Primary biliary cholangitis presenting with Fanconi syndrome: an important phenotype

A woman in her 50s was referred to nephrology clinic due to progressive chronic kidney disease. She exhibited features of proximal renal tubulopathy, namely Fanconi syndrome, including normoglycaemic glycosuria, normal anion gap metabolic acidosis, and intermittent hypouricaemia and hypophosphataemia. Kidney biopsy showed tubulointerstitial inflammation and focal chronic damage. In addition, antimitochondrial antibodies were present and she had abnormal liver blood tests. A unifying diagnosis of primary biliary cholangitis with an associated renal tubulopathy and interstitial nephritis was made. She was commenced on sodium bicarbonate, ursodeoxycholic acid and oral prednisolone, leading to an improvement in liver biochemistry. Kidney function was stabilised, but a sustained improvement was not seen. This case acts as a reminder of the rare association of tubulointerstitial nephritis and Fanconi syndrome with primary biliary cholangitis, which may be an under-recognised phenotype.

Research priorities for autosomal dominant polycystic kidney disease: a UK priority setting partnership

OBJECTIVES

Autosomal dominant polycystic kidney disease (ADPKD) is the most common inherited kidney condition, accounting for 7%-10% of patients with kidney failure. Fundamental basic science and clinical research on ADPKD is underway worldwide but no one has yet considered which areas should be prioritised to maximise returns from limited future funding. The Polycystic Kidney Disease Charity began a priority setting partnership with the James Lind Alliance (JLA) in the UK in 2019-2020 to identify areas of uncertainty in the ADPKD care pathway and allow patients, carers and healthcare professionals to rank the 10 most important questions for research.

DESIGN

The scope covered ADPKD diagnosis and management, identifying new treatments to prevent/slow disease progression and practical, integrated patient support (https://pkdcharity.org.uk/research/for-researchers/adpkd-research-priorities). We used adapted JLA methodology. Initially, an independent information specialist collated uncertainties in ADPKD care from recent consensus conference proceedings and additional literature. These were refined into indicative questions with Steering Group oversight. Finally, the 10 most important questions were established via a survey and online consensus workshop.

SETTING

UK.

PARTICIPANTS

747 survey respondents (76% patients, 13% carers, 11% healthcare professionals); 23 workshop attendees.

RESULTS

117 uncertainties in ADPKD care were identified and refined into 35 indicative questions. A shortlist of 17 questions was established through the survey. Workshop participants reached agreement on the top 10 ranking. The top three questions prioritised by patients, carers and healthcare professionals centred around slowing disease progression, identifying persons for early treatment and organising care to improve outcomes.

CONCLUSIONS

Our shortlist reflects the varied physical, psychological and practical challenges of living with and treating ADPKD, and perceived gaps in knowledge that impair optimal care. We propose that future ADPKD research funding takes these priorities into account to focus on the most important areas and to maximise improvements in ADPKD outcomes.

FC044: Heterozygous Variants in Kinase Domain of NEK8 cause an Autosomal-Dominant Ciliopathy

BACKGROUND AND AIMS

NEK8/NPHP9 encodes a protein that localizes to the primary cilium. Biallelic NEK8 variants are known to cause multiorgan developmental defects, including kidney cystic dysplasia and extensive extra-renal defects, with heterozygous carrier parents being asymptomatic [1]. This autosomal recessive inheritance is the most common inheritance mode for ciliopathies. Complementary to this, we now propose a dominant negative effect for specific heterozygous NEK8 missense variants in the kinase domain resulting in an autosomal-dominant ciliopathy.

METHOD

We performed genetic testing in patients from several medical centers. To explore the consequences of the identified NEK8 variants, we are performing cilia staining assays in patients' skin fibroblast and kidney cells, as well as in mIMCD3 cells overexpressing the identified variants. Furthermore, we are examining the impact of the NEK8 variants on replication stress response.

RESULTS

We identified three distinct heterozygous NEK8 variants in 12 families (Table 1), all leading to missense alterations in the kinase domain. Interestingly the p.Arg45Trp variant is a recurrent variant we detected in 10 unrelated families. All patients have a kidney phenotype that varies from mild focal segmental glomerulosclerosis to prenatal presentation with polycystic kidneys. Most patients have kidney failure needing kidney replacement therapy at varying ages of onset. In all patients, we thoroughly checked whether a second variant could be found. Furthermore, the large symptomatic family and de novo occurrences favor a dominant inheritance mode. Our preliminary results from functional studies show abnormal primary cilia formation in serum-starved cells as well as increased replication stress.

CONCLUSION

We present the first evidence for a pathogenic effect of heterozygous NEK8 variants. Remarkably our patients present with a kidney limited phenotype as compared to the multiorgan defects found in patients with biallelic variants. This reveals a new mode of inheritance for NEK8 variants and expands genotype-phenotype correlations for this gene.

MO042: Biallelic variants in TTC21B as a rare cause of early-onset arterial hypertension and tubuloglomerular kidney disease

BACKGROUND

Massively parallel sequencing (MPS) has propelled precision medicine into the next generation. With genetic data more accessible than ever, the focus has now shifted from obtaining data to converting the acquired data into applicable clinical information. A major obstacle to such task arises when there is limited knowledge of the phenotypic spectrum of a genetic entity, limiting the application of virtual panels and prioritization of genetic candidates.

METHOD

We performed in-depth clinical, imaging and histological phenotyping of an index family presenting with extremely early-onset hypertension and kidney disease. We then performed genetic investigations on the proband, starting with a limited MPS panel testing for monogenic causes of arterial hypertension. This was followed by Genomics England 100 000 Genomes Project whole genome sequencing (WGS) and application of a 26-gene virtual panel for ‘extreme early-onset hypertension’. Subsequently, we reviewed the 100 000 Genomes Project rare disease data for patients recruited with extreme early-onset hypertension. We also conducted a literature review to identify any existing studies correlating TTC21B mutations and systemic hypertension.

RESULTS

The proband (Table 1, II.1) was a 3.5-year-old girl presenting with severe hypertension, proteinuria, kidney failure, left ventricular hypertrophy, liver function test abnormalities and growth retardation. A kidney ultrasound scan showed bilateral small kidneys with loss of corticomedullary differentiation. Kidney biopsy showed sclerosed glomeruli, severe tubular atrophy with tubulointerstitial fibrosis in addition to arteriolar changes in secondary to systemic hypertension. Her sibling (Table 1, II.2) equally presented with early-onset hypertension and progressive kidney disease. MPS panel testing and WGS virtual panel for early-onset hypertension both failed to identify pathogenic variants. Manual curation of WGS data then revealed a heterozygous nonsense variant p.(Gln834Ter) in conjunction with a heterozygous missense variant p.(Pro209Leu) in TTC21B, both of which were predicted to be pathogenic according to ACMG criteria. This was missed as the gene did not form part of the hypertension virtual panel. TTC21B mutations have been previously associated with typical ciliopathies such as nephronophthisis (NPHP) and Jeune asphyxiating thoracic dystrophy, but only recently implicated in glomerular kidney disease such as focal segmental glomerulosclerosis (FSGS). Literature review suggests roles for TTC21B (IFT139) both in the primary cilium and in podocyte cytoskeleton, revealing a striking association between TTC21B missense variants and early-onset hypertension. Searching the 100 000 Genomes Project revealed one additional case of arterial hypertension and mild proteinuria explained by biallelic mutations in TTC21B.

CONCLUSION

In conclusion, biallelic mutations in TTC21B produce a spectrum of phenotypes from typical ciliopathies to kidney-limited phenotypes. The latter are mostly encountered in patients carrying two missense, often hypomorphic, variants, and are characterized by lesions of the glomerular as well as the tubulointerstitial compartment, resembling both FSGS and NPHP. Increased clinical recognition of this mixed glomerular and tubulointerstitial disease with often mild or absent features of a typical ciliopathy as well as inclusion of TTC21B on gene panels for early-onset arterial hypertension may shorten the diagnostic odyssey for patients affected by this rare tubuloglomerular kidney disease.

MO004PRIMARY BILIARY CHOLANGITIS PRESENTING WITH RENAL FANCONI SYNDROME: A FORGOTTEN PHENOTYPE

Background and Aims

Primary biliary cholangitits (PBC) is an autoimmune liver disease, leading to liver fibrosis and cirrhosis. It is a rare disease affecting 1 in 3-4000 people and is more common in females. Symptoms may go unnoticed and include itch and fatigue. Most patients have anti-mitochondrial antibodies (AMA) as well as raised gamma-glutamyl transferase (GGT) and alkaline phosphatase (ALP) levels. First line treatment for PBC is ursodeoxycholic acid and is usually continued lifelong. It improves liver biochemistry, histological progression of liver disease and liver transplant-free survival. Renal complications of PBC include distal renal tubular acidosis (RTA), tubule-interstitial nephritis (TIN) and renal Fanconi syndrome.

Method

We reviewed a case of PBC presenting with renal Fanconi syndrome.

Results

A 48-year-old female was referred to the renal clinic due to progressive decline in renal function since she was diagnosed with type 2 diabetes in 2007. She was also known to have AMA (>1:640) and previously had transient transaminitis. She was clinically well with no major symptoms but reported that she had had a few episodes of urinary tract infection in the previous year. Her diabetes was managed with lifestyle modifications in the past until a few months ago when Metformin was introduced. However, her HbA1c level had never been greater than 55 mmol/mol. Urine dipstick in the clinic showed pH of 6, blood+, glucose+++, protein+++ and ketone trace. The severity of glycosuria was inconsistent with her glycaemic control. There was a disparity between her urine albumin/creatinine ration (ACR) of 18.8g/mol and protein/creatinine ratio (PCR) of 124mg/mmol. Myeloma screen was negative and further urine analysis showed generalised aminoaciduria. She also had hypouricaemia, intermittent hypophosphataemia and non-anion gap metabolic acidosis. These results are in keeping with renal Fanconi syndrome. Her eGFR was 48 ml/min/1.72m2 in 2007 and was 21 ml/min/1.72m at the time of review. A renal biopsy was undertaken, and the appearances were suggestive of mild tubulo-interstitial nephritis; the glomeruli were unremarkable; there was mild chronic tubulo-interstitial damage. She was started on oral steroid, sodium bicarbonate and ursodeoxycholic acid. The course of steroid had a slight transitory beneficial effect on the renal function.

Conclusion

Distal RTA is the usual renal feature of PBC, occurring in 1/3 of cases with advanced disease. In contrast, proximal RTA associating with renal Fanconi syndrome occurs rarely. Like our case, the cases that have been previously reported show that Fanconi syndrome occurred during the early phase of PBC in the absence of marked hepatic abnormalities, and were associated with CKD.

Fanconi syndrome and TIN are renal features of mitochondrial cytopathies and are perhaps a forgotten association of PBC. Antimitochondrial antibodies may play a role in the onset of tubulo-interstitial nephritis and Fanconi syndrome.

MO040REAL-WORLD USE OF TOLVAPTAN AND ITS IMPACT ON EGFR IN A NORTH EAST UK COHORT

Background and Aims

Autosomal dominant polycystic kidney disease (ADPKD) is a cause of progressive chronic kidney failure (CKD) and end stage kidney disease (ESKD). Tolvaptan has been shown within clinical trials to slow down decline of kidney function in patients with ADPKD at risk of rapid progression. We performed a retrospective review of a cohort of ADPKD patients who had been established on tolvaptan therapy to determine its efficacy in a real- world clinic setting.

Method

Subjects who had a clinical diagnosis of ADPKD and who had been established on tolvaptan for a period of >18 months were reviewed retrospectively in terms of their eGFR. Subjects were between the ages of 18-65 years old and both males and females were included in this study. Other inclusion criteria involved a pre-treatment slope of <-2.5 ml/min/1.73m2 based on readings for a 3 year period, a pre-treatment eGFR of 30-90 ml/min/1.73m2 and ability to tolerate tolvaptan treatment and be maintained on treatment for at least12 months. We calculated based on eGFR slopes, predicted time to reach CKD stage 5 with and without tolvaptan therapy. Given this was a retrospective review, eGFR were estimated during clinic visits whilst on tolvaptan treatment, rather than after a drug washout period.

Results

The cohort of patients included 20 from Newcastle upon Tyne Hospitals and 2 from Sunderland Royal Infirmary. The mean rate of eGFR decline prior to treatment was -5.92 ml/min/1.73m2 per year for the cohort. Following tolvaptan treatment, the average decline in eGFR was reduced to -2.57 ml/min/1.73m2 per year. Therefore, tolvaptan lessened average eGFR decline within this cohort by 3.35 ml/min/1.73m2 per year, gaining 7 years and 9 months delay until CKD stage 5. The majority of patients (n=19) received full dose tolvaptan (90mg/30mg). At an individual level, 3 patients failed to respond at all to tolvaptan, with no improvement in decline of GFR and 2 others had a very mild improvement only (change in eGFR slope of <0.5 ml/min/1.73m2 per year). 6 patients had a dramatic improvement in eGFR slope (>5 ml/min/1.73m2 per year).

Conclusion

The real life use of tolvaptan seemed to give a dramatic improvement in eGFR slopes, much more than the previously reported clinical studies have shown. This may be in part due to patient selection and only including patients who tolerated therapy, a “tolvaptan clinic” effect where great personal care is given to these patients and to excellent compliance with medication. Reasons for both non-response and exaggerated response need to be evaluated carefully to determine how individualisation of tolvaptan therapy can be best used.

FC 014INFLUENCE OF GENETIC VARIATION IN SLC7A13/AGT1 IN HUMAN CYSTINURIA

Background and Aims

Cystinuria (CU) is an inherited renal disorder based on urinary wasting of dibasic amino acids, urinary precipitation, and consecutive cystine stone formation. It is caused by pathogenic variants in two distinct disease genes, SLC3A1 and SLC7A9, both of which encode subunits of a heterodimeric tubular amino acid transporter, rBAT/SLC3A1 and BAT1/SLC7A9, located at the apical membrane of proximal renal tubules. CU is marked by incomplete penetrance and substantial disease variability. Recently, a novel cystine transporter, consisting of the light chain AGT1/SLC7A13 and its heterodimeric partner rBAT/SLC3A1 has been identified in the S3 segment of murine proximal tubules. In this study, we aim at evaluating the role of AGT1 in cystinuric patients with or without mutations in either SLC3A1 or SLC7A9, analyzing the role of AGT1/SLC7A13 as novel disease gene or genetic modifier in CU.

Method

A multicenter European CU-cohort comprising 132 individuals was screened for pathogenic variants in SLC3A1, SLC7A9, and SLC7A13 using high-throughput multiplex PCR-based amplification and next-generation sequencing (MiSeq Illumina) followed by multiplex ligation-dependent probe amplification (MLPA) of SLC3A1 and SLC7A9. For functional in vitro studies, epitope-tagged human and murine rBAT and AGT1 proteins were transiently expressed in different cell systems. Heterodimer complex formation was analyzed by co-immunoprecipitation and western blot studies and membrane trafficking was evaluated by immunofluorescence microscopy.

Results

Genectic analysis of our CU-cohort did not reveal indiviuals with SLC7A13 variation only, however we found three patients harbouring heterozygous missense variants in addition to pathogenic or VUS variants in SLC3A1 or SLC7A9. To evaluate their influence on the generation of functional cystine transporters in vitro, different cell models were transiently transfected with plasmids expressing wildtype or mutant proteins. In line with previous reports, co-expression of AGT1 and rBAT wildtype allowed efficient complex formation as AGT1-induced maturation of rBAT was detected by increased mature N-glycosylation, co-immunoprecipitation and membrane insertion. Whereas AGT1 patient variants p.Met452Thr (SLC7A13 c.1355T>C) and p.Ile174Phe (SLC7A13 c.520A>T) behaved comparable to wildtype AGT1, variants p.Asn45Lys (SLC7A13 c.135C>G) and p.Leu270Phe (SLC7A13 c.808C>T) led to clearly reduced glycosylation patterns and trafficking deficits of rBAT wildtype protein. Next, the mutual influence of pathogenic variation in both, AGT1 and rBAT, will unravel the consequences of patient-specific molecular interactions on the functional expression of cystine transporter complexes.

Conclusion

Here, we report three CU-patients with variants in SLC7A13 combined with either SLC3A1 or SLC7A9. For two of these variants, in vitro functional analysis revealed pathogenic molecular mechanisms disturbing complex formation, maturation and trafficking of rBAT. We hypothesize that specific pathogenic variants in SLC7A13 interfere with efficient membrane localization of heterodimeric cystine transporters, which results in modulation of cystine transport in the S3 segment of proximal tubules in CU-patients.

Neurological rehabilitation following heat illness in the UK Armed Forces

Heat illness remains a significant threat to health in the UK Armed Forces despite recent improvements in the prevention of cases. A small number of heat illness survivors develop long-term neurological sequelae. Here we briefly review the background literature and present our experience of treating UK Armed Forces patients with neurological consequences of heat illness. In our cohort of patients, we observed significant improvements in subjective symptoms and objective assessments following a period of neurological rehabilitation at the Defence Medical Rehabilitation Centre. We conclude with recommendations for further research and for the incorporation of screening for neurological disability following heat illness into service policy.

SO094HUMAN URINE-DERIVED RENAL EPITHELIAL CELLS PROVIDE INSIGHTS INTO THE PATHOGENICITY OF PKHD1 VARIANTS

Background and Aims

A 26 year old woman was referred for the investigation of polycystic kidney disease. There was no family history of renal disease and no obvious extra-renal manifestations. A GEMINI ciliopathy gene panel was performed which identified two heterozygous sequence changes (segregating from each parent) in PKHD1: a missense variant c.7964A>C, p.(His2655Pro), listed as a pathogenic variant in association with ARPKD on the Human Gene Mutation Database and a synonymous variant c.6900C>T, p.(Asn2300Asn). The pathogenicity of the synonymous PKHD1 variant is not clear. It is reported as a variant of unknown significance on ClinVar and has a low population frequency in the gnomAD cohort. The altered nucleotide is weakly conserved, but the same heterozygous change has been previously reported in an individual prenatally presenting with multicystic kidneys together with a missense variant on the other allele. We aim to confirm the pathogenicity of this variant in our patient, analysing its effects on the splicing of PKHD1 mRNA.

Method

PKHD1 is expressed at low levels in the leukocytes, therefore it can be difficult to analyse the splicing of PKHD1, using routine methods that involve RNA extraction from the blood. Urine-derived renal epithelial cells were isolated and cultured from two wild type individuals and from the patient and total RNA was extracted from these cells. RT-PCR and RT-qPCR were carried out to analyse the effects of the synonymous variant on the splicing of the PKHD1 gene in renal epithelial cells.

Results

RT-PCR revealed that PKHD1 is alternatively spliced both in the controls and in the patient and Sanger sequencing following T-cloning of PCR products revealed that both controls and the patient express an in-frame transcript and a shorter transcript with a 47 nucleotide loss in the exon 43 of PKHD1, that leads to a frame-shift and to the formation of a premature stop codon. We hypothesized that, although both mRNA isoforms are expressed in controls as well as in the patient URECs, the variant p.(Asn2300Asn) may shift the expression ratio between the two transcript isoforms in favour of the shorter, out-of-frame transcript. We designed and tested two sets of transcript-specific primers and performed a SYBR-green based RT-qPCR on controls and patient URECs cDNA. RT-qPCR, revealed that PKHD1 is expressed at lower levels in patient URECs, compared to controls. Specifically, the in-frame PKHD1 isoform is expressed at lower levels in patient URECs, compared to controls, whereas the levels of the shorter transcript leading to a frame-shift are higher in patient cells.

Conclusion

Using urine-derived renal epithelial cells as a source of kidney-specific RNA, we confirmed the pathogenicity of the PKHD1 synonymous variant p.(Asn2300Asn), which leads to an increased expression of an out-of-frame PKHD1 transcript, predicted to result in a truncated protein and expressed at lower levels also in control cells. The significance of this isoform in control renal epithelial cells is unclear.

Clinical practice guideline monitoring children and young people with, or at risk of developing autosomal dominant polycystic kidney disease (ADPKD)

Autosomal Dominant Polycystic Kidney Disease (ADPKD) is thought to affect about 1 in 1000 people in the UK. ADPKD causes a progressive decline in kidney function, with kidney failure tending to occur in middle age. Children and young people with ADPKD may not have any symptoms. However they may have high blood pressure, which may accelerate progression to later stages of chronic kidney disease.There is uncertainty and variation in how health professionals manage children and young people with confirmed or a family history of ADPKD, because of a lack of evidence. For example, health professionals may be unsure about when to test children's blood pressure and how often to monitor it in the hospital clinic or at the GP. They may have different approaches in recommending scanning or genetic testing for ADPKD in childhood, with some recommending waiting until the young person is mature enough to make this decision his or herself.This guideline is intended to help families affected by ADPKD by making sure that: health professionals with specialist knowledge in ADPKD offer you information on inheritance and potential benefits and harms of testing for ADPKD. the decision to test and the method of testing for ADPKD in children and young people is shared between you or your family and the health professionals blood pressure assessment is undertaken regularly in children and young people at risk of developing ADPKD.

A preliminary survey of practice patterns across several European kidney stone centers and a call for action in developing shared practice

Currently an evidence-based approach to nephrolithiasis is hampered by a lack of randomized controlled trials. Thus, there is a need for common platforms for data sharing and recruitment of patients to interventional studies. A first step in achieving this objective would be to share practice methods and protocols for subsequent standardization in what is still a heterogeneous clinical field. Here, we present the results of a pilot survey performed across 24 European clinical kidney stone centers. The survey was distributed by a voluntary online questionnaire circulated between June 2017 and January 2018. About 46% of centers reported seeing on average 20 or more patients per month. Only 21% adopted any formal referral criteria. Centers were relatively heterogeneous in respect of the definition of an incident stone event. The majority (71%) adopted a formal follow-up scheme; of these, 65% included a follow-up visit at 3 and 12 months, and 41% more than 12 months. In 79% of centers some kind of imaging was performed systematically. 75% of all centers performed laboratory analyses on blood samples at baseline and during follow-up. All centers performed laboratory analyses on 24-h urine samples, the majority (96%) at baseline and during follow-up. There was good correspondence across centers for analyses performed on 24-h urine samples, although the methods of 24-h urine collection and analysis were relatively heterogeneous. Our survey among 24 European stone centers highlights areas of homogeneity and heterogeneity that will be investigated further. Our aim is the creation of a European network of stone centers sharing practice patterns and hosting a common database for research and guidance in clinical care.

Optimum dose of vitamin D for disease prevention in older people: BEST-D trial of vitamin D in primary care

This trial compared the effects of daily treatment with vitamin D or placebo for 1 year on blood tests of vitamin D status. The results demonstrated that daily 4000 IU vitamin D3 is required to achieve blood levels associated with lowest disease risks, and this dose should be tested in future trials for fracture prevention.

INTRODUCTION

The aim of this trial was to assess the effects of daily supplementation with vitamin D3 4000 IU (100 μg), 2000 IU (50 μg) or placebo for 1 year on biochemical markers of vitamin D status in preparation for a large trial for prevention of fractures and other outcomes.

METHODS

This is a randomized placebo-controlled trial in 305 community-dwelling people aged 65 years or older in Oxfordshire, UK. Outcomes included biochemical markers of vitamin D status (plasma 25-hydroxy-vitamin D [25[OH]D], parathyroid hormone [PTH], calcium and alkaline phosphatase), cardiovascular risk factors and tests of physical function.

RESULTS

Mean (SD) plasma 25(OH)D levels were 50 (18) nmol/L at baseline and increased to 137 (39), 102 (25) and 53 (16) nmol/L after 12 months in those allocated 4000 IU, 2000 IU or placebo, respectively (with 88%, 70% and 1% of these groups achieving the pre-specified level of >90 nmol/L). Neither dose of vitamin D3 was associated with significant deviation outside the normal range of PTH or albumin-corrected calcium. The additional effect on 25(OH)D levels of 4000 versus 2000 IU was similar in all subgroups except for body mass index, for which the further increase was smaller in overweight and obese participants compared with normal-weight participants. Supplementation with vitamin D had no significant effects on cardiovascular risk factors or on measures of physical function.

CONCLUSIONS

After accounting for average 70% compliance in long-term trials, doses of 4000 IU vitamin D3 daily may be required to achieve plasma 25(OH)D levels associated with lowest disease risk in observational studies.

Murine Cep290 phenotypes are modified by genetic backgrounds and provide an impetus for investigating disease modifier alleles

The study of primary cilia is of broad interest both in terms of disease pathogenesis and the fundamental biological role of these structures. Murine models of ciliopathies provide valuable tools for the study of these diseases. However, it is important to consider the precise phenotype of murine models and how dependant it is upon genetic background. Here we compare and contrast murine models of Cep290, a frequent genetic cause of Joubert syndrome in order to refine our concept of genotype-phenotype correlations.

Characterization of CSF2RA mutation related juvenile pulmonary alveolar proteinosis

Background

Juvenile pulmonary alveolar proteinosis (PAP) due to CSF2RA mutations is a rare disorder with only a few cases described worldwide.

Methods

We identified nine children with severe diffuse interstitial lung disease due to CSF2RA mutations. Clinical course, diagnostic findings and treatment were evaluated and correlated to the genotype. Functional impairment of the intracellular JAK/pStat5 signaling pathway was assessed using flow-cytometry of peripheral mononuclear cells (PBMC) and granulocytes.

Results

We identified six individuals with homozygous missense/nonsense/frameshift mutations and three individuals homozygous for a deletion of the complete CSF2RA gene locus. Overall, four novel mutations (c.1125 + 1G > A, duplication exon 8, deletion exons 2–13, Xp22.3/Yp11.3) were found. Reduced STAT5 phosphorylation in PBMC and granulocytes was seen in all cases examined (n = 6). Pulmonary symptoms varied from respiratory distress to clinically silent. Early disease onset was associated with a more severe clinical phenotype (p = 0.0092). No association was seen between severity of phenotype at presentation and future clinical course or extent of genetic damage. The clinical course was favorable in all subjects undergoing whole lung lavage (WLL) treatment.

Conclusions

Our cohort broadens the spectrum of knowledge about the clinical variability and genotype-phenotype correlations of juvenile PAP, and illustrates the favorable outcome of WLL treatment in severely affected patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s13023-014-0171-z) contains supplementary material, which is available to authorized users.

A role for CBS domain 2 in trafficking of chloride channel CLC-5

CLC-5 is a member of the CLC family of voltage-gated chloride channels. Mutations disrupting CLC-5 lead to Dent's disease, an X-linked renal tubular disorder, characterised by low molecular weight proteinuria, hypercalciuria, nephrocalcinosis, and renal stones. Sequence analysis of CLC-5 reveals a 746 amino acid protein with an intracellular amino-terminus, transmembrane spanning domains, and two CBS domains within its intracellular carboxy-terminus. CBS domains have been implicated in intracellular targetting and trafficking as well as protein-protein interactions. We investigate subcellular localisation of three naturally occurring CLC-5 mutants which all lead to a truncated protein, disrupting the second CBS domain. These mutants are unable to traffic normally to acidic endosomes but are retained in perinuclear compartments, colocalising with the Golgi complex. This is the first identification of the cellular pathogenesis of CBS domain mutations of CLC-5.

Views of nursing staff on the use of physical restraint

A postal questionnaire survey was employed in regional secure and psychiatric intensive care units in England and Wales, in respect of mental health nurses' training in the use of physical restraint. The nurses' views were sought relating to their last experience of implementing the procedure. Whilst most nurses (n = 259, 96.3%) reported positive outcomes in so far that the incident was brought under control, the views of the aftereffects of the procedure were of concern and ambivalence. The literature suggests that service users did not necessarily hold the same positive views. A range of alternatives, which were consistent with the literature, was made by staff to improve intervention in the management of violence. Negative aspects relating to the use of physical restraint were also highlighted. They included procedural, injury, clinical and management issues. Some respondents also expressed concerns about the negative attitudes of their colleagues. The findings of this aspect of the survey highlights that the therapeutic value of physical restraint can only be achieved with appropriate monitoring and with emphasis on psychological intervention in the prevention and management of violence.

Expression analyses and interaction with the anaphase promoting complex protein Apc2 suggest a role for inversin in primary cilia and involvement in the cell cycle

Homozygous inv mice lack a functional inversin protein and exhibit situs inversus plus severe cystic changes in the kidney and pancreas. Although the inversin sequence has provided few clues to its function, we and others have previously identified calmodulin as a binding partner. We now provide evidence that inversin interacts with the anaphase promoting complex protein Apc2. As expected of an Apc2 target, inversin possesses D-boxes and site-directed mutagenesis of the well-conserved D-box residues abrogates inversin-Apc2 interaction. An inversin-specific antibody reveals a dynamic expression pattern throughout the cell cycle and strong expression in the primary cilia of renal epithelium. Our data support a role for inversin in primary cilia and involvement in the cell cycle. Mutations of the proteins polaris, cystin and polycystin-2 which are expressed in renal epithelium primary cilia, lead to renal cystic changes. Aberrant cell proliferation is also involved in cyst development. The data reported here suggest that inversin may provide a link between these two mechanisms.

Reliability and validity of the CANDID--a needs assessment instrument for adults with learning disabilities and mental health problems

BACKGROUND

People with learning disabilities and mental health problems have complex needs. Care should be provided according to need.

AIM

To develop a standardised needs-assessment instrument for adults with learning disabilities and mental health problems.

METHOD

The Camberwell Assessment of Need for Adults with Developmental and Intellectual Disabilities (CANDID) was developed by modifying the Camberwell Assessment of Need (CAN). Concurrent validity was tested using the Global Assessment of Functioning (GAF) and the Disability Assessment Schedule (DAS). Test-retest and interrater reliability were investigated using 40 adults with learning disabilities and mental health problems.

RESULTS

CANDID scores were significantly correlated with both DAS (P < 0.05) and GAF scores (P < 0.01). Correlation coefficients for interrater reliability were 0.93 (user), 0.90 (career), and 0.97 (staff ratings); for test-retest reliability they were 0.71, 0.69 and 0.86 respectively. Mean interview duration was less than 30 minutes.

CONCLUSIONS

The CANDID is a brief, valid and reliable needs assessment instrument for adults with learning disabilities and mental health problems.

Beliefs about voices and their effects on coping strategies

Cognitive behavioural techniques are increasingly used as adjuncts to medication in the treatment of auditory hallucinations for people with schizophrenia. There are now literally hundreds of nurses trained in the use of cognitive behavioural interventions for psychosis. However, there is still disagreement about the nature of the cognitive processes that lead to deficits or biases in patients' processing of information about their psychotic experiences. Using Chadwick & Birchwood's Beliefs About Voices Questionnaire (BAVQ), the investigator collected data regarding voices from a sample of men and women being treated for schizophrenia by secondary mental health services. The investigator then carried out a cross-lagged panel analysis of the data. The investigator found, as predicted, positive relationships between a resistive coping style and an attribution of malevolence to voices, and between an engaging coping style and an attribution of benevolence to voices. Coping and attributional styles were not necessarily stable over time. There was a non-significant difference between women's and men's attributions and coping styles. There was less fluctuation over time in the women's scores on the BAVQ. This research shows that one cannot assume that either coping or attributional style becomes more stable over time. However, while there are strong relationships between attributions and coping styles, and particularly between malevolence and resistance and benevolence and engagement, these relationships are not necessarily mutually exclusive and some people in the study believe their voices to be both malevolent and benevolent. These findings suggest that clinicians need to make a very careful assessment of attribution and coping with regard to hallucinations and that systematic reassessment is very important. Further research is necessary in both the phenomenology of attribution and coping, but also to relate these variables to other aspects of schizophrenic illnesses.

Comparison of case fatality in south Asian and white patients after acute myocardial infarction: observational study

OBJECTIVE

To compare mortality in south Asian (Indian, Pakistani, and Bangladeshi) and white patients in the six months after hospital admission for acute myocardial infarction.

DESIGN

Observational study.

SETTING

District general hospital in east London.

PATIENTS

149 south Asian and 313 white patients aged < 65 years admitted to the coronary care unit with acute myocardial infarction from 1 December 1988 to 31 December 1992.

MAIN OUTCOME MEASURE

All cause mortality in the first six months after myocardial infarction.

RESULTS

The admission rate in the south Asians was estimated to be 2.04 times that in the white patients. Most aspects of treatment were similar in the two groups, except that a higher proportion of the south Asians received thrombolytic drugs (81.2% v 73.8%). After adjustment for age, sex, previous myocardial infarction, and treatment with thrombolysis or aspirin, or both, the south Asians had a poorer survival over the six months from myocardial infarction (hazard ratio 2.02 (95% confidence interval 1.14 to 3.56), P = 0.018), but a substantially higher proportion were diabetic (38% v 11%, P < 0.001), and additional adjustment for diabetes removed much of their excess risk (adjusted hazard ratio 1.26 (0.68 to 2.33), P = 0.47).

CONCLUSION

South Asian patients had a higher risk of admission with myocardial infarction and a higher risk of death over the ensuing six months than the white patients. The higher case fatality among the south Asians, largely attributable to diabetes, may contribute to the increased risk of death from coronary heart disease in south Asians living in Britain.

Migration of an implantable cardioverter-defibrillator generator into the small bowel

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Prospective study of high grade anal squamous intraepithelial neoplasia in a cohort of homosexual men: influence of HIV infection, immunosuppression and human papillomavirus infection

OBJECTIVE

To determine the risk of developing high grade anal squamous intraepithelial neoplasia (HG-AIN) in relation to HIV infection and immunosuppression, after controlling for the effects of human papillomavirus (HPV) infection.

DESIGN

Prospective cohort study of 158 HIV-seropositive and 147 HIV-seronegative homosexual men presenting to a community-based clinic with initially negative anal cytologic and colposcopic findings.

METHODS

Subjects completed self-administered questionnaires, underwent cytologic screening, and standardized unaided and colposcopic examination of the proximal anal canal for presence of abnormalities suggestive of AIN. Anal specimens were screened for HPV DNA.

RESULTS

HG-AIN developed in eight (5.4%) and 24 (15.2%) HIV-seronegative and -seropositive men, respectively. Risk of HG-AIN among HIV-seronegative men was associated with detection of anal HPV types 16 or 18 by Southern transfer hybridization (STH), detection of HPV 16 or 18 at the lower levels by polymerase chain reaction but not by STH, and with number of positive HPV tests; HG-AIN risk among HIV-seropositive men was associated with detection of HPV 16 or 18 only by STH, detection of HPV types other than 16 or 18, CD4 count < or = 500 x 10(6)/l, and number of positive HPV tests. HIV-induced immunosuppression remained an independent predictor of HG-AIN after adjusting for type and level of detection of HPV; HIV infection predicted HG-AIN risk after adjustment for number of positive HPV tests.

CONCLUSIONS

The association of HG-AIN with HIV, independent of HPV type, level of HPV detection and number of positive HPV tests, suggests that this increased risk cannot be entirely explained by an effect of HIV on HPV detection. Future studies focusing on factors more specific to the local microenvironment in the anal canal should help clarify these issues.

High grade anal dysplasia in visually normal mucosa in homosexual men: seven cases

BACKGROUND

Anal cancer and anal human Papillomavirus (HPV) infection are increased in homosexual men.

METHODS

We screened high risk homosexual men as part of a longitudinal study examining the effect of HIV infection on the risk of development of high grade anal intraepithelial neoplasia (AIN II, III).

RESULTS

We found seven men who had histological evidence of AIN II-III with visually normal findings by anoscopy. Two men were HIV-seronegative, five were HIV-seropositive, and only one of the HIV-seropositive men had a low CD4 count < 200. Abnormal cytological results seen over follow-up periods of 3 months to 2.5 yr suggest the persistence of visually inapparent anal abnormalities. Two of the men had had small internal warts at earlier examinations, and three of the seven men subsequently developed visually abnormal anal findings. All men had HPV 16 DNA detected at some point.

CONCLUSIONS

We hypothesize that high grade anal neoplasia may develop deep in the glands and can be detected by cytology before visible lesions are detected even with the aid of a colposcope. However, the implications of finding high grade anal cytology are not known at this time. Natural history studies are ongoing.

Radioimmunoscintigraphy of pelvic lymph nodes with 111indium-labeled monoclonal antibody CYT-356

In an attempt to define the possible role of radioimmunoscintigraphy to assess noninvasively the pelvic lymph nodes, we studied 19 patients with prostate cancer. All 19 men underwent conventional radiographic imaging of the pelvis with computerized tomography or magnetic resonance imaging before bilateral pelvic lymph node dissection. In addition, radioimmunological scanning with 111indium-labeled monoclonal antibody CYT-356 was performed. Pathologically 8 of the 19 patients had histological confirmation of metastatic nodal disease ranging from 1 to 15 mm. The monoclonal scan was positive at a site corresponding to the histologically confirmed nodal foci in 4 of the 8 patients. Since each hemipelvis could be independently assessed for pathological disease and imaging status, we report site-specific analysis of the monoclonal antibody scan in 38 hemipelves. The overall accuracy was 76% with a sensitivity and specificity of 44% and 86%, respectively. The negative predictive value was 83% and the positive predictive value was 50%. The administration of a single dose of CYT-356 antibody is safe, feasible and capable of detecting soft tissue nodal disease. A negative scan enables the physician to predict noninvasively a low probability of nodal disease for individuals at high risk. The detection threshold of this antibody scan appears to be disease foci 5 mm. or greater.

Anal dysplasia in homosexual men: role of anoscopy and biopsy

BACKGROUND

Both anal squamous cell cancer and human papilloma virus (HPV) are increased in homosexual men. This study evaluates histology of internal anal abnormalities in a high-risk population of human immunodeficiency virus (HIV) seropositive and seronegative homosexual men.

METHODS

Ninety men with abnormalities of the internal anal canal (referred from a cross-sectional study of 512 homosexual men) were evaluated by anoscopy, anal cytology, and directed biopsy. CD4 cell counts from blood and HPV types from anal tissue were also obtained.

RESULTS

Seventy-eight (86%) men had HPV-associated abnormalities: discrete warts in 39 (43%), a wart ring in 23 (26%), and flat white epithelium in 18 (20%). Dysplasia was detected by cytology in 36% and by biopsy in 92% (27% high grade). High-grade dysplasia was equally common in HIV-seropositive and -seronegative men. The morphology of anal lesions did not predict the presence of dysplasia. Both high- and low-risk HPV types were common in many of the biopsy specimens.

CONCLUSIONS

Anal dysplasia is common in biopsy specimens from homosexual men with visible HPV-associated internal anal abnormalities. Natural history studies are needed to determine the clinical significance of anal dysplasia, rates of progression to cancer, and the role of screening and therapy.

Association of anal dysplasia and human papillomavirus with immunosuppression and HIV infection among homosexual men

OBJECTIVE

To examine and quantify the association between anal squamous intraepithelial lesions (ASIL), anal human papillomavirus (HPV) infection and immunosuppression among HIV-seropositive and HIV-seronegative homosexual men.

DESIGN

Cross-sectional study among homosexual men presenting at a community-based clinic for HIV serologic screening.

RESULTS

Anal HPV DNA was detected in 55 and 23% of 285 HIV-seropositive and 204 HIV-seronegative men, respectively, by Southern transfer hybridization (STH) [odds ratio (OR), 4.0; 95% confidence interval (CI), 2.7-6.2], and in 92 and 78% by polymerase chain reaction (PCR) (OR, 3.1; 95% CI, 1.6-5.8). ASIL was noted in 26% of HIV-seropositive men and in 8% of HIV-seronegative men (compared with men with negative cytologic findings: OR, 5.6; 95% CI, 3.0-10.5), with high-grade lesions noted in 4% of HIV-seropositive and in 0.5% of HIV-seronegative men. Among HIV-infected men, ASIL, detection of specific anal HPV types, and detection of high levels of anal HPV DNA (i.e., levels of HPV DNA detectable by both STH and PCR) were all associated with immunosuppression. Nevertheless, HIV-seropositive men with CD4 counts > 500 x 10(6)/l had a higher prevalence of both anal HPV and ASIL than men without HIV infection. Overall, detection of HPV at high levels was associated with ASIL. However, after adjustment for level of detectable HPV DNA, the risk of ASIL among HIV-seropositive men with CD4 counts < 500 x 10(6)/l was increased 2.9-fold (95% CI, 1.4-6.2) over that of HIV-seropositive men with CD4 counts > 500 x 10(6)/l.

CONCLUSION

Given the high rates of ASIL in HIV-seronegative and both immunosuppressed and non-immunosuppressed HIV-seropositive homosexual men, natural history studies are now needed to assist in the development of strategies for the detection and management of such lesions. The increased prevalence of ASIL seen among immunosuppressed HIV-seropositive men may be the result of both a non-specific increase in productive HPV infection and HIV-induced immune alterations of HIV-related neoplasia.

Identification and significance of dysmorphic versus isomorphic hematuria

Hematuria may be of glomerular or nonglomerular origin. Dysmorphic erythrocytes are found in the urine of patients with glomerular bleeding, whereas isomorphic erythrocytes characterize nonglomerular or urological hematuria. Urine specimens from 100 patients with microscopic hematuria were collected: 50 had a known glomerular pathological condition and 50 had urological disease. Scanning electron microscopy of the urine specimens showed a marked difference in morphology between dysmorphic and isomorphic red blood cells. This differentiation can be made with a simpler instrument, the standard Coulter counter. Accurate prediction of glomerular versus nonglomerular hematuria was made in 97 of the 100 patients by Coulter counter analysis. The test is rapid, simple and readily reproducible. A permanent graphic record of the red blood cell morphology can be obtained for each patient. Identification of glomerular versus nonglomerular hematuria can be of practical use in the clinical management of patients.

Successful treatment of priapism with intracorporeal epinephrine

Prompt relief of priapism is essential to prevent importance. We report a case of priapism treated rapidly and effectively with intracorporeal epinephrine.