Bloodstream infections in haematological cancer patients colonized by multidrug-resistant bacteria.

Infections by multidrug-resistant (MDR) bacteria are a worrisome phenomenon in hematological patients. Data on the incidence of MDR colonization and related bloodstream infections (BSIs) in haematological patients are scarce. A multicentric prospective observational study was planned in 18 haematological institutions during a 6-month period. All patients showing MDR rectal colonization as well as occurrence of BSI at admission were recorded. One-hundred forty-four patients with MDR colonization were observed (6.5% of 2226 admissions). Extended spectrum beta-lactamase (ESBL)-producing (ESBL-P) enterobacteria were observed in 64/144 patients, carbapenem-resistant (CR) Gram-negative bacteria in 85/144 and vancomycin-resistant enterococci (VREs) in 9/144. Overall, 37 MDR-colonized patients (25.7%) developed at least one BSI; 23 of them (62.2%, 16% of the whole series) developed BSI by the same pathogen (MDRrel BSI), with a rate of 15.6% (10/64) for ESBL-P enterobacteria, 14.1% (12/85) for CR Gram-negative bacteria and 11.1% (1/9) for VRE. In 20/23 cases, MDRrel BSI occurred during neutropenia. After a median follow-up of 80 days, 18 patients died (12.5%). The 3-month overall survival was significantly lower for patients colonized with CR Gram-negative bacteria (83.6%) and VRE (77.8%) in comparison with those colonized with ESBL-P enterobacteria (96.8%). CR-rel BSI and the presence of a urinary catheter were independent predictors of mortality. MDR rectal colonization occurs in 6.5% of haematological inpatients and predicts a 16% probability of MDRrel BSI, particularly during neutropenia, as well as a higher probability of unfavourable outcomes in CR-rel BSIs. Tailored empiric antibiotic treatment should be decided on the basis of colonization.

Circulating endothelial cell count: a reliable marker of endothelial damage in patients undergoing hematopoietic stem cell transplantation.

The physio-pathologic interrelationships between endothelium and GvHD have been better elucidated and have led to definition of the entity 'endothelial GvHD' as an essential early phase prior to the clinical presentation of acute GvHD. Using the CellSearch system, we analyzed circulating endothelial cells (CEC) in 90 allogeneic hematopoietic stem cell transplantation (allo-HSCT) patients at the following time-points: T1 (pre-conditioning), T2 (pre-transplant), T3 (engraftment), T4 (onset of GvHD) and T5 (1 week after steroid treatment). Although CEC changes in allo-HSCT represent a dynamic phenomenon influenced by many variables (that is, conditioning, immunosuppressive treatments, engraftment syndrome and infections), we showed that CEC peaks were constantly seen at onset of acute GvHD and invariably returned to pre-transplant values after treatment response. Since we showed that CEC changes during allo-HSCT has rapid kinetics that may be easily missed if blood samples are drawn at pre-fixed time-points, we rather suggest an 'on demand' evaluation of CEC counts right at onset of GvHD clinical symptoms to possibly help differentiate GvHD from other non-endothelial complications. We confirm that CEC changes are a suitable biomarker to monitor endothelial damage in patients undergoing allo-transplantation and hold the potential to become a useful tool to support GvHD diagnosis (ClinicalTrials.gov NCT02064972).

Emerging resistant bacteria strains in bloodstream infections of acute leukaemia patients: results of a prospective study by the Rete Ematologica Lombarda (Rel).

Multiresistant bacterial infections are a potentially life-threatening condition in acute leukaemia (AL) patients. We aimed to better define the very recent epidemiology and outcome of bloodstream infections (BSIs) in a real-life setting. We prospectively collected all consecutive febrile/infectious episodes occurring in AL patients admitted to 9 haematology units. In 293 AL patients, 433 BSIs were diagnosed. Gram-positive (GP) bacteria were isolated in 44.8 % BSI and Gram-negative (GN) in 38.3 %, while polymicrobial aetiology- or fungi-related events were identified in 15.7 and 1.1 % of the cases, respectively. GP was observed more frequently in patients not in complete remission (p = 0.04), while GN during consolidation cycles (p = 0.003). Extended spectrum ß-lactamase-producing strains accounted for 23.2 % of enterobacteria. They were associated with previous antibiotic exposure, including fluoroquinolones prophylaxis (p = 0.01). Carbapenem-resistant (CR) strains occurred in 9 % of enterobacteria. Among Pseudomonas aeruginosa strains, 21.6 % were multiresistant. Overall 30-day mortality was 8.5 %. CR GN and multiresistant P. aeruginosa BSIs were independent predictors of death (p = 0.002), as well as relapsed/resistant AL (18.3 %; p = 0.0002) and the presence of pulmonary infiltrates (26.6 %; p < 0.001). Although GP still predominate over GN BSI, the percentage of antibiotic resistant GN strains is considerable in AL patients and it is associated with poor prognosis.

Managing chronic myeloid leukaemia in the elderly with intermittent imatinib treatment.

The aim of this study was to investigate the effects of a non-standard, intermittent imatinib treatment in elderly patients with Philadelphia-positive chronic myeloid leukaemia and to answer the question on which dose should be used once a stable optimal response has been achieved. Seventy-six patients aged ⩾65 years in optimal and stable response with ⩾2 years of standard imatinib treatment were enrolled in a study testing a regimen of intermittent imatinib (INTERIM; 1-month on and 1-month off). With a minimum follow-up of 6 years, 16/76 patients (21%) have lost complete cytogenetic response (CCyR) and major molecular response (MMR), and 16 patients (21%) have lost MMR only. All these patients were given imatinib again, the same dose, on the standard schedule and achieved again CCyR and MMR or an even deeper molecular response. The probability of remaining on INTERIM at 6 years was 48% (95% confidence interval 35-59%). Nine patients died in remission. No progressions were recorded. Side effects of continuous treatment were reduced by 50%. In optimal and stable responders, a policy of intermittent imatinib treatment is feasible, is successful in about 50% of patients and is safe, as all the patients who relapsed could be brought back to optimal response.

A specific Toll-like receptor profile on T lymphocytes and values of monocytes correlate with bacterial, fungal, and cytomegalovirus infections in the early period of allogeneic stem cell transplantation.

BACKGROUND: Bacterial, fungal, and viral infections often affect non-relapse mortality after allogeneic stem cell transplantation (alloSCT). Recovery from infections depends on a balanced integration between innate and adaptive immune responses. In this complex interplay, a key role is played by Toll-like receptors (TLRs), which are sensors of pathogen-associated molecular patterns. To our knowledge, no previous study deals with both expression and function of all human TLRs together, in relation to infections in the setting of alloSCT. METHODS: We prospectively evaluated 9 TLRs by flow cytometry on T lymphocytes and monocytes of 35 patients in relation to infectious events from day +30 to day +120. Tumor necrois factor-alpha, interleukin-4, interferon-gamma, and monocyte chemoattractant protein-1 induction upon TLR activation was assessed by enzyme-linked immunosorbent assay on cell supernatants. RESULTS: In multivariate Cox regression analysis, levels of TLR-9 expression on T lymphocytes (P = 0.01) and values of natural killer cells (P = 0.01) correlated negatively with bacterial infections, whereas cytomegalovirus (CMV) infection resulted as a positive predictor. We observed a trend for negative correlation between TLR-7 levels on T lymphocytes and fungal infections (P = 0.07). Values of monocytes were negatively associated with CMV infection (P = 0.03), whereas levels of TLR-5 on T lymphocytes were positive predictors (P = 0.01). Age (P = 0.03) and bacterial infections (P = 0.006) negatively influenced overall survival. Monocyte values were positive predictors of survival (P = 0.003). CONCLUSIONS: Bacterial, fungal, and CMV infections were associated with a different expression of some TLRs on T lymphocytes. The protective role of TLR-7 and TLR-9 seemed dominant over other TLRs involved in recognizing fungi and bacteria. We also observed an atypical involvement of TLR-5 in CMV infection. The dominant and atypical role of some TLRs could depend on their pleiotropic functions and the changing inflammatory environment of transplanted patients. A specific TLR profile and an adequate count of monocytes could improve survival, promoting an effective control of infections, and balanced immune responses. If our findings will be confirmed by further studies, these immunological variables could be useful as parameters to predict susceptibility to infections.

Kinetics of Th1/Th2 cytokines and lymphocyte subsets to predict chronic GVHD after allo-SCT: results of a prospective study.

The role of different cytokines and cells of immune system in the pathogenesis of chronic GVHD (cGVHD) is still controversial. Earlier studies, which were either retrospective or analysed one or a few factors, did not show unequivocal results. We prospectively evaluated cytokine levels and lymphocyte subsets in 30 patients who underwent Allo-SCT to investigate their possible correlation with cGVHD. Levels of IL-4, IL-6, IL-10, IFN-gamma, tumour necrosis factor-alpha (TNF-alpha) and its soluble receptors were assessed by ELISA in 30 patients at different times after SCT. Lymphocyte subsets were evaluated by flow cytometry in peripheral blood at the same times as cytokines. A multivariate analysis was performed using principal component analysis and multi-factor ANOVA (analysis of variance). Eighteen patients developed cGVHD at a median time of 6 months (range, 5-9) after SCT. In multivariate analysis, we observed a correlation between cGVHD and clusters of cytokines and lymphocyte subsets from the third to the sixth month after SCT. These clusters changed their composition over time, but they constantly included natural killer (NK) and CD152+ T cells as negative predictors of cGVHD. TNF-alpha prevailed among other cytokines before the onset of cGVHD. This prevalence could be related partly to the defect of immunoregulatory cells.

Incidence, outcome, and risk factors of late-onset noninfectious pulmonary complications after unrelated donor stem cell transplantation.

We evaluated the incidence, the risk factors, and the outcome of late-onset noninfectious pulmonary complications (LONIPCs) among 50 patients who underwent allogeneic stem cell transplantation from unrelated donors. Of the 39 patients surviving at least 3 months, 10 (26%) fulfilled the diagnostic criteria of LONIPCs and were further subclassified as having bronchiolitis obliterans (four patients), bronchiolitis obliterans with organizing pneumonia (four patients), and interstitial pneumonia (two patients). Two patients had a durable partial remission after treatment with prednisone and cyclosporine; the remaining eight patients did not respond to treatment and five of them died of respiratory failure. Advanced stage of disease at transplant and chronic extensive graft-versus-host disease (GVHD) were significantly associated with the development of LONIPCs. Pulmonary function test (PFT) results before transplantation were similar in all patients, but patients with LONIPCs had a significant decrease in PFT indexes at the third month after BMT compared with controls. Moreover, the rate of cyclosporine taper during the fourth and fifth months after BMT was significantly more rapid in patients with LONIPCs than in controls, suggesting that the risk of LONIPCs may be influenced by a faster reduction of GVHD prophylaxis.

CD34+-selected versus unmanipulated autologous stem cell transplantation in multiple myeloma: impact on dendritic and immune recovery and on complications due to infection.

BACKGROUND: Large-scale CD34+ enrichment has been demonstrated a safe method in autologous transplantation for multiple myeloma. However, the high CD34+ enrichment and the consequent plasma cell purging result in concomitant T-cell and dendritic-cell (DC) depletion, theoretically increasing the risk of life-threatening infections. PATIENTS AND METHODS: We evaluated immunological and dendritic reconstitution in 72 myeloma patients who had undergone CD34+-selected (n = 45) and unmanipulated (n = 27) stem cell transplant, and its correlation with infections. RESULTS: Haematological recovery occurred promptly in all patients. Only a slight delay in platelet recovery to >50 x 10(9)/l was observed in patients receiving CD34+-enriched graft. Natural killer (NK) cell count recovered in all patients within 2 months and B-cell count had recovered by 6 months post-transplant in both groups. CD3 cells remained lower than normal in both groups. CD8 cells increased above the normal level, reaching a peak at day 90, and lowered to normal level within 1 year post-transplant. CD4 lymphocytes remained <50% of normal, especially in selected patients. In both groups, both DC1 and DC2 counts were already significantly lower than in normal individuals before conditioning therapy. Pre-conditioning levels of DC1 were reached in unmanipulated patients at day 30 and became normal at 6 months. In selected patients, DC1 pre-transplant level was observed at day 60 and was maintained thereafter. DC2 recovery showed a similar trend. In unselected patients, DC2 count increased to pre-conditioning level at haematological recovery and was normal after 1 year. In selected transplants, DC2 increased more slowly than DC1 in the same patients: pre-transplant level was detected at day 90 but was still significantly lower than normal 1 year after transplant. The incidence of infection was similar in both groups. Sepsis had Gram+ aetiology in the majority of cases. After engraftment only viral infections were recorded, mostly due to herpes reactivation, with no difference between groups. DISCUSSION: In spite of a delay in immune recovery, CD34 enrichment is not associated with a significant increase of complications due to infection. Relatively fast NK cell recovery to pre-transplant levels and the presence of functionally efficient DCs can justify the low incidence of infections.

Dendritic cell recovery after autologous stem cell transplantation.

There is persistent immunosuppression not only in allogeneic but also in autologous stem cell transplantation because humoral and cellular immunity may take a year or more to return to normal, with increased risk of infectious complications. This immune defect may also involve antigen presentation, in particular dendritic cell (DC) function. We evaluated DC subset reconstitution in 58 patients who underwent bone marrow (BM) or peripheral blood (PB) autologous haematopoietic stem cell transplantation (HSCT). In all patients DC type 1 (DC1) and DC type 2 (DC2) were already significantly lower than in normal individuals before conditioning therapy (DC1/microl 3.1 +/- 1.0, DC2/microl 3.0 +/- 1.1). On day 0 and day +7 the mean DC1 and DC2 numbers were very low in both groups. Patients who received unmanipulated marrow or peripheral blood stem cells reached pre-conditioning levels of DC1 and DC2 cells on day +20. In patients receiving selected CD34 cells, DC increased slowly and pre-transplant counts were observed only on day +60. Nearly 'normal' levels of DC1 and DC2 could be observed in the first group from day +180, and were maintained thereafter; in CD34(+) selected patients DC1 and DC2 counts remained lower than normal. Our data emphasise that circulating antigen presenting cells (APC) recover quickly. It remains to be determined if DC frequency in PB reflects their tissue function. The relatively low incidence of infections in patients undergoing autologous transplantation, despite defective lymphocyte reconstitution, could be related to functionally efficient DC.

Autologous bone marrow transplantation in non-Hodgkin's lymphoma patients: effect of a brief course of G-CSF on harvest and recovery.

This study compares harvest and hematological recovery data of 100 lymphoma patients who underwent BM harvest either after a short course of G-CSF (16 microg/kg for 3 days) (n = 57) or in steady-state conditions (n = 43). G-CSF allowed the attainment of a significantly higher median number of total nucleated cells x 10(8)/kg (4.4, range 1.4-17, vs 2.1, range 0.6-4.2; P < 0.0001), mononuclear cells x 10(8)/kg (0.55, range 0.20-1.4, vs 0.41, range 0.15-0.76, P < 0.0001) and CFU-GM/ml (310, range 10-5500, vs 80, range 10-3800, P = 0.008), with lower volumes of blood collected (17.5 ml/kg, range 8-31 vs 21.0, range 15-30, P = 0.0001). Hematological recovery was faster in patients who received pre-treated BM (median time to PMN >0.5 x 10(9)/l and to platelets >20 x 10(9)/l was 12, range 10-14, and 13, range 10-18, days, respectively) than in those autotransplanted with steady-state BM (median time to PMN >0.5 x 10(9)/l and to platelets >20 x 10(9)/l 13, range 10-18 and 14, range 10-20 days, respectively, P = 0.004 and P = 0.01). Transfusional requirement was significantly different and patients of the G-CSF group needed shorter hospitalization (17 days, range 12-24, vs 20 days, range 14-32; P = 0.02). These data suggest that treating patients with G-CSF before BM harvest improves the quality of the harvest and accelerates engraftment and hematological recovery.