Risk factors for fatal infectious complications developing late after allogeneic stem cell transplantation

Comparison of valganciclovir versus foscarnet for the treatment of cytomegalovirus viremia in adult acute leukemia patients after allogeneic hematopoietic cell transplantation

Cytomegalovirus (CMV) reactivation increases treatment-related mortality (TRM) after allogeneic hematopoietic cell transplantation (allo-HCT). We analyzed 141 adult acute leukemia (AL) patients suffered allo-HCT between 2017 and 2021, who developed CMV viremia post-HCT and treated with valganciclovir or foscarnet, to evaluate effectiveness and safety of both drugs. Viremia clearance rates (14 and 21 d post treatment) and toxicities were similar in two groups. However, valganciclovir was associated with a lower cumulative incidence of CMV recurrence within 180 days (16.7% vs. 35.7%, p=0.029) post CMV clearance. Finally, 2-year TRM was lower in valganciclovir group (9.7% ± 0.2% vs. 26.2% ± 0.3%, p = 0.026), result a superior 2-year overall survival (OS; 88.1% ± 5.2% vs. 64.4% ± 5.5%, p = 0.005) and leukemia-free survival (LFS; 82.0% ± 5.9% vs. 58.9% ± 5.6%, p = 0.009). Valganciclovir might decrease CMV viremia recurrence and led to better long-term outcome than foscarnet in adult AL patients developed CMV viremia post-HCT. Considering the inherent biases of retrospective study, well-designed trials are warranted to validate our conclusion.

CMV Infection Post Allogeneic Hematopoietic Stem Cell Transplantation in a Resource Limited Country

Cytomegalovirus (CMV) infection is one of the common complications which can lead to significant morbidity and mortality in patients after allogeneic hematopoietic stem cell transplantation (HSCT). As the seroprevalence of CMV infection in Malaysia is high, this study aims to determine the prevalence of CMV infection in patients post HSCT and to evaluate the associated risk factors. Patients who underwent allogeneic HSCT in adult ward from 2008 to 2020 at a tertiary teaching hospital in Kuala Lumpur, Malaysia were studied retrospectively. They were followed up for a minimum of 100 days post-HSCT to determine the incidence of CMV infection. CMV infection was defined according to CMV Drug Development Forum 2014. Risk factors such as type of transplant, serostatus of donor and patients, age, gender, race, presence of graft versus host disease (GVHD) and underlying disease were included for analysis. A total of 112 patients were included. Forty (35.7%) patients had CMV infection with median of onset recorded as 40 days (range 13-95 days). Only haplo-identical HSCT and presence of GVHD were identified as significant risk factors. Patients who had CMV infection had a lower median survival time although this was not statistically significant. The CMV infection rate was comparable with previous reports in Asia and as expected, higher than the western countries. Therefore, vigilant monitoring of CMV infection should be implemented especially in patients who had haplo-identical HSCT and acute GVHD.

Successful Kidney and Hematopoietic Stem Cell Transplantation for Malignant Lymphoma from Different Donors: A Case Report and Literature Review

There are particularly few reports on kidney transplantation after hematopoietic stem cell transplantation (HSCT) for malignant lymphoma, and none of the cases reported a favorable outcome in patients who received kidney transplantation from a different donor to HSCT. In this report, we describe the first case of kidney transplantation from a different donor to HSCT with a successful outcome. Furthermore, we reviewed the previously reported cases. A 59-year-old female patient received an HSCT from her younger brother after chemotherapy for malignant lymphoma. After HSCT, she did not have graft-versus-host disease (GVHD) requiring maintenance treatment. The patient developed chronic kidney disease requiring kidney replacement therapy, probably due to drug toxicity or cardio-renal syndrome. At age 65, she underwent an ABO-compatible, HLA-A, -B, -DR 5/6 mismatched kidney transplantation from her husband. Immunosuppressive therapy with tacrolimus, mycophenolate mofetil, methylprednisolone, and basiliximab was administered. The patient had urinary tract infections at 7 days, 9 weeks, and 4 months after kidney transplantation, and cytomegalovirus antigenemia at 9 weeks after kidney transplantation, which improved with antibiotic and valganciclovir, respectively. When each infection occurred, we weakened immunosuppressive therapy. Four years after kidney transplantation, the patient is in good clinical condition with a serum creatinine of 1.2 mg/dL, without critical infection or malignancy. In this case, we believe that it was important to optimize the immunosuppressive therapy. In addition, from a review of previous cases, it seemed important that there was no GVHD requiring maintenance therapy in order to prevent excessive immunosuppression.

A Scoring System for Predicting the Prognosis of Late-Onset Severe Pneumonia after Allogeneic Hematopoietic Stem Cell Transplantation

Late-onset severe pneumonia (LOSP) is defined as severe pneumonia developing during the late phase of allogeneic hematopoietic stem cell transplantation (allo-HSCT). Because of the high mortality in patients with LOSP, it is important to identify prognostic factors. In this study, we aimed to develop a risk score system with broad applicability that can help predict the risk of LOSP-associated mortality. We retrospectively analyzed 100 patients with LOSP after allo-HSCT between June 2009 and July 2017. The assessment variables included immune, nutritional, and metabolic parameters at the onset of LOSP. Of these 100 patients, 45 (45%) eventually died, and 55 (55%) were positive for organisms, most commonly viruses. In the multivariate analysis, higher monocyte count (≥0.20 × 10⁹/L versus <0.20 × 10⁹/L; P = .001), higher albumin level (≥30.5 g/L versus <30.5 g/L; P = .044), lower lactic dehydrogenase level (<250 U/L versus ≥250 U/L; P = .008) and lower blood urea nitrogen concentration (<7.2 mmol/L versus ≥7.2 mmol/L; P = .026) at the onset of LOSP were significantly associated with better 60-day survival. A risk score system based on the foregoing results showed that the probability of 60-day survival decreased with increasing risk factors, from 96.3% in the low-risk group to 49.1% in the intermediate-risk group and 12.5% in the high-risk group. Our results indicate that this scoring system using 4 variables can stratify patients with different probabilities of survival after LOSP, which suggests that patients' immune, nutritional, and metabolic status are crucial factors in determining outcome.

Association between Antiviral Prophylaxis and Cytomegalovirus and Epstein-Barr Virus DNAemia in Pediatric Recipients of Allogeneic Hematopoietic Stem Cell Transplant

Background: Epstein–Barr virus (EBV) and cytomegalovirus (CMV) infections can have serious consequences during the period of aplasia and lymphopenia following hematopoietic stem cell transplantation (HSCT). Large pediatric cohort studies examining the effect of antiviral prophylaxis against these viruses are scarce. The present study aimed to analyse the potential effect of antiviral prophylaxis (acyclovir and famciclovir) on active post-transplant EBV and CMV infection in a pediatric cohort of allogeneic HSCT recipients. Methods: We used data from the TREASuRE cohort, consisting of 156 patients who had a first allogeneic HSCT, enrolled in four pediatric centers in Canada between July 2013 and March 2017. Follow-up was performed from the time of transplant up to 100 days post-transplant. Adjusted hazard ratio (HR) with 95% confidence intervals (CI) for the association between antiviral prophylaxis with acyclovir and/or famciclovir and EBV and CMV DNAemia was estimated using multivariate Cox regression models. Results: The post-transplant cumulative incidence of EBV and CMV DNAemia at 100 days of follow-up were, respectively, 34.5% (95% CI: 27.6–42.6) and 19.9% (95% CI: 14.5–27.1). For acyclovir, the adjusted hazard ratio (HR) for CMV and EBV DNAemia was 0.55 (95% CI: 0.24–1.26) and 1.41 (95% CI: 0.63–3.14), respectively. For famciclovir, the adjusted HR were 0.82 (95% CI: 0.30–2.29) and 0.79 (95% CI: 0.36–1.72) for CMV and EBV DNAemia, respectively. Conclusion: The antivirals famciclovir and acyclovir did not reduce the risk of post-transplant CMV and EBV DNAemia among HSCT recipients in our pediatric population.

Late infectious complications in hematopoietic cell transplantation survivors: a population-based study

Few studies have compared the incidence of infections occurring ≥2 years after hematopoietic cell transplant (HCT) with other cancer patients and the general population. In this study, ≥2-year HCT survivors who were Washington residents treated from 1992 through 2009 (n = 1792; median age, 46 years; 52% allogeneic; 90% hematologic malignancies) were matched to individuals from the state cancer registry (n = 5455, non-HCT) and driver's license files (n = 16 340; Department of Licensing [DOL]). Based on hospital and death registry codes, incidence rate ratios (IRRs; 95% confidence interval [CI]) of infections by organism type and organ system were estimated using Poisson regression. With 7-year median follow-up, the incidence rate (per 1000 person-years) of all infections was 65.4 for HCT survivors vs 39.6 for the non-HCT group (IRR, 1.6; 95% CI, 1.3-1.9) and 7.2 for DOL (IRR, 10.0; 95% CI, 8.3-12.1). Bacterial and fungal infections were each 70% more common in HCT vs non-HCT cancer survivors (IRR, 1.7; P < .01), whereas the risk for viral infection was lower (IRR, 1.4; P = .07). Among potentially vaccine-preventable organisms, the IRR was 3.0 (95% CI, 2.1-4.3) vs the non-HCT group. Although the incidences of all infections decreased with time, the relative risk in almost all categories remained significantly increased in ≥5-year HCT survivors vs other groups. Risk factors for late infection included history of relapse and for some infections, history of chronic graft-versus-host disease. Providers caring for HCT survivors should maintain vigilance for infections and ensure adherence to antimicrobial prophylaxis and vaccination guidelines.

Late-occurring infections in a contemporary cohort of hematopoietic cell transplantation survivors

Background

There is a paucity of studies describing the incidence and risk factors for late‐occurring (≥1 year) infectious complications in contemporary survivors of hematopoietic cell transplantation (HCT).

Methods

This was a retrospective cohort study of 641 1‐year survivors of HCT, transplanted between 2010 and 2013 as adults, and in remission from their primary disease. Standardized definitions were used to characterize viral, fungal, and bacterial infections. Cumulative incidence of infections was calculated, with relapse/progression considered as a competing risk event. Fine‐Gray subdistribution hazard ratio estimates and 95% confidence intervals (CI) were obtained, adjusted for relevant covariates.

Results

Median age at HCT was 55.2 years (range 18.1–78.1 years); 54.0% were survivors of allogeneic HCT. The 5‐year cumulative incidence of a late‐occurring infection for the entire cohort was 31.6%; the incidence of polymicrobial (≥2) infections was 10.1%. In survivors who developed at least one infection, the 5‐year incidence of a subsequent infection was 45.3%. Among allogeneic HCT survivors, patients with acute lymphoblastic (HR = 1.82 95% CI [1.12–2.96]) or myeloid (HR = 1.50 95% CI [1.02–2.20]) leukemia, and those with an elevated HCT‐Comorbidity index score (HR = 1.09 95% CI [1.01–1.17]) were more likely to develop late‐occurring infections; there was an incremental risk associated with severity of graft versus host disease (GVHD) at 1‐year post‐HCT (mild: HR = 2.17, 95% CI [1.09–4.33]; moderate/severe: HR = 3.78, 95% CI [1.90–7.53]; reference: no GVHD).

Conclusions

The burden of late‐occurring infections in HCT survivors is substantial, and there are important patient‐ and HCT‐related modifiers of risk over time. These findings may help guide personalized screening and prevention strategies to improve outcomes after HCT.

Patterns of infection and infectious-related mortality in patients receiving post-transplant high dose cyclophosphamide as graft-versus-host-disease prophylaxis: impact of HLA donor matching

Post-transplant cyclophosphamide (PTCy) has become a promising option after allo-SCT, but infections may be more common than in traditional protocols. We herein report 117 consecutive adults who received PTCy-based alloSCT in our hospital: HaploSCT (34%), MRD (19%), and VUD (47%), respectively. The 18-month incidence of severe bacterial, viral, and IFI was 56%, 69%, and 8.7%, without differences between donor type, except for CMV infection and viral hemorrhagic cystitis, which had a higher incidence in the haploSCT cohort (58% vs. 43% and 30% vs. 8% on day +90, p < 0.05). Late infections by conventional respiratory viruses were common in all groups [33/87 (38%)]. The 2-year survival was 72% and did not differ by donor type. IRM at day 30, day 100, and 18 months was 1.7%, 4.4%, and 12%, without differences by donor type (p = 0.7). The primary cause of IRM was bacterial infection (42%). Grade 2–4 acute GvHD was the only independent predictor of IRM. Donor type had no impact on IRM or on survival. In our study, severe infections were common in all donor types using PTCy, with higher rates of early post-engraftment CMV-I and viral HC in haploSCT recipients, although lethal infections were uncommon and similar in all donor types.

Infections in Allogeneic Stem Cell Transplantation

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) has become a widely used modality of therapy for a variety of malignant and nonmalignant diseases. Despite advances in pharmacotherapy and transplantation techniques, infection remains one of the most severe and frequently encountered complications of allo-HSCT.

This chapter will address the risk factors for development of infection following allo-HSCT, including those related to the host, the conditioning regimen, and the graft, as well as the timing of opportunistic infections after allo-HSCT. The most common bacterial, viral, fungal, and parasitic infections, as well as issues surrounding their diagnostics and treatment, will be discussed. Finally, this chapter will address vaccination and other preventative strategies to be utilized when caring for patients undergoing allo-HSCT.

National Institutes of Health Hematopoietic Cell Transplantation Late Effects Initiative: The Immune Dysregulation and Pathobiology Working Group Report

Immune reconstitution after hematopoietic stem cell transplantation (HCT) beyond 1 year is not completely understood. Many transplant recipients who are free of graft-versus-host disease (GVHD) and not receiving any immunosuppression more than 1 year after transplantation seem to be able to mount appropriate immune responses to common pathogens and respond adequately to immunizations. However, 2 large registry studies over the last 2 decades seem to indicate that infection is a significant cause of late mortality in some patients, even in the absence of concomitant GVHD. Research on this topic is particularly challenging for several reasons. First, there are not enough long-term follow-up clinics able to measure even basic immune parameters late after HCT. Second, the correlation between laboratory measurements of immune function and infections is not well known. Third, accurate documentation of infectious episodes is notoriously difficult. Finally, it is unclear what measures can be implemented to improve the immune response in a clinically relevant way. A combination of long-term multicenter prospective studies that collect detailed infectious data and store samples as well as a national or multinational registry of clinically significant infections (eg, vaccine-preventable severe infections, opportunistic infections) could begin to address our knowledge gaps. Obtaining samples for laboratory evaluation of the immune system should be both calendar and eventdriven. Attention to detail and standardization of practices regarding prophylaxis, diagnosis, and definitions of infections would be of paramount importance to obtain clean reliable data. Laboratory studies should specifically address the neogenesis, maturation, and exhaustion of the adaptive immune system and, in particular, how these are influenced by persistent alloreactivity, inflammation, and viral infection. Ideally, some of these long-term prospective studies would collect information on long-term changes in the gut microbiome and their influence on immunity. Regarding enhancement of immune function, prospective measurement of the response to vaccines late after HCT in a variety of clinical settings should be undertaken to better understand the benefits as well as the limitations of immunizations. The role of intravenous immunoglobulin is still not well defined, and studies to address it should be encouraged.

Reprint of: Long-Term Survivorship after Hematopoietic Cell Transplantation: Roadmap for Research and Care

The number of survivors after hematopoietic cell transplantation (HCT) is expected to dramatically increase over the next decade. Significant and unique challenges confront survivors for decades after their underlying indication (malignancy or marrow failure) has been cured by HCT. The National Institutes of Health (NIH) Late Effects Consensus Conference in June 2016 brought together international experts in the field to plan the next phase of survivorship efforts. Working groups laid out the roadmap for collaborative research and health care delivery. Potentially lethal late effects (cardiac/vascular, subsequent neoplasms, and infectious), patient-centered outcomes, health care delivery, and research methodology are highlighted here. Important recommendations from the NIH Consensus Conference provide fresh perspectives for the future. As HCT evolves into a safer and higher-volume procedure, this marks a time for concerted action to ensure that no survivor is left behind.

Long-Term Survivorship after Hematopoietic Cell Transplantation: Roadmap for Research and Care

The number of survivors after hematopoietic cell transplantation (HCT) is expected to dramatically increase over the next decade. Significant and unique challenges confront survivors for decades after their underlying indication (malignancy or marrow failure) has been cured by HCT. The National Institutes of Health (NIH) Late Effects Consensus Conference in June 2016 brought together international experts in the field to plan the next phase of survivorship efforts. Working groups laid out the roadmap for collaborative research and health care delivery. Potentially lethal late effects (cardiac/vascular, subsequent neoplasms, and infectious), patient-centered outcomes, health care delivery, and research methodology are highlighted here. Important recommendations from the NIH Consensus Conference provide fresh perspectives for the future. As HCT evolves into a safer and higher-volume procedure, this marks a time for concerted action to ensure that no survivor is left behind.

Milestones of Hematopoietic Stem Cell Transplantation - From First Human Studies to Current Developments

Since the early beginnings, in the 1950s, hematopoietic stem cell transplantation (HSCT) has become an established curative treatment for an increasing number of patients with life-threatening hematological, oncological, hereditary, and immunological diseases. This has become possible due to worldwide efforts of preclinical and clinical research focusing on issues of transplant immunology, reduction of transplant-associated morbidity, and mortality and efficient malignant disease eradication. The latter has been accomplished by potent graft-versus-leukemia (GvL) effector cells contained in the stem cell graft. Exciting insights into the genetics of the human leukocyte antigen (HLA) system allowed improved donor selection, including HLA-identical related and unrelated donors. Besides bone marrow, other stem cell sources like granulocyte-colony stimulating-mobilized peripheral blood stem cells and cord blood stem cells have been established in clinical routine. Use of reduced-intensity or non-myeloablative conditioning regimens has been associated with a marked reduction of non-hematological toxicities and eventually, non-relapse mortality allowing older patients and individuals with comorbidities to undergo allogeneic HSCT and to benefit from GvL or antitumor effects. Whereas in the early years, malignant disease eradication by high-dose chemotherapy or radiotherapy was the ultimate goal; nowadays, allogeneic HSCT has been recognized as cellular immunotherapy relying prominently on immune mechanisms and to a lesser extent on non-specific direct cellular toxicity. This chapter will summarize the key milestones of HSCT and introduce current developments.

Invasive fungal infection in allogeneic hematopoietic stem cell transplant recipients: single center experiences of 12 years

Invasive fungal infection (IFI) is a growing cause of morbidity and mortality among patients after allogeneic hematopoietic stem cell transplantation (allo-HSCT). We retrospectively reviewed the records of 408 patients undergoing allo-HSCTs during the period November 1998 to December 2009, analyzed the incidence and risk factors of IFI, and examined the impact of IFI on overall survival. A total of 92 (22.5%) episodes suffered proven or probable IFI (4 patients were proven, 88 patients were probable). Candida was the most common pathogen for early IFI, and mold was the most frequent causative organism for late IFI. A prior history of IFI, human leukocyte antigen (HLA) mismatch, long-time neutropenia, and acute graft-versus-host-disease (GVHD) were risk factors for early IFI. A prior history of IFI, corticosteroid therapy, cytomegalovirus (CMV) disease, and chronic GVHD were risk factors for late IFI. IFI-related mortality was 53.26%. The 12-year overall survival (OS) rate for IFI was significantly lower than that of patients without IFI (41.9% vs. 63.6%, P<0.01).

Pneumocystis jirovecii pneumonia: still a concern in patients with haematological malignancies and stem cell transplant recipients

The risk of patients with ALL and recipients of an allogeneic HSCT developing Pneumocystis jirovecii pneumonia is sufficiently high to warrant guidelines for the laboratory diagnosis, prevention and treatment of the disease. In this issue, the European Conference on Infections in Leukemia (ECIL) presents its recommendations in three companion papers.

Current Indications, Techniques, and Imaging Findings of Stem Cell Treatment and Bone Marrow Transplant

The role of stem cell therapy in the treatment of hematologic and nonhematologic conditions is ever increasing. A thorough knowledge of the applications of stem cells and transplant physiology is essential for understanding the imaging manifestations. Stem cell imaging includes molecular imaging, and diagnostic and interventional radiology. It is possible to make a diagnosis of various complications and diseases associated with stem cell transplant. This article presents a simplified overview of stem cell applications and techniques with focus on hematopoietic stem cell transplant imaging.

The incidence, mortality and timing of Pneumocystis jiroveci pneumonia after hematopoietic cell transplantation: a CIBMTR analysis

Pneumocystis jiroveci pneumonia (PJP) is associated with high morbidity and mortality after hematopoietic stem cell transplantation (HSCT). Little is known about PJP infections after HSCT because of the rarity of disease given routine prophylaxis. We report the results of a Center for International Blood and Marrow Transplant Research study evaluating the incidence, timing, prophylaxis agents, risk factors and mortality of PJP after autologous (auto) and allogeneic (allo) HSCT. Between 1995 and 2005, 0.63% allo recipients and 0.28% auto recipients of first HSCT developed PJP. Cases occurred as early as 30 days to beyond a year after allo HSCT. A nested case cohort analysis with supplemental data (n=68 allo cases, n=111 allo controls) revealed that risk factors for PJP infection included lymphopenia and mismatch after HSCT. After allo or auto HSCT, overall survival was significantly poorer among cases vs controls (P=0.0004). After controlling for significant variables, the proportional hazards model revealed that PJP cases were 6.87 times more likely to die vs matched controls (P<0.0001). We conclude PJP infection is rare after HSCT but is associated with high mortality. Factors associated with GVHD and with poor immune reconstitution are among the risk factors for PJP and suggest that protracted prophylaxis for PJP in high-risk HSCT recipients may improve outcomes.

Pneumonia After Hematopoietic Stem Cell Transplantation

Pneumonia is the main cause of morbidity and mortality after hematopoietic stem cell transplantation. Two thirds of pneumonias observed after both autologous and allogeneic stem cell transplantations are of infectious origin, and coinfections are frequent. One third is due to noninfectious process, such as alveolar hemorrhage, alveolar proteinosis, or alloimmune pulmonary complications such as bronchiolitis obliterans or idiopathic interstitial pneumonitis. Most of these noninfectious complications may require treatment with corticosteroids which may be deleterious in infection. On the other hand, these complications either mimic or may be complicated with infections. Therefore, a precise diagnosis of pneumonia is of crucial importance to decide of the optimal treatment. CT scan is the best procedure for imaging of the lung. Although several indirect biomarkers, such as serum or plasma galactomannan or (1-3) β(beta)-G-glucan, can help in the etiological diagnosis, only direct invasive investigations provide the best chance to identify the cause(s) of pneumonia. Bronchoalveolar lavage (BAL) under fiberoptic bronchoscopy is the procedure of choice to identify the cause of pulmonary infection. It is safe and reproducible, and its diagnostic yield is around 50 % if the BAL fluid is processed at the laboratory according to a prespecified protocol established between the transplanter, the infectious diseases’ specialist, the pneumologist, and the laboratory, allowing the identification of the most likely hypotheses. Transbronchial biopsy does not provide significant additional information to BAL in most cases and more often complicates with bleeding and pneumothorax. In case of a noncontributory BAL, the decision to proceed to a second BAL, a transthoracic biopsy, or a surgical biopsy should be cautiously weighted in a multidisciplinary approach in regard to the benefits and risks of invasive procedures versus empirical treatment.

Risks and Epidemiology of Infections After Hematopoietic Stem Cell Transplantation

Infections following HCT are frequently related to risk factors caused by the procedure itself. Neutropenia and mucositis predispose to bacterial infections. Prolonged neutropenia increases the likelihood of invasive fungal infection. GVHD and its treatment create the most important easily identifiable risk period for a variety of infectious complications, particularly mold infections. Profound, prolonged T cell immunodeficiency, present after T cell-depleted or cord blood transplants, is the main risk factor for viral problems like disseminated adenovirus disease or EBV-related posttransplant lymphoproliferative disorder.

Increased risk of infections and infection-related mortality in children undergoing haematopoietic stem cell transplantation compared to conventional anticancer therapy: a multicentre nationwide study

This nationwide multicentre study analysed the epidemiology of bacterial, viral and fungal infections in paediatric haematopoietic stem cell transplantation (HSCT) and paediatric haematology and oncology (PHO) patients over a period of 24 consecutive months, including incidence, hazard risk and outcome of infections as well as occurrence of multidrug-resistant bacteria. During this period, 308 HSCTs were performed and 1768 children were newly diagnosed for malignancy. Compared to PHO, the risk in HSCT patients was significantly higher for all infections (hazard ratio (HR) 2.7), bacterial (HR 1.4), fungal (HR 3.5) and viral (HR 15.7) infections. The risk was higher in allo- than auto-HSCT for bacterial (HR 1.4), fungal (HR 3.2) and viral (HR 17.7) infections. The incidence of resistant bacteria was higher in HSCT than in PHO patients for both G-negative (72.5% vs. 59.2%) and G-positive (41.4% vs. 20.5%) strains. Cumulative incidence of bacterial, fungal and viral infections in HSCT patients was 33.9, 22.8 and 38.3%, respectively. Cumulative incidence of viral infections in allo-HSCT was 28.0% for cytomegalovirus, 18.5% for BK virus, 15.5% for Epstein-Barr virus, 9.5% for adenovirus, 2.6% for varicella zoster virus, 0.9% for influenza, 0.9% for human herpesvirus 6 and 0.3% for hepatitis B virus. Survival rates from infections were lower in HSCT than in PHO patients in bacterial (96.0 vs. 98.2%), fungal (75.5 vs. 94.6%) and most viral infections. In conclusion, the risk of any infections and the occurrence of resistant bacterial strains in allo-HSCT patients were higher than in auto-HSCT and PHO patients, while the outcome of infections was better in the PHO setting.

Effectiveness of antibacterial prophylaxis with non-absorbable polymyxin B compared to levofloxacin after allogeneic hematopoietic stem cell transplantation

BACKGROUND

Fluoroquinolones are widely used for antibacterial prophylaxis during neutropenia following hematopoietic stem cell transplantation (HSCT). Nevertheless, data are inadequate as to whether fluoroquinolones decrease mortality rate compared with other antibiotics.

METHODS

We retrospectively compared the efficacy of antibacterial prophylaxis using non-absorbable polymyxin B (PB) (n = 106) or systemic levofloxacin (LVFX) (n = 140) after allogeneic SCT at our institute between 2004 and 2013.

RESULTS

No significant difference was observed between the 2 groups in the cumulative incidences of failure of prophylaxis (P = 0.21), clinically documented infections (P = 0.70), or non-relapse mortality within the first 100 days after transplantation (P = 0.42). With bacteremia, the rate of resistance to LVFX was 82% in the PB group and 100% in the LVFX group (P = 0.41). Also, no significant difference was found in overall survival between the 2 groups (P = 0.78).

CONCLUSION

Our results indicate no difference in the effectiveness of antibacterial prophylaxis between systemic antibiotic LVFX and non-absorbable antibiotic PB.

The yield of monitoring for HSV and VZV viremia in pediatric hematopoietic stem cell transplant patients

Reactivation of HSV and VZV is common following HSCT. Consensus guidelines do not support the use of routine screening for viremia following HSCT in adults, but no such clear guidelines exist in pediatrics. In our center, routine practice was to screen patients weekly for HSV and VZV viremia until engraftment in autologous transplant patients and up to day +100 in allogeneic transplant patients. We conducted a retrospective study of over 500 patients to establish whether this screening identified any patients with HSV or VZV viremia who would not have been identified by clinical signs or symptoms. Over a 4.5-yr period, routine screening identified three cases of HSV viremia and one case of VZV viremia. Two patients had persistent, unexplained fever and two patients had skin or mucosal lesions suggestive of HSV/VZV. We conclude that routine screening for HSV and VZV viremia in pediatric HSCT patients has a very low yield and that viremia can be reliably identified by targeted testing in patients with vesicular skin lesions, oral or genital ulceration, unexplained fever, neurological symptoms, or unexplained abnormal liver transaminases.

Invasive fungal infections in pediatric hematopoietic stem cell transplant patients

BACKGROUND

Pediatric hematopoietic stem cell transplant (HSCT) recipients are at high risk of invasive fungal infections (IFIs).

METHODS

To characterize IFIs and changes in fungal organisms over time in pediatric HSCT patients, we performed a retrospective cohort study of all HSCTs performed in pediatric patients at UCLA between 1991 and 2006.

RESULTS

In all, 318 patients underwent 324 HSCT transplants over the 15-year period and 69 unique fungal infections were identified in 47 transplant patients. The overall incidence of fungal infections in HSCT recipients was 14.5%, with predominant organisms including Candida species (51%) and Aspergillus species (26%), with Candida albicans accounting for 18.8% of all fungal species. The distribution of organisms over time demonstrated a strong trend towards an increase in rare molds in more recent years. The respiratory tract was the main site of infection (52.6%), with urine and blood also noted as significant sites. Of all deaths in the patients with IFIs, fungal-related mortality accounted for 67.6% of deaths.

CONCLUSIONS

HSCT patients have a much higher risk of fungal infections with rarer organisms becoming more prevalent, a finding likely linked to evolving antifungal practices over time. This emphasizes the need for the development and implementation of improved diagnostic, prophylactic, and therapeutic strategies to improve patient survival.

Disease severity and mortality can be independently regulated in a mouse model of experimental graft versus host disease

Graft versus host disease (GVHD) is the major limitation of allogeneic hematopoietic stem cell transplantation (HSCT) presenting high mortality and morbidity rates. However, the exact cause of death is not completely understood and does not correlate with specific clinical and histological parameters of disease. Here we show, by using a semi-allogeneic mouse model of GVHD, that mortality and morbidity can be experimentally separated. We injected bone marrow-derived dendritic cells (BMDC) from NOD2/CARD15-deficient donors into semi-allogeneic irradiated chimaeras and observed that recipients were protected from death. However, no protection was observed regarding clinical or pathological scores up to 20 days after transplantation. Protection from death was associated with decreased bacterial translocation, faster hematologic recovery and epithelial integrity maintenance despite mononuclear infiltration at day 20 post-GVHD induction with no skew towards different T helper phenotypes. The protected mice recovered from aGVHD and progressively reached scores compatible with healthy animals. Altogether, our data indicate that severity and mortality can be separate events providing a model to study transplant-related mortality.

Pulmonary complications in hematopoietic SCT: a prospective study

Pulmonary complications are common and often lethal in hematopoietic SCT recipients. The objective of this prospective interventional study was to evaluate the etiology, diagnostic procedures, risk factors and outcome of pulmonary complications in a cohort of hematopoietic SCT recipients followed up for 1 year. For patients suffering from a pulmonary complication, a diagnostic algorithm that included non-invasive and bronchoscopic procedures was performed. We identified 73 pulmonary complications in 169 patients: 50 (68%) were pneumonias; 21 (29%) were non-infectious complications and 2 (3%) were undiagnosed. Viruses (particularly Rhinovirus) and bacteria (particularly P. aeruginosa) (28 and 26%, respectively) were the most common causes of pneumonia. A specific diagnosis was obtained in 83% of the cases. A non-invasive test gave a specific diagnosis in 59% of the episodes. The diagnostic yield of bronchoscopy was 67 and 78% in pulmonary infections. Early bronchoscopy (⩽5 days) had higher diagnostic yield than late bronchoscopy (78 vs 23%; P=0.02) for pulmonary infections. Overall mortality was 22 and 32% of all fatalities were due to pulmonary complications. Pulmonary complications are common and constitute an independent risk factor for mortality, stressing the importance of an appropriate clinical management.

Predictors of mortality in non-neutropenic patients with invasive pulmonary aspergillosis: does galactomannan have a role?

We aimed to investigate the role of several host factors as predictors of mortality in non-neutropenic patients with invasive pulmonary aspergillosis (IPA). Contribution of respiratory galactomannan (GM) index was evaluated as well. In this retrospective study, we examined 27 patients with "proven" and "probable" IPA. Outcome measured was death within 6-week from diagnosis of possible IPA. Overall mortality was 33.3%. At univariate analysis, nonsurvivors were statistically more likely to be affected with cirrhosis. No independent variables predicting mortality were identified in the multivariate model. Mean bronchoalveolar lavage (BAL) GM index value in the nonsurvivor group was significantly higher. A GM index cutoff value ≥ 2.0 is able to classify patients with a poor outcome with a sensitivity of 100% and a specificity of 77%. Liver cirrhosis is a predictor of mortality in patients with IPA. GM index in BAL might be considered as a valuable tool in classifying patients at risk of poor outcome.

Detection of Herpesviridae in whole blood by multiplex PCR DNA-based microarray analysis after hematopoietic stem cell transplantation

Viral infections are important causes of morbidity and mortality in patients after hematopoietic stem cell transplantation. The monitoring by PCR of Herpesviridae loads in blood samples has become a critical part of posttransplant follow-up, representing mounting costs for the laboratory. In this study, we assessed the clinical performance of the multiplex PCR DNA microarray Clart Entherpex kit for detection of cytomegalovirus (CMV), Epstein-Barr virus (EBV), and human herpesvirus 6 (HHV-6) as a screening test for virological follow-up. Two hundred fifty-five blood samples from 16 transplanted patients, prospectively tested by routine PCR assays, were analyzed by microarray. Routine PCR detected single or multiple viruses in 42% and 10% of the samples, respectively. Microarray detected single or multiple viruses in 34% and 18% of the samples, respectively. Microarray results correlated well with CMV and EBV detections by routine PCR (kappa tests = 0.79 and 0.78, respectively), whereas a weak correlation was observed with HHV-6 (0.43). HHV-7 was also detected in 48 samples by microarray. In conclusion, the microarray is a reliable screening assay for a posttransplant virological follow-up to detect CMV and EBV infections in blood. However, positive samples must be subsequently confirmed and viral loads must be quantified by PCR assays. Limitations were identified regarding HHV-6 detection. Although it is promising, is easy to use as a first-line test, and allows a reduction in the cost of analysis without undue delay in the reporting of the final quantitative result to the clinician, some characteristics of this microarray should be improved, particularly regarding quality control and the targeted virus panel, such that it could then be used as a routine test.

Whole CMV proteome pattern recognition analysis after HSCT identifies unique epitope targets associated with the CMV status

Cytomegalovirus (CMV) infection represents a vital complication after Hematopoietic Stem Cell Transplantation (HSCT). We screened the entire CMV proteome to visualize the humoral target epitope-focus profile in serum after HSCT. IgG profiling from four patient groups (donor and/or recipient +/− for CMV) was performed at 6, 12 and 24 months after HSCT using microarray slides containing 17174 of 15mer-peptides overlapping by 4 aa covering 214 proteins from CMV. Data were analyzed using maSigPro, PAM and the ‘exclusive recognition analysis (ERA)’ to identify unique CMV epitope responses for each patient group. The ‘exclusive recognition analysis’ of serum epitope patterns segregated best 12 months after HSCT for the D+/R+ group (versus D−/R−). Epitopes were derived from UL123 (IE1), UL99 (pp28), UL32 (pp150), this changed at 24 months to 2 strongly recognized peptides provided from UL123 and UL100. Strongly (IgG) recognized CMV targets elicited also robust cytokine production in T-cells from patients after HSCT defined by intracellular cytokine staining (IL-2, TNF, IFN and IL-17). High-content peptide microarrays allow epitope profiling of entire viral proteomes; this approach can be useful to map relevant targets for diagnostics and therapy in patients with well defined clinical endpoints. Peptide microarray analysis visualizes the breadth of B-cell immune reconstitution after HSCT and provides a useful tool to gauge immune reconstitution.

Vaccination of hematopoietic stem cell transplantation recipients: perspective in Korea

Antibody titers to vaccine-preventable diseases such as tetanus, polio, measles, mumps, and rubella decline within 1-10 years after allogeneic or autologous hematopoietic stem cell transplantation (SCT) if the recipient is not vaccinated. Vaccine-preventable diseases such as pneumococcal diseases, Haemophilus influenzae type b infections, influenza, measles, and varicella can pose an increased risk for SCT recipients. Therefore, after SCT, the recipients should be routinely revaccinated. Vaccination recommendations have previously been developed and published by the European Group of Blood and Marrow Transplantation and the Centers for Disease Control, by the Infectious Diseases Society of America, and by the American Society for Blood and Marrow Transplantation in 2009. Different epidemiologies and strategies have existed in Korea. In 2012, the Korean Society of Infectious Diseases published "Vaccination for Adult" describing the guidelines for vaccination, one of the chapters assigned for vaccination of SCT recipients. The present article reviews the current available vaccination strategies for SCT recipients, their family members, and healthcare workers, with the focus on recent Korean perspectives.

Late mortality after hematopoietic SCT for a childhood malignancy

Hematopoietic SCT (HSCT) has been used as a curative therapy for pediatric malignancies. Survivors of HSCT are at risk for disease recurrence, late morbidity and mortality. We assessed late mortality (≥2 years post-HSCT) in a population-based cohort of children who underwent HSCT for a malignancy. Mortality outcomes were determined by linking a clinical transplant database with the Canadian province of Ontario's pediatric cancer mortality files. Seven hundred and fifty-four children underwent HSCT (371 allogeneic, 383 autologous). Of the 479 (63.5%) who were alive ≥2 years post HSCT, 98 (20.5%) suffered a late death. Late mortality in the allogeneic HSCT group was 14.9% (median follow-up 10.0 years; range: 2.0-25.6 years), mainly due to relapse of the primary malignancy (64.7%). Chronic GVHD and second malignancies were not major causes of late mortality. A total of 25.5% suffered a late death following autologous HSCT (median follow-up 6.7 years; range: 2.0-22.2 years). Recurrence of the primary malignancy accounted for 87.5% of these deaths. Recurrence of the primary malignancy is the predominant cause of late mortality after HSCT. In contrast to studies of adult patients, non-relapse mortality is less common in children, and death due to chronic GVHD and secondary malignancies is uncommon.

The significance of cytomegalovirus viremia at day 100 or more following allogeneic hematopoietic stem cell transplantation

We conducted a single-center retrospective review of patients who had received allogeneic hematopoietic stem cell transplantation (HSCT) between January 2003 and December 2007, to assess the incidence and risk factors for late CMV infection and evaluate its effects on outcomes. Twenty of 49 HSCT recipients (41%) developed CMV infection at day ≥ 100 after transplant. Univariable analysis showed that having a matched unrelated donor, having early CMV infection, having a diagnosis of lymphoma, and receipt of antithymocyte globulin were risks for developing late CMV. On multivariable analysis, the occurrence of CMV prior to day 100 and lymphoma conferred a significant risk for late CMV infection. Of the 20 patients with late CMV infection, two patients manifested CMV disease (10%). Despite the relatively low incidence of CMV disease, patients with late CMV infection had a 4.8-fold increased risk of death compared to patients without late CMV. Identifying patients at increased risk for developing late CMV infection may be important for prompting more intensive monitoring of infection late after HSCT, particularly because this manifestation of CMV is associated with poorer outcomes.

Timeline, epidemiology, and risk factors for bacterial, fungal, and viral infections in children and adolescents after allogeneic hematopoietic stem cell transplantation

Advances made in the field of hematopoietic stem cell transplantations (HSCT) over the past 20 years may have had an impact on the distribution of posttransplantation infections. We sought to retrospectively analyze the epidemiology and risk factors for bacterial, fungal, and viral infections in children after allogeneic HSCT in a cohort of 759 children who underwent allogeneic HSCT in a single institution between 1990 and 2009. The association between infections and risk factors of interest at 0 to 30 days, 31 to 100 days, and 101 days to 2 years posttransplantation was evaluated using logistic regression. Difference among the subtypes within each category was studied. There were 243 matched-related donors, 239 matched-unrelated donors (MUDs), and 176 haploidentical donor transplantations. Era of transplantation (0-30 days), peripheral blood stem cell product, acute graft-versus-host disease (aGVHD; 31-100 days), and chronic GVHD (cGVHD; 101-730 days) were associated with higher risk for bacterial infections at the respective time periods. Patients with aGVHD (31-100 days), cGVHD, and older age (101-730 days) were at higher risk for fungal infections. Cytomegalovirus (CMV) donor/recipient (D/R) serostatus (0-100 days), era of transplantation, MUD HSCT (31-100 days), and cGVHD (101-730 days), influenced viral infections. Gram-positive outnumbered gram-negative bacterial infections; aspergillosis and candidemia were equally prevalent in all time periods. Haploidentical donor HSCT was not associated with an increased risk of infections. There seems to be a continuum in the timeline of infections posttransplantation, with bacterial, fungal, and viral infections prevalent in all time periods, particularly late after the transplantation, the risk affected by GVHD, CMV, D/R status, product type, older age, and use of unrelated donors.

Dynamics in children and adolescents who experience varicella zoster virus infections after haematopoietic stem cell transplantation: a case-control study

We evaluated the incidence of varicella-zoster virus (VZV) infections, including herpes zoster (HZ), and investigated the associated risk factors for HZ and compared lymphocyte subsets of these patients at 1, 3 and 6 months following haematopoietic stem cell transplantation (HSCT) in a case-control study in children and adolescents. The incidence of HZ infection at the first year after HSCT was 17/125 (13·6%). The cumulative incidence of HZ infection was 22/125 (17·6%). Sixteen (73%) cases with HZ and 11 (32%) cases in the control group had a diagnosis of malignant disorder. No significant difference was noted between the HZ group and the control group in absolute lymphocyte number and subsets (except WBC) at the pre-transplant evaluation. Pre-transplant WBC count was statistically lower in the HZ group (P<0·05). The CD4/CD8 ratios were lower in the HZ group during the first 6 months after HSCT, and the decrease was statistically significant at 6 months compared to the control group. In conclusion, patients undergoing HSCT for a malignant disorder had a significantly higher risk of VZV infection than those with non-malignant disorders and pretransplant donor characteristics were not helpful in predicting risk of post-transplant VZV infection.

Valganciclovir as pre-emptive therapy for cytomegalovirus infection in allogeneic haematopoietic stem cell transplant recipients

BACKGROUND

In haematopoietic stem cell transplant (HSCT) recipients, cytomegalovirus (CMV) infection contributes significantly to morbidity and mortality in both the early and late post-transplant period. Ganciclovir (GCV) is the treatment of choice for CMV, but requires intravenous administration, a fact that complicates its long-term use. Oral valganciclovir (VGCV) and intravenous GCV were recently shown to have similar efficacy for pre-emptive CMV treatment in solid organ transplant recipients, but relatively limited data are available in HSCT recipients. The objectives of this study were to compare the efficacy of VGCV versus intravenous GCV or foscarnet (FOS) for pre-emptive therapy of active CMV infection in allogeneic HSCT and to determine the incidence of adverse effects and relapses.

METHODS

This was a 2-year prospective, comparative cohort study in which 237 episodes of pre-emptive therapy for active CMV infection were collected in 166 allogeneic HSCT recipients out of 717 included in the Spanish Network for Research on Infection in Transplantation (RESITRA/REIPI) database. Intravenous GCV was the first-line treatment in 112 episodes, intravenous FOS in 38 episodes, and oral VGCV in 87 episodes.

RESULTS

VGCV was used as pre-emptive therapy for active CMV infection in 87 episodes. Excluding episodes considered as relapse, VGCV was as successful (91.4% [74/81]) as GCV (83.7% [87/14]) or FOS (75.8% [25/33]). In the VGCV arm, 7 (8.6%) cases were considered treatment failures: 4 (4.9%) because of adverse events, 1 (1.2%) due to persistent viral activity and 2 (2.5%) based on clinical decision. There were also 6 (7.4%) cases of recurrent infection. No statistically significant differences were found when compared to GCV or FOS.

CONCLUSIONS

In allogeneic HSCT recipients, VGCV seemed effective and safe in the pre-emptive therapy of active CMV infection.

Invasive fungal infection among hematopoietic stem cell transplantation patients with mechanical ventilation in the intensive care unit

Background

Invasive fungal infection (IFI) is associated with high morbidity and high mortality in hematopoietic stem cell transplantation (HSCT) patientsThe purpose of this study was to assess the characteristics and outcomes of HSCT patients with IFIs who are undergoing MV at a single institution in Taiwan.

Methods

We performed an observational retrospective analysis of IFIs in HSCT patients undergoing mechanical ventilation (MV) in an intensive care unit (ICU) from the year 2000 to 2009. The characteristics of these HSCT patients and risk factors related to IFIs were evaluated. The status of discharge, length of ICU stay, date of death and cause of death were also recorded.

Results

There were 326 HSCT patients at the Linkou Chang-Gung Memorial Hospital (Taipei, Taiwan) during the study period. Sixty of these patients (18%) were transferred to the ICU and placed on mechanical ventilators. A total of 20 of these 60 patients (33%) had IFIs. Multivariate analysis indicated that independent risk factors for IFI were admission to an ICU more than 40 days after HSCT, graft versus host disease (GVHD), and high dose corticosteroid (p < 0.01 for all). The overall ICU mortality rate was 88% (53 of 60 patients), and was not significantly different for patients with IFIs (85%) and those without IFIs (90%, p = 0.676).

Conclusion

There was a high incidence of IFIs in HSCT patients requiring MV in the ICU in our study cohort. The independent risk factors for IFI are ICU admission more than 40 days after HSCT, GVHD, and use of high-dose corticosteroid.

Outcome and risk factors for late-onset complications 24 months beyond allogeneic hematopoietic stem cell transplantation

OBJECTIVES

The aim of this retrospective study was to assess the incidence of late complications occurring ≥2 years after allogeneic hematopoietic stem cell transplantation (HSCT) for malignant diseases using a T-cell depletion strategy.

METHODS

Between 1984 and 2004, 142 patients were eligible for the study. Total body irradiation (TBI) was carried out in 85% of the patients and T-cell depletion in 84%.

RESULTS

Non-relapse mortality (NRM) was 3% (95% CI 0-11) at 10 years, and serious late events affected a substantial number of patients. The cumulative incidence (CI) of chronic graft-versus-host disease (cGvHD) was 30% (95% CI 23-40), and that of infectious complications was 17% (95% CI 11-23). Multivariate analysis showed a higher risk for late complications in patients with cGvHD (HR 1.9, 95% CI 1.2-3.2, P=0.011) and patients receiving methylprednisolone during conditioning (HR 1.9, 95% CI 1.1-3.3, P=0.019 1), patients with cGvHD also having a higher risk for NRM (HR 13.2, 95% CI 1.2-143, P=0.03), as well as those receiving steroids for >3 months (HR 40.3, 95% CI 2.3-718, P=0.02) and those receiving antithymocyte globulin (HR 9.6, 95% CI 0.8-68, P=0.024).

CONCLUSIONS

A significant proportion of long-term survivors of HSCT had late complications. cGvHD remained an important risk factor for late complications despite T-cell depletion resulting in immunosuppression and infectious complications.

Pneumonia in allogeneic stem cell transplantation recipients: a multicenter prospective study

Pneumonia is a common cause of mortality after allogeneic hematopoietic stem cell transplantation (allo-HSCT) but updated and prospective information is partial. The aim of this nationwide prospective study is to determine the current epidemiology, etiology, and outcome of pneumonia in allo-HSCT recipients. From September-2003 to November-2005, 112 episodes in 427 consecutive allo-HSCT recipients were included (incidence 52.2 per 100 allo-HSCT/yr), and 72 of them (64.3%) were microbiologically defined pneumonia. Bacterial pneumonia (44.4%) was more frequent than fungal (29.2%) and viral pneumonia (19.4%). The most frequent microorganisms in each group were: Escherichia coli (n = 7, 8.9%), Streptococcus pneumoniae (n = 4, 5.0%), cytomegalovirus (n = 12, 15.4%), and Aspergillus spp. (n = 12, 15.4%). The development of pneumonia and chronic graft-versus-host disease (GVHD) was associated with increased mortality after allo-HSCT, and the probability of survival was significantly lower in patients that had at least one pneumonia episode (p < 0.01). Pneumonia development in the first 100 d after transplantation, fungal etiology, GVHD, acute respiratory failure, and septic shock were associated with increased mortality after pneumonia. Our results show that pneumonia remains a frequent infectious complication after allo-HSCT, contributing to significant mortality, and provide a large current experience with the incidence, etiology and outcome of pneumonia in these patients.

Influence of polymorphisms in innate immunity genes on susceptibility to invasive aspergillosis after stem cell transplantation

The innate immune system plays a pivotal role in the primary defence against invasive fungal infection. Genetic variation in genes that regulate this response, initiated by pulmonary macrophages, may influence susceptibility to invasive aspergillosis in patients at risk. We investigated in a clinical setting whether common polymorphisms in Toll-like receptor (TLR) and cytokine genes involved in macrophage regulation are associated with susceptibility to invasive aspergillosis. Forty-four allogeneic stem cell transplantation recipients diagnosed with probable or proven IA according to the criteria of the European Organization for Research and Treatment of Cancer/Mycoses Study Group, were enrolled. The control group consisted of 64 allogeneic stem cell transplantation recipients without invasive aspergillosis. The TLR4 1063A>G single nucleotide polymorphism was associated with invasive aspergillosis when present in donors of allogeneic stem cell transplantation recipients (unadjusted OR 3.77 95%CI 1.08–13.2, p = 0.03). In a multivariate analysis, adjusted for occurrence of graft-versus-host-disease, Cytomegalovirus serostatus and duration of neutropenia, paired presence of the TLR4 1063A>G and IFNG 874T>A single nucleotide polymorphisms showed a trend towards increased susceptibility to invasive aspergillosis (p = 0.04). These findings point to the relevant immunological pathway involved in resistance to invasive aspergillosis and warrant further study of the effects of TLR and cytokine polymorphisms and their interaction, which may occur on different levels of the complex biological interplay between the immunocompromised host and Aspergillus sp.

Reactivations of cytomegalovirus, human herpes virus 6, and Epstein-Barr virus differ with respect to risk factors and clinical outcome after hematopoietic stem cell transplantation

One hundred two recipients of hematopoietic stem cell transplants (HSCTs) 45, from siblings and 57 from matched unrelated donors, were followed for cytomegalovirus (CMV), human herpes virus (HHV) 6, and Epstein-Barr Virus (EBV) reactivation by quantitative polymerase chain reaction in the context of immunologic reconstitution and posttransplantation complications. CMV, EBV, and HHV6 DNA copies (>100 copies/10(5) cells) were detected in 34%, 27%, and 26% of patients, respectively. The presence of 100 copies of EBV or CMV was associated with posttransplant complications: 29/66 versus 6/36 (P<.01) or 24/66 versus 4/36 (P=.01). CMV reactivation was more frequent among patients with acute graft-versus-host disease grade≥I: 17/35 versus 18/67 (P<.05). Older patient age of adults>16 year (2/16 versus 33/86; P<.05) and, to a lesser extent, CMV IgG positivity before HSCT (34/84 versus 1/10; P=.08) or an HLA-mismatched graft (9/16 versus 26/86; P=.08) constituted risk factors for CMV reactivation, which resulted in a higher rate of bacterial pneumonia (7/11 versus 28/91; P=.04). EBV reactivation risk was associated with donor EBV IgG seropositivity (28/84 versus 0/10; P=.03) and donor female gender (18/47 versus 10/55; P=.03). In contrast to EBV and CMV, EBV reactivation itself was associated with encephalitis (5/8 versus 23/94; P=.013), which was also seen as a trend among HHV6 reactivations (8/8 versus 46/94; P=.08). Multivariate analysis demonstrated that these factors play independent roles in the reactivation of the investigated herpes viruses.