Incidence, nature and mortality of cytomegalovirus infection after double-unit cord blood transplant

Impact of Race and Ethnicity on Outcomes After Umbilical Cord Blood Transplantation

BACKGROUND

Umbilical cord blood transplant (UCBT) improves access to transplant for patients lacking a fully matched donor. Previous Center for International Blood and Marrow Transplant Research (CIBMTR) showed that Black patients had a lower overall survival (OS) than White patients following single UCBT. The current study draws on a larger modern cohort and compares outcomes among White, Latinx, Black, and Asian patients.

OBJECTIVE

To compare outcomes by social determinants of health.

STUDY DESIGN

We designed a retrospective study using CIBMTR data. US patients were between ages 1 and 80; 983 received single and 1529 double UCBT as reported to CIBMTR, following either a myeloablative (N = 1752) or reduced intensity conditioning (N = 759) for acute myeloid leukemia, acute lymphoid leukemia, or myelodysplasia. The primary outcome was 2-year OS. Secondary outcomes included disease free survival, transplant related mortality (TRM), acute and chronic graft vs host disease (GVHD), and GVHD free, relapse free survival (GRFS).

RESULTS

For 1705 adults, in univariate analysis, 2-year OS was 41.5% (99% CI, 37.6 to 45.3) for Whites, 36.1% (99% CI, 28.2 to 44.5) for Latinx, 45.8% (99% CI, 36.7 to 55.1) for Blacks, and 44.5% (99% CI, 33.6 to 55.6) for Asians. In multivariate analysis of adults, Latinx patients had inferior OS compared to black patients (p = .0005, HR 1.45, 99% CI 1.18 to 1.79). OS improved over time for all racial/ethnic groups. GVHD rates were comparable among the different racial/ethnic groups. In the 807 children, the 2-year OS in univariate analysis was 66.1% (99% CI, 59.7 to 72.2) for Whites, 57.1% (99%CI, 49 to 64.9) for Latinx, 46.8% (99%CI, 35.3 to 58.4) for Blacks, and 53.8% (99%CI, 32.7 to 74.2) for Asians. In multivariate analysis, no difference in OS was observed among racial/ethnic groups (p = .051). Grade III/IV acute GVHD was higher in Blacks compared with Whites (p = .0016, HR 2.25, 99% CI 1.36 to 3.74) and Latinx (p = .0016, HR 2.17, 99% CI 1.43 to 3.30). There was no survival advantage to receiving a UCB unit from a donor of similar race and ethnicity, for any racial/ethnic groups, for both children and adults. Black and Latinx adult patients were more likely to live in areas defined as high poverty. Patients from high poverty level areas had worse OS (p = .03), due to a higher rate of TRM (p=0.04). Educational level, and type of insurance did not impact overall survival, GVHD, TRM or other transplant outcomes. Children from areas with a higher poverty level had higher TRM, regardless of race and ethnicity (p = .02). Public health insurance, such as Medicaid, was also associated with a higher TRM (p = .02). However, poverty did not impact pediatric OS, DFS, or other post-transplant outcomes.

CONCLUSIONS

OS for UCBT has improved over time. In adults, OS is comparable among Whites, Blacks, and Asians and lower for Latinx patients. In children, OS is comparable among Whites, Blacks, Latinx, and Asians, but Grade III/IV acute GVHD was higher in Black patients. There was no survival benefit to matching UCB unit and patient by race and ethnicity for adults and children.

Effective CMV prophylaxis with high-dose valaciclovir in allogeneic hematopoietic stem-cell recipients at a high risk of CMV infection

BACKGROUND

Cytomegalovirus (CMV) infection increases mortality and morbidity following allogeneic hematopoietic stem-cell transplantation (alloHSCT). Universal antiviral prophylaxis with letermovir is effective but unsubsidized in Australia. Valaciclovir demonstrates anti-CMV activity in high doses, but few current real-world studies explore its use as primary prophylaxis in high-risk patients post-alloHSCT.

METHODS

We performed a retrospective analysis of alloHSCT recipients at high risk of clinically significant CMV infection (cs-CMVi), defined as a plasma CMV DNA viral load of >400 IU/ml requiring preemptive therapy, or CMV disease. High-risk recipients were CMV seropositive and underwent T-cell depleted, haploidentical or umbilical cord stem-cell transplants. Consecutive patients transplanted from July 2018 to January 2020, treated with valaciclovir 2 g TDS from day +7 to +100 (HD-VALA), were compared to a historical cohort (July 2017-June 2018) who only received preemptive CMV therapy, and standard valaciclovir (SD-VALA) for varicella/herpes prophylaxis. We compared incidence of and time to cs-CMVi.

RESULTS

In the SD-VALA cohort (n = 27, median CMV follow-up duration 259 days), 23/27 (85%) developed cs-CMVi at a median of 39 days. For the HD-VALA cohort (n = 35, median CMV follow-up duration 216 days), 19/35 (54%) developed cs-CMVi, at a median of 68 days. Time to cs-CMVi was significantly longer in HD-VALA cohort (p < .0001). On multivariate analysis, HD VALA reduced the risk of cs-CMVi (HR 0.32, p = .0005).

CONCLUSIONS

In alloHSCT recipients at high risk for cs-CMVi, HD-VALA resulted in lower cumulative reactivation, and delayed reactivation, reducing requirement for preemptive CMV therapy in the early post-engraftment period.

Diagnosis and treatment for the early stage of cytomegalovirus infection during hematopoietic stem cell transplantation

Cytomegalovirus (CMV) infection remains a frequent complication after hematopoietic stem cell transplantation (HSCT) and causes significant morbidity and mortality in transplantation recipients. In this review, we highlight the role of major risk factors that are associated with the incidence of CMV infection. Advances in immunosurveillance may predict CMV infection, allowing early interventions to prevent severe infection. Furthermore, numerous therapeutic strategies against CMV infection after HSCT are summarized. A comprehensive understanding of the current situation of CMV treatment may provide a hint for clinical practice and even promote the development of novel strategies for precision medicine.

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.

The changing impact of cytomegalovirus among hematopoietic cell transplant recipients during the past decade: A single institutional cohort study

BACKGROUND

With advancements in allogeneic hematopoietic cell transplantation (alloHCT), the need for cytomegalovirus (CMV) surveillance persists.

METHODS

We present a retrospective analysis on the impact of CMV with preemptive therapy in 1,065 alloHCT patients with donor and/or recipient CMV seropositivity from 2009-2019.

RESULTS

51% developed clinically significant CMV infection (CMV-CSI); 6.5% had CMV disease. In multivariate analysis stratified by serostatus and preparative regimen the use of ATG (HR 2.97, 95% CI 2.00 to 4.42, P < 0.001) was associated with development of CMV-CSI. Median length of stay for index hospitalization was longer in patients with CMV-CSI (27 d vs 25 d, respectively; P = .002), as were rates (32.9% vs 17.7%; P < .001) and duration (9 d vs 6 d; P < .001) of rehospitalization, and median total inpatient days (28 d vs 26 d; P < .001). Patients with CMV-CSI had higher rates of neutropenia (47% vs 20%; P < .001) and transfusion support (PRBC, median 5 vs 3; P < .001; platelets, median 3 vs 3; P < .001).

CONCLUSION

Preemptive therapy does not negate the impact of CMV-CSI on peri-engraftment toxicity and healthcare utilization. This cohort represents a large single center study on the impact of CMV in the pre-letermovir era and serves as a real-world comparator for assessing the impact of future prophylaxis. This article is protected by copyright. All rights reserved.

Delayed-onset cytomegalovirus infection is frequent after discontinuing letermovir in cord blood transplant recipients

Cytomegalovirus (CMV)-seropositive umbilical cord blood transplantation (CBT) recipients have a high incidence of CMV-associated complications. There are limited data regarding the efficacy of letermovir for preventing clinically significant CMV infection (CS-CMVi), and the impact of letermovir prophylaxis on delayed-onset CMV reactivation after letermovir discontinuation, in CBT recipients. We compared the cumulative incidence of CS-CMVi and CMV detection in 21 CMV-seropositive CBT recipients receiving letermovir prophylaxis with a historical cohort of 40 CBT recipients receiving high-dose valacyclovir prophylaxis. Letermovir was administered on day +1 up to day +98. The cumulative incidence of CS-CMVi was significantly lower by day 98 in the letermovir cohort (19% vs 65%). This difference was lost by 1 year due to a higher incidence of delayed-onset CMV reactivation in the letermovir cohort. No patients developed CMV disease in the letermovir cohort within the first 98 days compared with 2 cases (2.4%) in the high-dose valacyclovir cohort; 2 patients developed CMV enteritis after discontinuing letermovir. Median viral loads were similar in both cohorts. Thus, letermovir is effective at preventing CS-CMVi after CBT, but frequent delayed-onset infections after letermovir discontinuation mandate close monitoring and consideration for extended prophylaxis.

Guidelines for Infection Prophylaxis, Monitoring and Therapy in Cord Blood Transplantation

As an alternative stem cell source, cord blood (CB) has many advantages. However, delayed engraftment, lack of transferred immunity, and a significant incidence of acute graft-versus-host disease renders CB transplant (CBT) recipients at high risk of infectious complications. This guidance written by CBT and infectious disease experts outlines evidence-based recommendations for the prevention and treatment of opportunistic infections in adult patients undergoing CBT. Topics addressed include bacterial, fungal, viral, pneumocystis jirovcii and toxoplasmosis prophylaxis, suggested PCR monitoring for viruses, therapy for the most commonly encountered infections after CBT. We review key concepts including the recent important role of letermovir in the prevention of CMV reactivation. In instances where there is a paucity of data, practice recommendations are provided, including the duration of antimicrobial prophylaxis.

Prophylactic pretransplant ganciclovir to reduce cytomegalovirus infection after hematopoietic stem cell transplantation

OBJECTIVE/BACKGROUND

Cytomegalovirus (CMV) reactivation remains a serious complication after allogeneic hematopoietic cell transplantation (HCT) occurring in approximately 60-70% of CMV-seropositive HCT recipients. CMV reactivation leads to adverse outcomes including end-organ damage, graft-versus-host disease, and graft failure.

METHODS

Ganciclovir was administered pretransplant at 5 mg/kg twice daily intravenously from the start of conditioning to Day T-2 to CMV-seropositive patients receiving their first allogeneic HCT. CMV DNA was monitored weekly until at least Day 100 posttransplant.

RESULTS

A total of 109 consecutive patients were treated, median age 57 (range 20-73) years. Of these, 36 (33%) patients had a CMV reactivation within the first 105 days posttransplant with a median time of reactivation of 52.5 (range 36-104) days posttransplant. The cumulative incidence of CMV reactivation at Day 105 posttransplant was 33.1% (95% confidence interval: 24.4-42.0). One patient developed CMV disease.

CONCLUSION

The use of pretransplant ganciclovir was associated with low incidence of CMV reactivation and disease. These data suggest that pretransplant ganciclovir with preemptive therapy for viral reactivation may be a useful strategy to reduce CMV reactivation. Future prospective trials are needed to compare strategies for CMV prophylaxis.

Robust CD4+ T-cell recovery in adults transplanted with cord blood and no antithymocyte globulin

Quality of immune reconstitution after cord blood transplantation (CBT) without antithymocyte globulin (ATG) in adults is not established. We analyzed immune recovery in 106 engrafted adult CBT recipients (median age 50 years [range 22-70]) transplanted for hematologic malignancies with cyclosporine/mycophenolate mofetil immunoprophylaxis and no ATG. Patients were treated predominantly for acute leukemia (66%), and almost all (96%) underwent myeloablation. Recovery of CD4+ T cells was faster than CD8+ T cells with median CD4+ T-cell counts exceeding 200/mm3 at 4 months. Early post-CBT, effector memory (EM), and central memory cells were the most common CD4+ subsets, whereas effector and EM were the most common CD8+ T-cell subsets. Naive T-cell subsets increased gradually after 6 to 9 months post-CBT. A higher engrafting CB unit infused viable CD3+ cell dose was associated with improved CD4+ and CD4+CD45RA+ T-cell recovery. Cytomegalovirus reactivation by day 60 was associated with an expansion of total, EM, and effector CD8+ T cells, but lower CD4+ T-cell counts. Acute graft-versus-host disease (aGVHD) did not significantly compromise T-cell reconstitution. In serial landmark analyses, higher CD4+ T-cell counts and phytohemagglutinin responses were associated with reduced overall mortality. In contrast, CD8+ T-cell counts were not significant. Recovery of natural killer and B cells was prompt, reaching medians of 252/mm3 and 150/mm3 by 4 months, respectively, although B-cell recovery was delayed by aGVHD. Neither subset was significantly associated with mortality. ATG-free adult CBT is associated with robust thymus-independent CD4+ T-cell recovery, and CD4+ recovery reduced mortality risk.

Adoptive therapy with CMV-specific cytotoxic T lymphocytes depends on baseline CD4+ immunity to mediate durable responses

Adoptive cell therapy using cytomegalovirus (CMV)-specific cytotoxic T lymphocytes (CMV-CTLs) has demonstrated efficacy posttransplant. Despite the predicted limited engraftment of CMV-CTLs derived from third-party donors, partially matched third-party donor-derived CMV-CTLs have demonstrated similar response rates to those derived from primary hematopoietic cell transplantation donors. Little is known about the mechanisms through which adoptive cellular therapies mediate durable responses. We performed a retrospective analysis of patients receiving CMV-CTLs for treatment of CMV viremia and/or disease after allogeneic transplant between September of 2009 and January of 2018. We evaluated whether response to adoptively transferred CMV-CTLs correlated with immune reconstitution (IR), using validated CD4+ IR milestones of 50 × 106/L and 200 × 106/L. In this analysis, a cohort of 104 patients received CMV-CTLs derived from a primary transplant donor (n = 25), a third-party donor (n = 76), or both (n = 3). Response to therapy did not increase the likelihood of achieving CD4+ IR milestones at 1 (P = .53 and P > .99) or 2 months (P = .12 and P = .33). The origin of CMV-CTLs did not impact subsequent CD4+ IR. CMV-CTLs appeared to interact with host immunity in mediating responses. Recipients with a baseline CD4 >50 × 106/L had higher response to therapy (P = .02), improved overall survival (P < .001), and protection from CMV-related death (P = .002). Baseline endogenous immunity appears to improve CMV-related and overall survival in this cohort and can be an important marker at the initiation of therapy.

Letermovir Prophylaxis Decreases Burden of Cytomegalovirus (CMV) in Patients at High Risk for CMV Disease Following Hematopoietic Cell Transplant

Despite effective therapies, cytomegalovirus (CMV) continues to have a significant impact on morbidity and mortality in hematopoietic cell transplant recipients. At particular risk are recipients of alternative grafts such as umbilical cord blood (UCB), haploidentical transplants (haplo), or patients conditioned with T-cell depleting regimens such as anti-thymocyte globulin (ATG). With the approval of letermovir, its impact on high-risk patients is of particular interest. To evaluate the impact of letermovir prophylaxis at our center, we performed a retrospective analysis of 114 high-risk patients who received letermovir as prophylaxis (LET PPX) between January 2018 through December 2019, including 30 UCB and 22 haplo recipients, compared with 637 historical controls with comparable risk between January 2013 and December 2019. By post-transplant day 100 (D+100), letermovir prophylaxis significantly decreased the incidence of both CMV DNAemia compared with controls (45.37% versus 74.1%; P < .001) and clinically significant CMV infection (12.04% versus 48.82%; P < .001). The impact of LET PPX was even more profound on the incidence of clinically significant CMV infection (CSI), defined as the administration of antiviral therapy as preemptive therapy for CMV DNAemia or treatment for CMV disease. CSI was significantly lower in haplo recipients on LET PPX compared with controls (13.64% versus 73.33%; P= .02) and UCB recipients on LET PPX compared with controls (3.45% versus 37.5%; P < .001). No patients on LET primary PPX developed CMV disease in any treatment group by D+100 compared with controls (0% versus 5.34%, respectively; P = .006). Patients on LET PPX had fewer hospitalizations involving initiation of anti-CMV therapy compared with controls (0.93% versus 15.23%, respectively). Our analysis of the largest cohort of patients at high risk for CMV reactivation published to date demonstrates that letermovir prophylaxis significantly reduces the number of patients who receive CMV-active antiviral therapy for either DNAemia or disease due to CMV.

Incidence of viral and fungal complications after utilization of alternative donor sources in hematopoietic cell transplantation

Allogeneic hematopoietic cell transplantation (HCT) remains the only curable option for adult patients with hematologic malignancies. According to guidelines published by the American Society for Transplantation and Cellular Therapy, allogeneic HCT should be offered to all intermediate- and high-risk patients with acute leukemia. While matched-related donor (MRD) grafts continue to be the preferred stem cell source for allogeneic HCT, studies comparing MRD grafts to matched-unrelated donor (MUD) grafts showed comparable outcomes in patients with acute leukemia. Unfortunately, for those without a suitable matched-related graft, the probability of finding a suitable matched-unrelated donor varies significantly depending on racial and ethnic background. With allogeneic HCT procedures increasing year after year due to the increased availability of suitable donors, each of these alternative donor sources merits special clinical considerations, specifically with regard to infections. Infections remain a significant cause of morbidity and mortality after allogeneic transplant, especially in those receiving alternative donor grafts. Due to the high-risk nature associated with these donor grafts, it is important to understand the true risk of developing infectious complications. While there are a multitude of infections that have been described in patients post-allogeneic HCT, this review seeks to focus on the incidence of cytomegalovirus (CMV) and invasive fungal infections (IFI) in adult patients receiving alternative donor source transplantation for hematologic malignancies.

Letermovir prophylaxis through day 100 post transplant is safe and effective compared with alternative CMV prophylaxis strategies following adult cord blood and haploidentical cord blood transplantation

We compared CMV outcomes of three prophylactic approaches used for CBT and haploidentical cord transplants from December 2009 through 2018: letermovir (n = 32) through day 100 post transplant, "valacyclovir day 100" (valacyclovir 2 g orally three times daily through day 100) (n = 60), and "valacyclovir hospital discharge" (valacyclovir 2 g orally three times daily through hospital discharge then acyclovir 800 mg twice daily) (n = 41). Through day 100, none in the letermovir group, six (10%) in the "valacyclovir day 100," and nine (22%) in the "valacyclovir hospital discharge" group required CMV directed treatment (p = 0.005 and 0.06 comparing letermovir to "valacyclovir hospital discharge" and "valacyclovir day 100"). Fewer patients in the letermovir group (n = 7, 22%) had any CMV reactivation versus the "valacyclovir day 100" group (n = 20, 33%) versus the "valacyclovir hospital discharge" group (n = 23, 57%) (p = 0.003 and 0.21 comparing letermovir to "valacyclovir hospital discharge" and "valacyclovir day 100"). Among patients not reactivating CMV before 100 days, reactivation rates between day 100 and 180 were higher in the letermovir and "valacyclovir day 100" groups than the "valacyclovir hospital discharge" group. Letermovir is safe and effective compared with alternative prophylaxis approaches following CBT through day 100. Reactivation and monitoring after day 100 remain potential concerns.

Colon perforation due to antigenemia-negative cytomegalovirus gastroenteritis after liver transplantation: A case report and review of literature

BACKGROUND

Cytomegalovirus (CMV) remains a critical complication after solid-organ transplantation. The CMV antigenemia (AG) test is useful for monitoring CMV infection. Although the AG-positivity rate in CMV gastroenteritis is known to be low at onset, almost all cases become positive during the disease course. We treated a patient with transverse colon perforation due to AG-negative CMV gastroenteritis, following a living donor liver transplantation (LDLT).

CASE SUMMARY

The patient was a 52-year-old woman with decompensated liver cirrhosis as a result of autoimmune hepatitis who underwent a blood-type compatible LDLT with her second son as the donor. On day 20 after surgery, upper and lower gastrointestinal endoscopy (GE) revealed multiple gastric ulcers and transverse colon ulcers. The biopsy tissue immunostaining confirmed a diagnosis of CMV gastroenteritis. On day 28 after surgery, an abdominal computed tomography revealed transverse colon perforation, and simple lavage and drainage were performed along with an urgent ileostomy. Although the repeated remission and aggravation of CMV gastroenteritis and acute cellular rejection made the control of immunosuppression difficult, the upper GE eventually revealed an improvement in the gastric ulcers, and the biopsy samples were negative for CMV. The CMV-AG test remained negative, therefore, we had to evaluate the status of the CMV infection on the basis of the clinical symptoms and GE.

CONCLUSION

This case report suggests a monitoring method that could be useful for AG-negative CMV gastroenteritis after a solid-organ transplantation.

Cytomegalovirus colitis in inflammatory bowel disease and after haematopoietic stem cell transplantation: diagnostic accuracy, predictors, risk factors and disease outcome

BACKGROUND

Concurrent cytomegalovirus (CMV) colitis in inflammatory bowel disease (IBD) and after haematopoietic stem cell transplantation (HSCT) is an important clinical entity associated with high rates of morbidity and mortality.

METHODS

A retrospective study of 47 patients with IBD and 61 HSCT patients was performed regarding the evaluation of diagnostic accuracy of applied methods, predictors, risk factors for CMV disease manifestation, the proportion of patients with antiviral treatment and disease outcome.

RESULTS

The sensitivity of quantitative PCR (qPCR) with a cut-off value of >250 copies/mg for CMV colitis in patients with IBD and HSCT patients was 79% and 92%, respectively. Predictors for CMV colitis in the IBD cohort were anaemia and the presence of endoscopic ulcers. Glucocorticoids, calcineurin inhibitors and >2 concurrent lines of treatment with immunosuppressive drugs could be identified as risk factors for CMV colitis in the IBD cohort with an OR of 7.1 (95% CI 1.7 to 29.9), 21.3 (95% CI 2.4 to 188.7) and 13.4 (95% CI 3.2 to 56.1), respectively. Predictors and risk factors for CMV gastroenteritis in the HSCT cohort was the presence of endoscopic ulcers (OR 18.6, 95% CI 3.3 to 103.7) and >2 concurrent lines of treatment with immunosuppressive drugs. Antiviral therapy was administered in 70% of patients with IBD and 77% of HSCT patients with CMV disease. 71% of antiviral-treated patients with IBD showed an improvement of their disease activity and 14% underwent colectomy. The mortality rate of HSCT patients was 21% irrespective of their CMV status.

CONCLUSIONS

In addition to the implementation of histological methods, qPCR may be performed in patients with suspected high-risk IBD and HSCT patients for CMV colitis. Independent validations of these results in further prospective studies are needed.

Factors associated with cytomegalovirus infection in children undergoing allogeneic hematopoietic stem-cell transplantation

While preemptive therapy with ganciclovir (GCV) for cytomegalovirus (CMV) infection is used following allogeneic hematopoietic stem-cell transplantation (HSCT), risk factors for CMV infection in children undergoing HSCT are poorly understood.We studied CMV reactivation following allogeneic HSCT by retrospectively analyzing pediatric patients who received allogeneic HSCT and preemptive GCV therapy between 1998 and 2016. The level of viremia requiring preemptive GCV therapy was >1 CMV antigen-positive cells per 5 × 10 leukocytes during the antigenemia assay era and >1000 copies/mL in the polymerase chain reaction era. Among 290 at-risk patients, 54 (18.6%) patients had primary CMV infection or CMV reactivation occurring at a median of 76 days (range, 7-234) following HSCT. CMV reactivation occurred in 28.2% (44/156) of CMV-seropositive transplant recipients at a median of 26 days posttransplant.Univariate and multivariate analyses revealed statistically significant relationships between CMV infection and grade III-IV acute graft-vs-host disease, seronegative donor/seropositive recipient combination, and unrelated/mismatched donors. The remaining demographic factors were not predictive of CMV infection.The seronegative donor/seropositive recipient combination for HSCT was associated with an incomplete response to antiviral therapy. Human leukocyte antigen identical donors were the best choice for patients undergoing allogeneic HSCT to reduce the incidence of CMV disease and mortality.

Intrabone transplant provides full stemness of cord blood stem cells with fast hematopoietic recovery and low GVHD rate: results from a prospective study

Umbilical Cord Blood (UCB) represents a valid option for patients with hematopoietic malignancies lacking an HLA matched donor. To overcome the limitation of the low stem cell dose of UCB, the intrabone (IB) route has been proposed. We report the results of a prospective study on a poor-prognosis cohort of 23 patients receiving intrabone single UCB transplant (Clinicaltrials.gov NCT00886522). Cumulative incidence of hematological recovery at day 90 was 82 ± 9% (ANC > 0.5 × 10⁹/L) and 70 ± 10% (platelet > 50 × 10⁹/L) and correlated with CD34 + cells in the graft. NRM was 20 ±  9%. No severe aGVHD and only one extensive cGVHD occurred, with fast immune reconstitution. To test the hypothesis that the direct IB injection could affect the expression of stem cells regulatory pathways, CD34 + cells from BM aspirates at day + 10, + 20, + 30, processed in hypoxic conditions mimicking the BM-microenvironment (7%pO₂), were studied for the expression of c-Mpl, Notch1 and CXCR4. We found that the expression of c-Mpl in CD34 + cells at day + 10 significantly correlated with hematological recovery. In conclusion, IB-UCB transplant success is associated with low incidence of GVHD and high-speed platelet recovery; intrabone route may preserve full hematopoietic stemness by direct delivery of UCB stem cells into the hypoxic HSC niche.

A Modified Intensive Strategy to Prevent Cytomegalovirus Disease in Seropositive Umbilical Cord Blood Transplantation Recipients

We previously demonstrated a lower rate of cytomegalovirus (CMV) reactivation and disease among seropositive umbilical cord blood transplantation (CBT) recipients receiving an intensive prophylaxis strategy consisting of ganciclovir on days -8 to -2 pretransplantation, high-dose valacyclovir post-transplantation, and twice-weekly serum CMV polymerase chain reaction testing. We hypothesized that a modified intensive strategy excluding pretransplantation ganciclovir would be similarly effective. We compared the risk of CMV reactivation, occurrence of CMV disease, and duration of anti-CMV therapy by day 100 post-CBT in patients receiving the modified intensive and intensive strategies. Forty patients received the modified intensive strategy, and 43 received the intensive strategy. There was no difference in the hazard for CMV reactivation (hazard ratio, 1.1; P = .77). No patients in the modified intensive cohort, but 2 patients in the intensive cohort, developed CMV disease (P = .53). There was no difference in the hazard for early (≤30 days post-CBT; P = .76) or high-level (>1000 IU/mL; P = .37) CMV reactivation. Patients in the modified intensive cohort had marginally higher CMV viral loads and percentage of days of CMV detection and treatment, although the contribution of pretransplantation ganciclovir to these differences is unclear. The overall percentage of treatment days was 32% in both cohorts after accounting for pretransplantation ganciclovir. In conclusion, exclusion of prophylactic ganciclovir before CBT did not impact the risk of CMV reactivation or disease, although CMV kinetics appeared to differ by prevention strategy. Best practices for CMV prevention will need further study as new prophylactic strategies become available.

Cytomegalovirus viral load in cord blood and impact of congenital infection on markers of hematopoietic progenitor cell potency

BACKGROUND

The low incidence of cytomegalovirus (CMV) infection in neonates decreases the risk of viral transmission with cord blood transplantation. Cord blood donors are screened by testing the maternal sample for total antibodies to CMV. Some cord blood banks also screen cord blood for CMV-DNA. The aim of this study was to develop and validate a multiplex real-time polymerase chain reaction assay to measure CMV viral load in cord blood from asymptomatic infants with congenital CMV infection and to assess the impact of CMV infection on cord blood hematopoietic progenitor cell concentrations and colony-forming unit functionality.

STUDY DESIGN AND METHODS

CMV infection was evaluated in two groups of cord blood donors: 1) 30,308 neonates prospectively screened by saliva culture, including 41 positive cases (0.14%), all from mothers with total antibodies to CMV; and 2) 4712 newborns from mothers with total antibodies to CMV who were screened retrospectively by polymerase chain reaction, including 18 positive cases (0.38%). All 59 infants with CMV were asymptomatic at birth.

RESULTS

cells, and total nucleated cells measured in a cohort of CMV-positive cord blood samples were higher than those in the matched control group.

CONCLUSION

cells and some hematopoietic progenitor cells toward higher proliferation.

Optimal Practices in Unrelated Donor Cord Blood Transplantation for Hematologic Malignancies

Unrelated donor cord blood transplantation (CBT) results in disease-free survival comparable to that of unrelated adult donor transplantation in patients with hematologic malignancies. Extension of allograft access to racial and ethnic minorities, rapid graft availability, flexibility of transplantation date, and low risks of disabling chronic graft-versus-host disease (GVHD) and relapse are significant advantages of CBT, and multiple series have reported a low risk of late transplantation-related mortality (TRM) post-transplantation. Nonetheless, early post-transplantation morbidity and TRM and the requirement for intensive early post-transplantation management have slowed the adoption of CBT. Targeted care strategies in CBT recipients can mitigate early transplantation complications and reduce transplantation costs. Herein we provide a practical "how to" guide to CBT for hematologic malignancies on behalf of the National Marrow Donor Program and the American Society of Blood and Marrow Transplantation's Cord Blood Special Interest Group. It shares the best practices of 6 experienced US transplantation centers with a special interest in the use of cord blood as a hematopoietic stem cell source. We address donor search and unit selection, unit thaw and infusion, conditioning regimens, immune suppression, management of GVHD, opportunistic infections, and other factors in supportive care appropriate for CBT. Meticulous attention to such details has improved CBT outcomes and will facilitate the success of CBT as a platform for future graft manipulations.

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.

Does GVHD make amateurs out of professional APCs?

In this issue of Blood, Wikstrom and colleagues highlight antigen-presenting cell (APC) dysfunction as a potential cause of impaired antiviral immunity in graft-versus-host disease (GVHD).

High Disease-Free Survival with Enhanced Protection against Relapse after Double-Unit Cord Blood Transplantation When Compared with T Cell-Depleted Unrelated Donor Transplantation in Patients with Acute Leukemia and Chronic Myelogenous Leukemia

Double-unit cord blood (DCB) grafts are a rapidly available stem cell source for adults with high-risk leukemias. However, how disease-free survival (DFS) after DCB transplantation (DCBT) compares to that of unrelated donor transplantation (URDT) is not fully established. We analyzed 166 allograft recipients (66 8/8 HLA-matched URDT, 45 7/8 HLA-matched URDT, and 55 DCBT) ages 16 to 60 years with high-risk acute leukemia or chronic myelogenous leukemia (CML). URDT and DCBT recipients were similar except DCBT recipients were more likely to have lower weight and non-European ancestry and to receive intermediate-intensity conditioning. All URDT recipients received a CD34(+) cell-selected (T cell-depleted) graft. Overall, differences between the 3-year transplantation-related mortality were not significant (8/8 URDT, 18%; 7/8 URDT, 39%; and DCBT, 24%; P = .108), whereas the 3-year relapse risk was decreased after DCBT (8/8 URDT, 23%; 7/8 URDT, 20%; and DCBT 9%, P = .037). Three-year DFS was 57% in 8/8 URDT, 41% in 7/8 URDT, and 68% in DCBT recipients (P = .068), and the 3-year DFS in DCBT recipients was higher than that of 7/8 URDT recipients (P = .021). In multivariate analysis in acute leukemia patients, factors adversely associated with DFS were female gender (hazard ratio [HR], 1.68; P = .031), diagnosis of acute lymphoblastic leukemia (HR, 2.09; P = .004), and 7/8 T cell-depleted URDT (HR, 1.91; P = .037). High DFS can be achieved in adults with acute leukemia and CML with low relapse rates after DCBT. Our findings support performing DCBT in adults in preference to HLA-mismatched T cell-depleted URDT and suggest DCBT is a readily available alternative to T cell-depleted 8/8 URDT, especially in patients requiring urgent transplantation.

Monitoring of cytomegalovirus viral loads by two molecular assays in whole-blood and plasma samples from hematopoietic stem cell transplant recipients

Cytomegalovirus (CMV) viral loads in hematopoietic stem cell transplant (HSCT) recipients are typically monitored using quantitative molecular assays. The Roche Cobas AmpliPrep/Cobas TaqMan CMV test (Cobas CMV) has recently been cleared by the FDA for the monitoring of CMV viral loads in plasma samples from transplant patients. In this study, we compare and correlate the viral loads obtained by a laboratory-developed test (LC CMV) (using Roche analyte-specific reagents [ASR] on the LightCycler 2.0) on whole-blood specimens with those obtained on corresponding plasma and whole-blood specimens by the Cobas CMV assay. Testing was performed on 773 archived patient specimens. The strength of the agreement was good for the two assays performed on whole blood (κ=0.6; 95% confidence interval [CI], 0.51 to 0.7) and moderate when the tests were performed on different sample types (κ=0.54; 95% CI, 0.47 to 0.62 for the LC CMV whole blood [WB] assay versus Cobas plasma [PL], and κ=0.57; 95% CI, 0.5 to 0.65 for the Cobas WB assay versus Cobas PL), although the difference was not statistically significant. Using a combination gold standard (i.e., a true positive was a specimen that was positive by two or more methods), the sensitivity and specificity of the assays were 78.8% and 99.3% for the LC CMV assay, 85.2% and 98.1% for the Cobas CMV WB assay, and 100% and 90.5% for Cobas CMV PL assay, respectively. A comparison of the CMV viral load trends in both plasma and whole blood from a few patients with multiple positive successive samples showed similar slopes, with differences in the slope ranging from 0.01 to 0.22. However, the absolute value for individual viral load differed markedly with whole-blood viral loads, being on average 0.5- to 1.22-log higher than those in plasma. The Cobas CMV assay provides a valid option for the monitoring of viral loads in transplant patients. Due to its increased sensitivity, the detection of CMV DNA in patients with low viral loads (i.e., those below limit of quantification [LOQ]) is increased with the Cobas CMV assay in plasma specimens. Longitudinal prospective studies will be needed to examine the clinical significance of these low-level viral loads.