Umbilical Cord Blood Transplantation Recipients Research Articles

Charlson Comorbidity Index (CCI) Not Hematopoietic Cell Transplantation Specific-Comorbidity Index (HCT-CI) Successfully Predicts Transplant Related Mortality and Post-Transplant Outcomes in Elderly Patients Undergoing Reduced Intensity Conditioning (RIC) Umbilical Cord Blood (UCB) Transplantation

Abstract 3006▪FN2▪This icon denotes a clinically relevant abstractTransplant related mortality (TRM), drug toxicities, life-threatening infections, poor quality of life, and graft versus host disease (GVHD) are significant risks of hematopoietic cell transplantation (HCT). In addition, pre-transplant comorbidities can have significant impact on the transplant outcomes of elderly patients (pts). Two comorbidity measurement tools, the CCI and the HCT-CI have been inconsistent in predicting TRM and overall survival (OS) after conventional HCT. The HCT-CI and CCI scores have correlated less well with TRM and OS in UCB transplantation. These results may have been limited by the heterogeneity of the UCB transplantation study population in age, disease, disease-risk, comorbidities, and conditioning regimens used. This study was performed to explore the accuracy of the HCT-CI and CCI in predicting post-transplant outcomes in elderly pts with high risk hematologic malignancies undergoing uniform RIC UCB transplantation.A retrospective chart review was performed on 35 consecutive elderly (age ≥ 55 years (yrs)) UCB transplant recipients receiving the RIC regimen fludarabine, cyclophosphamide, ATG, and 200 cGy TBI. All pts received cyclosporine and mycophenolate mofetil for GVHD prophylaxis. Information on pre-transplant comorbidities was obtained from each pt’s CIBMTR pre-TED form and retrospective chart reviews. Demographic information, ECOG performance status (PS), identification of comorbidities, and post-transplant outcomes were obtained. HCT-CI and CCI scores were distributed in the following comorbidity risk groups 0, 1, > 1.Between 2002 and 2011, 35 pts underwent UCB transplantation with the above regimen. Median age was 65 yrs (range 55–71), 21 were male (60%) and 14 female (40%). Most pts had advanced stage or high risk hematologic malignancies; 28 had MDS/AML (80%) and 7 had other hematologic malignancies. All pts had a PS ≤ 2. Twenty-seven pts were in CR ≤ 2, with 31 pts having received ≤ 2 prior therapies. Eight pts had received prior transplants, including 2 pts with prior UCB transplantations and 6 pts with prior autografts. UCB cell dose was calculated on actual body weight (median 84 kg, range 56.1–135.1 kg). A total of 66 UCB grafts matched at a minimum 3/6 (3/6 = 4, 4/6 = 34, 5/6 = 22, 6/6 = 6) were infused. Pts received a range of 1 to 5 UCB units (1 unit = 12 pts, 2 units = 19 pts, 3 units = 2 pts, 5 units = 2 pts). VNTR/FISH analyses confirmed engraftment with median time of 21 days (d) (95% CI: 14–40 d) to achieve > 60% chimerism. Nine pts failed to achieve chimerism > 60%, and 3 had secondary engraftment failure. Median time to ANC > 500/μL for 3 consecutive values was 27 d (95% CI: 21–32 d) and median time to platelets > 20, 000/μL on the first day of 7 consecutive days without a platelet infusion was 40 d (95% CI: 35–71 d). No patient developed grade 4 acute GVHD. Grade 3 acute GVHD was seen in 3/35 pts (9%) and chronic GVHD was seen in 6/27 pts (22%). To date 31% (n = 11) of pts have relapsed. Pre-transplant cardiac comorbidities, A-fib/flutter and coronary artery disease, were the most common. Six pts had prior solid tumor malignancies, not active at the time of HCT, including breast (n=2), prostate (n=2), bladder (n=1), and kidney (n=1). After a median follow up of 13 months (range 1–70), 1 yr OS and progression free survival (PFS) were 61% and 55%, respectively. Median PFS and OS were both 16 months (mos) (PFS 95% CI: 8–70 mos, OS 95% CI: 9–70 mos). CCI but not PS or HCT-CI was a significant predictor of OS and PFS (Table and Figure).OS (%)PFS (%)FactorN1 yr2 yr4 yrp-value1 yr2 yr4 yrp-valuePS0175750330.885252350.811-218654534584538CCI01680582267593214100500.04100500.04>115333333333333HCT-CI0125443145644151108069690.296969690.25>113533535453636 [Display omitted] TRM occurred in 8 pts (23%). CCI was associated with TRM (p=0.05): pts with CCI ≥ 2 had a 40% (6/15) TRM vs 10% (2/20) with CCI 0–1. PS (p=0.69) and HCT-CI (p=0.47) did not correlate to TRM.In conclusion, elderly pts undergoing RIC UCB transplantation for high risk hematologic malignancies, the CCI was a statistically significant predictor of TRM, PFS, and OS. This index and not HCT-CI or PS identified elderly pts undergoing RIC UCB transplantation at higher risk of TRM and poor post-transplant outcomes. Larger validation studies of the predictive capacity of these comorbidity indexes need to be performed in the multi-institutional setting. Disclosures:Cooke:Amgen:.

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

AbstractSeropositive 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 transplanta-tion, 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.

CD8+ T-cell reconstitution in recipients of umbilical cord blood transplantation and characteristics associated with leukemic relapse

AbstractRecipients of umbilical cord blood (UCB) transplantation (UCBT) face a high risk of morbidity and mortality related to opportunistic infections (OI) and leukemic relapse. To understand the molecular basis of these UCBT-related complications, the characteristics of UCB-derived antigen-specific CD8+ T cells were examined in a group of pediatric UCBT recipients. Compared with the UCB graft inoculum and the late post-UCBT period (12-36 months), declining clonal diversity of UCB-derived CD8+ T cells specific for the Melan-A26-35 A27L peptide and high frequencies of PD-1-expressing CD8+ T cells were observed in the first 3 months after UCBT, a period during which OIs are most frequent. The CD8+ T-cell compartment predominantly comprised CD45RA+ CCR7− terminally differentiated effector-memory T cells until 6 months after UCBT, at which time the polyfunctionality of antigen-specific CD8+ T cells was reestablished. Finally, the frequency of PD-1+ CD8+ T cells was significantly higher in subjects who subsequently experienced leukemic relapse. This study informs the biologic properties of UCB-derived CD8+ T cells and provides a rationale for the characteristics of UCBT in terms of immune reconstitution and OI. These results also suggest that the elevated frequency of PD-1+ CD8+ T cells could be associated with leukemic relapse in pediatric UCBT recipients.

A comparison of immune reconstitution and graft‐versus‐host disease following myeloablative conditioning versus reduced toxicity conditioning and umbilical cord blood transplantation in paediatric recipients

Immune reconstitution appears to be delayed following myeloablative conditioning (MAC) and umbilical cord blood transplantation (UCBT) in paediatric recipients. Although reduced toxicity conditioning (RTC) versus MAC prior to allogeneic stem cell transplantation is associated with decreased transplant-related mortality, the effects of RTC versus MAC prior to UCBT on immune reconstitution and risk of graft-versus-host disease (GVHD) are unknown. In 88 consecutive paediatric recipients of UCBT, we assessed immune cell recovery and immunoglobulin reconstitution at days +100, 180 and 365 and analysed risk factors associated with acute and chronic GVHD. Immune cell subset recovery, immunoglobulin reconstitution, and the incidence of opportunistic infections did not differ significantly between MAC versus RTC groups. In a Cox model, MAC versus RTC recipients had significantly higher risk of grade II-IV acute GVHD [Hazard Ratio (HR) 6·1, P = 0·002] as did recipients of 4/6 vs. 5-6/6 HLA-matched UCBT (HR 3·1, P = 0·03), who also had significantly increased risk of chronic GVHD (HR 18·5, P = 0·04). In multivariate analyses, MAC versus RTC was furthermore associated with significantly increased transplant-related (Odds Ratio 26·8, P = 0·008) and overall mortality (HR = 4·1, P = 0·0001). The use of adoptive cellular immunotherapy to accelerate immune reconstitution and prevent and treat opportunistic infections and malignant relapse following UCBT warrants further investigation.

Pre-Transplant Ganciclovir and High-Dose Valacyclovir Prophylaxis Decrease Incidence of CMV Reactivation In High-Risk Seropositive UCBT Recipients

AbstractAbstract 678 Background:Umbilical cord blood transplant (UCBT) recipients are high risk for cytomegalovirus (CMV) complications due to delayed and insufficient immune reconstitution. Since CMV viral load has been shown to be associated with the development of disease, an intensified prevention strategy was adopted at the FHCRC (Seattle, WA) which consists of pre-transplant ganciclovir (from day -8 to day -2), and high-dose acyclovir ([HDA] 2 gm valacyclovir 3 times daily) with preemptive bi-weekly monitoring for CMV DNA in serum from day 0 until day +100. Methods:We set out to compare rates of CMV reactivation and disease through day +100 in high-risk CMV seropositive UCBT recipients who received either the intensified strategy (G+HDA) or standard dose of acyclovir/valacyclovir (SDA, acyclovir 800 mg or valacyclovir 500 mg twice daily). All patients underwent weekly plasma testing for CMV by polymerase chain reaction (PCR). Our primary outcomes of interest were any CMV reactivation or disease by day 100. Risk factors for CMV reactivation were assessed using a multivariate Cox proportional hazards model. Results:Of the 105 UCBT recipients transplanted at the FHCRC between 1/2006 and 12/2009, 61 (58%) were CMV seropositive and eligible for inclusion in the cohort. In total, 31/61 (51%) received SDA and 30 (49%) G+HDA. The median patient age was lower in the SDA group 21.3 (interquartile range [IQR] 14.8–46.7) years and 30.1 (IQR 10.1–41.8) for G+HDA group, but other demographic factors were similar. Overall, the cumulative incidence of CMV reactivation was significantly lower in the G+HDA group (60% vs. 96.7; p=0.001 [Gray's test]) (Figure 1). In patients receiving G+HDA, the median time to first positive CMV PCR occurred later (27 days [IQR 11–35]) when compared to those given SDA prophylaxis (17 days [IQR 8–25]) (p=0.26). Additionally, the G+HDA group had significantly lower initial (71 copies/mL [IQR 47–110] vs. 235 [IQR 63–760], p=0.006) and maximum PCR viral loads (VL) (170 copies/ml [IQR 88–310] vs. 3200 [1400-11000], p<0.001) when compared to those receiving SDA prophylaxis. In multivariate analyses, the G+HDA prophylactic strategy was also associated with a significant reduction in CMV reactivation (HR 0.31; 95% CI 0.16–0.58; p<0.001). Over the first 100 days following transplant, there were fewer episodes of invasive CMV disease in the G+HDA group (1/30, 3% [1 pneumonia]) than under SDA prophylaxis (5/31, 16% [1 disseminated, 2 pneumonia, and 2 GI]) (p=0.09). In the SDA group 2/5 (40%) patients died secondary to CMV disease, and an additional 2 patients developed fatal CMV pneumonia after day 100 (day 165 & 191); no CMV related death or cases of late disease developed in the group receiving G+HDA prophylaxis. There was no evidence of increased toxicity by either median and maximum creatinine levels or days to engraftment when comparing the two regimens. [Display omitted] Conclusions:Our study demonstrates that G+HDA was effective in preventing CMV complications in UCBT recipients. This intensified prevention strategy was associated with a decreased rate of CMV reactivation and appeared to significantly alter CMV replication dynamics. Importantly, the increased valacyclovir exposure did not alter the risk for developing either renal or hematologic toxicity. Disclosures:No relevant conflicts of interest to declare.

A Comprehensive Comparison Immune Recovery In Adult Patients Following Allogeneic Umbilical Cord Blood, Matched Sibling and Matched Unrelated Donor Stem Cell Transplantation

AbstractAbstract 2313Immunologic reconstitution following stem cell transplantation (SCT) arises from thymic-independent peripheral expansion of memory T-cells transplanted with the stem cell graft, and thymic-dependent maturation of stem cell derived lymphoid progenitor cells. As a consequence of thymic involution, adult stem cell transplant recipients rely largely upon the thymic-independent pathway. This process is facilitated by a plentiful supply of mature T-cells contained within peripheral blood or bone marrow grafts. Umbilical cord blood (UCB) grafts contain predominantly naive T-cells thereby limiting the potential for thymic-independent immune recovery. Recent reports have documented slow immune recovery in adult UCB recipients, however it has yet to be described in the context of a comparable population of adult allogeneic matched sibling or unrelated donor SCT. Methods:Between 2007 and 2009, we characterized cellular immune reconstitution in a consecutive cohort of adult patients undergoing myeloablative SCT using either matched sibling (MSD), matched unrelated donor (MUD) peripheral blood stem cell (PBSC) or dual UCB donor grafts. Dual UCB transplant recipients were conditioned with TBI 1350cGy and fludarabine 160mg/m2 (Flu). PBSC recipients were conditioned with either TBI 1350cGy or IV busulfan 12.8mg/kg (Bu) and cyclophosphamide 120mg/kg, or Bu/Flu. PBSC grafts were allele-level matched at HLA-A, B, C and DRB1. UCB grafts were mismatched at no more than 2 class I or class II loci. Both cohorts received GvHD prophylaxis with Tacrolimus for at least 6 months. UCB recipients received mycophenolate mofetil 2g/day for at least 60 days instead of standard dose methotrexate GvHD prophylaxis for PBSC recipients. Quantification of the following lymphoid subsets were performed by flow cytometry on fresh peripheral blood prior to, and then at approximately 45, 100, 180, and 360 days following transplantation: NK and NKT cells, B-cells, plasmacytoid dendritic cells, CD3+, CD4+, CD8+, regulatory and na•ve T-cells. T-cell receptor excision circles (sjTREC) were quantified by real time PCR on DNA collected from an isolated fraction of CD3+ T-cells. Cumulative corticosteroid usage prior to day 100 (as determined by area under the curve) was determined as a method for comparing acute GvHD severity. The Kruskal-Wallis test with adjustments for multiple comparisons was used compare immune recovery values at 45, 100, 180 and 360 days post transplantation. The PearsonÕs Chi-square test was used to compare the CMV reactivation rate of UCB to MSD/MUD. Results:Forty-two recipients of allogeneic SCT (MSD-13, MUD-14, UCB-15) with successful donor engraftment and who survived a minimum of 6 months were evaluated. The MSD, MUD and UCB recipients had a median age of 41, 42 and 31 years, respectively (p = 0.13). There was no significant difference in corticosteroid administration before day 100 or chronic GvHD in the three cohorts (p=0.74). There were no differences in the kinetics of immune recovery between MSD and MUD recipients. At 45 days following transplantation, UCB recipients had significantly lower levels of CD4+ (figure), CD8+ and NKT-cells. By day 100, UCB recipients had similar numbers of CD4+ T-cells, but remained lower in the other major T-cell subsets. By day 180 however, all T-cell subsets except NKT cells (p=0.033) were similar to the MSD/MUD recipients. NK cell recovery was faster in the UCB recipients (figure). There was also no difference in B-cell recovery among the 3 cohorts. TREC levels were not significantly different in recipients of all graft types, but were uniformly low (figure). The slow recovery of T-cells in the UCB cohort corresponds with a higher Kaplan-Meier estimate of CMV reactivation compared to the MSD/MUD cohort (90% vs. 36%; p = 0.0078). Conclusion:Compared to HLA-identical MSD and MUD adult SCT recipients, quantitative lymphoid recovery in UCB transplant recipients is slower in the first two months, but these differences are erased by 4–6 months following transplantation. NK reconstitution is more rapid in UCB recipients. Reduction of early opportunistic infections affecting UCB transplant recipients may arise from effective techniques to boost early T-cell recovery. [Display omitted] Disclosures:No relevant conflicts of interest to declare.

Immune Reconstitution After Double Umbilical Cord Blood Transplantation in Adults without In Vivo T Cell Depletion of the Graft.

AbstractAbstract 1246Infusion of two partially matched units can overcome the barrier of cell dose in umbilical cord blood transplantation (UCBT). Besides engraftment, restoration of adaptive immunity remains a major problem resulting in higher transplant-related mortality in UCBT compared to marrow or peripheral blood transplantation. According to reported data, prolonged immunodeficiency in adult recipients of single-unit UCBT is characterized by long-term impairment of thymopoiesis, whereas the impact of double UCBT on immune reconstitution has not been elucidated. We prospectively monitored cellular and humoral immunity in consecutive adult recipients of double UCBT to assess the time frame and pattern of immune reconstitution. From 08/2006 until 07/2010, 27 patients underwent double UCBT at our center. Twenty-two, who fulfilled defined criteria [conditioning without antithymocyte globulin (ATG), sustained donor engraftment, no relapse before day 100], were included in study analysis. Patients received double UCBT for high-risk acute leukemia or lymphoma (AML: 15, ALL: 5, type 2 dendritic cell leukemia: 1, hepatosplenic γδ T-cell lymphoma: 1), at a median age of 37 years (range, 16–59). The conditioning regimen was ablative in 16, and reduced-intensity in 6 cases. The combination of mycophenolate mofetil to calcineurin inhibitor (cyclosporine: 18, or FK506: 4) was used for prevention of acute graft-versus-host disease (GvHD). The majority of units (36/44) were 4/6 matched to recipient at HLA-A, -B, and -DRB1 loci, the remaining being 5/6 matched. Median total nucleated and CD34+ cell doses from both units were 4.36 × 10^7/kg (range, 2.65–6.86) and 1.56 × 10^5/kg (range, 0.6–5.13) at infusion, respectively. Intravenous immune globulin (IVIG) was routinely administered every 2–4 weeks during the first 6 months from transplant. Absolute counts of B, NK, and T lymphocytes as well as serum immunoglobulin levels (prior to infusion of IVIG), were routinely assessed at 1, 2, 3, 6, 9, 12, 15, 18, 24 months, and annually thereafter. Neutrophil engraftment (absolute count >500/μl) was achieved at a median of 19 days (range, 6–52). Twenty patients developed acute GvHD (grade II: 17, grade III-IV: 3). Chronic GvHD occurred in 4 patients, and was extensive in 2. Cytomegalovirus (CMV) infection was detected in 6 out of 16 seropositive recipients (at a median of 58, range 25–116, days after UCBT), and in none of the 6 seronegative. In addition, 5 patients developed HHV-6 infection, and 1 EBV-related lymphoproliferation. Relapse occurred in 4 patients. There were 5 deaths of infection, 3 of GvHD, and 2 of other causes. The absolute counts of T and B cells were extremely low early post transplant, while NK cells recovered from the first month and reached normal values by the second month (median count, 147/μl). The number of CD8+ T cells started to increase from the third month, and exceeded lower normal limit after 6 months (median count, 234/μl). CD4+ T cells remained substantially low (<100/μl) for the first 3 months, increased moderately afterwards, but achieved normal values only at 18 months (median count, 465/μl). CD4+/CD45RA+ naïve T cells were significantly impaired over the first year, but appeared at increasing counts at 18 months (median count, 157/μl) and beyond. CD19+ B cells were severely suppressed for the entire first semester (median count at 3 months, 5/μl), increased to moderate normal counts by 9 months, and showed a marked elevation exceeding normal range between 12 (median count, 985/μl) and 18 months (median count, 1501/μl). Notably, that was consistent with delayed achievement of normal serum IgG levels at 15 months (median, 1130 mg/dl) and normal IgA levels at 24 months (median, 133.5 mg/dl). Our results differ from previously reported data regarding immune reconstitution post UCBT, mainly due to the absence of in vivo T cell depletion in our series. By elimination of ATG from conditioning, we did not observe rapid recovery of B cells in the early post-transplant period. Moreover, B cells remained severely depressed for 6 months, a finding that may be accounted for by the increased incidence of acute GvHD in our series. On the other hand, T cell reconstitution was relatively faster, and a stable rise of naïve CD4+ T cells suggestive of thymopoietic recovery was noted after the first year from transplant. In conclusion, immune reconstitution patterns following UCBT may be divergent depending on the conditioning regimen. Disclosures:No relevant conflicts of interest to declare.

Preemptive therapy of human herpesvirus-6 encephalitis with foscarnet sodium for high-risk patients after hematopoietic SCT

Human herpesvirus-6 (HHV-6) is a major cause of limbic encephalitis with a dismal prognosis after allogeneic hematopoietic SCT (HSCT). A prospective, multicenter study was conducted to assess the safety and efficacy of preemptive therapy with foscarnet sodium (PFA) for the prevention of HHV-6 encephalitis. Plasma HHV-6 DNA was measured thrice weekly from day 7 until day 36 after umbilical cord blood transplantation (UCBT) or HSCT from HLA-haploidentical relatives. PFA, 90 mg/kg/day, was started when HHV-6 DNA exceeded 5 × 10(2) copies/mL. Mild and transient adverse events were associated with PFA in 7 of 8 patients. Twelve of 15 UCBT recipients became positive for HHV-6 DNAemia, defined by greater than 1 × 10(2) copies/mL of HHV-6 DNA in plasma. The virus exceeded 5 × 10(2) copies/mL in seven patients, whereas none of the five HLA-haploidentical HSCT recipients became positive. One patient developed mild limbic encephalitis just after initial PFA administration. Preemptive PFA therapy is safe, but as HHV-6 DNAemia can abruptly develop before neutrophil engraftment in UCBT recipients, prophylactic PFA administration from day 7 or earlier after UCBT may be needed.

Detection and Ex Vivo Expansion of Anti-Viral T Cells Isolated From Recipients of Unrelated Umbilical Cord Blood Transplant.

Abstract 2245Poster Board II-222 Background:Viral infection is commonly detected within the first weeks after umbilical cord blood transplant (UCBT), likely triggering T cell activation and in vivo priming of infused naïve T cells. This hypothesis is supported by the observation that despite the continuous exposure to immunosuppressive (IS) drugs, viremia may resolve even in the absence of antiviral agents. However, IS may delay or even prevent effective T cell priming and the development of protective immunity, therefore causing significant morbidity and mortality. Hypothesis and Objective:Our laboratory has a long standing interest in defining pre-requisites of protective immunity after UCBT. In this study we focused on two of the most common potentially fatal viruses, CMV and Adenovirus to assess antigen-specific immune reconstitution. We hypothesized that 1) threshold numbers of CTL precursors can be identified for each virus that will impact clinical outcome 2) there may be circulating CTL precursors even if below the level of detection in lymphopenic patients that receive IS drugs, however, ex vivo restimulation could lead to expansion and subsequent quantitation. Methods:We have established in vitro assays to test the impact of cytokines and new culture techniques to promote anti-viral precursor survival and expansion. Monocytes in bulk cultures, infected with replication incompetent adenovirus vectors encoding the pp65 CMV matrix protein (Ad5f35pp65), served as APC. Antiviral responses were quantitated by ELISPOT, utilizing computerized enumeration of interferon gamma (IFNg) producing spot forming cells (SFC) in response to overlapping peptide spanning immunodominant viral antigens. Hexon and penton for adenovirus, and pp65 and EI-1 for CMV. Results:There were 8 patients enrolled on this IRB approved study transplanted at a median age of 9.9 years (range 2-17). Blood samples was obtained at a median of 70 days (range 34-470). Only 1 of 3 patients with adenovirus infection ( stool x1, urine x1, respiratory tract x 1) had previous viremia while all five (5) patients with CMV had viremia. Only 1 of the 3 adeno patients had detectable SFC from freshly drawn peripheral blood, 11 SFC/1×10e5 cells against hexon and penton respectively. None of the 5 CMV+ patients had detectable pp65 or EI-1-specific T cell responses from freshly drawn blood. However, after 9-12 days of ex vivo culture, in the presence of IL7 (10ng/ml), we were able to enumerate significantly amplified CTL responses in 7 of the 8 patients, with one CMV viremic the exception. In the remaining patients the median adenovirus hexon-specific response was 52 SFC/1×10e5 cells (range 20-90). the median penton-specific CTLp frequency was 13 SFC/1×10e5 (range 1 - 25). The median CMV pp65-specific response was 6.7 SFC/1×10e5 (range 0-14) while no responses were recorded against EI-1 demonstrating the critical role of antigenic restimulation provided by the Ad5f35pp65 construct lacking IE. The amplified immune responses were highly restricted; in the CMV+ patients (all adeno-) we were able to detect SFC only against pp65 and to neither IE or penton/hexon, while in the adenovirus+/CMV- patients (n=-3) we were able to detect SFC solely in those wells that were stimulated by hexon and penton peptides. All patients have survived at a median of 220 days after transplant (range 81-532). Conclusion:To our knowledge these ongoing experiments are the first to demonstrate that dormant virus-specific immune responses are present already in the first 100 days in most UCBT recipients (7/8 in this dataset) if infected with either adenovirus or CMV despite failure to detect these extremely rare events by standard ELISPOT assays from freshly isolated blood. Moreover, these data suggests that anti-viral CTLp can be expanded ex vivo by antigen specific restimulation that lends support to further efforts aimed at developing adoptive anti-viral T cell therapies. Disclosures:No relevant conflicts of interest to declare.

HHV-6 Encephalitis in Pediatric Unrelated Umbilical Cord Blood Transplantation: Role for Ganciclovir Prophylaxis?

Abstract 4667 BackgroundThe role of ganciclovir as HHV-6 prophylaxis in unrelated hematopoietic stem cell transplant (HSCT) setting remains controversial. MethodsWe performed a 8-year retrospective review of patients received unrelated HSCT from January 2000 to September 2008. From January 2002, ganciclovir prophylaxis 5mg/kg twice daily for 7 days for all unrelated HSCT before transplant was adopted. The other transplant policies including antibacterial, antifungal, antiviral and graft-versus-host disease control policies remained unchange in that period. The prevalence of HHV-6 encephalitis was studied before and after the change in policy. ResultFifty-four unrelated HSCT were performed from January, 2000 to September, 2008. Total four cases (7.4%) of HHV-6 encephalitis were diagnosed. Two cases out of 16 cases (12.5%) diagnosed before adoption of the policy; 2 cases out of 38 cases (5.3%) diagnosed afterward. All of them were unrelated umbilical cord blood (UCB) transplant recipients. Two cases had significant residual neurological deficit and refractory seizure. The other two cases died of other transplant-related mortalities. ConclusionWe conclude that HHV-6 encephalitis is still a rare complication of unrelated HSCT and may be more common in unrelated UCB transplantation. Routine use of ganciclovir as HHV-6 prophylaxis in all unrelated HSCT recipients may not be justified. Disclosures:No relevant conflicts of interest to declare.

Preemptive Therapy of HHV-6 Encephalitis with Foscarnet Sodium for High Risk Patients After Hematopoietic Stem Cell Transplantation.

Abstract 4655Umbilical cord blood from unrelated donors has been successfully used as an alternative hematopoietic stem cell source to treat hematologic malignancies in patients lacking HLA-matched donors. However, umbilical cord blood transplantation (UCBT) is associated with a higher risk of engraftment failure and more delayed immunological recovery than bone marrow transplantation and peripheral blood stem cell transplantation (PBSCT). Recently, human herpesvirus-6 (HHV-6) has been recognized as an important pathogen in allogeneic hematopoietic stem cell transplantation (HSCT). In particular, HHV-6 reactivation often causes limbic encephalitis with a dismal prognosis. We conducted a prospective, multicenter study to assess the safety and efficacy of preemptive therapy with foscarnet sodium (PFA) to prevent HHV-6 encephalitis after HSCT. Materials and methodsEligible patients were aged from 16 to 75 years with hematologic disorders refractory to conventional therapy and considered to require UCBT or HLA 1-haplotype mismatched HSCT (haplo HSCT) due to the unavailability of an HLA-identical relatives or a suitable unrelated donor. Informed consent was obtained from all subjects according to the Declaration of Helsinki, and this study protocol was approved by the institutional ethical committee. The amount of plasma HHV-6 DNA was measured 3 times per week between day 7 and day 36 after UCBT or PBSCT from HLA-haploidentical relative donors. PFA, 90 mg/kg/day, was given when the amount of HHV-6 DNA exceeded 5 ×102 copies/ml. ResultsOf 20 cases registered between September 2007 and January 2009, 12 of 15 UCBT recipients (80%) became positive for HHV-6 DNAemia, and 7 cases exceeded 5×102 copies/ml, while none of the 5 patients who received haplo HSCT became positive (UCBT vs. haplo HSCT; p<0.004). HHV-6 reactivation occurred earlier in patients who eventually required PFA due to an increase in the HHV-6 DNA copy number greater than 5×102 copies/ml than in patients who did not require PFA treatment (median date of developing HHV-6 DNAemia, day 17 vs. day 22 after HSCT, p<0.02). PFA was given to 7 patients whose HHV-6 DNA copy number exceeded 5×102 copies/ml on day 15 to day 20 (median, day 17) after UCBT. The amount of HHV-6 DNA in the plasma decreased the day after PFA administration in 4 of 7 patients, while the other 3 patients required 3-4 days until the copy number decreased. Two patients showed an increase in HHV-6 DNA copy number greater than 1×104 /ml prior to the initiation of PFA without accompanying symptoms suggestive of encephalitis. One patient developed limbic encephalitis with mild symptoms just after initial PFA administration, but the encephalitis resolved without any neurologic sequelae. Mild and transient adverse effects were associated with PFA in only 2 of 8 patients. ConclusionPFA administration guided by the HHV-6 copy number in the early posttransplant period is safe and may reduce the risk of severe limbic encephalitis. Disclosures:Nakao:Alexion: Research Funding.

Post‐transplant EBV‐related lymphoproliferative disorder complicating umbilical cord blood transplantation in patients of adrenoleukodystrophy

EBV-associated post-transplant lymphoproliferative disorder (PTLD) is a well-recognized complication following solid organ transplantation and hematopoietic stem cell transplantation (HSCT) using bone marrow or peripheral blood as stem cell sources, but rarely reported in umbilical cord blood transplantation (UCBT). We report two cases in unrelated UCBT setting and added the following new information to the literature: (i) EBV-related PTLD can be presented late in recipients of unrelated UCBT; (ii) in contrast to reported literatures that PTLD is a serious complication with unfavorable outcome, especially in monomorphic form, our cases showed that the clinical course may be relatively benign if treatment is initiated promptly.

Acute graft-versus-host disease after unrelated donor umbilical cord blood transplantation: analysis of risk factors

Acute graft-versus-host disease (GVHD) occurs less frequently after umbilical cord blood transplantation (UCBT). More recent investigations include the use of 2 partially human leukocyte antigen (HLA)-matched UCB units, or double UCB graft, to meet the minimum cell-dose requirement. The purpose of this analysis was to assess the relative risk of acute GVHD in 265 consecutive patients receiving transplants with UCB graft composed of 1 (n = 80) or 2 (n = 185) units. The incidence of grade III-IV acute GVHD was similar between cohorts. However, the incidence of grade II-IV acute GVHD was higher among double UCBT recipients (58 vs 39%, P < .01). Three risk factors for grade II-IV acute GVHD were identified in multiple regression analysis: use of 2 UCB units, use of nonmyeloablative conditioning, and absence of antithymocyte globulin in the conditioning regimen. Transplantation-related mortality (TRM) at 1 year, however, was significantly lower after double UCBT (24 vs 39%, P = .02) even if recipients had grade II-IV acute GVHD (20 vs 39%, P = .05). These data suggest that, despite a higher incidence of grade II acute GVHD in recipients of 2 partially HLA-matched UCB units, there is no adverse effect on TRM. This study is registered at (http://www.clinicaltrials.gov) under the identifiers NCT00305682 and NCT00309842.

Analysis of Risk Factors for Outcomes After Unrelated Cord Blood Transplantation in Adults With Lymphoid Malignancies: A Study by the Eurocord-Netcord and Lymphoma Working Party of the European Group for Blood and Marrow Transplantation

To determine risk factors of umbilical cord blood transplantation (UCBT) for patients with lymphoid malignancies. We evaluated 104 adult patients (median age, 41 years) who underwent unrelated donor UCBT for lymphoid malignancies. UCB grafts were two-antigen human leukocyte antigen-mismatched in 68%, and were composed of one (n = 78) or two (n = 26) units. Diagnoses were non-Hodgkin's lymphoma (NHL, n = 61), Hodgkin's lymphoma (HL, n = 29), and chronic lymphocytic leukemia (CLL, n = 14), with 87% having advanced disease and 60% having experienced failure with a prior autologous transplant. Sixty-four percent of patients received a reduced-intensity conditioning regimen and 46% low-dose total-body irradiation (TBI). Median follow-up was 18 months. Cumulative incidence of neutrophil engraftment was 84% by day 60, with greater engraftment in recipients of higher CD34(+) kg/cell dose (P = .0004). CI of non-relapse-related mortality (NRM) was 28% at 1 year, with a lower risk in patients treated with low-dose total-body irradiation (TBI; P = .03). Cumulative incidence of relapse or progression was 31% at 1 year, with a lower risk in recipients of double-unit UCBT (P = .03). The probability of progression-free survival (PFS) was 40% at 1 year, with improved survival in those with chemosensitive disease (49% v 34%; P = .03), who received conditioning regimens containing low-dose TBI (60% v 23%; P = .001), and higher nucleated cell dose (49% v 21%; P = .009). UCBT is a viable treatment for adults with advanced lymphoid malignancies. Chemosensitive disease, use of low-dose TBI, and higher cell dose were factors associated with significantly better outcome.

HHV6-Associated Limbic Encephalitis after Reduced-Intensity Umbilical Cord Blood Transplantation.

Background: HHV6 reactivation has been increasingly recognized in allogeneic haematopoietic stem cell transplant recipients, particularly in umbilical cord blood transplantation. In adult recipients, HHV6 has been associated with limbic encephalitis (HHV6-LE), which causes anterograde amnesia and epilepsy. The CNS disorder confined to the hippocampal regions; the presence of abnormal MRI signals involving the hippocampus, and detection of HHV6 DNA inCSF. However, the clinical features of the syndrome have not been well characterized.Methods: In this study we retrospectively reviewed the medical records of 139 umbilical cord blood transplantation recipients with reduced-intensity conditioning between January 2006 and December 2007 at Toranomon Hospital in Japan to determine the incidence of HHV6-LE among these patients. The diagnosis was based on the acute development of retrograde amnesia, confusion, coma and seizures accompanied by charascteristic MRI findings of abnormal high signal intensity on flair and T2 weighted images in the hippocampus and mesial temporal lobes, and the detection of HHV6 DNA in CSF. Eighty-six were received foscarnet before the onset of HHV6-LE as prophylaxis. All the patients who manifested suspicious symptoms of HHV6-LE were treated with foscarnet.Results: HHV6-LE was diagnosed in 11/139 for a cumulative incidence of 7.2%. The median age was 49 years (range 36–82), 3 were female. Diseases treated were AML/MDS (8), ALL (1), diffuse large B-cell lymphoma (1), and aplastic anemia (1). All 11 were conditioned with fludarabine-based reduced-intensity regimen, and tacrolimus alone (5) or tacrolimus+mycophenolate mofetil (6) were used as GVHD prophylaxis. Five of them had started foscarnet before the onset of HHV6-LE as a prophylaxis. Median symptom onset was on day +20 (range, 12–50). Initial symptoms included confusion in 9, retrograde amnesia in 8, and seizures in 5. MRI demonstrated hyppocampal and mesial temporal lobe FLAIR/T2 high signal intensity in 8/11. Initial CSF analysis demonstrated a median WBC count was 7 (range, 1–21)/μl, median protein was 49 (range, 44–337) mg/dl, median glucose was 107 (range, 62–269) mg/dl. No positive results of bacterial or viral cultures were observed in any of the patients. Median HHV6 DNA levels in the CSF was 20000 (range, 200–80000) copies/ml. Median HHV6 DNA levels in peripheral blood was 200 (range, 0–300000) copies/ml. Remarkably, 7 patients were negative for HHV6 in peripheral blood even within 6 days prior to the onset of CNS symptoms. All were treated with foscarnet at 50–100mg/kg of body weight, and clinical symptoms improved in 9 evaluable patients (2 were not evaluable due to severe pulmonary complications). The virus was cleared in the CSF successfully in 7 patients evaluated. Seven died with the median survival of 32 days (range, 7–346) from diagnosis of limbic encephalitis. HHV6-LE was not a direct cause of death in any of them (2 were from infection, 2 from IP, 2 from relapse, and 1 from MOF). Four were alive as of July 31, 2008, and what is of extreme interest is that all were those who received foscarnet as a prophylaxis. None of the factors analysed failed to reach statistical significance regarding the impact on the onset of HHV6-LE.Conclusions: High incidence of HHV6-LE as well as reactivation of the virus was observed in CB recipients. HHV6 DNA monitoring in peripheral blood may not be sufficient to predict the development of HHV6-LE. Although clinical manifestations were severe in some cases, foscarnet therapy was effective in all evaluable cases. Possible positive impact of prophylactic foscarnet therapy on better survival was suggested, which needs further evaluation by prospective study.

Outcomes and Immune Phenotype Recovery after Double Cord Blood Transplantation in Patients with High Risk Hematological Diseases

Umbilical cord blood transplantation (UCBT) is a valid option to treat haematological disease when an HLA-matched donor is lacking. Advantages of UCB include the absence of risk for the donors, and its prompt availability when an unrelated donor needs urgently. The naivety of the UCB, allows UCBT recipients to a decreased risk of graft versus host disease (GvHD). Due to the low cell dose contained in a UCB unit, double UCBT (dUCBT) is used for adult patients. UCBT may be associated with an increased risk of graft failure with delayed immune recovery and infections. We report a phase II study on 35 dUCBT from 2004 to 2007. Twenty one patients had high risk malignant disorders (ALL=6, AML=6, MDS=4, CML=3, Hodgkin disease= 2) and 14 high risk of rejection (Fanconi Anemia=8, SAA=4, PNH=1 and congenital dyskeratosis= 1). Among all patients, 9 had undergone previous non-engrafted transplants (previous source: UCB and BM in 5 and 4 cases respectively). Median age was 19 years (6–55). CMV serology was negative for 14 patients. Median follow-up was 21 months (4–42 months). Half of patients received myeloablative conditioning, reduced intensity regimen was performed mostly for second transplant. ATG was used in 22 patients. Most of patients received at least 1 or 2-HLA antigen and/or allelic mismatched unit. aGVHD prophylaxis consisted in cyclosporine+steroids in 21 patients and associated with mycophenolate in 14. Median infused cell doses were 4×10/7 NC/Kg (1.8–9.7) and 3×10/5 CD34+cells/Kg (0.5–7.46). Twenty four patients (69%) engrafted with a median time of 25 days (11–42), 11 subjects had primary graft failure. Among the patients who did not engrafted, 5 patients died early due to rejection, 2 had autologous reconstitution and 1 patient relapsed. The remaining 3 patients underwent a second dUCBT. Median time to platelet recovery >20 ×10/9 cells/L was 103 days (36–180). Before day 100 chimerism data were evaluable in 29 patients. A single UCB unit predominated in 18 patients with full donor chimerism. In 6 patients a combination of both UCB units was detected and 5 patients had persistent host hematopoiesis. In eight out of 15 patients, the predominant UCB unit was the first infused. After day 100, 16 out of 19 evaluable patients had a complete donor chimerism with only one unit contributing to hematopoiesis and 3 showed both CB units engraftment. No patients had secondary graft failure. aGVHD developed in 18 patients (grade III–IV, n=6) and cGVHD in 15 out of 26 patients at risk. During the first 100 days 19 CMV reactivations were observed, 4 disseminated HSV, 1 HHV6-related meningoencephalitis, 4 EBV infections, 4 VRS infections, 3 adenovirus diseases, 5 bacterial infections, 2 probable toxoplasmosis. Twelve patients had a probable or proved IFI. After day 100 we observed 9 CMV reactivations, 3 HSV, 1 EBV-PTLD and 2 fungal infections. Lymphocyte subset phenotype analyses were performed in the patients with donor cells engraftment at 3, 6, 9, 12 months after dUCBT. Median numbers of lymphocytes were 400 mm3 at 3 months (n=19); 430 at 6 months (n=18), 710 at 9 months (n=11), 630 at 12 months (n=12), 860 at 15 months (n=7). Median numbers of CD3/CD4 at 3, 6, 9, 12 and 15 months were: 46, 55, 130, 80, 180 mm3, respectively; of NK cells 220, 230, 250, 190, 190 mm3 and of B cells were 1, 10, 70, 80, 240 mm3, respectively. Naive cells (CD45RA+CCR7+), early or central memory cells (CD45RA+CCR7+), effector memory cells (CD45RA+CCR7+), and late effector memory cells (CD45RA+CCR7+) were analysed. Over a period of 9 months after transplant a high proportion of central and effector memory T cells and a paucity of naïve cells were detected. Naïve cells increased consistently during the follow up period, reaching a trend towards normalization at 15 months, compared with the normal value. At 1 year overall survival was 57±8%. Relapse occurred in 5/35 patients and was cause of death in 3. TRM at 100 days was 29±7%. Seventeen patients died. Infection was a major cause of death in 6 subjects. Five of 9 patients have been rescued of previous non-engraftment and are alive and well (10–41 months). In conclusion, dUCBT is an option to treat patients with high risk diseases lacking a suitable HLA matched donor. In this high risk population immune recovery and consequently infections are major complications after dUCBT. Modifications in the conditioning regimen and GVHD prophylaxis, better surveillance and treatment of infections after dUCBT may improve outcomes.

Transplantation of ex-vivo culture-expanded parental haploidentical mesenchymal stem cells to promote engraftment in pediatric recipients of unrelated donor umbilical cord blood: results of a phase I–II clinical trial

Suboptimal neutrophil and platelet recovery after unrelated donor umbilical cord blood transplantation (UCBT) may be due in part to an impaired microenvironment after intensive chemoradiotherapy. In an attempt to speed hematopoietic recovery, 15 pediatric patients with high-risk acute leukemia were enrolled on a single-institution phase I-II clinical trial in which ex-vivo culture-expanded MSCs from haploidentical parental donors were infused at the time of UCBT. Eight patients received MSCs on day 0, with three patients having a second dose infused on day 21. No serious adverse events were observed with any MSC infusion. All eight evaluable patients achieved neutrophil engraftment at a median of 19 days. Probability of platelet engraftment was 75%, at a median of 53 days. With a median follow-up of 6.8 years, five patients remain alive and disease free. The results of this pilot study show that infusion of ex-vivo culture-expanded haploidentical MSCs into unrelated pediatric UCBT recipients can be performed safely. This encouraging safety profile with haploidentical MSCs supports the investigation of unrelated 'off the shelf' allogeneic HLA-mismatched MSC products.

14: A “No-Wash” Albumin-Dextran Dilution Strategy for Umbilical Cord Blood (UCB) Thaw for Adolescent and Adult UCB Transplant Recipients: Superior to Wash?

14: A “No-Wash” Albumin-Dextran Dilution Strategy for Umbilical Cord Blood (UCB) Thaw for Adolescent and Adult UCB Transplant Recipients: Superior to Wash?

Hematopoietic Engraftment in Recipients of Unrelated Donor Umbilical Cord Blood Is Affected by the CD34 + and CD8 + Cell Doses

Umbilical cord blood (UCB) transplantation is limited by the low number of hematopoietic stem cells in UCB units, which results in a low engraftment rate in transplant recipients. Here, we measured the total nucleated cell count and CD34 +, CD3 +, CD4 +, CD8 +, CD14 +, and CD16 +/56 + cell doses in each UCB unit and evaluated their influence on engraftment and other outcomes in 146 recipients. Multivariate analysis showed a significant association between a higher incidence of successful engraftment and a dose of CD34 + and CD8 + cells above the median (1.4 × 10 5 and 15.7 × 10 5 cells/kg, respectively). Engraftment occurred 4 days earlier in patients who received UCB with more than the median dose of CD34 + cells than those receiving UCB at or below the median. Stratification of the group according to CD34 + cell dose revealed a significant influence of the CD8 + cell dose on the time to achieve neutrophil engraftment in patients receiving a lower CD34 + cell dose, whereas there was no significant influence in the patients receiving a higher CD34 + cell dose. These results suggest that consideration of CD34 + and CD8 + cell doses in UCB units may improve the engraftment in recipients of UCB transplantation.

32: Single versus double umbilical cord blood transplantation (UCBT): Higher risk of acute graft-versus-host disease (GVHD) but lower transplant related mortality (TRM) in recipients of double UCBT

32: Single versus double umbilical cord blood transplantation (UCBT): Higher risk of acute graft-versus-host disease (GVHD) but lower transplant related mortality (TRM) in recipients of double UCBT