation (allo-SCT) is performed as a curative option in adult T cell leukemia-lymphoma (ATL) patients, its high transplantation-related mortality raises a serious issue. The clinical features of infectious complications after transplantation are not well known. To analyze the impact of infections after allo-SCT for ATL, we retrospectively compared infectious complications in 210 patients at 3 institutions in Nagasaki prefecture between 1997 and 2009. There were 91 patients with acute myeloid leukemia (AML), 51 with acute lymphoblastic leukemia/lymphoblastic lymphoma (ALL/LBL), and 68 with ATL. No patient received ganciclovir or foscarvir as prophylaxis, and most patients received antifungal prophylaxis with fluconazole or itraconazole. The cumulative incidence of cytomegalovirus (CMV) infection at 3 years was 69.2% in ATL patients versus 54.4% in AML patients (P = .0255). Cumulative infection-related mortality was significantly higher in ATL patients than in the 2 other groups (ATL versus AML, P = .0496; ATL versus ALL/LBL, P = .0075), and most death-causing pathogens were bacteria and fungus. The appearance of CMV infection was negatively associated with infectious mortality in ATL patients, but the P value for this association was near the borderline of significance (P = .0569). In multivariate analysis, transplantation using unrelated bone marrow and episodes of CMV infection were associated with worse overall survival in ATL patients, but were not in either AML or ALL/LBL patients. Collectively, the impact of infectious complications after transplantation in ATL patients was different from that in AML and ALL/LBL patients, suggesting that a more intensive strategy for infection control in ATL patients is required to reduce infectious mortality.

Reconstitution of protective immune responses against cytomegalovirus and varicella zoster virus does not require disease development in pediatric recipients of umbilical cord blood transplantation

CMV and varicella zoster virus (VZV) are significant causes of morbidity and mortality following umbilical cord blood transplantation (UCBT). However, the kinetics of reconstitution and protective potential of antiviral cell-mediated immune responses following UCBT remain poorly characterized. In this study, the reconstitution of CMV- and VZV-specific T cell responses was assessed using IFN-γ ELISPOT in 28 children who underwent UCBT to treat hematological or inherited disorders. Barely detectable in the first 3 mo posttransplantation, CMV- and VZV-specific T cell responses were observed in 30.4% and 40.3% of study subjects after 36 mo of follow-up. Four of five CMV-seropositive subjects developed detectable levels of circulating CMV DNA (DNAemia), and 5 of 17 VZV-seropositive patients experienced herpes zoster during the posttransplant period. Four CMV-seronegative subjects developed IFN-γ responses against CMV, and four subjects developed a VZV-specific IFN-γ response without clinical signs of infection. No CMV- or VZV-related events were observed in study subjects following the development of CMV- or VZV-specific responses > 150 spot-forming units/10(6) PBMCs, consistent with T cell-mediated protection. Finally, famciclovir prophylaxis did not strictly prevent the reconstitution of the VZV-specific T cell repertoire, because the frequency of T cells producing IFN-γ in response to VZV Ags reached levels consistent with protection in two nonzoster subjects. Monitoring of CMV- and VZV-specific cell-mediated immunity could inform immunocompetence and guide the initiation and cessation of antiherpetic prophylaxis in UCBT recipients.

Single-unit umbilical cord blood transplantation from unrelated donors in patients with hematological malignancy using busulfan, thiotepa, fludarabine and ATG as myeloablative conditioning regimen

Attempts to optimize outcomes in cord blood transplantation (CBT) by using new conditioning regimens and standardization of cord blood unit selection are warranted. In all, 88 patients (18 children and 70 adults) with hematological malignancy from nine Spanish institutions underwent a single-unit CBT after an i.v. BU-based myeloablative conditioning regimen. All evaluable patients except one engrafted. The overall cumulative incidence (CI) of myeloid engraftment was 94% at a median time of 19 days. In multivariate analysis, nonadvanced disease stage was the only factor with a favorable impact on myeloid engraftment. The CI of acute GVHD grades II-IV and chronic extensive GVHD were 24% each. The CI of nonrelapse mortality at 100 days, 180 days and 5 years was 14, 23 and 44%, respectively. The 5-year CI of relapse was 18%, whereas disease-free survival (DFS) was 46%, 39% and 11% for patients transplanted in early, intermediate and advanced stages of the disease, respectively. Our study shows high rates of engraftment with fast neutrophil recovery in patients undergoing single-unit CBT using a BU-based conditioning regimen. Long-term DFS can be achieved in a substantial number of patients with high-risk hematological malignancies, particularly when transplanted in an early stage of the disease.

Intensive strategy to prevent CMV disease in seropositive umbilical cord blood transplant recipients

Seropositive umbilical cord blood transplant (UCBT) recipients are at increased risk for CMV complications. To reduce CMV complications, we adopted an intensive strategy that consisted of ganciclovir administered before transplantation (5 mg/kg intravenously daily from day -8 to day -2), high-dose acyclovir (2 g, 3 times daily) after transplantation, and biweekly monitoring with a serum CMV PCR for preemptive therapy. Hazard rates and cumulative incidence of CMV complications along with days treated were compared in high-risk CMV-seropositive UCBT recipients who received the intensive strategy and a historical cohort who received a standard strategy. Of 72 seropositive patients, 29 (40%) received standard prophylaxis and 43 (60%) the new intensive approach. The hazard rate (HR) for CMV reactivation was lower for patients receiving the intensive strategy (HR 0.27, 95% confidence interval 0.15-0.48; P < .001) and led to fewer cases of CMV disease by 1 year (HR 0.11, 95% confidence interval 0.02-0.53; P = .006). In patients who reactivated, the intensive strategy also led to fewer days on CMV-specific antiviral therapy (median 42% [interquartile range 21-63] vs 70% [interquartile range 54-83], P < .001). Use of an intensive CMV prevention strategy in high-risk CMVseropositive UCBT recipients results in a significant decrease in CMV reactivation and disease.

An overview of the progress on double umbilical cord blood transplantation

Umbilical cord blood transplantation has been increasingly used over the past years for both malignant and non-malignant hematologic and other diseases as an alternative to mismatched-related or matched-unrelated bone marrow or peripheral blood hematopoietic stem cell transplantation. A disadvantage of cord blood is its low cell content which limits cord blood transplantation to generally low weight recipients, such as children. Various alternatives have been used to overcome this limitation, including co-infusion of two partially HLA-matched cord blood units. According to Eurocord Registry data, this strategy has been applied in approximately 993 adult patients with hematologic diseases since the first double umbilical cord blood transplantation in 1999. In fact, since 2005, the number of adult patients receiving double umbilical cord blood transplantation has surpassed the number of adults transplanted with single cord blood units. The engraftment rate is comparable for both single and double umbilical cord blood transplantation, although the latter is accompanied by a higher incidence of grade II acute graft-versus-host disease and lower leukemia relapse for patients in first complete remission. In the majority of patients undergoing double umbilical cord blood transplantation, transient chimerism, due to the presence of cells from both donor units early post transplant, is replaced by sustained dominance of one unit from which long-term hematopoiesis is derived. Although the biology and the factors that determine unit dominance have not been clarified, the implication of immune-mediated mechanisms has been reported. Preliminary data have demonstrated the safety of double umbilical cord blood transplantation. Ongoing clinical trials and prolonged follow up of the patients will clarify the immunology and determine the efficacy of this approach. We present here a brief overview of the clinical experience on double umbilical cord blood transplantation and its underlying biology.

High efficacy and low toxicity of short-course oral valganciclovir as pre-emptive therapy for hematopoietic stem cell transplant cytomegalovirus infection

BACKGROUND

Cytomegalovirus (CMV) infection is a major infectious complication post-allogeneic hematopoietic stem cell transplantation (HSCT). CMV seropositivity in Eastern Mediterranean and certain Asian countries is reported to be close to 100%; hence, the need for effective pre-emptive treatment strategy that has low toxicity. Valganciclovir (VGC) is a prodrug of ganciclovir with high bioavailability.

PATIENTS AND METHODS

HSCT patients with documented CMV infection (as defined by positive CMV antigenemia) were treated as outpatients with VGC at a starting dose of 900 mg twice daily for 1 week. Those who were antigenemia negative after one week received 900 mg once daily for another week and treatment was subsequently discontinued. Those who were positive after one week of therapy continued on the twice-daily treatment schedule for another week and changed to a daily schedule once they converted to antigenemia negativity.

RESULTS

From January 2004 to December 2007, 47 HSCT patients received preemptive treatment with VGC for 61 episodes of CMV infection. The antigenemia range was 1 to 700 infected cells/slide. Complete responses were observed in 92% and 97% after the 1st and 2nd week of treatment, respectively. Three percent of the episodes were considered refractory, requiring alternative therapy. No CMV disease was observed in this cohort.

CONCLUSION

Neutropenia was the main observed toxicity, requiring granulocyte-colony stimulating factor in 8 episodes. Outpatient treatment of CMV infection with "short-course oral VGC" given as a one-week twice-daily treatment and one week once daily maintenance is a highly effective therapy with minimal toxicity. These results require validation in a larger, randomized study.

Current status of pediatric umbilical cord blood transplantation in Korea: a multicenter retrospective analysis of 236 cases

We report the outcome of 236 pediatric umbilical cord blood transplantations (UCBT) performed in Korea. Given that the sources of the grafts were mostly unrelated donors (n = 226; 95.8%), only the results of unrelated UCBT were included for all statistics. The most frequent primary disease was acute leukemia (n = 167). In total, 91.7% of recipients were seropositive for cytomegalovirus (CMV). The median doses of nucleated cells and CD34+ cells were 4.84 × 10(7)/kg and 2.00 × 10(5)/kg, respectively. The median times to neutrophil (>0.5 × 10(9)/L) and platelet recovery (>20 × 10(9)/L) were 18 and 45 days, respectively. Grade 2-4 acute graft-versus-host-disease (GVHD) and chronic GVHD developed in 41.1 and 36.1% of cases, respectively. Forty-five patients developed CMV disease. The 5-year overall and event-free survival were 47.5 and 36.9%, respectively. Multivariate analysis revealed that adverse factors for survival of the whole cohort were total body irradiation-based conditioning (P = 0.007), salvage transplant (P = 0.001), failure to achieve early complete chimerism (P < 0.0005), and CMV disease (P = 0.001). The outcomes of the single- and double-unit UCBT (n = 64) were similar, while double-unit recipients were heavier (P < 0.0005) and older (P < 0.0005). We conclude that double-unit UCBT is a reasonable option for older or heavier children and that the thorough surveillance of CMV infection and the development of an effective CMV therapeutic strategy may be especially important for Korean children, whose CMV seroprevalence exceeds 90%.

Double umbilical cord blood transplantation for children and adolescents

Umbilical cord blood transplantation (UCBT) with two units has been conducted with promising results in adults to overcome the limitation of low cell numbers. In an attempt to improve the outcomes, double UCBT was performed in children and adolescents. Sixty-one patients, including 44 acute leukemia, and 17 other hematologic diseases, received double UCBT. Donor-type engraftment achieved in 82% of patients. Except one patient with persistent mixed chimerism of two units, other 49 patients showed dominancy of one unit and only the CFU-GM was significant factor influencing dominancy. The event-free survival (EFS) of leukemia and other hematologic disease were 59% and 53%, respectively, and the EFS of acute leukemia patients who received transplant in first or second CR (68.6%) was significantly better than in those with advanced disease (22.2%) (P = 0.007). Among the factors influencing outcomes, low cell dose difference between two units (TNC difference/TNC of large unit <15%) were associated with higher TRM, relapse, and lower EFS. Double UCBT was a promising modality of transplant in children and adolescence. However, engraftment and other results were not so satisfactory yet. To improve the outcomes, development of new selection guideline, probably including cell dose difference between two units and technology to enhance engraftment and reduce transplantation-related mortality are warranted.

Cord blood transplantation for haematological malignancies: conditioning regimens, double cord transplant and infectious complications

Growing evidence supports the efficacy of cord blood transplantation (CBT) to treat patients with haematological malignancies, and the number of CBTs is rapidly increasing. Herein, we review considerations regarding conditioning regimens for CBT, the impact of double unit transplantation on CBT outcomes, and data regarding infectious complications following CBT.

Impact of cytomegalovirus (CMV) reactivation after umbilical cord blood transplantation

This study investigated the impact of pretransplant cytomegalovirus (CMV) serostatus and posttransplant CMV reactivation and disease on umbilical cord blood transplant (UCBT) outcomes. Between 1994 and 2007, 332 patients with hematologic malignancies underwent UCBT and 54% were CMV seropositive. Pretransplant recipient CMV serostatus had no impact on acute or chronic graft-versus-host disease (aGVHD, cGVHD), relapse, disease-free survival (DFS), or overall survival (OS). There was a trend toward greater day 100 treatment-related mortality (TRM) in CMV-seropositive recipients (P=.07). CMV reactivation occurred in 51% (92/180) of patients with no difference in myeloablative (MA) versus reduced-intensity conditioning (RIC) recipients (P=.33). Similarly, reactivation was not influenced by the number of UCB units transplanted, the degree of HLA disparity, the CD34(+) or CD3(+) cell dose, or donor killer cell immunoglobulin-like receptor (KIR) gene haplotype. Rapid lymphocyte recovery was associated with CMV reactivation (P=.02). CMV reactivation was not associated with aGVHD (P=.97) or cGVHD (P=.65), nor did it impact TRM (P=.88), relapse (P=.62), or survival (P=.78). CMV disease occurred in 13.8% of the CMV-seropositive patients, resulting in higher TRM (P=.01) and lower OS (P=.02). Thus, although recipient CMV serostatus and CMV reactivation have little demonstrable impact on UCB transplant outcomes, the development of CMV disease remains a risk, associated with inferior outcomes.

Expanding multiviral reactive T cells from cord blood

In this article, Hanley and colleagues describe a novel method to rapidly expand polyclonal populations of viral reactive CTLs from naive cord blood T cells that target CMV, adenovirus, and EBV.1