Infections following peripheral blood progenitor cell transplantation for lymphoproliferative malignancies: etiology and potential risk factors

Inflammation and infection in plasma cell disorders: how pathogens shape the fate of patients

The role of infection and chronic inflammation in plasma cell disorders (PCD) has been well-described. Despite not being a diagnostic criterion, infection is a common complication of most PCD and represents a significant cause of morbidity and mortality in this population. As immune-based therapeutic agents are being increasingly used in multiple myeloma, it is important to recognize their impact on the epidemiology of infections and to identify preventive measures to improve outcomes. This review outlines the multiple factors attributed to the high infectious risk in PCD (e.g. the underlying disease status, patient age and comorbidities, and myeloma-directed treatment), with the aim of highlighting future prophylactic and preventive strategies that could be implemented in the clinic. Beyond this, infection and pathogens as an entity are believed to also influence disease biology from initiation to response to treatment and progression through a complex interplay involving pathogen exposure, chronic inflammation, and immune response. This review will outline both the direct and indirect role played by oncogenic pathogens in PCD, highlight the requirement for large-scale studies to decipher the precise implication of the microbiome and direct pathogens in the natural history of myeloma and its precursor disease states, and understand how, in turn, pathogens shape plasma cell biology.

The D-index is not correlated with invasive fungal infection during the early-post engraftment phase among allogeneic hematopoietic stem cell transplant recipients

The D-index assesses neutropenia dynamics. Prolonged neutropenia is a major risk for invasive fungal infection (IFI); we hypothesized that D-index is predictive of IFI risk. We retrospectively reviewed 789 adults who underwent allogeneic hematopoietic transplant (HSCT) from 1/1/2005 to 9/30/2015. Medical records were reviewed from transplant (D0) through Day 100. The D-index was calculated as area over the neutrophil curve until engraftment. 714 patients were included for analysis. Sixteen (2%) developed probable (11) or proven (5) IFI. Median time to IFI was 40 days (range 8-98) after HSCT. Groups with and without IFI did not differ significantly in duration of mild or profound neutropenia. Median D-index of those with IFI was 4293 days neutrophil/µl compared to 3590 days neutrophil/µl for those without IFI (P = 0.17). Patients who were neutropenic on D0 showed higher rates of IFI than those who were not (10/123 [8%] vs 6/591 [1%]; P < 0.001). Only 2% developed IFI, likely due to mold-active antifungal prophylaxis. The D-index was not significantly higher in those with IFI. Duration of profound neutropenia and neutropenia at D0 may be better markers for IFI among HSCT recipients during the first 30 and 100 days after transplant.

A Japanese single-hospital observational trial with a retrospective case-control analysis of varicella zoster virus reactivation after autologous peripheral blood stem cell transplantation

BACKGROUND

Varicella zoster virus (VZV) reactivation following hematopoietic stem cell transplantation (SCT) is common. To help reduce its incidence and to identify predictive factors for VZV reactivation after autologous SCT (auto-SCT), we conducted a retrospective analysis in patients with hematologic malignancy at our hospital.

METHODS

We conducted a single-hospital observational trial with a retrospective case-control analysis of post-auto-SCT VZV reactivation in patients with malignant lymphoma (ML) and multiple myeloma (MM) between January 2001 and December 2010, in the Department of Hematology at our hospital. First, we analyzed the cumulative incidence of VZV reactivation during the post-SCT period. Second, we conducted a case-control analysis to identify the risk factors for VZV reactivation within 1 year after SCT. Univariate analyses were performed using Fisher's exact test for categorical variables. A multivariable model and logistic regression were used to assess the risk factors for VZV reactivation.

RESULTS

We included 97 patients in this study. The median duration of follow-up was 1027 days. Forty-two patients experienced VZV reactivation after SCT, while 29 (69.0%) experienced reactivation within 1 year after SCT. The cumulative incidence was 30.7% at 1 year and 51.2% for the total observation period. Multivariate analysis showed that engraftment after day 10 was an independent risk factor for VZV reactivation (P = 0.03).

CONCLUSIONS

Our study showed a high incidence of VZV reactivation in the first year after auto-SCT in ML and MM patients. Patients with delayed engraftment are at high risk for VZV reactivation and should be considered for prolonged VZV prophylaxis.

Postexposure Prophylaxis Against Varicella-Zoster Virus Infection Among Recipients of Hematopoietic Stem Cell Transplant: Unresolved Issues

Recent guidelines for the prevention of opportunistic infections have addressed a variety of issues germane to recipients of hematopoietic stem cell transplant. However, there are several issues regarding postexposure prophylaxis against varicella-zoster virus that remain unresolved. We address these questions and offer several consensus recommendations.

Infections After High-Dose Chemotherapy and Autologous Hematopoietic Stem Cell Transplantation

Infection represents an important cause of morbidity after autologous hematopoietic stem cell transplantation (HSCT). Immunodeficiency is the key risk factor and results from interplay between the underlying disease and its therapy. Various defects in the immune system coexist in HSCT recipients. In the early post-transplant period, neutropenia, oral and gastrointestinal mucositis, and the presence of central venous catheters are the main risk factors. Bacterial infections predominate, and the agents and antibiotic susceptibility profiles vary widely in different regions. Invasive candidiasis is infrequent with fluconazole use, but the incidence of invasive aspergillosis is on the rise, mainly in patients receiving purine analogues or intensive chemotherapy before transplant. In the post-engraftment period, infections are less frequent, but may contribute to significant non-relapse mortality. The dynamics of immune reconstitution drives the risk for infection in this period. The most frequent infections are varicella-zoster virus disease and respiratory tract infections. Assessment of the risk of infection in each period and the identification of patients at higher risk of specific infections are critical to the appropriate management of infectious complications after autologous hematopoietic stem cell transplantation.

Changing treatment paradigms for patients with plasma cell myeloma: impact upon immune determinants of infection

Plasma cell myeloma (PCM) is increasing in prevalence in older age groups and infective complications are a leading cause of mortality. Patients with PCM are at increased risk of severe infections, having deficits in many arms of the immune system due to disease and treatment-related factors. Treatment of PCM has evolved over time with significant impacts on immune function resulting in changing rates and pattern of infection. Recently, there has been a paradigm shift in the treatment of PCM with the use of immunomodulatory drugs and proteasome inhibitors becoming the standard of care. These drugs have wide-ranging effects on the immune system but their impact on infection risk and aetiology remain unclear. The aims of this review are to discuss the impact of patient, disease and treatment factors on immune function over time for patients with PCM and to correlate immune deficits with the incidence and aetiology of infections seen clinically in these patients. Preventative measures and the need for clinically relevant tools to enable infective profiling of patients with PCM are discussed.

Antimicrobial therapy of febrile complications after high-dose chemotherapy and autologous hematopoietic stem cell transplantation--guidelines of the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Oncology (DGHO)

More than 18,000 autolgous transplantation were performed in Europe in the year 2009. It as a routine procedure in experienced centres. Even if there is a low mortality rate, infections are a major issue after transplantation, occurring in more than 60 % of the patients. In this review we discuss all aspects of infections after autologous stem transplantation, including epidemiology, diagnostics, therapeutic algorithms, prophylaxis and supportive therapy.

Immune reconstitution after double umbilical cord blood stem cell transplantation: comparison with unrelated peripheral blood stem cell transplantation

Double umbilical cord blood (DUCB) transplantation is an accepted transplantation strategy for patients without suitable human leukocyte antigen (HLA) matched donors. However, DUCB transplantation is associated with increased morbidity and mortality because of slow recovery of immunity and a high risk of infection. To define the differences in immune reconstitution between DUCB transplantation and HLA matched unrelated donor (MUD) transplantation, we performed a detailed, prospective analysis of immune reconstitution in 42 DUCB recipients and 102 filgrastim-mobilized unrelated peripheral blood stem cell recipients. Reconstitution of CD3 T cells was significantly delayed in the DUCB cohort compared with the MUD cohort for 1 to 6 months posttransplantation (P < .001), including naive (CD45RO-) and memory (CD45RO+) CD4 T cells, regulatory (CD4CD25) T cells, and CD8 T cells. In contrast, CD19 B cells recovered more rapidly in the DUCB cohort and numbers remained significantly greater from 3 to 24 months after transplantation (P = .001). CD56CD16 natural killer (NK) cells also recovered more rapidly in DUCB recipients and remained significantly greater from 1 to 24 months after transplantation. B cell activating factor (BAFF) levels were higher in the DUCB cohort at 1 month (P < .001), were similar in both cohorts at 3 and 6 months, and were lower in the DUCB cohort at 12 months (P = .002). BAFF/CD19 B cell ratios were lower in the DUCB cohort at 3 (P = .045), 6 (P = .02), and 12 months (P = .002) after transplantation. DUCB recipients had more infections within the first 100 days after transplantation (P < .001), and there was less chronic graft-versus-host disease (P < .001), but there were no differences in cumulative incidence of relapse, nonrelapse death, progression-free survival, or overall survival between the 2 groups. These results suggest that increased risk of infections is specifically associated with delayed reconstitution of all major T cell subsets, but the increased risk is limited to the first 3 months after DUCB transplantation. There is no increased risk of relapse, suggesting that graft-versus-leukemia activity is maintained. Early reconstitution of B cells and NK cells may, in part, account for these findings.

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

Incidence and characteristics of early bacterial infection within 100 days after unrelated cord blood transplantation (UCBT) were assessed for 664 pediatric and 1208 adult recipients in Japan. Cumulative incidence of early bacterial infection at day 100 post-UCBT was 11% (95% confidence interval [CI], 8%-13%) for children and 21% (CI, 19%-24%) for adults (P < .0001). Early bacterial infection in adults had a significant impact on mortality (hazard ratio [HR] = 2.1, CI, 1.7-2.6; P < .0001), although no significant risk factors were identified. Multivariate analysis identified older age group (6-10, and 11-15 years versus 0-5 years of age) at transplant (HR = 2.0 and 2.7, CI, 1.1-3.5 and 1.4-4.9; P = .020 and .002, respectively) as an independent risk factor of early bacterial infection for children. Early bacterial infection in children did not have a significant impact on mortality when adjusted. Of 315 bacteremia, 74% were caused by Gram-positive microorganisms. Pneumonia occurred in 39 patients including 13 cases of Stenotrophomonas maltophilia pneumonia. Early bacterial infection had a negative effect on survival for adults and the median day of development was 10 days after transplant, suggesting that the prevention of bacterial infection in the very early post-UCBT phase is important.

Management of HSV, VZV and EBV infections in patients with hematological malignancies and after SCT: guidelines from the Second European Conference on Infections in Leukemia

These guidelines on the management of HSV, VZV and EBV infection in patients with hematological malignancies and after SCT were prepared by the European Conference on Infections in Leukemia following a predefined methodology. A PubMed search was conducted using the appropriate key words to identify studies pertinent to management of HSV, VZV and EBV infections. References of relevant articles and abstracts from recent hematology and SCT scientific meetings were also reviewed. Prospective and retrospective studies identified from the data sources were evaluated, and all data deemed relevant were included in this analysis. The clinical and scientific background was described and discussed, and the quality of evidence and level of recommendation were graded according to the Centers for Disease Control criteria.

Post-transplant adoptive T-cell immunotherapy

Immune reconstitution following haematopoietic stem cell transplantation (SCT) is an often slow and incomplete process that leads to increased risk of infection and malignant disease. Immunization in SCT is frequently unsuccessful due to the prolonged lymphopenia, especially of CD4 T cells, seen following transplant. The transfusion of T cells, also called 'adoptive T-cell therapy', has the potential to enhance anti-tumour and overall immunity, and augment vaccine efficacy in the post-transplant setting. Recent advances in tissue culture, cellular immunology and tumour biology are guiding new approaches to adoptive T-cell therapy. This chapter will discuss the challenges that face the field before adoptive T-cell therapy can be translated into routine clinical practice.

Characteristics of and risk factors for pneumonia in patients with hematological malignancies developing fever after autologous blood stem cell transplantation

We analyzed the incidence, etiology, risk factors and outcomes of 49 episodes of pneumonia that developed in 326 adult patients undergoing autologous stem-cell transplantation (ASCT) from January 1990 to December 2005. The median time for the onset of pneumonia after transplantation was 11 days (range 0-148). Empirical antibiotic therapy in patients with pneumonia consisted of piperacillin-tazobactam (20 cases, 49%), third-generation cephalosporin (11 cases, 27%) and carbapenem (8 cases, 19%). Multivariate analysis showed that a higher risk of pneumonia could be predicted for patients with myeloma (P = 0.006) and for patients with an absolute neutrophil count <0.5 x 10(9)/L >7 days (P = 0.008). Cumulative incidence of transplant-related mortality at 6 months was 51% versus 8% for patients with or without pneumonia, respectively (P = 0.001). Pneumonia after ASCT is a severe complication more commonly observed in patients with myeloma and with prolonged duration of neutropenia.

Transplantation without growth factor: engraftment kinetics after stem cell transplantation for primary systemic amyloidosis (AL)

Stem cell transplantation is increasingly used in the management of immunoglobulin light-chain amyloidosis (AL). It is considered the standard of care to administer growth factors to accelerate neutrophil recovery after transplantation. However, unique toxicities occur with growth factor use in patients with AL who receive a stem cell transplant. We report a cohort of patients who underwent transplantation without receiving posttransplantation growth factors. In total, 282 patients received a stem cell transplant. A neutrophil count of 500/mul was achieved in 50, 75 and 90% of patients at 14, 16 and 22 days, respectively. A platelet count of 20 000/mul was achieved in 50, 75 and 90% of patients at 14, 20 and 31 days, respectively. Non-staphylococcal bacteremia was detected in 16% of patients. The median hospital stay was 9 days. It is feasible and reasonable to withhold growth factor therapy after autologous stem cell transplantation in patients with AL.

CD4+ T lymphocyte counts after autologous transplantation in multiple myeloma: a retrospective study

The risk for opportunistic infections is correlated with low CD4+ T lymphocyte counts in patients with HIV. We performed a retrospective analysis in 54 patients with multiple myeloma undergoing high-dose melphalan chemotherapy + autologous peripheral blood stem cell transplantation to better define the value of routine control of CD4+ T lymphocyte counts in this important patient group. In 61% of our patients, CD4+ T lymphocyte counts after recovery from neutropenia were <200/microl and <100/microl in 24% (median = 181/microl). Overall survival, progression-free survival, response to antineoplastic therapy and frequency of post-transplant infections were not significantly different when patients with CD4+ T lymphocyte counts <200/microl and >200/microl were compared. However, overall survival was significantly shorter in the subgroup of 13 patients with very low CD4+ T lymphocyte counts (<100/microl) (P = 0.036). In 79.6% of all patients, at least one infection NCI-CTC grade II - IV developed within 100 days post-transplant. Opportunistic infections were rare. This analysis suggests that patients with CD4+ T lymphocyte counts < 100/microl may have a poorer prognosis.

Late non-relapse mortality among adult autologous stem cell transplant recipients: a nation-wide analysis of 1482 patients transplanted in 1990–2003

Data on the incidence and causes of late (>100 d) non-relapse mortality (NRM) in autologous stem cell transplant (ASCT) recipients is limited. We have analysed NRM in a cohort of 1,482 adult patients who received ASCT in 1990-2003 in six Finnish transplant centres. The most common diagnoses included non-Hodgkin's lymphoma (NHL) (n = 542), multiple myeloma (MM) (n = 528), breast cancer (n = 132); Hodgkin's lymphoma (HL) (n = 86) and chronic lymphocytic leukaemia (CLL) (n = 63). Until September 2005, 646 patients (44%) have died. Late NRM was observed in 68 patients (4.6% of ASCT recipients; 11% of all deaths). There were 38 males and 30 females with a median age of 58 yr (20-69) at the time of ASCT. The median time to NRM was 27 months from ASCT (3-112). The risk of NRM was highest in patients with CLL (9.5%) and those with HL (8.1%) followed by MM and NHL (4.9% and 4.8%, respectively). The risk of late NRM was comparable in patients who received total body irradiation (TBI) and those who received chemotherapy-only regimens (6.7% vs. 4.3%). Another malignancy was the most common cause of late NRM (24 patients, 35% of late NRM). Twelve patients (0.8% of ASCT recipients) have died due to secondary haematological malignancy. Altogether 22 patients (32% of late NRM) died from infectious causes. Malignancies and late infections are important causes of NRM after ASCT. These facts point out the importance of prolonged follow-up in ASCT recipients.

Iron overload is a major risk factor for severe infection after autologous stem cell transplantation: a study of 367 myeloma patients

We evaluated the risk factors for infection of 367 consecutive myeloma patients who underwent high-dose melphalan and autologous stem cell transplantation (ASCT). Examination of bone marrow iron stores (BMIS) prior to ASCT was used to evaluate body iron stores. Other variables included age, sex, active smoking, myeloma remission status, severity of mucositis and duration of severe neutropenia post-ASCT (<100 absolute neutrophils counts (ANC)/microl). Median age was 56 years; 61% of patients were males. 140 episodes of severe infections occurred in 116 patients, including bacteremia (73), pneumonia (40), severe colitis (25) and bacteremia with septic shock (two). The infection incidence per 1,000 days at risk was 45.2. Pre-ASCT risk factors for severe infection by univariate analysis were increased BMIS (OR=2.686; 95% CI 1.707-4.226; P<0.0001), smoking (OR=1.565; 95% CI 1.005-2.437; P=0.0474) and male gender (OR=1.624; 95% CI 1.019-2.589; P=0.0414). Increased BMIS (OR=2.716; 95% CI 1.720-4.287; P<0.0001) and smoking (OR=1.714; 95% CI 1.081-2.718; P=0.022) remained significant by multivariate analysis. Duration of ANC <100 micro/l (OR=1.129; 95% CI 1.039-1.226; P=0.0069 and OR=1.127; 95% CI 1.038-1.224; P=0.0045 by both univariate and multivariate analysis, respectively) was the only post-ASCT risk factor for infection. Increased pre-transplant BMIS and smoking are significant predictors of severe infection after myeloablative chemotherapy followed by ASCT in myeloma patients.

Long-term acyclovir for prevention of varicella zoster virus disease after allogeneic hematopoietic cell transplantation--a randomized double-blind placebo-controlled study

Varicella-zoster virus (VZV) disease occurs in 30% of allogeneic hematopoietic cell transplant recipients who had a history of VZV infection. A safe and effective prevention strategy has not been established. In a double-blind controlled trial, 77 hematopoietic cell transplant recipients at risk for VZV reactivation were randomized to acyclovir 800 mg twice daily or placebo given from 1 to 2 months until 1 year after transplantation. VZV disease at 1 year was the primary end point; VZV disease after discontinuation of prophylaxis, VZV-specific T-cell immunity, herpes simplex virus (HSV) infection, cytomegalovirus (CMV) disease, survival, and safety were secondary end points. Acyclovir significantly reduced VZV infections at 1 year after transplantation (HR, 0.16; 95% CI, 0.035-0.74; P = .006). In the post-intervention observation period, this difference was not statistically significant (2 years: HR, 0.52; 95% CI, 0.21-1.3; 5 years: HR, 0.76; 95% CI, 0.36-1.6). There was no statistically significant difference in reconstitution of VZV-specific T-helper cell responses, HSV infections, CMV disease, chronic graft-versus-host disease, and overall survival between the groups. Acyclovir was well tolerated. Post-study VZV disease predominantly occurred in patients with continued need for systemic immunosuppression. In conclusion, acyclovir effectively and safely prevents VZV disease during the first year after hematopoietic cell transplantation. Periods of prophylaxis longer than 12 months may be beneficial for those hematopoietic cell transplant recipients on continued immune suppression.

Immunity for tumors and microbes after autotransplantation: if you build it, they will (not) come

Relapses after autologous stem cell transplants for hematopoietic malignancies are frequent and post-transplant infections continue to cause significant post-transplant morbidity and even mortality. The post-transplant period is typically characterized by low lymphocyte counts and impaired immune cell function. Early restoration of immune function may contribute to better disease control and enhance protection from infections. Indeed the attainment of a 'minimal residual disease' status following high-dose therapy makes the early post-transplant period ideal for the introduction of antitumor immunotherapy. Attempts to generate immunity against tumor and microbial antigens after autotransplantation have included vaccinations, T cell infusions (both resting and activated) and combinations of vaccinations and adoptive T cell infusions. One successful strategy for generating robust immune responses against microbial antigens was the combination of pre and post-transplant immunizations along with an early (post-transplant) infusion of in vivo vaccine-primed and ex vivo co-stimulated autologous T cells. Whether this or similar strategies will lead to the generation of effective antitumor immunity is unknown. The lessons gained from efforts to rebuild immune system function in the setting of autotransplantation may also be applicable to the problem of restoring immunity in other immunodeficient groups such as patients with cancer or HIV disease and the elderly.

Evaluation of potential risk factors for early infectious complications after autologous peripheral blood stem cell transplantation in patients with lymphoproliferative diseases

A number of risk factors for the occurrence of neutropaenic fever after haematopoietic stem cell transplantation (HSCT) have been proposed. We were interested in whether these factors remain valid for several early infection-related outcomes when applied to a homogeneous group of patients in uni- and multivariate analyses. Therefore, we analysed 144 consecutive patients with lymphoproliferative disorders receiving autologous peripheral blood HSCT. Variables tested as potential risk factors for the occurrence of fever, documented infection (DI), microbiologically documented infection (MDI) or failure of first-line antimicrobial therapy were sex, conditioning regimen, prolonged neutropaenia, low number of CD34+ cells transplanted, purging, lack of selective gut decontamination, higher age and increased body mass index. In uni- and multivariate analyses, conditioning including total body irradiation was the only risk factor for the occurrence of fever, and neutropaenia >or=10 days was the only factor associated with failure of first-line antimicrobial therapy. None of the variables tested was associated with an increased risk for DI or MDI. This analysis suggests that a number of previously proposed risk factors actually are of minor clinical relevance for early infections in the majority of patients receiving autologous HSCT.

Steroids prevent engraftment syndrome after autologous hematopoietic stem cell transplantation without increasing the risk of infection

Engraftment syndrome (ES) following autologous hematopoietic stem cell transplantation (AHSCT) is characterized by fever and rash. In January 2002, we instituted steroid prophylaxis for ES from day +4 to +14. This study was conducted to assess whether this practice increased the risk of infection. In total, 194 consecutive patients were reviewed, 111 did not receive steroid prophylaxis (group A), and 83 did (group B). Initial antimicrobial prophylaxis was the same in both groups. There were no significant differences between groups in age, gender, race, prior radiation therapy, number of prior chemotherapy regimens, disease status at transplant, mobilization regimen, days of leukopheresis, CD34(+) cell dose, and days to platelet and neutrophil engraftment. Group B had significantly fewer patients with non-Hodgkin's lymphoma and multiple myeloma, shorter median duration from diagnosis to transplant, lower risk of ES, and shorter mean length of hospital stay. The incidence of early and late microbiologically confirmed infections was not significantly different between groups. Types of infections and types of organisms identified were similar in both groups. Hospital readmission rates were similar in both groups. Steroid prophylaxis significantly decreases the risk of ES following AHSCT, and is associated with shortened hospitalization, without increasing risk of infection.

Invasive fungal infections in autologous stem cell transplant recipients: a nation-wide study of 1188 transplanted patients

Based on small single-centre series, the risk of invasive fungal infections (IFI) has been considered small in autologous stem cell transplant (ASCT) recipients.

PURPOSE

To analyse epidemiological and clinical features of (IFI) among ASCT recipients in Finland 1990-2001.

PATIENTS

During the study period, 1188 adult patients received high-dose therapy supported by ASCT in six centres. Altogether, 1112 patients (94%) received blood progenitor cells. The graft was CD34+ selected in 261 patients (22%). The major diagnostic groups were non-Hodgkin's lymphoma (n = 417), multiple myeloma (n = 395), breast cancer (n = 132) and Hodgkin's lymphoma (n = 53).

RESULTS

Eighteen patients (1.5%) with IFI were identified. The incidence of proven or probable invasive aspergillosis was 0.8%, followed by candidaemia with an incidence of 0.3%. The median time to the diagnosis of IFI was 35 d (6-162) from the progenitor cell infusion. In fourteen patients (78%) IFI was diagnosed during lifetime and they were treated with antifungal therapy for a median of 50 d. Nine patients (64%) were cured.

CONCLUSIONS

IFI appears to be a rare event after ASCT and Aspergillus infections seem to be predominant. These epidemiological features have an impact in planning prophylactic and empirical antifungal strategies in ASCT recipients.

Kinetics of myeloid and lymphocyte recovery and infectious complications after unrelated umbilical cord blood versus HLA-matched unrelated donor allogeneic transplantation in adults

Sources for allogeneic stem cells for patients with haematological disorders lacking a histocompatible sibling donor include matched unrelated donor (MUD) and umbilical cord blood (UCB). A total of 51 patients with haematological disorders, treated with myeloablation and transplantation with either unrelated human leucocyte antigen (HLA) partially matched UCB (28 patients) or HLA-matched MUD grafts (23 patients) during 1997-2003, were evaluated for life-threatening infections, haematological reconstitution, graft versus host disease, relapse and event-free survival (EFS). The median duration of neutropenia after transplantation was longer (29 d vs. 14 d) in the UCB group. The probability of donor-derived neutrophil engraftment by day 42 was 0.86 [95% confidence interval (CI) 0.71-1.0] in UCB recipients versus 0.96 (95% CI 0.87-1.0) in MUD recipients surviving >28 d. Overall infection rates were higher in UCB recipients, particularly at the early time points (before day +50) after transplantation. Graft failure occurred in five UCB recipients and two MUD recipients and was associated with the occurrence of bacteraemia during neutropenia. The EFS at 3-year follow-up was 0.25 in UCB and 0.35 in MUD recipients. UCB transplantation in adults is associated with delayed neutrophil and lymphocyte recovery compared with MUD grafting, and higher rates of bacteraemia at early time points after transplantation.

Trends in bacteraemia on the haematology and oncology units of a UK tertiary referral hospital

As part of ongoing surveillance of infection in the haematology and oncology units at Belfast City Hospital, microbiologically documented bloodstream infections over three 12-month periods 1994/5, 1998/9 and 1999/00 were reviewed. Gram-positive organisms were the most common cause of blood stream infection in the haematology unit causing 66%, 56% and 64% of episodes of monomicrobial bacteraemia in 1994/5, 1998/9 and 1999/00, respectively. In haematology patients, enterococci have emerged as an important cause of bacteraemia, with increasing levels of glycopeptide resistance, and the 'non-fermenting Gram-negative rods other than Pseudomonas aeruginosa' are an increasingly common cause of monomicrobial and polymicrobial bacteraemia. In oncology patients, Gram-negative organisms (predominantly enterobacteriaceae) were more common than Gram-positive organisms, causing 50% and 54% of monomicrobial bacteraemia in 1998/9 and 1999/00, respectively. Changes in patient population, underlying diseases and chemotherapeutic agents may explain these findings. The spectrum of infection seen in haematology and oncology patients changes as management evolves. Ongoing co-operation between haematologists, oncologists and microbiologists is important to detect trends in epidemiology, which can be used to design empirical antibiotic regimens and guide infection control policies.

Longitudinal study of bacterial, viral, and fungal infections in adult recipients of bone marrow transplants

The epidemiology of infections was studied in a retrospective cohort of 446 recipients of bone marrow transplants (BMTs; 92 of which were allogeneic and 354 of which were autologous) during 1993--1996. Infections that were microbiologically documented in 274 recipients included bacteremia, urinary tract infections, cytomegalovirus viremia, fungemia, invasive aspergillosis, and catheter-related infections. During the period of neutropenia, no differences were found between recipients of allogeneic BMTs and recipients of autologous BMTs with regard to the incidence and the nature of infection. After patients underwent engraftment, bacteremia, cytomegalovirus viremia, and invasive aspergillosis were significantly more common in recipients of allogeneic BMTs than in recipients of autologous BMTs. Deaths caused by infection were uncommon and were mainly the result of invasive aspergillosis. Therefore, empirical antimicrobial therapy should be the same for recipients of both allogeneic and autologous BMTs during the period of neutropenia; after engraftment, more attention should be paid to the risk of infection in allogeneic BMT recipients, particularly with regard to detection and prevention of invasive aspergillosis.

Infections in multiple myeloma

Multiple myeloma is a relatively rare but severe hematologic malignancy. Marked depression in production of normal immunoglobulins, mild neutropenia, and alkylant/steroid therapy or BMT/SCT all produce major suppression of the immune system in the totality of patients. Recurrent bacterial, fungal, and viral infections are an important cause of morbidity and the most common cause of death in these subjects. Prompt diagnosis and appropriate anti-infective chemotherapy are essential in order to reduce the risk of mortality.

Low infectious morbidity after intensive chemotherapy and autologous peripheral blood progenitor cell transplantation in the outpatient setting for women with breast cancer

Autologous peripheral blood progenitor cell (PBPC) transplantation is increasingly employed in the outpatient setting, yet data on early complications following PBPC transplantation are scant. We evaluated 105 women with high-risk primary or metastatic breast cancer who were treated at a single institution during 1996--1997. The mean duration of neutropenia (absolute neutrophil count, <500 cells/mm(3)) was 7.5 days. Twenty-nine percent of women remained afebrile throughout the neutropenic period. Of the remaining 71%, most (64 of 75) had fever of unknown origin. Infections, mostly of mild severity, occurred in 34% of women; these infections included bacteremia due to gram-positive organisms, catheter site infection, cellulitis, pneumonia, oral candidiasis, herpes simplex virus infection, and vaginitis. Fifty percent of PBPC transplant recipients required hospital admission, usually because of persistent fever; the mean duration of hospitalization was 3 days. No deaths or serious adverse events occurred. Such reduced infectious morbidity may be a consequence of minimal oral and/or gastrointestinal mucositis associated with the conditioning regimen and broad-spectrum antimicrobial prophylaxis used for this patient population.

Utility of obtaining blood cultures in febrile neutropenic patients undergoing bone marrow transplantation

Infection remains an important cause of morbidity and mortality after bone marrow or stem cell transplantation. To evaluate the role of obtaining blood cultures for intermittent or persistent fever in neutropenic patients on antibiotic therapy, we performed a retrospective chart review of 196 consecutive patients admitted to the Bone Marrow Transplant Unit at the University of North Carolina Hospitals from 1995 to 1998. From the cohort of 196 patients, 154 patients developed neutropenic fever. The initial blood culture was positive in 16 of 145 patients during the first fever episode giving a prevalence of 11%. From the total of 109 patients that had blood cultures drawn after day 1 of fever, five patients had blood cultures positive for a pathogen, a prevalence of 4.6%. In only one patient, did blood cultures drawn after day 1 identify an organism not present on day 1 (prevalence 0.9%). After reviewing the results in the first 105 patients, we changed our timing of collection of blood cultures. Forty-nine patients were treated in this manner and we found that the mean number of blood cultures decreased from 9.2 to 4.7 per patient without a change in the frequency of infectious complications or length of hospitalization.

Strategies offering protection from the toxic effects of anticancer treatments with a focus on chemoprotective agents

Side effects associated with chemotherapy and radiotherapy affect mainly a patient's quality of life. Means or agents designed to alleviate toxicities of anticancer treatments have been marketed or are under active investigation. In this paper, we review the reports published in this field in 1999.