Intercontinental study on pre-engraftment and post-engraftment Gram-negative rods bacteremia in hematopoietic stem cell transplantation patients: Risk factors and association with mortality.

OBJECTIVES: We present here data on Gram-negative rods bacteremia (GNRB) rates, risk factors and associated mortality. METHODS: Data on GNRB episodes were prospectively collected in 65 allo-/67 auto-HSCT centers in 24 countries (Europe, Asia, Australia). In patients with and without GNRB, we compared: demography, underlying disease, HSCT-related data, center` fluoroquinolone prophylaxis (FQP) policy and accreditation status, and involvement of infection control team (ICT). RESULTS: The GNRB cumulative incidence among 2818 allo-HSCT was: pre-engraftment (pre-eng-allo-HSCT), 8.4 (95% CI 7-9%), post-engraftment (post-eng-allo-HSCT), 5.8% (95%CI: 5-7%); among 3152 auto-HSCT, pre-eng-auto-HSCT, 6.6% (95%CI: 6-7%), post-eng-auto-HSCT, 0.7% (95%CI: 0.4-1.1%). GNRB, especially MDR, was associated with increased mortality. Multivariate analysis revealed the following GNRB risk factors: (a) pre-eng-allo-HSCT: south-eastern Europe center location, underlying diseases not at complete remission, and cord blood source; (b) post-eng-allo-HSCT: center location not in northwestern Europe; underlying non-malignant disease, not providing FQP and never accredited. (c) pre-eng-auto-HSCT: older age, autoimmune and malignant (vs. plasma cell) disease, and ICT absence. CONCLUSIONS: Benefit of FQP should be explored in prospective studies. Increased GNRB risk in auto-HSCT patients transplanted for autoimmune diseases is worrying. Infection control and being accredited are possibly protective against bacteremia. GNRB are associated with increased mortality.

Viral Infections in HSCT: Detection, Monitoring, Clinical Management, and Immunologic Implications.

In spite of an increasing array of investigations, the relationships between viral infections and allogeneic hematopoietic stem cell transplantation (HSCT) are still controversial, and almost exclusively regard DNA viruses. Viral infections per se account for a considerable risk of morbidity and mortality among HSCT recipients, and available antiviral agents have proven to be of limited effectiveness. Therefore, an optimal management of viral infection represents a key point in HSCT strategies. On the other hand, viruses bear the potential of shaping immunologic recovery after HSCT, possibly interfering with control of the underlying disease and graft-versus-host disease (GvHD), and eventually with HSCT outcome. Moreover, preliminary data are available about the possible role of some virome components as markers of immunologic recovery after HSCT. Lastly, HSCT may exert an immunotherapeutic effect against some viral infections, notably HIV and HTLV-1, and has been considered as an eradicating approach in these indications.

Prospective evaluation of metabolic syndrome and its features in a single-center series of hematopoietic stem cell transplantation recipients.

Available studies on metabolic syndrome (MS) after hematopoietic stem cell transplantation (HSCT) are retrospective with heterogeneous inclusion criteria, and little is known about the early post-transplant phase. In our prospective study, clinical and laboratory data were collected in 100 HSCT recipients, 48 allogeneic and 52 autologous, at baseline, at + 30, + 100 and + 360 days. At baseline, MS was observed in 24 patients, significantly associated with insulin resistance and leptin on multivariate analysis. At + 30, the diagnosis of MS was confirmed in 43 patients, significantly related to insulin resistance and allogeneic transplants. If the whole series was considered, patients with MS had significantly higher mortality from any cause. The baseline presence of any MS feature was a predictor of + 30 MS. Isolated occurrences of MS features were related to hyperleptinemia and hyperinsulinemia, except in the case of low HDL cholesterol, linked to adiponectin and resistin. Our data confirm that patients undergoing HSCT have a high prevalence of MS, with hyperleptinemia playing a major role. The early peak of new MS cases is primarily attributable to insulin resistance, notably but not exclusively immunosuppression-induced; the subsequent long-term increase in MS cases may be an effect of persistent adipokine imbalance.

Incidence, Risk Factors and Outcome of Pre-engraftment Gram-Negative Bacteremia After Allogeneic and Autologous Hematopoietic Stem Cell Transplantation: An Italian Prospective Multicenter Survey.

BACKGROUND: Gram-negative bacteremia (GNB) is a major cause of illness and death after hematopoietic stem cell transplantation (HSCT), and updated epidemiological investigation is advisable. METHODS: We prospectively evaluated the epidemiology of pre-engraftment GNB in 1118 allogeneic HSCTs (allo-HSCTs) and 1625 autologous HSCTs (auto-HSCTs) among 54 transplant centers during 2014 (SIGNB-GITMO-AMCLI study). Using logistic regression methods. we identified risk factors for GNB and evaluated the impact of GNB on the 4-month overall-survival after transplant. RESULTS: The cumulative incidence of pre-engraftment GNB was 17.3% in allo-HSCT and 9% in auto-HSCT. Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa were the most common isolates. By multivariate analysis, variables associated with GNB were a diagnosis of acute leukemia, a transplant from a HLA-mismatched donor and from cord blood, older age, and duration of severe neutropenia in allo-HSCT, and a diagnosis of lymphoma, older age, and no antibacterial prophylaxis in auto-HSCT. A pretransplant infection by a resistant pathogen was significantly associated with an increased risk of posttransplant infection by the same microorganism in allo-HSCT. Colonization by resistant gram-negative bacteria was significantly associated with an increased rate of infection by the same pathogen in both transplant procedures. GNB was independently associated with increased mortality at 4 months both in allo-HSCT (hazard ratio, 2.13; 95% confidence interval, 1.45-3.13; P <.001) and auto-HSCT (2.43; 1.22-4.84; P = .01). CONCLUSIONS: Pre-engraftment GNB is an independent factor associated with increased mortality rate at 4 months after auto-HSCT and allo-HSCT. Previous infectious history and colonization monitoring represent major indicators of GNB. CLINICAL TRIALS REGISTRATION: NCT02088840.

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) role in hematopoiesis and in hematologic diseases: A critical review.

Dioxin exposure and its effect on hematopoiesis and cancer have been largely investigated in both human and non-human settings. Here we systematically reviewed literature to address the question of what we know about TCDD biology and exposure. Most effects are due to TCDD interaction with a receptor of xenobiotics called AHR, which is ubiquitously represented and also works on hematopoietic myeloid and lymphoid stem cells, inducing proliferation and stem cell release from bone marrow to peripheral circulation. Epidemiologic studies on TCDD exposure demonstrated an association with onco-hematologic diseases, particularly with non Hodgkin lymphomas and multiple myeloma, and non hematologic cancers, such as sarcomas, although these relationships are affected by multiple confounding factors.

Severe fludarabine neurotoxicity after reduced intensity conditioning regimen to allogeneic hematopoietic stem cell transplantation: a case report.

We present a case of severe, irreversible neurotoxicity in a 55-year-old-patient with myelofibrosis undergoing hematopoietic stem cell transplantation following a reduced intensity conditioning including fludarabine. The patient developed progressive sensory-motor, visual and consciousness disturbances, eventually leading to death. MRI imaging pattern was unique and attributable to fludarabine neurotoxicity.

Metabolic syndrome in patients with hematological diseases.

The term metabolic syndrome (MS) defines a clustering of cardiovascular risk factors, formerly known as syndrome X. There is some debate about the diagnostic criteria; but the most widely accepted framework is that defined by the National Cholesterol Education Program Adult Treatment Panel III, which requires the simultaneous occurrence of at least three of abdominal obesity, arterial hypertension, hyperglycemia, hypertrigliceridemia and low high-density lipoprotein cholesterol (HDL-C). The prevalence of MS increases with age and varies depending on genetic factors. An abnormally high prevalence has been observed in patients with heterogeneous conditions, such as solid organ transplant recipients, AIDS patients and long-term cancer survivors. As some of the pathogenetic factors possibly involved include cyclosporine A, corticosteroids and cancer chemoradiotherapy, it is possible that MS may also be a complication in hematological patients. Some of the characteristics of MS have been reported with a certain frequency in thalassemia patients, and are mainly attributed to iron overload. Impaired hemostasis is a feature of MS rather than a factor predisposing to its development. In oncohematology, an abnormally high prevalence of MS features has been observed in survivors of pediatric acute lymphoblastic leukemia. In addition to corticosteroid- and cancer therapy-related hypogonadism, hypothyroidism and defective growth hormone incretion are other factors related to the development of MS. Moreover, the highest frequency of MS is observed in hematopoietic stem cell transplantation (HSCT) recipients. Pediatric patients and allogeneic HSCT recipients have been the subject of foremost investigations; but adult patients and autologous HSCT recipients have also been studied more recently. A wide range of factors may contribute to the development of MS in HSCT recipients. Unfortunately, the real entity of the problem is far from clear because of the retrospective design of the studies, the limited size of their populations and their heterogeneous selection criteria, thus making it difficult to determine whether MS is a transient and possibly reversible phenomenon or a true late effect of the procedure.

Immunomodulatory effects of unselected haematopoietic stem cells autotransplantation in refractory Crohn's disease.

BACKGROUND: Autologous haematopoietic stem cells transplantation (HSCT) has been shown to be effective in refractory Crohn's disease. AIM: We analysed the effects of HSCT on the immune response of patients treated for moderate-severe Crohn's disease, refractory or intolerant to multiple drugs. METHODS: Unselected peripheral blood stem cells were collected after mobilisation with cyclophosphamide (CTX) and G-CSF. The conditioning regimen included CTX and rabbit antithymocyte globulin. Blood samples for immunological analyses were collected at baseline, after mobilisation, and 3, 6 and 12 months after transplantation. Immunological analyses evaluated: (1) CD4(+)/CD25(high+)/FoxP3(+) regulatory T cells (T-regs); (2) Toll-like receptor 2-(TLR2) and TRL4-expressing monocytes (CD14(+) cells); (3) IL-12, IL-10, TNF-alpha-production by mitogen-stimulated CD14(+) cells and IFN-gamma production by CD4(+) T cells. Immunological results were compared with healthy donors and associated with clinical and endoscopic response during 12 months of follow-up. RESULTS: Overall, T-regs increased, whilst TLR4-expressing cells, as well as TNF-alpha and IL-10, all higher than healthy donors at baseline, significantly decreased after transplantation. Full responders at T(3) had higher T-regs and lower IFN-gamma and IL12. T-regs decreased and IL12 and TLR2 increased in the only relapsed patient. CONCLUSIONS: HSCT can induce and maintain clinical and endoscopic remission in refractory Crohn's disease, which is associated with immunomodulation.

Autologous hematopoietic stem cell transplantation in autoimmune diseases.

The term 'autoimmune diseases' encompasses a spectrum of diseases whose clinical manifestations and, possibly, biological features vary widely. The results of conventional treatment are considered unsatisfactory in aggressive forms, with subsets of patients having short life expectancies. Relying on wide experimental evidence and more feeble clinical data, some research groups have used autologous hematopoietic stem cell transplantation (HSCT) in the most disabling autoimmune diseases with the aim of resetting the patient's immune system. Immunoablative conditioning regimens are preferred over their myeloablative counterparts, and some form of in vivo and/or ex vivo T-cell depletion is generally adopted. Despite 15 years' experience, published controlled clinical trials are still lacking, with the evidence so far available coming from pilot studies and registry surveys. In multiple sclerosis, clinical improvement, or at least lasting disease stabilization, can be achieved in the majority of the patients; nevertheless, the worst results are observed in patients with progressive disease, where no benefit can be expected from conventional therapy. Concerning rheumatologic diseases, wide experience has been acquired in systemic sclerosis, with long-term improvements in cutaneous disease being frequently reported, although visceral involvement remains unchanged at best. Autografting has proved to be barely effective in rheumatoid arthritis and quite toxic in juvenile idiopathic arthritis, whereas it leads to clinical remission and the reversal of visceral impairment in the majority of patients with systemic lupus erythematosus. A promising indication is Crohn's disease, in which long-term endoscopic remission is frequently observed. Growing experience with autologous HCST in autoimmune diseases has progressively reduced concerns about transplant-related mortality and secondary myelodysplasia/leukemia. Therefore, a sustained complete remission seems to be within the reach of autografting in some autoimmune diseases; in others, the indications, risks and benefits of autografting need to be better defined. Consequently, the search for new drugs should also be encouraged.

Essential thrombocythemia or chronic idiopathic myelofibrosis? A single-center study based on hematopoietic bone marrow histology.

We reviewed a large series of patients with essential thrombocythemia diagnosed on the basis of the Polycythemia Vera Study Group criteria, and reclassified them by evaluating their major morphologic features and clinical course using the World Health Organization classification. The morphologic review of the bone marrow biopsies of 116 patients (44 males and 72 females; aged 19 - 83 years, median 55 years; median follow-up 121 months) led to 22 cases (19%) being classified as essential thrombocythemia (ET), 24 (21%) as chronic idiopathic myelofibrosis (CIMF)-0, 44 (37%) as CIMF-1, 13 (12%) as CIMF-2, 9 (8%) as latent phase polycythemia vera, and four (3%) as chronic myeloproliferative disorder, unclassifiable. There was a significant difference in the median age of the ET and fibrotic CIMF patients (54.7 +/- 13.55 vs. 59.13 +/- 15.05 years; P = 0.03). Histologic analysis showed that the simultaneous presence of loose clusters of large/giant megakaryocytes and nuclear hyperlobulation was significantly different between the ET and the prefibrotic CIMF (P<0.01) and fibrotic CIMF patients (P<0.01), and that the association of dense clusters of megakaryocytes with maturation defects and bulbous nuclei also distinguished the prefibrotic CIMF (P<0.05) and fibrotic CIMF patients (P<0.001) from those with ET. The association of cellularity, granulocytic proliferation and reticulin fibers was helpful in distinguishing prefibrotic from fibrotic CIMF (P<0.001).

Risk factors and severe outcome in thrombotic microangiopathy after allogeneic hematopoietic stem cell transplantation.

BACKGROUND: Thrombotic microangiopathy (TMA) has been described as severe complication after hematopoietic stem cell transplantation (HSCT). The principal aim of this study was to focus the incidence and the outcome of TMA in the era of more complex HSCTs. METHODS: We analyzed the role of some predicting factors for the incidence and the outcome of TMA after HSCT. We enrolled 539 consecutive patients (307 males, median age 31 years) undergoing HSCT from match or mismatch human leukocyte antigen family donor (314) or match/mismatch unrelated (195) and haploidentical donor (30) for malignant or nonmalignant diseases. TMA diagnosis was performed by homogeneous clinical and laboratory criteria. RESULTS: Sixty-four of 539 patients presented TMA (11,87%) and the five-year cumulative incidence of TMA was 14% (HR=0.13). Fifty nine of 64 patients were affected by malignant and 5/64 by non-malignant diseases. On multivariate analysis, TMA occurrence was influenced by graft versus host disease >grade II (P=0.0001), donor type (P=0.029), gender (P=0.0233), total body irradiation based conditioning regimen (P=0.0041). Three factors for TMA outcome proved to be statistically significant by multivariate analysis: age (P=0.009), donor type (P=0.0187) and TMA index (P=0.029). The TMA mortality rate was 50%. The outcome was influenced by defibrotide (P=0.02 in univariate analysis). CONCLUSIONS: The study underlines the possibility of finding out which patients are more prone to developing post-HSCT TMA, and identifies which risk factors are more frequently associated with a dismal outcome after TMA.

A long-term follow-up analysis in adult acute myeloid leukemia patients after hematopoietic stem cell transplantation.

AIMS AND BACKGROUND: Over the last 17 years, 119 adult acute myeloid leukemia patients have undergone hematopoietic stem cell transplantation at our Center. STUDY DESIGN: Seventy patients in first complete remission received hematopoietic stem cell transplantation (28 allogeneic and 42 autologous HSCT) as late intensification after conventional chemotherapy; 38 patients received allogeneic hematopoietic stem cell transplantation in a more advanced phase. A reference group was built up by collecting 40 acute myeloid leukemia patients who received high-dose cytosine arabinoside as late intensification and whose complete remission lasted more than 10 months. RESULTS: Results of the study led to conclude that an earlier timing of allogeneic hematopoietic stem cell transplantation can be recommended in order to treat patients who would otherwise suffer an early relapse. CONCLUSIONS: The outcome of autologous hematopoietic stem cell transplantation in patients not in first complete remission supports the possibility of achieving good quality second complete remissions and suggests that autografting may be a life-saving strategy in selected acute myeloid leukemia patients with advanced disease.

Hyperuricemia and bone marrow transplantation.

Blood uric acid levels and purine metabolism are affected in many ways after bone marrow transplantation (BMT). Although BMT is usually performed when patients have a low residual disease burden, a proportion of them are still at risk of tumor lysis syndrome, even with limited disease or after nonmyeloablative conditioning regimens; moreover, an alteration in uric acid turnover can also be observed in patients with persistently normal uric acid blood levels. Apart from this obvious complication, multiple physiopathological events occurring after transplantation may derange uric acid homeostasis. Although there is only indirect evidence (derived from obstetric eclampsia and experimental gout arthritis), a transplant-related increase in cytokine production (particularly TNF, IL-1 and IL-6) may activate xanthine oxidase which, in turn, may be responsible for a further cytokine bout: deranged cytokine homeostasis is involved in the pathogenesis of some of the main acute post-BMT complications, such as hepatic veno-occlusive disease (VOD) and acute graft-versus-host disease (aGVHD). Hyperuricemia is also a well-known side effect of cyclosporine A, the reference drug for the prevention of post-BMT GVHD, which may affect uric acid turnover by reducing glomerular filtration and/or affecting tubular handling; the available evidence favors the former explanation. Hyperuricemia is found in long-term transplanted patients as part of a metabolic pattern reminiscent of the so-called 'X' or 'metabolic'syndrome related to insulin resistance: there is still no precise interpretation of this post-transplant complication nor any definite data concerning its real incidence and outcome. Hyperuricemia is frequently regarded as a marginal finding in the context of X syndrome, but it is pathogenetically linked to the other component of the syndrome and has proved to be autonomously responsible for tissue and vessel damage. Finally, BMT is a possible therapeutic strategy for some inherited forms of hyperuricemia, particularly Lesch- Nyhan disease, although there is still some perplexity concerning the possibility of preventing the development of neurological impairment.

Four-year survival after trans-jugular intrahepatic porto-systemic shunt for veno-occlusive disease following autologous bone marrow transplantation.

Severe hepatic veno-occlusive disease is still a potentially lethal complication after bone marrow transplantation. We here report the case of a patient who developed liver veno-occlusive disease with severe hemodynamic dysfunction and was successfully treated by means of a trans-jugular intrahepatic portosystemic shunt. After three years, he is still disease-free with a functioning shunt and a normal laboratory liver profile. A trans-jugular intrahepatic portosystemic shunt is a treatment option that has been used in very few patients affected by hepatic veno-occlusive disease; its indications and timing remain to be established.

Hematopoietic stem cell transplantation in adult acute lymphoblastic leukemia: a single-centre analysis.

The role of autologous or allogeneic hematopoietic stem cell transplantation (HSCT) in ALL is controversial because of its adverse risk/benefit ratio, and the main policy is to reserve it for high-risk patients. In our Institution, between 1984 and 2002, 40 patients received an allogeneic HSCT and 39 underwent autografting. The conditioning regimen included HD-Ara-C, HD-CTX and 10 Gy fractionated TBI. After allogeneic SCT in first CR, four patients relapsed, leading to a 10-year EFS chance of 78.3%; of the other patients, 5 are still in CR. After autografting in first CR, there was an early death, one secondary AML, one death in CR and six relapses, leading to a 10-year EFS chance of 44.4%; of the other patients, 6 are still in CR. Even considering the limited number of patients and the slow accrual rate, selection bias cannot be considered a sufficient explanation for the favorable outcome of allografting in first CR as the majority of the patients had adverse prognostic factors. It cannot be claimed that allogeneic SCT was performed in patients already cured, as the autografted patients had a notably worse outcome, and a 10-year EFS chance of about 80% is an uncommon finding even in standard-risk ALL patients. It might be inferred that the timing of SCT as late intensification, in addition to a rather aggressive conditioning regimen, helped to minimize the leukemic burden, thus favoring the expression of a GVL effect. Conversely, the results in more advanced disease phases are discouraging, due to poor quality CRs and inefficacy of GVL in managing large residual disease.

Harvesting of autologous blood stem cells after a mobilising regimen with low-dose cyclophosphamide.

Although high-dose cyclophosphamide (HD-CTX) is commonly used as a mobilising regimen for autologous peripheral blood stem cell (PBSC) collection, significant morbidity and insufficient harvesting may complicate the procedure. Alternative regimens and lower doses of cyclophosphamide (CTX) have been investigated as possible ways of overcoming these difficulties. Low-dose CTX (1.5 g/m2) was administered to 102 lymphoma patients as an autologous PBSC mobilising regimen. The collection of 6 x 10(6) CD34+ cells/kg was chosen as the target of the apheresis sessions, whereas 3 x 10(6)/kg were considered the minimum necessary to perform autologous stem cell transplantation (ASCT) safely. The apheretic sessions were started a median of eight days after CTX administration; a median of two aphereses was required. More than 6 x 10(6) CD34+ cells/kg were collected from 78 patients, between 3 and 6 x 10(6)/kg from 19, and fewer than 3 x 10(6)/kg from 5, two of whom underwent bone marrow harvesting and one a successful second PBSC harvesting session using the same mobilising regimen. Eighty-two patients underwent autografting, six of whom received a second transplant after relapse (five using autologous PBSCs coming from the first apheretic course). Low-dose CTX proved to be a safe and effective regimen for autologous PBSC mobilization and also compared favourably with alternative regimens in terms of the rate of harvesting insufficiency. This does not imply that low-dose CTX is the best mobilising regimen for all patients, and the identification of prognostic factors predicting mobilising potential may help in choosing the best individualised regimen.

Lethal pulmonary complications significantly correlate with individually assessed mean lung dose in patients with hematologic malignancies treated with total body irradiation.

PURPOSE: To assess the impact of lung dose on lethal pulmonary complications (LPCs) in a single-center group of patients with hematologic malignancies treated with total body irradiation (TBI) in the conditioning regimen for bone marrow transplantation (BMT). METHODS: The mean lung dose of 101 TBI-conditioned patients was assessed by a thorough (1 SD around 2%) in vivo transit dosimetry technique. Fractionated TBI (10 Gy, 3.33 Gy/fraction, 1 fraction/d, 0.055 Gy/min) was delivered using a lateral-opposed beam technique with shielding of the lung by the arms. The median lung dose was 9.4 Gy (1 SD 0.8 Gy, range 7.8--11.4). The LPCs included idiopathic interstitial pneumonia (IIP) and non-idiopathic IP (non-IIP). RESULTS: Nine LPCs were observed. LPCs were observed in 2 (3.8%) of 52 patients in the group with a lung dose < or = 9.4 Gy and in 7 (14.3%) of 49 patients in the >9.4 Gy group. The 6-month LPC risk was 3.8% and 19.2% (p = 0.05), respectively. A multivariate analysis adjusted by the following variables: type of malignancy (acute leukemia, chronic leukemia, lymphoma, myeloma), type of BMT (allogeneic, autologous), cytomegalovirus infection, graft vs. host disease, and previously administered drugs (bleomycin, cytarabine, cyclophosphamide, nitrosoureas), revealed a significant and independent association between lung dose and LPC risk (p = 0.02; relative risk = 6.7). Of the variables analyzed, BMT type (p = 0.04; relative risk = 6.6) had a risk predictive role. CONCLUSION: The mean lung dose is an independent predictor of LPC risk in patients treated with the 3 x 3.33-Gy low-dose-rate TBI technique. Allogeneic BMT is associated with a higher risk of LPCs.