Current practice in nutrition after allogeneic hematopoietic stem cell transplantation - Results from a survey among hematopoietic stem cell transplant centers.

BACKGROUND: Allogeneic hematopoietic stem cell transplantation (alloHSCT) is frequently associated with impaired oral intake and malnutrition, which potentially increases morbidity and mortality. Therefore, nutrition is one of the major challenges in the post-transplant period. METHODS: To document the current clinical approach in nutritional treatment, we designed a questionnaire concerning the current practice in nutrition after alloHSCT and distributed it to German speaking centers performing alloHSCT in Germany, Austria and Switzerland between November 2018 and March 2020. Twenty-eight (39%) of 72 contacted centers completed the survey, 23 from Germany, two from Austria and three from Switzerland, representing 50% of alloHSCT activity within the participating countries in 2018. RESULTS: All centers reported having nutritional guidelines for patients undergoing alloHSCT, whereby 86% (n = 24) provided a low-microbial diet during the neutropenic phase. The criteria to start parenteral nutrition (PN) directly after alloHSCT seemed to be consistent, 75% (n = 21) of the corresponding centers started PN if the oral nutritional intake or the bodyweight dropped below a certain limit. In the setting of intestinal graft-versus-host disease (GvHD) the current practice appeared to be more heterogenous. About 64% (n = 18) of the centers followed a special diet, added food stepwise modulated by GvHD symptoms, while only four centers regularly stopped oral intake completely (intestinal GvHD grade >1). Half of the centers (54%, n = 15) applied a lactose-free diet, followed by 43% (n = 12) which provided fat- and 18% (n = 5) gluten-free food in patients with intestinal GvHD. Supplementation of micronutrients in acute intestinal GvHD patients was performed by 54% (n = 15) of the centers, whereas vitamin D (89%, n = 25) and vitamin B12 (68%, n = 19) was added regularly independently of the presence of GvHD. Only 5 (18%) participating centers ever observed a food-associated infection during hospitalization, whereas food-associated infections were reported to occur more often in the outpatient setting (64%, n = 18). CONCLUSION: The survey documented a general consensus about the need for nutritional guidelines for patients undergoing alloHSCT. However, the nutritional treatment in clinical practice (i.e. lactose-, gluten- or fat-free in intestinal GvHD) as well as the use of food supplements was very heterogeneous. In line with current general recommendations the centers seemed to focus on safe food handling practice rather than providing a strict neutropenic diet. More high-quality data are required to provide evidence-based nutrition to patients during and after alloHSCT.

Management of growth failure and growth hormone deficiency after pediatric allogeneic HSCT: Endocrinologists are of importance for further guidelines and studies.

Growth failure (GF) is a frequent problem after pediatric allogeneic hematopoietic stem cell transplantation (HSCT). Growth hormone deficiency (GHD) occurs in 20 to 85%, but published data on the efficacy of growth hormone treatment (GHT) are conflicting. Currently, there are no recommendations on screening for and treatment of GHD after HSCT. We aimed to describe the management of endocrine follow-up (FU)and details of GHT within European Society for Blood and Marrow Transplantation (EBMT) centers.In a retrospective questionnaire study, all EBMT centers performing pediatric HSCT were invited. Results were evaluated in correlation with the structure of endocrine aftercare (HSCT-clinicians and endocrinologists).The majority of centers (80%) reported endocrine FU by an endocrinologist - either within the HSCT-center or in a separate endocrine clinic. Fifty-four percent reported FU outside of the HSCT-center. As diagnostic tests the insulin-like growth factor IGF-I and insulin-like growth factor binding protein IGFBP3, insulin tolerance test and arginine stimulation test were most frequently used. Sixty-four percent of centers performed GHT and endocrinologists were more likely to prescribe GH (74%) compared to HSCT-clinicians (33%). The most frequent indication for GHT was GHD in 60%, with a distinct different approach of endocrinologists in comparison with HSCT-clinicians.Our study reveals substantial variation in practice and emphasizes the need for endocrine aftercare performed by dedicated endocrinologists in close collaboration with the HSCT-center. Our results indicate that the management of GHT depends on the structure of endocrine aftercare, which is important for the future development and distribution of studies and guidelines.

Biomarkers in chronic graft-versus-host disease: quo vadis?

Biomarkers are increasingly used for diagnosis and treatment of transplant-related complications including the first biomarker-driven interventional trials of acute graft-versus-host disease (GvHD). In contrast, the development of biomarkers of chronic GvHD (cGvHD) has lagged behind due to a broader variety of manifestations, overlap with acute GvHD, a greater variation in time to onset and maximum severity, and lack of sufficient patient numbers within prospective trials. An international workshop organized by a North-American and European consortium was held in Marseille in March 2017 with the goal to discuss strategies for future biomarker development to guide cGvHD therapy. As a result of this meeting, two areas were prioritized: the development of prognostic biomarkers for subsequent onset of moderate/severe cGvHD, and in parallel, the development of qualified clinical-grade assays for biomarker quantification. The most promising prognostic serum biomarkers are CXCL9, ST2, matrix metalloproteinase-3, osteopontin, CXCL10, CXCL11, and CD163. Urine-proteomics and cellular subsets (CD4+ T-cell subsets, NK cell subsets, and CD19+CD21low B cells) represent additional potential prognostic biomarkers of cGvHD. A joint effort is required to verify the results of numerous exploratory trials before any of the potential candidates is ready for validation and subsequent clinical application.

Fertility preservation issues in pediatric hematopoietic stem cell transplantation: practical approaches from the consensus of the Pediatric Diseases Working Party of the EBMT and the International BFM Study Group.

Fertility preservation is an urgent challenge in the transplant setting. A panel of transplanters and fertility specialists within the Pediatric Diseases Working Party of the European Society for Blood and Marrow Transplantation (EBMT) and the International BFM Study Group provides specific guidelines. Patients and families should be informed of possible gender- and age-specific cryopreservation strategies that should be tailored according to the underlying disease, clinical condition and previous exposure to chemotherapy. Semen collection should be routinely offered to all postpubertal boys at the diagnosis of any disease requiring therapy that could potentially impair fertility. Testicular tissue collection might be offered to postpubertal boys; nevertheless, its use has been unsuccessful to date. Oocyte collection after hormonal hyperstimulation should be offered to postpubertal girls facing gonadotoxic therapies that could be delayed for the 2 weeks required for the procedure. Ovarian tissue collection could be offered to pre-/post-pubertal girls. Pregnancies have been reported after postpubertal ovarian tissue reimplantation; however, to date, no pregnancy has been reported after the reimplantation of prepubertal ovarian tissue or in vitro maturation of pre-/post-pubertal ovarian tissue. Possible future advances in reproductive medicine could change this scenario. Health authorities should prioritize fertility preservation projects in pediatric transplantation to improve patient care and quality of life.

State-of-the-art fertility preservation in children and adolescents undergoing haematopoietic stem cell transplantation: a report on the expert meeting of the Paediatric Diseases Working Party (PDWP) of the European Society for Blood and Marrow Transplantation (EBMT) in Baden, Austria, 29-30 September 2015.

Nowadays, allogeneic haematopoietic stem cell transplantation (allo-HSCT) is a well-established treatment procedure and often the only cure for many patients with malignant and non-malignant diseases. Decrease in short-term complications has substantially contributed to increased survival. Therefore long-term sequelae are reaching the focus of patient care. One of the most important risks of stem cell transplant survivors is infertility. As well as in the field of allo-HSCT also the field of reproductive medicine has achieved substantial advances to offer potential options for fertility preservation in both boys and girls. Access to these procedures as well as their financing differs significantly throughout Europe. As all European children and adolescents should have the same possibility, the Paediatric Diseases Working Party of the European Society for Blood and Marrow Transplantation organised an expert meeting in September 2015. This manuscript describes the recommendations for the diagnosis and pre-emptive procedures that should be offered to all children and adolescents in Europe who have to undergo an allo-HSCT.

Comparison of different approaches to quantitative adenovirus detection in stool specimens of hematopoietic stem cell transplant recipients.

BACKGROUND: Adenoviruses almost invariably proliferate in the gastrointestinal tract prior to dissemination, and critical threshold concentrations in stool correlate with the risk of viremia. Monitoring of adenovirus loads in stool may therefore be important for timely initiation of treatment in order to prevent invasive infection. OBJECTIVES: Comparison of a manual DNA extraction kit in combination with a validated in-house PCR assay with automated extraction on the NucliSENS-EasyMAG device coupled with the Adenovirus R-gene kit (bioMérieux) for quantitative adenovirus analysis in stool samples. STUDY DESIGN: Stool specimens spiked with adenovirus concentrations in a range from 10E2-10E11 copies/g and 32 adenovirus-positive clinical stool specimens from pediatric stem cell transplant recipients were tested along with appropriate negative controls. RESULTS: Quantitative analysis of viral load in adenovirus-positive stool specimens revealed a median difference of 0.5 logs (range 0.1-2.2) between the detection systems tested and a difference of 0.3 logs (range 0.0-1.7) when the comparison was restricted to the PCR assays only. Spiking experiments showed a detection limit of 102-103adenovirus copies/g stool revealing a somewhat higher sensitivity offered by the automated extraction. The dynamic range of accurate quantitative analysis by both systems investigated was between 103 and 108 virus copies/g. CONCLUSIONS: The differences in quantitative analysis of adenovirus copy numbers between the systems tested were primarily attributable to the DNA extraction method used, while the qPCR assays revealed a high level of concordance. Both systems showed adequate performance for detection and monitoring of adenoviral load in stool specimens.

Incidence and severity of crucial late effects after allogeneic HSCT for malignancy under the age of 3 years: TBI is what really matters.

Younger children are considered to be more vulnerable to late effects (LE), which prompted us to study LE in patients after haematopoietic stem cell transplantation (HSCT) for a haematological malignancy before the age of 3. In this multicentre EBMT study, cumulative incidence (CI) and severity of endocrine LE, central nervous system complications and secondary malignancies at 5, 10, 15 and 20 years of follow-up were assessed. Risk factors (RF) like gender, diagnosis, age at and year of HSCT, TBI- or chemo-conditioning and GVHD were analysed. CI of any LE was 0.30, 0.52, 0.66 and 0.72 at 5, 10, 15 and 20 years after HSCT, respectively. In 25% of the patients, LE were severe at a median follow-up of 10.4 years. In multivariate analysis, only TBI was a RF for having any LE and for thyroid dysfunction and growth disturbance. Female gender was a RF for delayed pubertal development. Some more insight could be gained by descriptive analysis regarding the role of TBI and GVHD on the severity of LE. Although only five selected LE have been studied and median follow-up is relatively short, the incidence and severity of these LE are considerable but not different from what has been found in older children and TBI is the main RF.

Persistence and reactivation of human adenoviruses in the gastrointestinal tract.

Reactivation of persistent human adenoviruses (HAdVs) is associated with high morbidity and mortality in paediatric haematopoietic stem cell transplant (HSCT) recipients. Although invasive HAdV infections mainly arise from the gastrointestinal (GI) tract, the specific sites of HAdV persistence are not well characterised. We prospectively screened biopsies from 143 non-HSCT paediatric patients undergoing GI endoscopy and monitored serial stool specimens from 148 paediatric HSCT recipients for the presence of HAdV by real-time PCR. Persistence of HAdV in the GI tract was identified in 31% of children, with the highest prevalence in the terminal ileum. In situ hybridisation and immunohistochemistry identified HAdV persistence in lymphoid cells of the lamina propria, whereas biopsies from five transplant recipients revealed high numbers of replicating HAdV in intestinal epithelial cells. The prevalence of HAdV species, the frequencies of persistence in the GI tract and reactivations post transplant indicated a correlation of intestinal HAdV shedding pre-transplant with high risk of invasive infection. HAdV persistence in the GI tract is a likely origin of infectious complications in immunocompromised children. Intestinal lymphocytes represent a reservoir for HAdV persistence and reactivation, whereas the intestinal epithelium is the main site of viral proliferation preceding dissemination. The findings have important implications for assessing the risk of life-threatening invasive HAdV infections.

Recommendations on hematopoietic stem cell transplantation for inherited bone marrow failure syndromes.

Allogeneic hematopoietic stem cell transplantation (HSCT) offers the potential to cure patients with an inherited bone marrow failure syndrome (IBMFS). However, the procedure involves the risk of treatment-related mortality and may be associated with significant early and late morbidity. For these reasons, the benefits should be carefully weighed against the risks. IBMFS are rare, whereas case reports and small series in the literature illustrate highly heterogeneous practices in terms of indications for HSCT, timing, stem cell source and conditioning regimens. A consensus meeting was therefore held in Vienna in September 2012 on behalf of the European Group for Blood and Marrow Transplantation to discuss HSCT in the setting of IBMFS. This report summarizes the recommendations from this expert panel, including indications for HSCT, timing, stem cell source and conditioning regimen.

Paediatric reduced intensity conditioning: analysis of centre strategies on regimens and definitions by the EBMT Paediatric Diseases and Complications and Quality of Life WP.

The aim of this analysis was to explore the diversity of reduced intensity conditioning (RIC) in paediatric allo-SCT in daily practice across Europe. Data from the European Group for Blood and Marrow Transplantation (EBMT) Promise database from 1994 to 2008 were supplemented by a survey of EBMT centres performing paediatric allo-SCT on the current policy asking for the underlying diseases and for the drug combinations. Records from 161 centres from 30 countries were analysed and 139 various RIC regimens were reported. More centres applied RIC for malignant rather than for non-malignant diseases. In general, fludarabine (FLU)-based regimens predominated except for BU-based regimens in myeloid malignancies and haemoglobinopathies. Treosulfan (TREO) was mainly applied for unspecified malignant diseases and for haemophagocytic diseases. FLU-based regimens revealed the greatest number of different combinations. Correlating the number of regimens with the number of treating centres revealed the lowest variety in FLU and the highest variety in TBI and TREO. FLU/melphalane and FLU/CY were the most frequent combinations. This extreme heterogeneity in RIC may influence both the efficacy and the safety of the procedures, which requires further investigation. Optimization and standardization of RIC is the final goal to provide a platform for future prospective studies.

Consensus on performing skin biopsies, laboratory workup, evaluation of tissue samples and reporting of the results in patients with suspected cutaneous graft-versus-host disease.

BACKGROUND: Histopathological diagnosis including selection of lesions, the determination of the best point of time for biopsy and workup is not trivial in cutaneous graft-versus-host disease (GvHD). OBJECTIVES: To develop interdisciplinary recommendations on performing, the laboratory work up and reporting of the results of skin biopsies in patients with suspected cutaneous GvHD. METHODS: A working group consisting of dermatopathologists, dermatologists, transplant-physicians and transplant-pathologists prepared recommendations for performing skin biopsies, laboratory workup and evaluation of tissue samples, and reporting of the results in patients with cutaneous GvHD. After achieving a consensus within the working group, a survey that comprised the core issues of the recommendations was electronically sent out to 72 alloHSCT centres within Germany, Austria, and Switzerland and their Departments of Pathology. The answers were discussed in a Consensus Conference and final recommendations were established. RESULTS: Twenty-five centres responded to the clinical and 17 centres to the histopathological survey. Questions addressed to the clinicians comprised the indication for skin biopsy in chronic GvHD (cGvHD) and acute GvHD (aGvHD) and the appropriate point of time for skin biopsy. Eighty-eight per cent agreed that the skin biopsy is generally indicated in patients with suspected cGvHD lacking diagnostic features. In contrast, with suspected aGvHD, only 62% of respondents felt that skin biopsy was necessary even if GvHD had not been confirmed in another organ. Although restricted due to the fact that immunosuppression is often applied in an emergency setting most centres supported skin biopsies before initiation of topical or systemic immunosuppression. The majority of pathologists agreed that in non-sclerotic GvHD a punch biopsy is adequate, whereas in sclerotic GvHD a scalpel biopsy is preferred. CONCLUSION: While a consensus on the need for biopsies in cGvHD was reached the value of skin biopsies in aGvHD and subsequent biopsies during therapy requires further evaluation.

Clinical guidelines for gynecologic care after hematopoietic SCT. Report from the international consensus project on clinical practice in chronic GVHD.

Despite similarities relevant age- and gender-specific issues exist in the care of patients after allogeneic hematopoietic SCT (HSCT). Female genital chronic GVHD (cGVHD) has been markedly underreported in the past but has a significant impact on the patients' health and quality of life. Data on prevention and treatment of this complication are still limited. Here we present a comprehensive review summarizing the current knowledge, which was discussed during several meetings of the German, Austrian and Swiss Consensus Project on clinical practice in cGVHD. In this report, we provide recommendations for post-transplant gynecological care of cGVHD manifestations agreed upon by all participants. This includes guidelines for diagnosis, prevention, and therapeutic options and topical treatments in female patients with genital cGVHD and hormonal replacement treatment of premature ovarian failure for adult and pediatric patients and underlines the necessity for regular gynecological care and screening programs for women after HSCT.

Health-related quality of life in pediatric patients after allogeneic SCT: development of the PedsQL Stem Cell Transplant module and results of a pilot study.

With increased survival after pediatric allogeneic hematopoietic SCT health-related quality of life (HRQL) has emerged as an essential health outcome. The impact of transplant and chronic GVHD (cGVHD)-associated morbidity remains a major obstacle. In 2005, the National Institutes of Health (NIH) Consensus Conference on Criteria for Clinical Trials in cGVHD recommended HRQL tools as an independent measure of the impact of disease burden. The NIH recommendations did not provide a cGVHD-specific tool for HRQOL measures in children. This report focuses on the development of an SCT-specific instrument to assess HRQL in children and adolescents. For the assessment of generic HRQL we chose the PedsQL (Pediatric Quality of Life Inventory) Generic Cores Scales, which have been used in a large number of healthy, acutely ill and chronically ill children and adolescents. To capture SCT- and, specifically, cGVHD-related problems, we developed the PedsQL Stem Cell Transplant module by reviewing the literature, taking over some items/scales of other PedsQL modules, interviewing patients, parents and members of the health-care team, and applying the PedsQL measurement methods. The final PedsQL Stem Cell Transplant module consists of the HRQL domains: pain and hurt, fatigue/sleeping problems/weakness, nausea, worry/anxiety about disease/treatment, nutritional problems, neurocognitive problems, communication about disease/treatment, loneliness, physical functioning and additional somatic complaints (pruritus, skin inflammation, oral problems, eyes or breathing) including patients' and parents' assessment. It was tested in 35 pediatric patients, who were referred to our SCT Outpatient Clinic about 100 days post SCT. Both the generic PedsQL and the SCT-specific scales showed high internal consistency, with Cronbach alpha levels of ⩾0.70 in almost all scales. Most problems were detected within the HRQL domains of physical functioning and pain. The summary scores of the generic PedsQL and the PedsQL Stem Cell Transplant module showed high correlations (r=0.89 in patients' and r=0.81 in parents' assessments). Moreover, both tools discriminated between patients with and without cGVHD. The PedsQL Stem Cell Transplant module is practical for use and suitable across a broad age range (2-18 years) both in patients with and without cGVHD. However, it is still a pilot instrument and needs further development and testing in a larger patient population.

Prophylaxis and treatment of GVHD: EBMT-ELN working group recommendations for a standardized practice.

GVHD remains the major impediment to broader application of allogeneic haematopoietic SCT. It can be prevented completely, but at the expense of other complications, rejection, relapse or delayed immune reconstitution. No optimal prevention or treatment method has been defined. This is reflected by enormous heterogeneity in approaches in Europe. Retrospective comparisons between different policies, although warranted, do not give definite answers. In order to improve the present situation, an European Group for Blood and Marrow Transplantation and the European LeukemiaNet working group has developed in a Delphi-like approach recommendations for prophylaxis and treatment of GVHD in the most common allogeneic transplant setting, transplantation from an HLA-identical sibling or unrelated donor for standard risk malignant disease. The working group proposes these guidelines to be adopted as routine standard in transplantation centres and to be used as comparator in systematic studies evaluating the advantages and disadvantages of practices differing from these recommendations.

Ferritin concentrations correlate to outcome of hematopoietic stem cell transplantation but do not serve as biomarker of graft-versus-host disease.

Clinical presentation and laboratory data are often too unspecific to distinguish the onset or activity of graft-versus-host disease (GvHD) from infections or toxicity. Antigen-presenting cells such as monocytes/macrophages and dendritic cells are involved in GvHD pathogenesis after allogeneic hematopoietic stem cell transplantation (HSCT). To test whether ferritin, an iron storage marker and macrophage activation-linked acute-phase protein, represents a candidate biomarker for acute or chronic GvHD in pediatric HSCT, we retrospectively evaluated a 2-year follow-up data from 131 eligible consecutive patients with different malignant and nonmalignant diseases who underwent allogeneic HSCT. Thirteen patients (10 %) suffered from acute GvHD II-IV°, 18 (14 %) had limited, and 14 (11 %) had extensive chronic GvHD. In extension of previous studies in adults investigating pre-transplant ferritin, our data show that post-HSCT hyperferritinemia (analyzed on days 0, +30, +60, +100, +180, +360, and +720) was significantly associated with decreased long-term survival (p < 0.001-0.03) in children and adolescents. Increased ferritin concentrations were associated with number and timing of red blood cell transfusions and toxic or infectious multi-organ failure but did not show significant differences between patients without GvHD and with acute grades II-IV, limited, or extensive chronic GvHD. Thus, our data do not identify ferritin as specifically GvHD-linked biomarker; however, they support the prognostic value of ferritin levels for outcome after HSCT in children.

Exhaled nitric oxide and pulmonary complications after paediatric stem cell transplantation.

UNLABELLED: Pulmonary complications are major causes of morbidity and mortality after haematopoietic stem cell transplantation (HSCT). We hypothesise that elevated exhaled nitric oxide (FeNO) levels early after HSCT in children are predictive for pulmonary complications. The present prospective study included 30 children (age, 4-18 years) before HSCT. FeNO levels were evaluated 10 days before transplant, at day 0, day +28 and day +60 after HSCT. During the follow-up period until day +100, pulmonary complications and lung function were assessed. Before HSCT, the mean FeNO levels were comparable in children with or without post-transplant pulmonary complications. However, they differed at day 0 and day +28 with a mean of 7 (±1.95) and 13 (±3.44) ppb at day 0 and a mean of 13 (±3.44) and 14 (±3.57) ppb at day +28, respectively. CONCLUSION: Children with pulmonary complications after day +28 have higher mean FeNO levels 28 days after HSCT than children without later pulmonary complications. Therefore, FeNO could be an important diagnostic tool for hyperinflammatory response in bronchial epithelium after paediatric HSCT.

Non-atopic IgE and eosinophil cationic protein after allogeneic hematopoietic stem cell transplantation in children.

Allogeneic hematopoietic stem cell transplantation (HSCT) in childhood is associated with severe pulmonary complications, but the pathophysiologic mechanisms remain unclear. Our aim was to evaluate the association of total and specific IgE, eosinophil cationic protein (ECP) and eosinophilia in HSCT recipients with pulmonary complications. We prospectively measured total and specific serum IgE, eosinophils, and ECP before and 28, 100, and 180 days after HSCT. We included 30 children (age 2-17 years) undergoing HSCT. Nine patients had a history of previous atopy without being associated with pulmonary complications after HSCT until day +360. Specific IgE levels showed a decline after HSCT, associated with the absence of allergy symptoms, suggesting a reduction of atopy. Elevated total serum IgE levels occurred in seven patients on day +28 after HSCT. This elevation did not coincide with allergy symptoms. ECP showed no correlation with total allergy symptoms, eosinophilia, IgE levels, or pulmonary complications. There was a significant correlation (p = 0.0367) between ECP levels on day +28 and concurrent acute graft-versus-host disease (GvHD). Non-atopic serum ECP and IgE levels are elevated on day +28 after HSCT in children, with ECP showing a potential relation to acute GvHD.

Early recipient chimerism testing in the T- and NK-cell lineages for risk assessment of graft rejection in pediatric patients undergoing allogeneic stem cell transplantation.

Timely diagnosis of impending graft rejection is crucial for effective therapeutic intervention after allogeneic hematopoietic stem cell transplantation (SCT). We have investigated the predictive potential of early leukocyte subset-specific chimerism for graft loss in children undergoing SCT. In total, 192 pediatric patients transplanted for the treatment of malignant and non-malignant diseases after reduced-intensity or myeloablative conditioning were investigated. Surveillance of lineage-specific chimerism was initiated upon first appearance of leukocyte counts amenable to cell sorting. Graft rejection occurred in 23 patients between 24 and 492 days post-transplant (median 63 days). The first chimerism analysis of T and NK cells performed at a median of 20 days after SCT identified three different risk groups that were independent from the conditioning regimen: recipient chimerism (RC) levels in T cells below 50% indicated a very low risk of rejection (1.4%), whereas high levels of RC (>90%) both in T and NK cells heralded graft loss in the majority of patients (90%) despite therapeutic interventions. RC >50% in T cells and ≤90% in NK cells defined an intermediate-risk group in which timely immunotherapy frequently prevented rejection. Early assessment of T- and NK-cell chimerism can therefore be instrumental in the risk assessment and therapeutic management of imminent graft rejection.

Fertility after allogeneic haematopoietic stem cell transplantation in childhood and adolescence.

Infertility is a major late effect in patients receiving haematopoietic stem cell transplantation (HSCT). The aim of this study was to determine the proportion of patients having fertility impairment after allogeneic HSCT in childhood/adolescence and to identify the potential risk factors. Treatment and fertility data of paediatric patients with malignant and non-malignant diseases treated with allogeneic HSCT between 2000 and 2005 were collected from seven European centres. Data were obtained for 138 female and 206 male patients after a median follow-up of 6 years (range 3-12). The patients' median age was 13 years (range 4-28) at the time of HSCT and 19 (range 12-35) years at the time of the enquiry. Seven children were born to the overall group, all at term and healthy. Fertility impairment was suspected in 69% males and 83% females. Start of treatment at age 13 years was a risk factor in females (odds ratio (OR) 4.7; 95% confidence interval (CI), 1.5 to 14.9), whereas pre-pubertal therapy was a risk factor in males (OR 0.4; 95% CI, 0.2 to 0.8). The major treatment-related risk factors were BU in females (OR 47.4; 95% CI, 5.4 to 418.1) and TBI in males (OR 7.7; 95% CI, 2.3 to 25.4). In light of the significant proportion of HSCT patients reviewed with impaired fertility, fertility conservation procedures should be considered for all patients undergoing HSCT, particularly those receiving TBI or BU-based preparative regimens.