Cerebral toxoplasmosis in an adolescent post allogeneic hematopoietic stem cell transplantation: successful outcome by antiprotozoal chemotherapy and CD4+ T-lymphocyte recovery.

Toxoplasmosis is a rare opportunistic infection in pediatric allogeneic hematopoietic stem cell transplant (allo-HSCT) recipients and associated with severe T-cell deficiency. Here, we report the successful management of cerebral toxoplasmosis in a 15-year-old adolescent 4 months post allo-HSCT for non-Hodgkin lymphoma through rapid invasive diagnostics, long-term antiprotozoal chemotherapy, and an hematopoietic stem cell boost for persistently poor graft function. While supportive care and antiprotozoal chemotherapy achieved stabilization, definite improvement only occurred following recovery of CD4(+) T lymphocytes to >100 cells/µL. At 5 years after the diagnosis of toxoplasmosis, the patient is in continuing remission with normalized clinical and imaging findings.

Bloodstream infection in paediatric cancer centres--leukaemia and relapsed malignancies are independent risk factors.

UNLABELLED: In a prospective multicentre study of bloodstream infection (BSI) from November 01, 2007 to July 31, 2010, seven paediatric cancer centres (PCC) from Germany and one from Switzerland included 770 paediatric cancer patients (58% males; median age 8.3 years, interquartile range (IQR) 3.8-14.8 years) comprising 153,193 individual days of surveillance (in- and outpatient days during intensive treatment). Broviac catheters were used in 63% of all patients and Ports in 20%. One hundred forty-two patients (18%; 95% CI 16 to 21%) experienced at least one BSI (179 BSIs in total; bacteraemia 70%, bacterial sepsis 27%, candidaemia 2%). In 57%, the BSI occurred in inpatients, in 79% after conventional chemotherapy. Only 56 % of the patients showed neutropenia at BSI onset. Eventually, patients with acute lymphoblastic leukaemia (ALL) or acute myeloblastic leukaemia (AML), relapsed malignancy and patients with a Broviac faced an increased risk of BSI in the multivariate analysis. Relapsed malignancy (16%) was an independent risk factor for all BSI and for Gram-positive BSI. CONCLUSION: This study confirms relapsed malignancy as an independent risk factor for BSIs in paediatric cancer patients. On a unit level, data on BSIs in this high-risk population derived from prospective surveillance are not only mandatory to decide on empiric antimicrobial treatment but also beneficial in planning and evaluating preventive bundles. WHAT IS KNOWN: • Paediatric cancer patients face an increased risk of nosocomial bloodstream infections (BSIs). • In most cases, these BSIs are associated with the use of a long-term central venous catheter (Broviac, Port), severe and prolonged immunosuppression (e.g. neutropenia) and other chemotherapy-induced alterations of host defence mechanisms (e.g. mucositis). What is New: • This study is the first multicentre study confirming relapsed malignancy as an independent risk factor for BSIs in paediatric cancer patients. • It describes the epidemiology of nosocomial BSI in paediatric cancer patients mainly outside the stem cell transplantation setting during conventional intensive therapy and argues for prospective surveillance programmes to target and evaluate preventive bundle interventions.

Fatal human metapneumovirus infection following allogeneic hematopoietic stem cell transplantation.

Respiratory viruses are an important yet underestimated cause of infectious morbidity and mortality in immunocompromised children and adolescents. Here, we report the occurrence of fatal lower respiratory tract disease associated with human metapneumovirus (HMPV) infection in a 10-year-old girl with chronic graft-versus-host disease following allogeneic hematopoietic stem cell transplantation (HSCT) for secondary chronic myeloid leukemia. Symptoms occurred 8 months after HSCT while on immunosuppression with 0.2 mg/kg/day of prednisone, and presented as dry cough, bilateral pneumonitis, and progressive respiratory distress. Non-invasive and invasive microbiological investigations revealed HMPV type B as the sole pathogen. Histopathological findings showed interstitial and intra-alveolar pneumonitis with profound alveolar cell damage. The patient was treated with intravenous and oral ribavirin and polyvalent immunoglobulins, but ultimately died from respiratory failure. The case reflects the potentially fatal impact of infections by respiratory viruses in immunocompromised patients and the need for effective approaches to their prevention and treatment.

Surveillance for ototoxicity in platinum-based chemotherapy using mobile health audiometry with extended high frequencies.

OBJECTIVE: This study investigated mobile health enabled surveillance in ototoxicity. METHOD: This was a longitudinal study of 32 participants receiving chemotherapy. Baseline and exit audiograms that included conventional and extended high frequency audiometry were recorded within the patient's treatment venue using a validated mobile health audiometer. RESULTS: Average hearing thresholds at baseline were within the normal range (81.2 per cent left; 93.8 per cent right), reducing at exit testing (71.9 per cent left; 78.1 per cent right). Half of participants presented with a threshold shift according to ototoxicity monitoring criteria. The frequencies affected the most were between 4000 and 16 000 Hz, with left ears significantly more affected than right ears. Noise levels exceeded the maximum permissible ambient noise levels in up to 43.8 per cent of low frequencies (250-1000 Hz). CONCLUSION: Mobile health supported audiometry proved to be an efficacious tool for ototoxicity monitoring at the treatment venue. Changes in hearing ability over time could be tracked, improving surveillance in patients with full treatment schedules.

Catheter-associated aspergillosis of the chest wall following allogeneic hematopoietic stem cell transplantation.

Invasive aspergillosis (IA) at the insertion site of central venous catheters is a rare event. Here we report the occurrence of chest wall aspergillosis at the insertion site of a Broviac catheter in a 5-year-old child undergoing allogeneic hematopoietic stem cell transplantation. The infection arose during profound granulocytopenia under conditions of reverse isolation with laminar air flow and high efficiency particulate air filtration and was successfully managed with repeat surgical debridement, voriconazole/caspofungin combination therapy guided by therapeutic drug monitoring, and adjunctive use of granulocyte colony-stimulating factor. The case reflects the occurrence of IA despite reverse isolation and air decontamination, the principles of treatment of Aspergillus soft tissue infections in granulocytopenic patients, and the need for therapeutic drug monitoring of voriconazole particularly in young children.

Reduced intensity conditioning in unrelated donor transplantation for refractory cytopenia in childhood.

Myelodysplastic syndromes (MDS) are a heterogenous group of acquired hematopoietic stem cell disorders. Refractory cytopenia (RC) is the most common subtype of childhood MDS and hematopoietic stem cell transplantation (HSCT) is the only curative treatment. HSCT following a myeloablative preparative regimen is associated with a low probability of relapse and considerable transplant-related mortality. In the present European Working Groups of MDS pilot study, we investigated whether a reduced intensity conditioning regimen (RIC) is able to offer reduced toxicity without increased rates of graft failure or relapse. Nineteen children with RC were transplanted from an unrelated donor following RIC consisting of fludarabine, thiotepa and anti-thymocyte globulin. Three patients experienced graft failure. Neutrophil and platelet engraftment occurred at a median time of 23 and 30 days, respectively. Cumulative incidence of grade II-IV and grade III and IV acute graft-versus-host disease (GVHD) was 0.48 and 0.13, respectively; three patients developed extensive chronic GVHD. Although infections were the predominant complications, only one patient with extensive chronic GVHD died from infectious complications. Overall and event-free survival at 3 years were 0.84 and 0.74, respectively. In conclusion, our results were comparable to those of patients treated with myeloablative HSCT. Long-term follow-up is needed to demonstrate the expected reduction in long-term sequelae.

Methicillin-resistance in Staphylococcus aureus - molecular basis, novel targets and antibiotic therapy.

Methicillin-resistant S. aureus are the major cause of nosocomial bacteremias showing a high morbidity rate in intensive care units. These strains are often resistant against almost all antibiotics in clinical use with the exception of vancomycin. However, the first isolation of a S. aureus strain with a diminished susceptibility to vancomycin from a hospitalized patient in Japan has been reported very recently. Therefore, current antibiotic therapy is difficult and expensive, often a combination of several antibiotics has to be used. For this reason novel antibiotics to combat staphylococcal bacteremias, which prevent further spread of resistance are urgently needed. One approach might be the investigation of the mechanism of methicillin resistance, which is mediated by PBP2a, an additional penicillin-binding protein present in resistant strains with low affinity to ss-lactams. Beside PBP2a other housekeeping genes, the so called fem factors, are involved in expression of methicillin resistance. Two of these fem factors, the FemAB proteins, have been shown to participate in the formation of the pentaglycine crossbridge, which is a unique staphylococcal cell wall component. The biosynthesis of the pentaglycine side chains is not fully elucidated, but follows an interesting novel mechanism with unusual glycyl-tRNA as a substrate. Furthermore, inactivation of femAB, which have been reported as essential for bacterial growth, causes a completely restoration of antibiotic susceptibility in MRSA strains. Thus, these proteins might serve as attractive novel anti-staphylococcal targets for a small-range antibiotic.

Lif, the lysostaphin immunity factor, complements FemB in staphylococcal peptidoglycan interpeptide bridge formation.

The formation of the Staphylococcus aureus peptidoglycan pentaglycine interpeptide chain needs FemA and FemB for the incorporation of glycines Gly2-Gly3, and Gly4-Gly5, respectively. The lysostaphin immunity factor Lif was able to complement FemB, as could be shown by serine incorporation and by an increase in lysostaphin resistance in the wild-type as well as in a femB mutant. However, Lif could not substitute for FemA in femA or in femAB-null mutants. Methicillin resistance, which is dependent on functional FemA and FemB, was not complemented by Lif, suggesting that serine-substituted side chains are a lesser substrate for penicillin-binding protein PBP2' in methicillin resistance.

The fib locus in Streptococcus pneumoniae is required for peptidoglycan crosslinking and PBP-mediated beta-lactam resistance.

Penicillin resistance in pneumococci is mediated by modified penicillin-binding proteins (PBPs) that have decreased affinity to beta-lactams. In high-level penicillin-resistant transformants of the laboratory strain Streptococcus pneumoniae R6 containing various combinations of low-affinity PBPs, disruption of the fib locus results in a collapse of PBP-mediated resistance. In addition, crosslinked muropeptides are highly reduced. The fib operon consists of two genes, fibA and fibB, homologous to Staphylococcus aureus femA/B which are also required for expression of methicillin resistance in this organism. FibA and FibB belong to a family of proteins of Gram-positive bacteria involved in the formation of interpeptide bridges, thus representing interesting new targets for antimicrobial compounds for this group of pathogens.

Identification of three additional femAB-like open reading frames in Staphylococcus aureus.

Three new proteins, FmhA, FmhB and FmhC, with significant identities to FemA and FemB were identified in the Staphylococcus aureus (ATCC 55748) genome database. They were mapped to the SmaI-C, SmaI-H and SmaI-A fragments of the S. aureus 8325 chromosome, respectively. Whereas insertional inactivation of fmhA and fmhC had no effects on growth, antibiotic susceptibility, lysostaphin resistance, or peptidoglycan composition of the strains, fmhB could not be inactivated, strongly suggesting that fmhB may be an essential gene. As deduced from the functions of FemA and FemB which are involved in the synthesis of the peptidoglycan pentaglycine interpeptide, FmhB may be a candidate for the postulated FemX thought to add the first glycine to the nascent interpeptide.

Anti-resorptive agents reduce the size of resorption cavities: a three-dimensional dynamic bone histomorphometry study.

Alterations in resorption cavities and bone remodeling events during anti-resorptive treatment are believed to contribute to reductions in fracture risk. Here, we examine changes in the size of individual remodeling events associated with treatment with a selective estrogen receptor modulator (raloxifene) or a bisphosphonate (risedronate). Adult female rats (6months of age) were submitted to ovariectomy (n=17) or sham surgery (SHAM, n=5). One month after surgery, the ovariectomized animals were separated into three groups: untreated (OVX, n=5), raloxifene treated (OVX+Ral, n=6) and risedronate treated (OVX+Ris, n=6). At 10months of age, the lumbar vertebrae were submitted to three-dimensional dynamic bone histomorphometry to examine the size (depth, breadth and volume) of individual resorption cavities and formation events. Maximum resorption cavity depth did not differ between the SHAM (23.66±1.87µm, mean±SD) and OVX (22.88±3.69µm) groups but was smaller in the OVX+Ral (14.96±2.30µm) and OVX+Ris (14.94±2.70µm) groups (p<0.01). Anti-resorptive treatment was associated with reductions in the surface area of resorption cavities and the volume occupied by each resorption cavity (p<0.01 each). The surface area and volume of individual formation events (double-labeled events) in the OVX+Ris group were reduced as compared to other groups (p<0.02). Raloxifene treated animals showed similar amounts of bone remodeling (ES/BS and dLS/BS) compared to sham-operated controls but smaller cavity size (depth, breadth and volume). The current study shows that anti-resorptive agents influence the size of resorption cavities and individual remodeling events and that the effect of anti-resorptives on individual remodeling events may not always be directly related to the degree of suppression of bone remodeling.

Long-term follow-up of children conditioned with Treosulfan: German and Austrian experience.

We report the long-term follow-up of children transplanted with Treosulfan (TREO)-based conditioning in Germany and Austria. Nine centres reported a total of 109 transplantations. Patients were stratified according to the paediatric TRM risk score derived from the paediatric BMT registry (PRST) and compared with the historical transplant population of this registry. Underlying diseases were malignancies, immunodeficiencies, and haematologic and metabolic disorders. TREO total dose ranged from 21-42 g/m(2). Additional conditioning drugs included fludarabine, thiotepa, melphalan, CY and/or TBI. EFS at 3 years for non-malignant and malignant diseases was 88% and 49%, respectively. Leukaemia patients in remission had a survival of 51% at 3 years; nonremission patients relapsed and died within 18 months. TRM and OS in the low-risk groups 0 and 1 were similar to PRST controls. TRM in the high-risk groups 2 and 3 was markedly lower (9% vs 28% and 13% vs 53%, respectively) than in the PRST group, but OS was similar. In conclusion, TREO-based conditioning regimens in children resulted in excellent engraftment and long-term survival in nonmalignant disease. In high-risk malignancy, low acute toxicity was followed by low TRM but it did not translate into increased survival.

Allo-SCT using BU, CY and melphalan for children with AML in second CR.

Based on the results from the AML-BFM 98 trial, hematopoietic SCT (HSCT) is recommended for children with AML in second CR only. Here, we retrospectively analyze interphase data of children who underwent HSCT after myeloablative conditioning with BU, CY, and melphalan (BuCyMel) for AML in second remission (CR2) between 1998 and 2009. Out of 152 children, transplant data were available on 109 individuals. Sixty out of 109 children (55%) received BuCyMel. Median age at HSCT was 12.2 years (range 3.0; 18.3). GVHD prophylaxis mostly consisted of CsA and short term MTX with or without antithymocyte globulin. Matched-sibling donors were used for 6/60 analyzed recipients, the remainder either received grafts from matched unrelated (30/60) or mismatched donors. OS after 5 years was 62% (s.e. 6%), relapse incidence 35% (18/60 children) and treatment-related mortality accounted for 12% (7/60) of fatal events. In conclusion, even taking into account possible selection bias in this retrospective analysis, HSCT in CR2 using BuCyMel resulted in a respectable OS. Based on this data the prospective, controlled and centrally monitored AML SCT-BFM 2007 trial has started to recruit patients in January 2010 aiming to generate valid outcome data for further strategy decisions.

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.

Mechanical failure begins preferentially near resorption cavities in human vertebral cancellous bone under compression.

The amount of bone turnover in the body has been implicated as a factor that can influence fracture risk and bone strength. Here we test the idea that remodeling cavities promote local tissue failure by determining if microscopic tissue damage (microdamage) caused by controlled loading in vitro is more likely to form near resorption cavities. Specimens of human vertebral cancellous bone (L4, 7 male and 2 female, age 70±10, mean±SD) were loaded in compression to the yield point, stained for microscopic tissue damage and submitted to three-dimensional fluorescent imaging using serial milling (image voxel size 0.7×0.7×5.0 µm). We found the resulting damage volume per bone volume (DV/BV) was correlated with percent eroded surface (p<0.01, r(2)=0.65), demonstrating that whole specimen measures of resorption cavities and microdamage are related. Locations of microdamage were more than two times as likely to have a neighboring resorption cavity than randomly selected sites without microdamage (relative risk 2.39, 95% confidence interval of relative risk: 2.09-2.73), indicating a spatial association between resorption cavities and microdamage at the local level. Individual microdamage sites were 48,700 (40,100; 62,700) µm(3) in size (median, 25th and 75th percentiles). That microdamage was associated with resorption cavities when measured at the whole specimen level as well as at the local level provides strong evidence that resorption cavities play a role in mechanical failure processes of cancellous bone and therefore have the potential to influence resistance to clinical fracture.

Comparison of the migration of melamine from melamine-formaldehyde plastics ('melaware') into various food simulants and foods themselves.

A variety of melaware articles were tested for the migration of melamine into the food simulant 3% w/v acetic acid as a benchmark, and into other food simulants, beverages and foods for comparison. The results indicate that the acidity of the food simulant plays a role in promoting migration, but not by as much as might have been anticipated, since 3% acetic acid gave migration values about double those obtained using water under the same time and temperature test conditions. In contrast, migration into the fatty food simulant olive oil was not detectable and at least 20-fold lower than with the aqueous food simulants. This was expected given the solubility properties of melamine and the characteristics of the melaware plastic. Migration levels into hot acidic beverages (apple juice, tomato juice, red-fruit tea and black coffee) were rather similar to the acetic acid simulant when the same time and temperature test conditions are used, e.g. 2 h at 70°C. However, migration levels into foods that were placed hot into melaware articles and then allowed to cool on standing were much lower (6-14 times lower) than if pre-heated food was placed into the articles and then maintained (artificially) at that high temperature in the same way that a controlled time-temperature test using simulants would be conducted. This very strong influence of time and especially temperature was manifest in the effects seen of microwave heating of food or beverage in the melaware articles. Here, despite the short duration of hot contact, migration levels were similar to simulants used for longer periods, e.g. 70°C for 2 h. This is rationalized in terms of the peak temperature achieved on microwave heating, which may exceed 70°C, counterbalancing the shorter time period held hot. There was also evidence that when using melaware utensils in boiling liquids, as for stovetop use of spatulas, the boiling action of circulating food/simulant can have an additional effect in promoting surface erosion, increasing the plastic decomposition and so elevating the melamine release.

Delay in B-lymphocyte recovery and function following rituximab for EBV-associated lymphoproliferative disease early post-allogeneic hematopoietic SCT.

Treatment with rituximab is highly effective for EBV-associated post transplant lymphoproliferative disease. However, little is known about its immunological sequelae in pediatric allogeneic hematopoietic SCT (HSCT). Time to normal CD19+ B-lymphocyte values in blood and intravenous immunoglobulin (IVIG) substitution needed to maintain an IgG>400 mg per 100 ml in six consecutive pediatric allogeneic HSCT patients treated with rituximab for symptomatic EBV reactivation were compared with a matched cohort of non-rituximab-treated patients. Follow-up of the six patients ranged from 149 to 1546 days; all but one survived. The mean (+/-s.d.) time to recovery of CD19+ B-lymphocytes was 353+/-142 days as compared with 139+/-42 in the controls (P<0.01). Similarly, substitution of IVIG as a measure of functional B-cell recovery was extended from a mean of 122+/-45 to a mean of 647+/-320 days, and the cumulative dose of IVIG increased from a mean of 1.86+/-0.51 to 4.4+/-0.97 g/kg, respectively (P<0.05). One patient had functional B-lymphocyte deficiency for >3 years and ultimately required two stem cell boosts. Rituximab is a live-saving treatment for pediatric HSCT patients but may lead to prolonged and even persistent B-cell deficiency.

Migration of bisphenol A into water from polycarbonate baby bottles during microwave heating.

A comprehensive migration database was established for bisphenol A from polycarbonate baby bottles into water during exposure to microwave heating. Eighteen different brands of polycarbonate baby bottles sold in Europe were collected. Initial residual content of bisphenol A and migration after microwave heating were determined. Residual content of bisphenol A in the polycarbonate baby bottles ranged from 1.4 to 35.3 mg kg(-1). Migration of bisphenol A was determined by placing a polycarbonate bottle filled with water in a microwave oven and heating to 100 degrees C; the level of bisphenol A in the water was analysed by GC-MS. The procedure of microwave heating and analysis was repeated twice for the same bottle and, thus, three migration extracts were prepared for each test specimen. Migration of bisphenol A into water ranged from <0.1 to 0.7 microg l(-1). There was no correlation between the amount of residual content of bisphenol A in the bottles and the migration of bisphenol A into water. Furthermore, there was no correlation between the amounts of bisphenol A in consecutive migration extracts. Data show that during three microwave-heating cycles of a baby bottle made from polycarbonate, microwave radiation had no effect on the migration of bisphenol A into water from polycarbonate. All levels found were well below the specific migration limit of 0.6 mg kg(-1) specified for bisphenol A in Commission Directive 2004/19/EC.