An unusual case of nephrotic syndrome.

BACKGROUND: Alport syndrome is a genetically heterogenous disorder resulting from variants in genes coding for alpha-3/4/5 chains of Collagen IV, which results in defective basement membranes in the kidney, cochlea and eye. The syndrome has different inheritance patterns and historically, was thought of as a disease affecting solely males. CASE: A 15-year-old female presented with pedal oedema, hypertension and proteinuria. She underwent a kidney biopsy which showed findings in keeping with focal segmental glomerulosclerosis. Her condition was refractory to steroids. Steroid-resistant nephrotic syndrome genetics were sent, revealing a rare pathogenic variant in the COL4A5 gene. CONCLUSION: Heterozygous females with X-linked Alport syndrome can develop chronic kidney disease and hearing loss. Clinicians should be mindful when reviewing kidney histology to include Alport syndrome as a differential for female patients. COL4A3-5 genes should be included in all steroid-resistant nephrotic syndrome genetic panels.

Point prevalence of non-melanoma and melanoma skin cancers in Australian surfers and swimmers in Southeast Queensland and Northern New South Wales.

Background: Surfing and swimming are two popular outdoor aquatic activities in Australia with an estimated 2.7 million surfers and three million swimmers; however, these activities are associated with intermittent exposure to ultraviolet radiation. Our aim was to determine the point prevalence of pre-skin cancer (actinic keratosis (PSC)), non-melanoma (NMSC) and melanoma skin cancers (MSC) in Australian surfers and swimmers. Methods: This cross-sectional study involved Australian surfers who completed a survey that included physiological demographics, aquatic activity-specific demographics, history of skin cancer followed by screening. Results: A total of 171 surfers (n = 116) and swimmers (n = 55) participated in the study. Both groups were identified as having a history of skin cancer (surfers 41.4%, swimmers 36.4%) and a family history of skin cancer (surfers 52.6%, swimmers 43.6%). The majority of both groups reported using a high percentage of a chemical or physical skin cancer prevention strategy (surfers 100%, Swimmers 92.7%, P = 0.003). Significantly more surfers were identified with a skin cancer of any type vs. swimmers (50% vs. 27.3%; OR 2.67; P = 0.005) with most the common skin cancer being PSC (44.7% vs. 11.3%, P = 0.076) followed by basal cell carcinoma (BCC) (24.2% vs. 7.6%, P = 0.068). There was a total of seven MSC identified in surfers and swimmers (4.6% vs. 0.8%, respectively, P = 0.137). Most skin cancers in surfers were located on the face (28.0%) followed by the arm and back (12.1% each), whereas in swimmers, the majority of skin cancers were identified on the face (17.3%), followed by the arm and lower leg (15.4% each). The highest number of melanomas were identified in surfers (n = 6) and mainly located on the face (n = 2) and back (n = 2). There was a single melanoma identified on the back in a swimmer. With the groups combined, the majority (42.9%) of melanomas were identified on the back in participants, followed by the face (28.6%). Rates per 100,000 of NMSC and MSC in surfers and swimmers (respectively) were BCC (11,206 vs. 14,545), squamous cell carcinoma (SCC) in situ (13,793 vs. 12,727), SCC (1,724 vs. 3,636) and MSC (5,172 vs. 1,818). When compared to the general Australian population, surfers and swimmers had higher odds ratios (OR), which included BCCs (OR 7.3 and 9.4, respectively), SCCs (OR 1.7 and 3.5, respectively) and MSC (OR 96.7 and 18.8, respectively). Conclusion: Surfers and swimmers had consistently higher rates of PSC, NMSC and MSC than the general Australian population. Point prevalence of MSC (groups combined) was 76-fold higher than the general Australian population. These findings highlight the clinical importance of regular skin cancer screenings in individuals who surf or swim for early detection and treatment of skin cancer. Additionally, these aquatic enthusiasts should be advised of the benefits of sun protection strategies such as chemical and physical barriers to reduce the likelihood of developing skin cancer.

The utility of a genetic kidney disease clinic employing a broad range of genomic testing platforms: experience of the Irish Kidney Gene Project.

BACKGROUND AND AIMS: Genetic testing presents a unique opportunity for diagnosis and management of genetic kidney diseases (GKD). Here, we describe the clinical utility and valuable impact of a specialized GKD clinic, which uses a variety of genomic sequencing strategies. METHODS: In this prospective cohort study, we undertook genetic testing in adults with suspected GKD according to prespecified criteria. Over 7 years, patients were referred from tertiary centres across Ireland to an academic medical centre as part of the Irish Kidney Gene Project. RESULTS: Among 677 patients, the mean age was of 37.2 ± 13 years, and 73.9% of the patients had family history of chronic kidney disease (CKD). We achieved a molecular diagnostic rate of 50.9%. Four genes accounted for more than 70% of identified pathogenic variants: PKD1 and PKD2 (n = 186, 53.4%), MUC1 (8.9%), and COL4A5 (8.3%). In 162 patients with a genetic diagnosis, excluding PKD1/PKD2, the a priori diagnosis was confirmed in 58% and in 13% the diagnosis was reclassified. A genetic diagnosis was established in 22 (29.7%) patients with CKD of uncertain aetiology. Based on genetic testing, a diagnostic kidney biopsy was unnecessary in 13 (8%) patients. Presence of family history of CKD and the underlying a priori diagnosis were independent predictors (P < 0.001) of a positive genetic diagnosis. CONCLUSIONS: A dedicated GKD clinic is a valuable resource, and its implementation of various genomic strategies has resulted in a direct, demonstrable clinical and therapeutic benefits to affected patients.

Gene delivery to the hypoglossal motor system: preclinical studies and translational potential.

Dysfunction and/or reduced activity in the tongue muscles contributes to conditions such as dysphagia, dysarthria, and sleep disordered breathing. Current treatments are often inadequate, and the tongue is a readily accessible target for therapeutic gene delivery. In this regard, gene therapy specifically targeting the tongue motor system offers two general strategies for treating lingual disorders. First, correcting tongue myofiber and/or hypoglossal (XII) motoneuron pathology in genetic neuromuscular disorders may be readily achieved by intralingual delivery of viral vectors. The retrograde movement of viral vectors such as adeno-associated virus (AAV) enables targeted distribution to XII motoneurons via intralingual viral delivery. Second, conditions with impaired or reduced tongue muscle activation can potentially be treated using viral-driven chemo- or optogenetic approaches to activate or inhibit XII motoneurons and/or tongue myofibers. Further considerations that are highly relevant to lingual gene therapy include (1) the diversity of the motoneurons which control the tongue, (2) the patterns of XII nerve branching, and (3) the complexity of tongue muscle anatomy and biomechanics. Preclinical studies show considerable promise for lingual directed gene therapy in neuromuscular disease, but the potential of such approaches is largely untapped.

Integration of genetic and histopathology data in interpretation of kidney disease.

For many years renal biopsy has been the gold standard for diagnosis in many forms of kidney disease. It provides rapid, accurate and clinically useful information in most individuals with kidney disease. However, in recent years, other diagnostic modalities have become available that may provide more detailed and specific diagnostic information in addition to, or instead of, renal biopsy. Genomics is one of these modalities. Previously prohibitively expensive and time consuming, it is now increasingly available and practical in a clinical setting for the diagnosis of inherited kidney disease. Inherited kidney disease is a significant cause of kidney disease, in both the adult and paediatric populations. While individual inherited kidney diseases are rare, together they represent a significant burden of disease. Because of the heterogenicity of inherited kidney disease, diagnosis and management can be a challenge and often multiple diagnostic modalities are needed to arrive at a diagnosis. We present updates in genomic medicine for renal disease, how genetic testing integrates with our knowledge of renal histopathology and how the two modalities may interact to enhance patient care.

Diagnostic utility of genetic testing in patients undergoing renal biopsy.

High-throughput DNA testing is becoming established as a standard diagnostic test in the renal clinic. Previously published studies on cohorts of patients with unexplained chronic kidney disease of a suspected genetic aetiology have suggested a diagnostic yield for genomic sequencing of up to 18%. Here we determine the yield of targeted gene panel in a clinically unscreened cohort of patients referred for percutaneous native renal biopsy. Patients who underwent renal biopsy for investigation of chronic kidney disease were sequenced using a genomic sequencing panel covering 227 genes in which variation is known to be associated with monogenic chronic kidney disease (CKD). Candidate disease-causing variants were assessed for pathogenicity using guidelines from the American College for Medical Genetics and Genomics. Fifty CKD patients were recruited and sequenced. A molecular diagnosis was obtained for two patients (4%). A molecular diagnosis is possible using genomic testing in ∼4% of clinically unscreened patients undergoing renal biopsy. Genetic screening may be useful for diagnosis in a subset of CKD patients but is most valuable when applied to patients with suspected heritable forms of kidney disease.

Karyomegalic Interstitial Nephritis: Cancer Risk Following Transplantation.

A brother and sister presented individually in their forties with progressive renal failure, bronchiectasis and mild derangements of their liver function tests. Both developed end-stage renal disease before the age of 50. Both siblings were found to carry a pathogenic, recessive, compound heterozygote mutation in the gene FAN1, which causes karyomegalic interstitial nephritis. Both siblings underwent renal transplantation. The sister developed small cell carcinoma of the lung 18 months after transplantation. Despite intensive chemotherapy she died 6 months later. Six years after transplant, the brother has developed prostate cancer and over 30 individual skin cancers. To our knowledge, only 6 other patients with FAN1 mutations have undergone solid organ transplantation. Outcomes have been poor, with only 3 patients surviving beyond 1 year. While cancer is a significant risk for all patients in the post-transplant period, only 0.01% of patients develop >10 skin cancers. Transplantation may be an unrecognised risk in patients with FAN1 mutations.

An Exome Sequencing Study of 10 Families with IgA Nephropathy.

BACKGROUND: Immunoglobulin A nephropathy (IgAN) is a heterogeneous disorder with a strong genetic component. The advent of whole exome sequencing (WES) has accelerated the discovery of genetic risk factors underlying familial disorders. OBJECTIVES: We set out to test whether damaging variants in known kidney disease genes explain a proportion of IgAN cases recruited in Ireland. METHODS: We performed WES in 10 Irish families with multiple affected members having kidney disease where at least one member had biopsy confirmed IgAN. Candidate variants were identified based on being shared between affected family members, minor allele frequency, function and predicted pathogenicity. Pathogenicity of variants was determined according to American College of Medical Genetics and Genomics guidelines. RESULTS: We detected candidate variants in 3 of 10 families. We identified a likely pathogenic variant in COL4A5 in one family and a variant of unknown significance (VUS) in COL4A3 in another. Variants in COL4A5 and COL4A3 are known to cause Alport syndrome. In the third family, we identified a VUS in LMX1B, a gene associated with Nail-patella syndrome. CONCLUSIONS: We identified a number of cases of familial IgAN where the families harbored variants in known kidney disease-related genes indicating that potentially a number of cases of familial IgAN are mistaken for other familial kidney disorders. However, the majority of families studied did not carry a candidate variant in a known kidney disease causing gene indicating that there may be >1 underlying genetic mechanism present in these families.

Utility of Genomic Testing after Renal Biopsy.

BACKGROUND: Renal biopsy is the mainstay of renal pathological diagnosis. Despite sophisticated diagnostic techniques, it is not always possible to make a precise pathological diagnosis. Our aim was to identify a genetic cause of disease in patients who had undergone renal biopsy and determine if genetic testing altered diagnosis or treatment. METHODS: Patients with suspected familial kidney disease underwent a variety of next-generation sequencing (NGS) strategies. The subset of these patients who had also undergone native kidney biopsy was identified. Histological specimens were reviewed by a consultant pathologist, and genetic and pathological diagnoses were compared. RESULTS: Seventy-five patients in 47 families underwent genetic sequencing and renal biopsy. Patients were grouped into 5 diagnostic categories based on pathological diagnosis: tubulointerstitial kidney disease (TIKD; n = 18); glomerulonephritis (GN; n = 15); focal segmental glomerulosclerosis and Alport Syndrome (n = 11); thrombotic microangiopathy (TMA; n = 17); and nonspecific pathological changes (n = 14). Thirty-nine patients (52%) in 21 families (45%) received a genetic diagnosis; 13 cases (72%) with TIKD, 4 (27%) with GN, 6 (55%) with focal segmental glomerulosclerosis/Alport syndrome, and 10 (59%) with TMA and 6 cases (43%) with nonspecific features. Genetic testing resulted in changes in understanding of disease mechanism in 21 individuals (54%) in 12 families (57%). Treatment would have been altered in at least 26% of cases (10/39). CONCLUSIONS: An accurate genetic diagnosis can result in changes in clinical diagnosis, understanding of pathological mechanism, and treatment. NGS should be considered as a complementary diagnostic technique to kidney biopsy in the evaluation of patients with kidney disease.

AAV Gene Therapy Utilizing Glycosylation-Independent Lysosomal Targeting Tagged GAA in the Hypoglossal Motor System of Pompe Mice.

Pompe disease is caused by mutations in the gene encoding the lysosomal glycogen-metabolizing enzyme, acid-alpha glucosidase (GAA). Tongue myofibers and hypoglossal motoneurons appear to be particularly susceptible in Pompe disease. Here we used intramuscular delivery of adeno-associated virus serotype 9 (AAV9) for targeted delivery of an enhanced form of GAA to tongue myofibers and motoneurons in 6-month-old Pompe (Gaa -/- ) mice. We hypothesized that addition of a glycosylation-independent lysosomal targeting tag to the protein would result in enhanced expression in tongue (hypoglossal) motoneurons when compared to the untagged GAA. Mice received an injection into the base of the tongue with AAV9 encoding either the tagged or untagged enzyme; tissues were harvested 4 months later. Both AAV9 constructs effectively drove GAA expression in lingual myofibers and hypoglossal motoneurons. However, mice treated with the AAV9 construct encoding the modified GAA enzyme had a >200% increase in the number of GAA-positive motoneurons as compared to the untagged GAA (p < 0.008). Our results confirm that tongue delivery of AAV9-encoding GAA can effectively target tongue myofibers and associated motoneurons in Pompe mice and indicate that the effectiveness of this approach can be improved by addition of the glycosylation-independent lysosomal targeting tag.

Differential Expression Profiles of Oxidative Stress Levels, 8-oxo-dG and 4-HNE, in Barrett's Esophagus Compared to Esophageal Adenocarcinoma.

Barrett's esophagus (BE), a chronic inflammatory condition, is the leading risk factor for esophageal adenocarcinoma (EAC). In inflammation to cancer pathways, oxidative stress profiles have been linked to cancer progression. However, the relevance of oxidative stress profiles along the BE-disease sequence remains to be elucidated. In this study, markers of oxidative stress; DNA adducts (8-oxo-dG) and lipoperoxidation (4-HNE), and markers of proliferation (Ki67) were measured in patient biopsies representing the BE-disease sequence. Differences in expression of these markers in Barrett's patients with cancer-progression and non-progression were examined. Proliferation was reduced in Barrett's specialized intestinal metaplasia (SIM) compared with EAC (p < 0.035). Correcting for cell proliferation levels, a confounding factor, linked to oxidative stress profiles, SIM demonstrated increased levels of 8-oxo-dG and 4-HNE (p < 0.05) compared with EAC. Longitudinal analysis of Barrett's patients demonstrated decreased levels of 8-oxo-dG in SIM cancer progression (p < 0.05). BE is an environment of increased oxidative stress and inflammation. Patients with progressive disease demonstrated reduced oxidative stress levels in 8-oxo-dG. Perhaps these alterations facilitate Barrett's progression, whereas in non-progressive disease, cells follow the rules of increased oxidative stress ultimately triggers cell apoptosis, thereby preventing propagation and survival.

Granulomatous interstitial nephritis secondary to adalimumab therapy.

Tumour necrosis factor α (TNF-α) inhibitors are frequently used for the treatment of immune-mediated diseases. Conversely, cytokine therapy has the potential to paradoxically induce autoimmunity. A number of case reports have emerged concerning sarcoid-like granulomatosis secondary to TNF-α therapy, an adverse effect that typically affects the pulmonary and cutaneous systems. Granulomatous interstitial nephritis (GIN) is a relatively unknown, relatively under-reported consequence of adalimumab therapy that can have important clinical implications. To our knowledge, this is the first case report of GIN secondary to anti-TNF-α therapy necessitating a prolonged period of dialysis and the first report demonstrating the successful use of secukinumab as an alternative immunomodulatory agent.

Clinical Heterogeneity in Familial IgA Nephropathy.

BACKGROUND: IgA nephropathy is the most common primary glomerulonephritis worldwide and a significant cause of end-stage renal disease (ESRD). While most cases of IgA nephropathy are considered sporadic, familial cases have been reported. METHODS: We performed a national audit of 1,809 patients attending renal clinics and dialysis units to identify a family history among patients with kidney disease. We reviewed all renal biopsies performed at our institution spanning a 30-year period. Paediatric cases were not included. RESULTS: We identified 14 families involving 41 affected individuals with biopsy-proven IgA nephropathy and at least one other member with either biopsy-proven IgA nephropathy or ESRD. Detailed family histories were obtained, medical records reviewed and family pedigrees constructed. Retrospective application of the MESTC criteria to all familial IgA biopsies was performed. Seven families had 2 or more members with biopsy-proven IgA nephropathy, equating to 23 (1.8%) of 1,283 biopsies with IgA nephropathy over the last 30 years. A complex inheritance pattern was observed, with autosomal dominant and autosomal recessive families identified with varying penetrance. There was a male preponderance (68%), and a complex heterogeneity in the clinical and histopathological features of familial IgA patients (age range 16-60 years; creatinine range 60-350 µmol/L). We observed a high rate (66%) of progression to ESRD, with a mean time to progression of 5.13 years (SD 1.8 years; range 2-8 years). Among those patients who had undergone transplantation, recurrence of disease was reported in 5 (50%) cases. CONCLUSION: These data suggests familial aggregation of IgA nephropathy, confirm the clinical and histopathological heterogeneity and raise the possibility of monogenic inheritance.

Renal transplant outcomes in primary FSGS compared with other recipients and risk factors for recurrence: A national review of the Irish Transplant Registry.

INTRODUCTION: Primary focal segmental glomerular sclerosis (p-FSGS) is commonly complicated by recurrence (r-FSGS) post-transplantation. Our objective was to describe Irish outcomes for transplantation after end-stage renal disease (ESRD) due to p-FSGS, specifically rates of, and treatments for, r-FSGS. PATIENTS AND METHODS: Irish patients with biopsy-proven FSGS were identified from the Irish National Kidney Transplant database (1982-2015). Medical record review was performed to identify predictors of r-FSGS and treatments for r-FSGS. Transplant outcomes were compared to outcomes in all renal transplants performed during the same time period using registry data. Demographic and clinical predictors of r-FSGS were identified. Statistical analysis was performed using Stata (version 13, College Station, TX, USA). RESULTS: Thirty-eight transplant recipients had biopsy-proven p-FSGS, 16 received a second transplant. A total of 3846 transplants formed the comparator group. r-FSGS complicated 60.5% (23/38) of first transplants. Eighty-six percent (10/12) of patients with previous r-FSGS developed recurrent disease after further transplantation. Patients with p-FSGS receiving a first renal transplant had higher rate of graft failure than those with another cause of ESRD (HR 1.9, 95% CI 1.152-3.139). Sixteen patients received immunotherapy for r-FSGS; 12 (86%) had at least partial response, but two (14%) developed significant complications. DISCUSSION: We demonstrate high rates of r-FSGS and describe modest success from with treatments for r-FSGS.

CD10-/ALDH- cells are the sole cisplatin-resistant component of a novel ovarian cancer stem cell hierarchy.

It is long established that tumour-initiating cancer stem cells (CSCs) possess chemoresistant properties. However, little is known of the mechanisms involved, particularly with respect to the organisation of CSCs as stem-progenitor-differentiated cell hierarchies. Here we aimed to elucidate the relationship between CSC hierarchies and chemoresistance in an ovarian cancer model. Using a single cell-based approach to CSC discovery and validation, we report a novel, four-component CSC hierarchy based around the markers cluster of differentiation 10 (CD10) and aldehyde dehydrogenase (ALDH). In a change to our understanding of CSC biology, resistance to chemotherapy drug cisplatin was found to be the sole property of CD10-/ALDH- CSCs, while all four CSC types were sensitive to chemotherapy drug paclitaxel. Cisplatin treatment quickly altered the hierarchy, resulting in a three-component hierarchy dominated by the cisplatin-resistant CD10-/ALDH- CSC. This organisation was found to be hard-wired in a long-term cisplatin-adapted model, where again CD10-/ALDH- CSCs were the sole cisplatin-resistant component, and all CSC types remained paclitaxel-sensitive. Molecular analysis indicated that cisplatin resistance is associated with inherent- and adaptive-specific drug efflux and DNA-damage repair mechanisms. Clinically, low CD10 expression was consistent with a specific set of ovarian cancer patient samples. Collectively, these data advance our understanding of the relationship between CSC hierarchies and chemoresistance, which was shown to be CSC- and drug-type specific, and facilitated by specific and synergistic inherent and adaptive mechanisms. Furthermore, our data indicate that primary stage targeting of CD10-/ALDH- CSCs in specific ovarian cancer patients in future may facilitate targeting of recurrent disease, before it ever develops.

Deoxycholic acid promotes development of gastroesophageal reflux disease and Barrett's oesophagus by modulating integrin-αv trafficking.

The fundamental mechanisms underlying erosive oesophagitis and subsequent development of Barrett's oesophagus (BO) are poorly understood. Here, we investigated the contribution of specific components of the gastric refluxate on adhesion molecules involved in epithelial barrier maintenance. Cell line models of squamous epithelium (HET-1A) and BO (QH) were used to examine the effects of bile acids on cell adhesion to extracellular matrix proteins (Collagen, laminin, vitronectin, fibronectin) and expression of integrin ligands (α3 , α4, α5 , α6 and αν ). Experimental findings were validated in human explant oesophageal biopsies, a rat model of gastroesophageal reflux disease (GORD) and in patient tissue microarrays. The bile acid deoxycholic acid (DCA) specifically reduced adhesion of HET-1A cells to vitronectin and reduced cell-surface expression of integrin-αν via effects on endocytic recycling processes. Increased expression of integrin-αv was observed in ulcerated tissue in a rat model of GORD and in oesophagitis and Barrett's intestinal metaplasia patient tissue compared to normal squamous epithelium. Increased expression of integrin-αν was observed in QH BO cells compared to HET-1A cells. QH cells were resistant to DCA-mediated loss of adhesion and reduction in cell-surface expression of integrin-αν . We demonstrated that a specific component of the gastric refluxate, DCA, affects the epithelial barrier through modulation of integrin αν expression, providing a novel mechanism for bile acid-mediated erosion of oesophageal squamous epithelium and promotion of BO. Strategies aimed at preventing bile acid-mediated erosion should be considered in the clinical management of patients with GORD.