Non-transferrin-bound iron during allogeneic stem cell transplantation

Hydroxyl radical formation catalysed by non-transferrin-bound iron (NTBI) might contribute to transplantation-related complications. The occurrence of NTBI in 10 adult allogeneic stem cell transplantation (SCT) patients was followed for 20 d. The transferrin saturation reached 99% on d -4 and remained > 80% thereafter. NTBI, measured as bleomycin-detectable iron, was detected for 6-18 d in all patients with a peak on d -4. High transferrin saturation levels were associated with the appearance of NTBI with a threshold at 80% saturation. Prevention of the potential deleterious effects of NTBI might reduce transplantation-related morbidity.     

Non‐transferrin‐bound iron in haematological patients during chemotherapy and conditioning for autologous stem cell transplantation

Free iron induced hydroxyl radical formation is one possible mechanism for tissue injury during cytotoxic therapy. We studied the appearance of free, non‐transferrin‐bound iron (NTBI) at baseline and during the 20‐d period after the onset of cytotoxic chemotherapy in patients with haematological malignancy undergoing intensive chemotherapy or conditioning for autologous stem cell transplantation (aSCT). NTBI was detected on average for 15.6 d in patients treated with chemotherapy only, and for 6.1 d in patients undergoing aSCT. The recovery of the bone marrow function coincided with the disappearance of NTBI. The type of the conditioning regimen was also associated with the appearance of NTBI. The timing of the presence of NTBI accords with the presence of the most important non‐infectious complication of intensive chemotherapy and autologous transplantation, mucosal injury, and free iron is likely to contribute to this and probably other complications of the intensive treatments.     

Effect of repeated apotransferrin administrations on serum iron parameters in patients undergoing myeloablative conditioning and allogeneic stem cell transplantation

Myeloablative conditioning prior to allogeneic stem cell transplantation causes a rapid increase in transferrin saturation and potentially toxic non-transferrin-bound iron (NTBI) in plasma. We have studied the ability of repeatedly administered apotransferrin to maintain this iron in a transferrin-bound form. Twenty adult patients undergoing myeloablative conditioning and allogeneic stem cell transplantation were enrolled to receive apotransferrin with one of three dosage regimens. Ten consecutive patients with the same preconditioning were studied as controls. At the highest dose level, full transferrin saturation and appearance of NTBI were prevented in five of the eight patients. Serum iron increased significantly more in the patients receiving apotransferrin than in the controls and remained elevated until erythropoietic recovery. From the increment of iron saturation and the amount of endogenous and administered apotransferrin, an average 180 mumol of iron per day was bound to transferrin during the first 4 d after the start of the conditioning therapy. Thereafter, iron accumulation levelled off in most patients. The results suggested that about half of the amount of iron normally transported to erythropoiesis was initially released to plasma after induction of the erythroid arrest. Complete iron binding with apotransferrin would apparently require very high apotransferrin doses.     

Trends in hematopoietic stem cell transplant activity in Lebanon

Hematopoietic stem cell transplantation (HSCT) has been accessible to the population residing in Lebanon and surrounding countries since 1997. HSCT programs were developed in two major hospitals in Beirut: American University of Beirut Medical Center (AUBMC) and Makassed General Hospital. Mount Lebanon Hospital initiated an autologous HSCT activity later. Between 2012 and 2016, the HSCT activity in Lebanon reached a total of 897 transplants, among which 303 (33.8%) were allogeneic HSCT and 594 (66.2%) were autologous HSCT. Overall, autologous HSCT activity has remained stable over the past 5 years, whereas allogeneic HSCT activity has seen a steep increase between 2012 and 2013 followed by a modest increase later. Haploidentical transplantation has mushroomed and represented almost half of allogeneic HSCT activity in 2016. AUBMC and Makassed General Hospital are members of the European Blood and Marrow Transplantation (EBMT) and East Mediterranean Blood and Marrow Transplantation groups, and AUBMC has been accredited by JACIE (Joint Accreditation Committee – ISCT & EBMT) since 2016. The past 5 years have seen an increase in HSCT-related research and publications, mainly from AUBMC. These research activities were predominantly focused on personalized conditioning for allogeneic HSCT and post-transplant maintenance therapy.     

Inhibition of erythroid and granulocyte-macrophage colony formation by non-transferrin-bound iron in vitro: protective effect of apotransferrin

OBJECTIVES: The aim of the study was to investigate in vitro the effect of free iron on erythroid and granulocyte-macrophage colony formation and the effect of binding free iron with apotransferrin. METHODS: Normal haematopoietic progenitors were cultured in vitro with different concentrations of free iron in the form of ferric nitrilotriacetic acid (FeNTA). Parallel cultures were performed after the preincubation of FeNTA with apotransferrin. RESULTS: Free iron inhibited colony formation by erythroid and granulocyte-macrophage progenitors and reduced the size of the colonies in a dose-dependent manner. Preincubation of FeNTA with apotransferrin diminished the inhibitory effect of FeNTA on colony formation increasing both the number and the size of colonies. CONCLUSIONS: Free iron was toxic to haematopoietic progenitors in in vitro cultures; the toxic effect could be reduced with apotransferrin.     

Incidence of chronic renal injury in patients undergoing autologous stem cell transplant therapy

Background

Haemopoietic stem cell transplant (HSCT) is a well-established treatment option for many haematologic immunologic and oncologic diseases, allowing the safe administration of high-dose chemotherapy. Increased risk of acute renal injury is associated with HSCT; however, the risk of chronic kidney injury in autologous HSCT remains unclear.

Aims

This cohort study investigates the incidence of chronic renal injury and its predisposing factors in a single-centre population of 139 patients who underwent autologous HSCT.

Methods

Estimated glomerular filtration rate (eGFR) was measured at baseline and at 3, 6, 12 and 24 months following autologous stem cell reinfusion and used as a marker of renal dysfunction.

Results

A significant reduction in mean eGFR of patients was observed from baseline (80.62 ± 2.97 mL/min) to 24 months (71.54 ± 4.14 mL/min), independent of primary diagnosis (P = 0.0019). At baseline, 12% of the cohort had stage 3 or worse chronic renal injury and this increased to 38% by 24 months. By univariate analysis, age at baseline greater than the mean of 58 years and the occurrence of acute kidney injury during the peritransplant period emerged as predictive factors for the development of chronic kidney disease at 24 months.

Conclusions

The current results indicate there is an increased incidence of chronic renal injury in patients who have undergone autologous peripheral blood haemopoietic stem cell transplantation therapy and this injury is potentiated by the autologous stem cell transplant procedure.     

Labile plasma iron levels in chronic hemodialysis patients treated by intravenous iron supplementation

The increased usage of intravenous iron in hemodialysis patients during recent years has led to increasing concern over the potential development of iron overload. Current methods for detecting iron overload, transferrin saturation, and serum ferritin are neither sensitive nor specific. Labile plasma iron (LPI) represents a component of nontransferrin‐bound iron and may be a more accurate indicator of impending iron overload. We studied whether LPI measured can serve as an early indicator of impending iron overload and mortality in hemodialysis patients. Chronic hemodialysis patients from two medical centers in Israel and Poland who received intravenous iron were included. Baseline clinical and laboratory parameters were recorded. LPI was measured before and 48 hours after a single IV administration. Correlation of positive LPI with laboratory parameters and 2‐year mortality was evaluated. One hundred and one hemodialysis patients were included in the study. LPI became positive post‐administration in 18 (17.8%) patients. Ferritin levels >526 ng/mL and monthly iron doses >250 mg were associated with positive LPI after intravenous iron. At a 2‐year follow‐up, higher mortality was observed in the positive LPI group (61.1% compared to 25.3%, P ≤ .05), although this effect was not statistically significant after multivariate adjustment. A substantial number of hemodialysis patients have positive LPI after intravenous iron administration. LPI positively correlates with laboratory parameters that are currently in routine clinical use for detecting iron overload and with higher intravenous iron dose. Further studies should be conducted to establish the clinical implications of LPI monitoring in hemodialysis patients.     

Studies of T cell reconstitution after hematopoietic stem cell transplant

Hematopoietic stem cell (HSC) transplantation, whatever its conditions, is associated with an increased risk of infections and tumoral complications, because of a delayed immune reconstitution. T-cell regeneration has been mostly investigated and appears to come more from graft and/or host mature T-cells, rather than from the differentiation/maturation of reinfused progenitors. In allogeneic setting, the immune defect is enhanced by the immune host/donor conflict and the use of prophylactic or curative immunosuppressive therapy. The tools used for studying post-transplant immunity are the following: immunophenotyping (kinetics and alterations of lymphocyte subset reconstitution), functional studies of T cell proliferation, cytokine production, cytotoxicity and signal transduction, as well as studies of T cell repertoire diversity. The CD4/CD8 cell immunophenotyping might be enough for routine clinical evaluation, allowing an adapted prophylaxis of opportunistic infections in those immune-suppressed patients, while functional assays might be useful to evaluate the persistence overtime of defects in immune reconstitution. These overall assays are useful both for basic and clinical research and allow better understanding in the mechanisms for T cell regeneration in the diverse types of HSC transplants performed nowadays particularly after graft of purified HSC where immune reconstitution remains a key question.     

Results of autologous stem cell transplant in multiple myeloma patients with renal failure

Data are presented on 81 multiple myeloma (MM) patients with renal failure (creatinine > 176.8 micromol/l) at the time of autologous stem cell transplantation (auto-SCT), including 38 patients on dialysis. The median age was 53 years (range: 29-69) and 26% had received more than 12 months of prior chemotherapy. CD34+ cells were mobilized with granulocyte colony-stimulating factor (G-CSF) alone (n = 51) or chemotherapy plus G-CSF (n = 27), yielding medians of 10 and 16 x 106 CD34+ cells/kg respectively (P = 0.003). Sixty patients (27 on dialysis) received melphalan 200 mg/m2 (MEL-200). Because of excessive toxicity, the subsequent 21 patients (11 on dialysis) received MEL 140 mg/m2 (MEL-140). Thirty-one patients (38%) completed tandem auto-SCT, including 11 on dialysis. Treatment-related mortality (TRM) was 6% and 13% after the first and second auto-SCT. Median times to absolute neutrophil count (ANC) > 0.5 x 109/l and to platelets > 50 x 109/l were 11 and 41 d respectively. Non-haematological toxicities included mucositis, pneumonitis, dysrhythmias and encephalopathy. At a median follow up of 31 months, 30 patients have died. Complete remission (CR) was achieved in 21 patients (26%) after first SCT and 31 patients (38%) after tandem SCT. Two patients discontinued dialysis after SCT. Median durations of complete remission (CR) and overall survival (OS) have not been reached; probabilities of event-free survival (EFS) and OS at 3 years were 48% and 55% respectively. Dialysis dependence and MEL dose did not affect EFS or OS. Sensitive disease prior to SCT, normal albumin level and younger age were independent prognostic factors for better OS. In conclusion, renal failure had no impact on the quality of stem cell collections and did not affect engraftment. MEL-140 had an acceptable toxicity and appeared equally effective as MEL-200. In the setting of renal failure, the role of auto-SCT early in the disease course and benefits of tandem SCT require further evaluation.     

Antifungal prophylaxis in adult stem cell transplantation and haematological malignancy

Antifungal prophylaxis can be recommended in patients undergoing induction chemotherapy for acute myeloid leukemia and treatment for grade 2 or greater or chronic extensive graft versus host disease. The evidence for prophylaxis is less clear in other clinical settings although certain groups such as patients with prolonged neutropenia after stem cell transplants using bone marrow or cord blood sources and with impaired cell mediated immunity secondary to treatments such as Alemtuzumab are at high risk. The decision to use prophylaxis and which agent to use will be influenced by effectiveness, number needed to treat and the likelihood of toxicity and drug interactions. The availability of rapid diagnostic tests for fungal infection and institutional epidemiology will also influence the need for and choice of prophylaxis. Whilst prophylaxis can be beneficial, it may impede the ability to make a rapid diagnosis of fungal infection by reducing the yield of diagnostic tests and change the epidemiology of fungal infection. As non-culture based diagnostic tests are refined and become more available there may be a shift from prophylaxis to early diagnosis and treatment.     

Infection prevention strategies in a stem cell transplant unit: impact of change of care in isolation practice and routine use of high dose intravenous immunoglobulins on infectious complications and transplant related mortality

Objective: Nursing in ‘live islands’ and routine high dose intravenous immunoglobulins after allogeneic hematopoietic stem cell transplantation were abandoned by many teams in view of limited evidence and high costs. Methods: This retrospective single‐center study examines the impact of change from nursing in ‘live islands’ to care in single rooms (SR) and from high dose to targeted intravenous immunoglobulins ( IVIG) on mortality and infection rate of adult patients receiving an allogeneic stem cell or bone marrow transplantation in two steps and three time cohorts (1993–1997, 1997–2000, 2000–2003). Results: Two hundred forty‐eight allogeneic hematopoetic stem cell transplantations were performed in 227 patients. Patient characteristics were comparable in the three cohorts for gender, median age, underlying disease, and disease stage, prophylaxis for graft versus host disease ( GvHD) and cytomegalovirus constellation. The incidence of infections (78.4%) and infection rates remained stable (rates/1000 days of neutropenia for sepsis 17.61, for pneumonia 6.76). Cumulative incidence of GvHD and transplant‐related mortality did not change over time. Conclusions: Change from nursing in ‘live islands’ to SR and reduction of high dose to targeted IVIG did not result in increased infection rates or mortality despite an increase in patient age. These results support the current practice.     

Mechanisms of plasma non‐transferrin bound iron generation: insights from comparing transfused diamond blackfan anaemia with sickle cell and thalassaemia patients

In transfusional iron overload, extra‐hepatic iron distribution differs, depending on the underlying condition. Relative mechanisms of plasma non‐transferrin bound iron (NTBI) generation may account for these differences. Markers of iron metabolism (plasma NTBI, labile iron, hepcidin, transferrin, monocyte SLC40A1 [ferroportin]), erythropoiesis (growth differentiation factor 15, soluble transferrin receptor) and tissue hypoxia (erythropoietin) were compared in patients with Thalassaemia Major (TM), Sickle Cell Disease and Diamond‐Blackfan Anaemia (DBA), with matched transfusion histories. The most striking differences between these conditions were relationships of NTBI to erythropoietic markers, leading us to propose three mechanisms of NTBI generation: iron overload (all), ineffective erythropoiesis (predominantly TM) and low transferrin‐iron utilization (DBA).     

Tuberculosis in hematopoletk stem cell transplant recipients in Korea

Hematopoietic stem cell transplantation (HSCT) results in impaired cell-mediated immunity, which subsequently increases the risk of infection from bacterial, fungal, and viral pathogens. Mycobacterial infections are commonly seen in immunodeficient patients, especially in endemic areas. Several series that have reviewed mycobacterial infections in HSCT patients reported incidences varying from less than 0.1% to 5.5%. From February 1996 to July 2003, we retrospectively reviewed records of 295 adult patients who underwent HSCT at Samsung Medical Center, Korea. Mycobacterial infections were diagnosed in 9 (3.1%) of the 295 transplant recipients. The time from HSCT to tuberculosis (TB) infection ranged from 45 days to 165 days posttransplantation. Analysis at the univariate level indicated that a conditioning regimen with total body irradiation (TBI), chronic graft-versus-host disease, and a previous history of TB infection were significant risk factors for the development of TB infection after HSCT. Multivariate analysis revealed that only a previous history of TB infection and TBI increased the risk of TB infection in HSCT patients (relative risk, 4.8 and 12.5, respectively). Isoniazid prophylaxis in HSCT recipients with only radiologic findings suggestive of past inactive TB infection did not significantly alter the incidence of TB infections (P = .236). In conclusion, a previous history of active TB infection and TBI were significant risk factors of TB infection following HSCT, and isoniazid prophylaxis may benefit HSCT recipients with a previous history of active TB infection.     

The role of haploidentical stem cell transplantation in the management of children with haematological disorders

The broader application of stem cell transplantation (SCT) for paediatric diseases has been limited by a lack of human leucocyte antigen (HLA)-matched donors. Virtually all children, however have at least one haploidentical parent who could serve as a donor. Such a donor is immediately available and the considerable costs of additional HLA typing, registry and banking expenditures that are necessary to procure an unrelated donor, could be reduced. Recent technological advances appear to have overcome the historical problems of graft rejection and severe graft versus host disease in the haploidentical setting, and in the latest studies the overall survival for children undergoing haploidentical SCT for leukaemia is now comparable with that following unrelated donor bone marrow or cord blood transplantation. Post-transplant infectious complications and leukaemia relapse remain the most important barriers yet to overcome, and new directions in the use of adoptive cellular immunity appear to be promising in this respect. Haploidentical SCT is now a viable option for those children who do not have an HLA compatible sibling or fully matched unrelated donor. The relative merits of a haploidentical family donor versus mismatched unrelated bone marrow or cord blood donation needs to be assessed in prospective, randomized clinical trials.     

CD34+ cell dose predicts relapse and survival after T-cell-depleted HLA-identical haematopoietic stem cell transplantation (HSCT) for haematological malignancies

Seventy-eight patients with haematological malignancies, received T-cell-depleted stem cell transplants and cyclosporin followed by delayed add-back of donor lymphocytes to prevent leukaemia relapse. The source of stem cells was bone marrow in 50 patients and granulocyte colony-stimulating factor (G-CSF)-mobilized peripheral blood in 28 patients. In univariate analysis, only the CD34+ cell dose (but not the stem cell source or the T lymphocyte dose) and disease status were predictive for transplant-related mortality, relapse and survival. Patients receiving >/= 3 x 106 CD34+ cells/kg had an overall actuarial survival of 68% compared with 52%, 35% and 10%, respectively, for cell doses of 2-2.99, 1-1.99 and < 1 x 106/kg. Multivariate analysis of risk factors for relapse identified disease risk and CD34+ cell dose as the only factors. Relapse was 62.5% in 38 patients at high risk of relapse vs. 25% for 40 patients at intermediate or low risk. CD34+ cell doses of >/= 3 x 106/kg were associated with a 13.5% relapse vs. 48% for recipients of lower doses. This favourable effect of CD34+ cell dose on relapse was apparent in both high- and intermediate- plus low-risk groups. Our results support the potential benefit of a high stem cell dose in lowering transplant-related mortality (TRM) and in reducing relapse after allogeneic marrow or blood stem cell transplants.     

Analysis of rotavirus antigenemia in hematopoietic stem cell transplant recipients

Systemic rotavirus infection, such as rotavirus antigenemia, has been found in immunocompetent rotavirus gastroenteritis patients. However, the pathogenesis of rotavirus infection in immunocompromised transplant recipients remains unclear. Enzyme-linked immunosorbent assay was used to measure rotavirus antigen levels in serially collected serum samples obtained from 62 pediatric patients receiving allogeneic hematopoietic stem cell transplants (HSCT). Rotavirus antigen was detected in 43 (6.8%) of 633 serum samples (8 of 62 patients). The duration of rotavirus antigenemia ranged between 1 and 10 weeks, and diarrhea was concurrent with rotavirus antigenemia in Cases 3, 6, 7, and 8. The level of viral antigen in the transplant recipients (0.19 ± 0.20) was significantly lower than that observed in serum samples collected from immunocompetent patients on either day 1 (0.49 ± 0.18, P = 0.0011) or day 3 (0.63 ± 0.09, P = 0.0005). A patient who received a graft from a human leukocyte antigen (HLA)-mismatched donor was at significant risk for rotavirus antigenemia (P = 0.024; odds ratio = 9.44) in comparison to patients who received grafts from HLA-matched donors. Although the duration of antigenemia was clearly longer in HSCT patients than in immunocompetent rotavirus gastroenteritis patients, the levels of viral antigen were not as high. Therefore, mismatched HLA may be a risk factor for rotavirus antigenemia after HSCT.     

Poor outcome of adenovirus infections in adult hematopoietic stem cell transplant patients with sustained adenovirus viremia

H. Omar, Z. Yun, I. Lewensohn‐Fuchs, L. Pérez‐ Bercoff, C. Örvell, L. Engström, G.‐K. Vuong, P. Ljungman. Poor outcome of adenovirus infections in adult hematopoietic stem cell transplant patients with sustained adenovirus viremia.
Transpl Infect Dis 2010: 12: 465–469. All rights reserved Abstract: The outcome of adenovirus (ADV) infections in adult hematopoietic stem cell transplant (HSCT) patients remains poorly characterized. We studied 14 adults and 3 children, who had undergone HSCT and had developed ADV viremia. Peak ADV DNA levels were significantly higher in patients with ADV diseases than in those without (P=0.03). All children survived the ADV infections. Among the 14 adult HSCT patients, 11 were treated with cidofovir, 2 with ribavirin, and 1 did not receive antiviral treatment. Six of the 13 (46%) treated patients developed ADV diseases and 3 of them (23%) died of ADV infections. Sustained viremia (≥3 positive polymerase chain reaction assays during follow‐up) was detected in all patients who finally died of ADV infections. However, 2 adults having had transient ADV viremia either survived or died of diseases other than ADV infections. Our study indicates that the outcome of adult HSCT patients with sustained ADV viremia may be poor, even for those who have received anti‐ADV treatment.     

Chemomobilization with high‐dose etoposide and G‐CSF results in effective and safe stem cell collection in heavily pretreated lymphoma patients: report from a single institution study and review

The optimal mobilization strategy prior to autologous stem cell transplantation (auto‐SCT) for patients with lymphoma is yet to be determined. We reviewed our institutional experience using chemomobilization with high‐dose (HD) etoposide (1.6 g/m²) and G‐CSF (300 μg/day) in 79 patients with lymphoma. The majority (76%) had received at least two prior regimens of chemotherapy, and 12 (15.2%) patients had previously failed to mobilize following HD cyclophosphamide or DHAP or ICE with G‐CSF. HD etoposide and G‐CSF chemomobilization resulted in successful collection (>2 × 10⁶ CD34+ cells/kg) in 82.3% of patients within a median 2 (1–6) apheresis days. Patients had stem cells collected between days +8 and +15, with a median +12 day. Median total CD34+ cells/kg collected was 5.95 × 10⁶ (0.1–36.8). Seventy‐one percent of patients yielded >2 × 10⁶ CD34+ cells/kg in ≤2 d of apheresis and were defined as good mobilizers. While median CD34+ cells/kg collected for good mobilizers was 7.6 × 10⁶, it was 2.6 × 10⁶ for poor mobilizers (P < 0.001). This regimen was safe with a low rate of febrile neutropenia (7.6%) and acceptable rates of RBC (40.5%) and platelet transfusions (22.8%). Hematopoietic recovery after auto‐SCT was achieved on expected time. Therapy‐related myelodysplastic syndrome/acute myeloid leukemia occurred in only one patient (1.3%) with in a median follow‐up of 16 months after chemomobilization. We conclude that HD etoposide and G‐CSF chemomobilization appear to result in effective, tolerable, and safe stem cell collection in the majority of heavily pretreated lymphoma patients.     

Therapeutic drug monitoring-guided dosing of busulfan differs from weight-based dosing in hematopoietic stem cell transplant patients

Busulfan (Bu)-based preparative regimens in hematopoietic stem cell transplantation are commonly used. Previous studies have shown that Bu at a fixed dose of 3.2 mg/kg/day (FBD) given intravenously decreases variability in drug pharmacokinetics and this decreases the dependency on therapeutic drug monitoring (TDM) of Bu. We compared the Bu dose given using TDM with the FBD of 3.2 mg/kg/day. Seventy-three patients with acute leukemia, myelodysplasia, chronic myeloid leukemia, thalassemia major, and sickle cell disease were included. The mean age at transplant was 15 years (range 2–55 years) with 57% adults. Indication for transplantation was leukemia/myelodysplastic syndrome in 46% of the patients, while the remaining 54% were transplanted for inherited blood disorders. We found that the median FBD was lower than the median TDM dose by 39 mg/day with a statistically significant difference (p < 0.001) even after adjusting for the weight (median total FBD of 349 mg, median TDM dose of 494 mg, p < 0.0001). Age and underlying condition (malignant vs. nonmalignant) were the main factors affecting Bu clearance (p < 0.001 and p < 0.07, respectively). TDM remains an important tool for the appropriate dosing of Bu in preparative regimens of hematopoietic stem cell transplantation, especially in populations with genetic admixture.