Correction: Population pharmacokinetics of fludarabine in patients with aplastic anemia and Fanconi anemia undergoing allogeneic hematopoietic stem cell transplantation

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Examining the pathophysiology of short bowel syndrome and glucagon-like peptide 2 analogue suitability in chronic intestinal failure: experience from a national intestinal failure unit

INTRODUCTION

Short bowel syndrome (SBS) is a leading cause of intestinal failure (IF). Home parenteral nutrition (HPN) remains the standard treatment, with small intestinal transplantation reserved for cases with severe complications to HPN. There have recently been significant developments in growth factor therapy. We aimed to develop a greater contemporary understanding of our SBS-IF subset.

METHOD

We performed a retrospective observational study of a prospectively maintained HPN audit database in October 2017. Intestinal anatomical details and parenteral requirements were recorded. Each case was assessed for eligibility for growth factor therapy using recently published trials.

RESULTS

Of 273 patients receiving HPN, 152 (55.7%) had type three IF as a result of SBS (SBS-IF), with a mean duration of HPN of 61 months (range 4-416). Mean length of small intestine was 98 cm. Furthermore, 114 (41.8%) patients had an end jejunostomy (SBS-J), 18 (6.6%) had an end ileostomy, and 7.3% of patients had all or part of the colon-in-continuity. Crohn's disease was the most common underlying pathology. Univariate analysis for the whole HPN cohort demonstrated SBS-IF and a longer duration of HPN to be associated with higher PN energy requirements, p ≤ 0.0001. Of all, 73 (48%) patients with SBS-IF were deemed suitable for GLP-2 analogue therapy, with co-morbidity being the most frequent cause of non-suitability (29.1%).

CONCLUSION

We describe a large U.K. HPN cohort using ESPEN pathophysiological and clinical severity classification. The majority of patients with SBS-IF had a jejunostomy and relatively few had colon-in-continuity. Co-morbidity is the most common contra-indication to GLP-2 analogue therapy.

CLINICAL RELEVANCY

GLP-2 analogues are emerging as an important treatment for patients with short bowel syndrome. Our study explores patient suitability in a large HPN cohort managed in a national IF centre. Furthermore, the international variation in the pathophysiology of SBS-IF varies significantly, which can have a bearing on PN requirements and outcomes when GLP-2 analogues are used.

Biogenic Amine Production by and Phylogenetic Analysis of 23 Photobacterium Species

Photobacterium species are members of the bacterial communities typically associated with scombrotoxin-forming fish. Reclassification and discovery of new Photobacterium species has caused confusion as to which species are capable of biogenic amine production. We analyzed histamine, cadaverine, and putrescine production by 104 Photobacterium strains representing 23 species. The presence of the genes for histidine decarboxylase ( hdc), lysine decarboxylase ( ldc), and ornithine decarboxylase ( odc) was determined by real-time or conventional PCR and whole genome sequencing. Significant histamine production (>200 ppm) was detected in five Photobacterium species: P. angustum, P. aquimaris, P. kishitanii, P. damselae, and P. phosphoreum. The hdc gene was detected in all of these histamine-producing species except P. phosphoreum. Cadaverine was produced by eight Photobacterium species: P. angustum, P. aquimaris, P. damselae, P. iliopiscarium, P. kishitanii, P. leiognathi, P. mandapamensis, and P. phosphoreum. Putrescine was produced by six Photobacterium species: P. angustum, P. aquimaris, P. kishitanii, P. leiognathi, P. mandapamensis, and Photobacterium sp. Cadaverine production correlated closely with the presence of the ldc gene, but putrescine production did not correlate closely with the presence of the odc gene. Characterization of the biogenic amine production by Photobacterium species will allow identification of these marine bacteria and help ensure that current guidelines account for mitigation of these bacteria.

Type-3 von Willebrand disease in India-Clinical spectrum and molecular profile

INTRODUCTION

Type 3 von Willebrand disease (VWD) is the rare and most severe form of VWD which results from a near-complete deficiency of the von Willebrand factor (VWF). This study evaluates in detail the molecular pathology of type-3 VWD in India. One hundred and two patients from 90 families were evaluated.

PATIENTS AND METHODS

Phenotypic data, including bleeding scores (BS), were documented using structured questionnaires. Diagnosis of type 3 VWD was based on undetectable VWF antigen levels in the plasma. Genomic DNA from these patients was screened for mutations in VWF gene. Structural modeling and expression studies were carried out for missense mutations.

RESULTS

Out of 102 patients, mutations could be identified in 91% (n = 93). Fifty-five different gene variants were identified. Thirty-four (61.8%) were novel. Mutations could be identified in both the alleles in 90 patients, while no causative mutation could be identified in 9 patients; twenty-four (23.5%) patients had mutations clustered in the propeptide region of VWF. Interestingly, five mutations accounted for the defects in 37/93 (39.8%) patients. Structural analysis and in vitro studies on missense mutations imply impaired processes associated with secretion of VWF.

CONCLUSION

This study is one of the largest series to define the molecular basis of type-3 VWD.

Toronto Clinical Neuropathy Score is valid for a wide spectrum of polyneuropathies

BACKGROUND AND PURPOSE

The Toronto Clinical Neuropathy Score (TCNS) is a valid and reliable scale for the diagnosis and staging of diabetic sensorimotor polyneuropathy. In this study, we aimed to explore the performance of the TCNS in non-diabetic polyneuropathies.

METHODS

We performed a prospective study from November 2016 to May 2017 of patients with non-diabetic polyneuropathy. Patients had clinical, electrophysiological and functional assessments of their polyneuropathy, and the findings were correlated with the TCNS.

RESULTS

The TCNS correlated with all clinical, electrophysiological and disability measures of polyneuropathy, mostly at a moderate level (e.g. r = -0.58 for sural nerve action potential amplitude). Higher TCNS severity grades were associated with worse polyneuropathy on all measures in the lower limbs, and with worse electrophysiological parameters and vibration perception thresholds in the upper limbs. The scale also showed excellent reliability and accuracy (kappa, 0.92-0.93 for inter- and intra-observer reliability; area under the receiver operating characteristics curve, 0.93).

CONCLUSION

The TCNS is a valid and reliable scale for a wide spectrum of polyneuropathies, and might be useful in clinical practise and research for the diagnosis and staging of polyneuropathy.

Managing Successful Pregnancies in Patients with Chronic Intestinal Failure on Home Parenteral Nutrition: Experience from a UK National Intestinal Failure Unit

BACKGROUND AND AIM

There are minimal reports of pregnancy in the chronic intestinal failure (CIF)/ home parenteral nutrition (HPN) population, with some concern relating to the risk associated with such pregnancies. The aim of this retrospective observational study was to evaluate pregnancy experience and outcomes in patients with CIF requiring HPN in a national UK CIF referral centre.

METHOD

All known pregnancies in patients treated with HPN for CIF between 1982 and 2016 were identified retrospectively from a prospectively maintained database. Maternal and foetal outcomes were collated, along with PN requirements before and during pregnancy.

RESULTS

There were 5 pregnancies in 5 mothers in our cohort consisting of over 700 patients, males and females. The median age at conception was 28 years (range 24-33 years). The median duration on HPN prior to pregnancy was 26 months (range 4-85 months). One patient had Crohn's disease, another had pan-enteric dysmotility and the other three patients had ischaemic complications leading to short bowel syndrome (SBS). All mothers were intensively monitored in an obstetric clinic and a dedicated CIF multi-disciplinary clinic throughout pregnancy. There were 2/5 preterm deliveries. One of the preterm deliveries was associated with spontaneous labour and the other had a planned induction as a result of maternal clinical need. Neonatal complications were seen in both prenates. There were no recorded maternal catheter related line infections during the 5 pregnancies.

CONCLUSION

Successful pregnancy whilst receiving HPN is feasible but requires close, intensive monitoring and dedicated optimisation of PN in order to minimise maternal and foetal complications. All women of child-bearing age on HPN should be counselled about pregnancy.

Effect of Etanercept Concentration on Human Islet Integrity

BACKGROUND

Etanercept is widely used as an antiinflammatory drug to improve engraftment after intraportal islet transplantation. In contrast to other immunosuppressive agents, very little is known about detrimental effects of etanercept on islets. The aim of this pilot study was to define the toxic range of etanercept.

METHODS

Human islets isolated from 8 donors were cultured for 4-5 days at 37°C in culture medium supplemented with etanercept at concentrations from 2.5 to 40 μg/mL, corresponding to potential in vivo levels within the portal vein. After culture, islet equivalent (IEQ) yield, fragmentation index (islet number/IEQ), purity, viability, and stimulated insulin release (2 vs 20 mmol/L) were assessed and normalized to islets before culture.

RESULTS

Yield (73 ± 8%) and viability (91 ± 4%) were highest with 5 μg/mL etanercept. Islet loss was evident when etanercept was ≥10 μg/mL (55 ± 7%; P < .05 vs control). Fragmentation (154 ± 34%; P < .05) was markedly increased and viability (81 ± 4%, P < .05) markedly decreased with etanercept >10 μg/mL. The accumulation of cell debris at concentrations ≥20 μg/mL resulted in a significant reduction of islet purity (84 ± 3%; P < .05). Etanercept did not interfere with stimulated insulin secretion at concentrations ≤10 μg/mL. The maximum stimulation index was noted at 2.5 μg/mL (1.8 ± 0.1).

CONCLUSIONS

Etanercept is tolerated by isolated human islets at concentrations <10 μg/mL. Our data suggest that the tight range between benefit and toxicity should be considered for dosage and administration of etanercept.

Outcomes following autologous hematopoietic stem cell transplant for patients with relapsed Wilms' tumor: a CIBMTR retrospective analysis

Despite the marked improvement in the overall survival (OS) for patients diagnosed with Wilms' tumor (WT), the outcomes for those who experience relapse have remained disappointing. We describe the outcomes of 253 patients with relapsed WT who received high-dose chemotherapy (HDT) followed by autologous hematopoietic stem cell transplant (HCT) between 1990 and 2013, and were reported to the Center for International Blood and Marrow Transplantation Research. The 5-year estimates for event-free survival (EFS) and OS were 36% (95% confidence interval (CI); 29-43%) and 45% (95 CI; 38-51%), respectively. Relapse of primary disease was the cause of death in 81% of the population. EFS, OS, relapse and transplant-related mortality showed no significant differences when broken down by disease status at transplant, time from diagnosis to transplant, year of transplant or conditioning regimen. Our data suggest that HDT followed by autologous HCT for relapsed WT is well tolerated and outcomes are similar to those reported in the literature. As attempts to conduct a randomized trial comparing maintenance chemotherapy with consolidation versus HDT followed by stem cell transplant have failed, one should balance the potential benefits with the yet unknown long-term risks. As disease recurrence continues to be the most common cause of death, future research should focus on the development of consolidation therapies for those patients achieving complete response to therapy.

Decoding material-specific memory reprocessing during sleep in humans

Neuronal learning activity is reactivated during sleep but the dynamics of this reactivation in humans are still poorly understood. Here we use multivariate pattern classification to decode electrical brain activity during sleep and determine what type of images participants had viewed in a preceding learning session. We find significant patterns of learning-related processing during rapid eye movement (REM) and non-REM (NREM) sleep, which are generalizable across subjects. This processing occurs in a cyclic fashion during time windows congruous to critical periods of synaptic plasticity. Its spatial distribution over the scalp and relevant frequencies differ between NREM and REM sleep. Moreover, only the strength of reprocessing in slow-wave sleep influenced later memory performance, speaking for at least two distinct underlying mechanisms between these states. We thus show that memory reprocessing occurs in both NREM and REM sleep in humans and that it pertains to different aspects of the consolidation process.