Incidence and risk factors of early bacterial infections after unrelated cord blood transplantation

Clinical implications of augmented renal clearance after unrelated single cord blood transplantation in adults

Augmented renal clearance (ARC) is a phenomenon characterized by increased renal functionality, which can impact the pharmacokinetics and pharmacodynamics of antimicrobial drugs eliminated by the kidneys. It is a potential concern for infection treatment. Cord blood transplantation (CBT) is primarily impeded by delayed neutrophil recovery and immune reconstitution, thereby increasing susceptibility to infection. However, the clinical implications of ARC following CBT remain unexplored. We retrospectively assessed the influence of ARC on post-transplant outcomes at various time points in 194 adult recipients of single-unit unrelated CBT between 2007 and 2022 at our institution. ARC was observed in 52.9% of patients at 1 day, 39.8% at 15 days, and 26.5% at 29 days post-CBT. ARC was not significantly associated with bloodstream infection, acute graft-versus-host disease, or veno-occlusive disease/sinusoidal obstruction syndrome at any time point. ARC at 1 day, 15 days, and 29 days post-CBT was not significantly associated  with overall survival, non-relapse mortality, or relapse rates. These findings suggest that ARC is common in adults during the early stages of CBT, but does not discernibly influence clinical outcomes or post-CBT complications.

The impact of graft cell source on bloodstream infection in the first 100 days after allogeneic hematopoietic cell transplantation

Bloodstream infection (BSI) is a major infectious complication after allogeneic hematopoietic cell transplantation (HCT). To clarify the impact of graft cell source on the incidence of BSI after transplantation, we retrospectively examined 782 adult patients receiving their first allogeneic HCT: 122 recipients of related peripheral blood stem cells or bone marrow, 215 recipients of unrelated bone marrow, and 445 recipients of unrelated umbilical cord blood (U-CB). The cumulative incidence of BSI was 42.5% at 100 days after transplantation (95% confidence interval, 39.0-46.0). Gram-positive cocci were present in 64.2% of detected isolates. Among the pre-transplant factors including age, performance status, primary disease, disease status, graft cell source, sex and ABO blood type matching, and the intensity of conditioning regimen, U-CB use was identified as the most significant risk factor for BSI by multivariate analysis (hazard ratio, 1.76; 95% confidence interval, 1.40-2.22; p < 0.00001). Among the U-CB recipients, those who are not in remission at the time of transplantation were at the greatest risk of BSI (hazard ratio, 1.69; 95% confidence interval, 1.14-2.50; p < 0.01). The study makes it clear that graft cell source has an impact on BSI development after allogeneic HCT.

Stenotrophomonas maltophilia bloodstream infections in adult recipients of umbilical cord blood transplantation

Limited data are available on Stenotrophomonas maltophilia bloodstream infections (SM-BSIs) and the therapeutic efficacy of trimethoprim-sulfamethoxazole (SXT) against SM-BSI in umbilical cord blood transplant (uCBT) recipients. Medical and microbiological records of adult patients who received uCBTs between December 2008 and December 2015 at Toranomon Hospital (Tokyo, Japan) were reviewed. The efficacy and safety of SXT were evaluated only for recipients who were treated with ≥7 days of intravenous SXT for SM-BSI (evaluation cohort). Of 561 uCBT recipients, 34 developed SM-BSI. Diabetes mellitus (P = .005) and age ≥ 60 years (P = .013) were significant independent risk factors for SM-BSI. Moreover, SM-BSI was identified as an independent risk factor for all-cause mortality up to 100 days following uCBT (P = .025). Of the 34 recipients with SM-BSI, 24 were treated with an intravenous SXT-containing regimen (iSXT-CR). Septic shock (P = .0021), pneumonia (P = .011), neutropenia (P = .0015), and systemic steroid administration (P = .018) were identified as significant independent risk factors for 7-day crude mortality. The evaluation cohort included nine recipients. Doses of SXT were 2.4 to 6.9 mg/kg/day of the trimethoprim component. Of the nine recipients, five developed SM-BSI during the pre-engraftment phase. The 30-day crude-mortality rate and clinical cure rate of the cohort were 22% and 67%, respectively. Only one of the nine recipients experienced significant neutrophil toxicity. In this study, the epidemiology of SM-BSI in uCBT recipients was determined and its negative impact on survival was demonstrated. A low- to moderate-dose iSXT-CR appeared to be a tolerable and important therapeutic option for SM-BSI in the uCBT setting, including during the pre-engraftment phase.

Disseminated Tuberculosis with Cholecystitis in a Patient after Cord Blood Transplantation

The incidence of an active tuberculosis infection after allogeneic hematopoietic cell transplantation is high. We herein report the case of a patient with acute myeloid leukemia after cord blood transplantation (CBT). On day 36 after CBT, the patient developed fever, and a computed tomography scan on day 36 showed mild thickening of the wall of the gallbladder. Subsequently, a sputum specimen and a blood culture returned positive for the growth of Mycobacterium tuberculosis. After 2 months of administering combination therapy, both the symptoms and gallbladder findings improved. We therefore describe a case of disseminated tuberculosis with the gallbladder mimicking acute cholecystitis in a CBT recipient.

SEMIPARAMETRIC REGRESSION MODEL FOR RECURRENT BACTERIAL INFECTIONS AFTER HEMATOPOIETIC STEM CELL TRANSPLANTATION

Patients who undergo hematopoietic stem cell transplantation (HSCT) often experience multiple bacterial infections during the early post-transplant period. In this article, we consider a semiparametric regression model that correlates patient- and transplant-related risk factors with inter-infection gap times. Existing regression methods for recurrent gap times are not directly applicable to study post-transplant infection because the initiating event (transplant) is different than the recurrent events of interest (post-transplant infections); as a result, the time from transplant to the first infection and the time elapsed between consecutive infections have distinct biological meanings and hence follow different distributions. Moreover, risk factors may have different effects on these two types of gap times. We propose a semiparametric estimation procedure to evaluate the covariate effects on time from transplant to thefirst infection and on gap times between consecutive infections simultaneously. The proposed estimator accounts for dependent censoring induced by within-subject correlation among recurrent gap times and length bias in the last censored gap time due to intercept sampling. We study the finite sample properties through simulations and present an application of the proposed method to the post-HSCT bacterial infection data collected at the University of Minnesota.

Synthesis and evaluation of pyrimidoindole analogs in umbilical cord blood ex vivo expansion

The scarcity of hematopoietic stem cells (HSCs) significantly hindered their clinical potentials. Umbilical cord blood (UCB) has become the leading source of HSCs for both research and clinical applications. But the low content of HSCs in a single UCB unit limited its use only to pediatric patients. Various cytokines and small molecules have demonstrated strong abilities in promoting HSC ex vivo expansion, of which UM171 is the newest and by far the most potent HSC ex vivo expansion agent. In this study, we synthesized 37 pyrimidoindole analogs and identified 6 compounds to be potent in promoting HSC ex vivo expansion. In particular, analog 11 was found to be the most effective in stimulating ex vivo expansion of UCB CD34⁺ cells and CD34⁺CD38^- cells. Initial data indicated that compound 11 promoted the absolute number of long term HSCs and inhibited their differentiation. UCB HSCs expanded with 11 retained adequate multi-lineage differentiation capacity. In addition, compound 11 is not cytotoxic at its test concentrations, suggesting that it merits further investigation for potential clinical applications.

Increased opportunity for prolonged survival after allogeneic hematopoietic stem cell transplantation in patients aged 60-69 years with myelodysplastic syndrome

We conducted a nationwide retrospective study to evaluate the outcomes of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in 651 patients aged 60-69 years with de novo myelodysplastic syndrome (MDS). We divided patients into two groups: 152 and 499 patients with an early and advanced disease status, respectively. The 3-year overall survival (OS) rate of patients with an early disease status was 45.9% (95% confidence interval [CI], 37.0 to 54.2%). A multivariate analysis revealed five adverse factors for OS: performance status (PS) 2-4 (hazard ratio [HR] 4.48; P < .001), poor cytogenetic risk group (HR 1.83; P = .041), male recipient (HR 2.58; P = .003), use of HLA-mismatched related grafts (HR 4.75; P = .003), and unrelated cord blood (HR 2.47; P = .023). The 3-year OS rate of patients with an advanced disease status was 37.2% (95% CI 32.4 to 41.9%). Five factors correlated with worse OS: PS 2-4 (HR 1.72; P = .003), poor cytogenetic risk group (HR 1.49; P = .003), use of HLA-mismatched related grafts (HR 1.96; P = .015), unrelated cord blood (HR 2.05; P < .001), and the high number of red blood cell transfusions before transplantation (HR 1.85; P = .018). The present results revealed the more frequent utilization of allo-HSCT for MDS patients aged 60-69 years, which increases the curative potential.

The incidence, risk factors and outcomes of early bloodstream infection in patients with malignant hematologic disease after unrelated cord blood transplantation: a retrospective study

BACKGROUND

Bloodstream infection (BSI) is one of the major causes of morbidity and mortality for patients undergoing hematopoietic stem cell transplantation (HSCT). The unrelated cord blood transplantation (UCBT) can provided opportunities for patients without suitable donors for bone marrow transplantation (BMT) and peripheral blood stem cell transplantation (PBSCT), while few studies have addressed BSI after UCBT. The aim of this study was to analyse the incidence and risk factors of BSI, causative organisms, microbial resistance, and its impact on the clinical outcomes and survival of patients.

METHODS

There are 336 patients, were divided into two groups depending on whether developing BSI. Demographic characteristics, laboratory data, and clinical outcome were compared between different groups. The risk factors of BSI was examined using logistic regression and the survival was examined using the Kaplan-Meier method and log-rank test.

RESULTS

Ninety-two patients (27.4%) developed early BSI with 101 pathogenic bacteria isolated, and the median day of developing initial BSI was 4.5 d. Gram-negative bacteria were the most common isolate (60, 59.4%), followed by Gram-positive bacteria (40, 39.6%) and fungi (1, 1.0%). Thirty-seven (36.6%) isolates were documented as having multiple drug resistance (MDR). Myeloid malignancies, conditioning regimens including total body irradiation (TBI), and prolonged neutropenia were identified as the independent risk factors for early BSI. The 3-year OS was 59.9% versus 69.2% in the BSI group and no-BSI group (P = 0.0574), respectively. The 3-year OS of the MDR group was significantly lower than that of the non-BSI group (51.1% versus 69.2%, p = 0.013).

CONCLUSIONS

Our data indicate that the incidence of early BSI after UCBT was high, especially in patients with myeloid disease and a conditioning regimen including TBI and prolonged neutropenia. Early BSI with MDR after UCBT had a negative impact on long-term survival.

Efficacy and Safety of Low-Dose Liposomal Amphotericin B in Adult Patients Undergoing Unrelated Cord Blood Transplantation

Liposomal amphotericin B (L-AMB) is widely used for empirical or preemptive therapy and treatment of invasive fungal infections after cord blood transplantation (CBT). We retrospectively examined the efficacy and safety of low-dose L-AMB in 48 adult patients who underwent CBT between 2006 and 2017 in our institute. Within the entire cohort, 42 patients (88%) received L-AMB as empirical or preemptive therapy. The median daily dose of L-AMB and the median cumulative dose of L-AMB were 1.20 mg/kg/day (range, 0.62 to 2.60 mg/kg/day) and 30.6 mg/kg (range, 0.7 to 241.5 mg/kg), respectively. The median duration of L-AMB administration was 21.5 days (range, 1 to 313 days). A documented breakthrough fungal infection occurred in 1 patient during L-AMB treatment, and 43 patients (90%) survived for at least 7 days after the end of L-AMB treatment. Grade 3 or higher hypokalemia and hepatotoxicity were frequently observed during L-AMB treatment. However, no patient developed an increase in serum creatinine levels of grade 3 or higher. In univariate analyses using a logistic regression model, a duration of L-AMB treatment of more than 21 days and a cumulative dose of L-AMB of more than 30 mg/kg were significantly associated with nephrotoxicity and grade 3 hypokalemia. These data suggest that low-dose L-AMB may be safe and effective in adult patients undergoing CBT.

Risk factors and survival impact of readmission after single-unit cord blood transplantation for adults

Hospital readmissions have been used as a prognostic indicator for patients receiving allogeneic hematopoietic cell transplantation (HCT). However, the impact of readmission during early and mid-phase of cord blood transplantation (CBT) on long-term outcomes has not been fully investigated. We retrospectively analyzed 156 adult patients who received single-unit CBT in our institute. Among this cohort, thirteen patients (8%) were readmitted within 30 days after discharge, and 27 (17%) were readmitted within 90 days after discharge. The most common causes for readmission within 30 and 90 days of discharge were infection, chronic graft-versus-host disease, and relapse. Higher cryopreserved cord blood CD34⁺ cell count was only significantly associated with lower readmission within 90 days after discharge. The probabilities of overall survival were significantly lower in patients readmitted within 90 days after discharge compared with those who were not readmitted within 90 days after discharge in univariate and multivariate analysis. These data suggest that readmission within 90 days after discharge may have a significant impact on long-term mortality after single-unit CBT.

Transplantation of Ex Vivo Expanded Umbilical Cord Blood (NiCord) Decreases Early Infection and Hospitalization

Delayed hematopoietic recovery contributes to increased infection risk following umbilical cord blood (UCB) transplantation. In a Phase 1 study, adult recipients of UCB stem cells cultured ex vivo for 3 weeks with nicotinamide (NiCord) had earlier median neutrophil recovery compared with historical controls. To evaluate the impact of faster neutrophil recovery on clinically relevant early outcomes, we reviewed infection episodes and hospitalization during the first 100 days in an enlarged cohort of 18 NiCord recipients compared with 86 standard UCB recipients at our institution. The median time to neutrophil engraftment was shorter in NiCord recipients compared with standard UCB recipients (12.5 days versus 26 days; P < .001). Compared with standard UCB recipients, NiCord recipients had a significantly reduced risk for total infection (RR, 0.69; P = .01), grade 2-3 (moderate to severe) infection (RR, 0.36; P < .001), bacterial infection (RR, 0.39; P = .003), and grade 2-3 bacterial infection (RR, 0.21; P = .003) by Poisson regression analysis; this effect persisted after adjustment for age, disease stage, and grade II-IV acute GVHD. NiCord recipients also had significantly more time out of the hospital in the first 100 days post-transplantation after adjustment for age and Karnofsky Performance Status (69.9 days versus 49.7 days; P = .005). Overall, transplantation of NiCord was associated with faster neutrophil engraftment, fewer total and bacterial infections, and shorter hospitalization in the first 100 days compared with standard UCB transplantation. In conclusion, rapid hematopoietic recovery from an ex vivo expanded UCB transplantation approach is associated with early clinical benefit.

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.

Discovery of novel INK4C small-molecule inhibitors to promote human and murine hematopoietic stem cell ex vivo expansion

Hematopoietic stem cells (HSCs) have emerged as promising therapeutic cell sources for high-risk hematological malignancies and immune disorders. However, their clinical use is limited by the inability to expand these cells ex vivo. Therefore, there is an urgent need to identify specific targets and effective probes that can expand HSCs. Here we report a novel class of INK4C (p18^INK4C or p18) small molecule inhibitors (p18SMIs), which were initially found by in silico 3D screening. We identified a lead p18 inhibitor, XIE18-6, confirmed its p18-targeting specificity and bioactivity of promoting HSCs expansion, and then performed structure-activity relationship (SAR) studies by synthesizing a series of analogs of XIE18–6. Among these, compound 40 showed the most potent bioactivity in HSCs expansion (ED₅₀ = 5.21 nM). We confirmed that compound 40 promoted expansion of both murine and human HSCs, and also confirmed its p18-targeting specificity. Notably, compound 40 did not show significant cytotoxicity toward 32D cells or HSCs, nor did it augment leukemia cell proliferation. Taken together, our newly discovered p18SMIs represent novel chemical agents for murine and human HSCs ex vivo expansion and also can be used as valuable chemical probes for further HSC biology research towards promising utility for therapeutic purposes.

Similar outcomes of allogeneic hematopoietic cell transplantation from unrelated donor and umbilical cord blood vs. sibling donor for pediatric acute myeloid leukemia: Multicenter experience in China

In a multicenter study, we have conducted a retrospective study on 73 pediatric AML patients who were primary refractory or in greater than CR1 and investigated MSD (or MMSD) (n = 20), URD (n = 23), and UCB (n = 30) HCT between January 1998 and October 2009. The median day to neutrophil engraftment was similar in all groups. The median day to platelet engraftment was longer in the UCB group. The number of HLA mismatch was higher in the UCB group (p = 0.034); however, the cumulative incidence of grade III-IV aGVHD was not different among all groups (p = 0.125); furthermore, cGVHD was lower in the UCB group (p = 0.078). The risk of relapse did not differ among all groups (RR = 1.28, p = 0.125), but the patients of MSD (or MMSD) grafts had a trend of higher risk recurrence. Sixty-two patients survived with a median follow-up of 58.2 months. Five-yr LFS was 73.1%, 59.8%, and 59.6% for URD, UCB, and MSD (or MMDS), respectively (p = 0.426). Five-yr LFS in CR1 was 68.9%, with a significantly better result compared to 41.7% in CR2 (p = 0.025). Our comparisons suggest that pediatric AML patients receiving UCB had a higher early TRM, a lower cGVHD rate, and a similar long-term survival. The outcome of URD and UCB is comparable to that of a suitable sibling for pediatric AML.

Bloodstream infections in adult patients undergoing cord blood transplantation from unrelated donors after myeloablative conditioning regimen

The incidence, epidemiology, and risk factors of bloodstream infection (BSI) and their impact on transplant outcomes after umbilical cord blood transplantation (UCBT) are not well defined. Between May 1997 and December 2012, 202 isolates in 189 episodes of BSI were registered in 134 of 241 patients who underwent single-unit myeloablative UCBT. Cumulative incidence (CI) of developing at least 1 episode of BSI was 21%, 29%, 34%, 42%, and 52% at days +7, +14, +30, +100, and +365, respectively. The median time of onset for the first BSI episode was day +10 (range, day -7 to +1217). Early BSI before day 7 was associated with increased nonrelapse mortality (relative risk [RR], 1.5; 95% confidence interval [CI], 1.1 to 2.3; P = .04), whereas BSI before day 14 was an independent adverse risk factor for neutrophil recovery (RR, .6; 95% CI, .5 to .9; P = .002). A higher CD8(+) cell dose of the graft was the only variable independently associated with reduced risk of BSI (RR, .1; 95% CI, .02 to .7; P = .02). The gram-negative rod (GNR) to gram-positive bacteria ratio was .9 before day +30 and 1.6 thereafter (P = .03). Escherichia coli (31%) and Pseudomonas sp. (28%) were the most frequently isolated among GNR. The overall crude mortality rate was 12% at day 7 and was higher for GNR (18%) compared with gram-positive bacteria (7%) (P = .03). These findings emphasize the importance of preventing bacterial infections during conditioning and the very early post-UCBT period.

Aetiology and resistance in bacteraemias among adult and paediatric haematology and cancer patients

OBJECTIVES

A knowledge of current epidemiology and resistance patterns is crucial to the choice of empirical treatment for bacteraemias in haematology and cancer patients.

METHODS

A literature review on bacteraemias in cancer patients considered papers published between January 1st 2005 and July 6th 2011. Additionally, in 2011, a questionnaire on the aetiology and resistance in bacteraemias, and empirical treatment, was sent to participants of the European Conference on Infections in Leukemia (ECIL) meetings; recipients were from 80 haematology centres.

RESULTS

For the literature review, data from 49 manuscripts were analysed. The questionnaire obtained responses from 39 centres in 18 countries. Compared with the published data, the questionnaire reported more recent data, and showed a reduction of the Gram-positive to Gram-negative ratio (55%:45% vs. 60%:40%), increased rates of enterococci (8% vs. 5%) and Enterobacteriaceae (30% vs. 24%), a decreased rate of Pseudomonas aeruginosa (5% vs. 10%), and lower resistance rates for all bacteria. Nevertheless the median rates of ESBL-producers (15-24%), aminoglycoside-resistant Gram-negatives (5-14%) and carbapenem-resistant P. aeruginosa (5-14%) were substantial, and significantly higher in South-East vs. North-West Europe.

CONCLUSIONS

The published epidemiological data on bacteraemias in haematology are scanty and mostly dated. Important differences in aetiology and resistance exist among centres. Updated analyses of the local epidemiology are mandatory to support appropriate empirical therapy.

Microbial screening of unrelated cord blood units in a Chinese cord blood bank

BACKGROUND

Given limited sample volume available for sterility testing, optimal testing methods and algorithms of cord blood (CB) have not been established according to standards.

STUDY DESIGN AND METHODS

The volume of CB unit was reduced to 20 mL in a closed system. Hetastarch and cryopreservation solution was added to the processed CB unit in Class 100 environment. In the routine sterility testing, 20 mL of red blood cells (RBC) sample was cultured in aerobic and anaerobic culture bottles. In verification post-thaw culture of the final product, some of the discarded final product units were also sampled and cultured after thaw. All the culture bottles were incubated in the BacT/ALERT 3D system.

RESULTS

In the routine sterility testing, 139 of 7032 CB units (1·98%) were contaminated with microorganism. In 84 of these 139 units (60·4%) only the anaerobic bottle was positive. Lactobacillus spp. were the most prevalent contaminant. Sixty-two discarded CB stem cell units were recultured after thaw. Of these, 10 of 48 units with a positive culturing of RBC sample were negative in the post-thaw reculture. One of 14 units with negative culturing of RBC sample was contaminated with Bifidobacterium breve in special verification test.

CONCLUSION

Our study demonstrates the predominant organisms implicated in CB microbial contamination were part of the human intestinal and vaginal flora. The larger sample volume and anaerobic culture would significantly increase the detection rate of microbial contaminated CB. We also found that potential transfusion-transmitted bacterial infection risk still existed in final product although microbial screening was performed.

Umbilical cord blood transplantation: review of factors affecting the hospitalized patient

The use of umbilical cord blood (UCB) as a stem cell donor source has dramatically increased over the last 2 decades. Patients undergoing UCB transplantation share medical management issues with patients receiving a hematopoietic stem cell transplantion using adult donor sources (peripheral blood stem cells or bone marrow stem cells) and may also have more complex medical issues that appear to be related to delayed immune recovery from UCB-derived stem cells. The interface with critical care providers is likely to occur in the transplant and posttransplant setting. Patients may experience UCB infusion reactions that range from mild to rarely severe. Following transplant, patients are transfusion dependent for long periods due to the prolonged engraftment of UCB cells. They are at high risk of infection, particularly viral. Once engrafted, UCB transplant patients have a lower rate of graft versus host disease compared to other donor sources. Some of the other complications that are seen in patients undergoing UCB transplant are posttransplant lymphoproliferative disease, diffuse alveolar hemorrhage, and posterior reversible encephalopathy will also be discussed.

Acute kidney injury after myeloablative cord blood transplantation in adults: the efficacy of strict monitoring of vancomycin serum trough concentrations

BACKGROUND

Acute kidney injury (AKI) is a common medical complication after myeloablative allogeneic stem cell transplantation (SCT). We have previously performed a retrospective analysis of AKI after cord blood transplantation (CBT) in adults, and found that the maximum of vancomycin (VCM) trough levels were significantly higher in patients with AKI. Following these results, we have monitored VCM serum trough concentrations more strictly, to not exceed 10.0 mg/L, since 2008.

METHODS

In this report, we performed an analysis of AKI in a new group of 38 adult patients with hematological malignancies treated with unrelated CBT after myeloablative conditioning between January 2008 and July 2011.

RESULTS

Cumulative incidence of AKI at day 100 after CBT was 34% (95% confidence interval 19-50). The median of the maximum value of VCM trough was 8.8 (4.5-12.2) mg/L. In multivariate analysis, no factor was associated with the incidence of AKI. No transplant-related mortality was observed. The probability of disease-free survival at 2 years was 83%.

CONCLUSION

These findings suggest that strict monitoring of VCM serum trough concentrations has a beneficial effect on outcomes of CBT.

Allogeneic cord blood transplantation for adult acute lymphoblastic leukemia: retrospective survey involving 256 patients in Japan

We investigated the efficacy of cord blood transplantation (CBT) for adult acute lymphoblastic leukemia (ALL) by reviewing medical records of 256 patients reported to the Japan Cord Blood Bank Network between June 1997 and August 2006. Cumulative incidence of neutrophil engraftment at day 100 was 78%. Infused CD34-positive cell dose (>1 × 10(5) cells/kg) was associated with successful neutrophil engraftment. Cumulative incidence of grade II-IV acute graft-versus-host disease (GVHD) at day 100 was 37%. A 2-year disease-free and overall survival (OS) rates were 36% and 42%, respectively. Multivariate analysis showed that age (51 or older vs younger than 50) (hazard ratio 1.9, 95% confidence interval (CI), 1.3-2.8, P=0.001), disease status (non-remission vs remission) (hazard ratio 2.2, 95% CI, 1.5-3.2, P<0.0001), grade III-IV acute GVHD (hazard ratio 2.0, 95% CI, 1.2-3.2, P=0.006) and absence of chronic GVHD (hazard ratio 2.4, 95% CI, 1.1-5.1, P=0.02) were negatively associated with OS. CBT is effective for some patients with advanced ALL. It is worth considering for further evaluation.

Lymphocyte recovery predicts outcomes in cord blood and T cell-depleted haploidentical stem cell transplantation

Alternative donor stem cell transplantation from cord blood or haploidentical peripheral blood donors is increasingly being used for patients who lack a matched related or unrelated donor. A higher nonrelapse mortality (NRM) rate has been noted with these 2 types of transplants, primarily because of infectious complications. Here, we hypothesized that the time to lymphocyte recovery (absolute lymphocyte count [ALC] of ≥1000/μL for the first 3 consecutive days) after transplant correlates with outcomes. We retrospectively analyzed 65 consecutive patients treated at our institution with cord blood (n = 37) and haploidentical (n = 28) transplantation with myeloablative fludarabine, melphalan, and thiotepa conditioning. Patients with lymphocyte recovery at day 60 posttransplant were more likely to survive long term than those without lymphocyte recovery. In multivariate analysis, ALC recovery was the only independent prognostic factor associated with mortality; patients without ALC recovery were 10.5 times (95% confidence interval [CI]: 4.3-25.4) more likely to die than those with ALC recovery (P < .0001). This difference appeared to be related to NRM (hazard ratio [HR] = 0.1, 95% CI: 0.02-0.6, P = .008), whereas ALC recovery did not influence the rate of disease relapse. These results suggest that ALC recovery is an important prognostic indicator for patients treated with cord blood and T cell-depleted peripheral haploidentical transplants.

The impact of anti-HLA antibodies on unrelated cord blood transplantations

The majority of cord blood transplantations (CBTs) have human leukocyte antigen (HLA) disparities. We investigated the impact that patients' pretransplantation anti-HLA antibodies have on the outcome of CBTs. Testing for anti-HLA antibody and its specificity was performed retrospectively at the Japanese Red Cross Tokyo Blood Center with sensitive solid-phase antibody detection assays. Among 386 CBTs, which were first myeloablative stem cell transplantations for malignancies and used a single unit of cord blood, 89 tested positive. Among the antibody-positive group, the cord blood did not have the corresponding HLA type for the antibody in 69 cases (ab-positive), while 20 cases had specificity against the cord blood HLA (positive-vs-CB). Cumulative incidence of neutrophil recovery 60 days after transplantation was 83% (95% confidence interval [CI], 79%-87%) for the antibody-negative group (ab-negative), 73% (95% CI, 61%-82%) for ab-positive, but only 32% (95% CI, 13%-53%) for the positive-vs-CB (P < .0001, Gray test). With multivariate analysis, the ab-positive showed significantly lower neutrophil recovery than the ab-negative (relative risk [RR] = 0.69, 95% CI, 0.49-0.96, p = .027). The positive-vs-CB had significantly lower neutrophil recovery (RR = 0.23, 95% CI, 0.09-0.56, P = .001) and platelet recovery (RR = 0.31, 95% CI, 0.12-0.81, P = .017) than the ab-negative. Patients' pretransplantation anti-HLA antibodies should be tested and considered in the selection of cord blood.

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.

Infectious complications after unrelated umbilical cord blood transplantation in adult patients with hematologic malignancies

Unrelated umbilical cord blood (UCB) is being increasingly used as an alternative stem cell source for allogeneic stem cell transplantation (allo-SCT). This retrospective study assessed infectious complications occurring in adult patients after UCB transplantation (UCBT). 31 patients received a single (n=4) or double UCBT (n=27) with a median dose of 4.7x10(7) nucleated cells/kg (range: 2.4-7.7). Patients received either a reduced-intensity conditioning (RIC; n=23) or a standard myeloablative (MA) regimen (n=8). The cumulative incidence of neutrophil recovery was 90%. Neutrophil recovery was achieved at a median time of 24 (range: 8-60) days after UCBT. The cumulative incidences of bacterial, fungal, and parasitic infections were, respectively, 16%, 10%, and 6%. Bloodstream infections were neither lethal nor required any intensive care therapy. Similarly, invasive fungal infections and parasitic infections did not cause any death in those patients with sustained engraftment. Although the cumulative incidence of cytomegalovirus (CMV) recurrence was 21%, no CMV disease was observed. With a median follow-up of 10 (range: 3-30) months, 10 patients have died (relapse, n=5; nonrelapse mortality, [NRM] n=5). Overall, the cumulative incidence of infectious-related mortality (IRM) was 8%. In conclusion, this data suggests that UCBT can be performed in adult patients with hematologic malignancies with an acceptable incidence of IRM provided a sufficient dose of nucleated cells is infused to the patient.