Autosomal dominant ApoA4 mutations present as tubulointerstitial kidney disease with medullary amyloidosis.

Sporadic cases of apolipoprotein A-IV medullary amyloidosis have been reported. Here we describe five families found to have autosomal dominant medullary amyloidosis due to two different pathogenic APOA4 variants. A large family with autosomal dominant chronic kidney disease (CKD) and bland urinary sediment underwent whole genome sequencing with identification of a chr11:116692578 G>C (hg19) variant encoding the missense mutation p.L66V of the ApoA4 protein. We identified two other distantly related families from our registry with the same variant and two other distantly related families with a chr11:116693454 C>T (hg19) variant encoding the missense mutation p.D33N. Both mutations are unique to affected families, evolutionarily conserved and predicted to expand the amyloidogenic hotspot in the ApoA4 structure. Clinically affected individuals suffered from CKD with a bland urinary sediment and a mean age for kidney failure of 64.5 years. Genotyping identified 48 genetically affected individuals; 44 individuals had an estimated glomerular filtration rate (eGFR) under 60 ml/min/1.73 m2, including all 25 individuals with kidney failure. Significantly, 11 of 14 genetically unaffected individuals had an eGFR over 60 ml/min/1.73 m2. Fifteen genetically affected individuals presented with higher plasma ApoA4 concentrations. Kidney pathologic specimens from four individuals revealed amyloid deposits limited to the medulla, with the mutated ApoA4 identified by mass-spectrometry as the predominant amyloid constituent in all three available biopsies. Thus, ApoA4 mutations can cause autosomal dominant medullary amyloidosis, with marked amyloid deposition limited to the kidney medulla and presenting with autosomal dominant CKD with a bland urinary sediment. Diagnosis relies on a careful family history, APOA4 sequencing and pathologic studies.

Intragraft gene expression in native kidney BK virus nephropathy versus T cell-mediated rejection: Prospects for molecular diagnosis and risk prediction.

Novel tools are needed to improve diagnostic accuracy and risk prediction in BK virus nephropathy (BKVN). We assessed the utility of intragraft gene expression testing for these purposes. Eight hundred genes were measured in 110 archival samples, including a discovery cohort of native kidney BKVN (n = 5) vs pure T cell-mediated rejection (TCMR; n = 10). Five polyomavirus genes and seven immune-related genes (five associated with BKVN and two associated with TCMR) were significantly differentially expressed between these entities (FDR < 0.05). These three sets of genes were further evaluated in samples representing a spectrum of BK infection (n = 25), followed by a multicenter validation cohort of allograft BKVN (n = 60) vs TCMR (n = 10). Polyomavirus 5-gene set expression reliably distinguished BKVN from TCMR (validation cohort AUC = 0.992), but the immune gene sets demonstrated suboptimal diagnostic performance (AUC ≤ 0.720). Within the validation cohort, no significant differences in index biopsy gene expression were identified between BKVN patients demonstrating resolution (n = 35), persistent infection (n = 14) or de novo rejection (n = 11) 6 months following a standardized reduction in immunosuppression. These results suggest that, while intragraft polyomavirus gene expression may be useful as an ancillary diagnostic for BKVN, assessment for concurrent TCMR and prediction of clinical outcome may not be feasible with current molecular tools.

Dysregulated expression but redundant function of the long non-coding RNA HOTAIR in diabetic kidney disease.

AIMS/HYPOTHESIS: Long non-coding RNAs (lncRNAs) are garnering increasing attention for their putative roles in the pathogenesis of chronic diseases, including diabetic kidney disease (DKD). However, much about in vivo lncRNA functionality in the adult organism remains unclear. To better understand lncRNA regulation and function in DKD, we explored the effects of the modular scaffold lncRNA HOTAIR (HOX antisense intergenic RNA), which approximates chromatin modifying complexes to their target sites on the genome. METHODS: Experiments were performed in human kidney tissue, in mice with streptozotocin-induced diabetes, the db/db mouse model of type 2 diabetes, podocyte-specific Hotair knockout mice and conditionally immortalised mouse podocytes. RESULTS: HOTAIR was observed to be expressed by several kidney cell-types, including glomerular podocytes, in both human and mouse kidneys. However, knockout of Hotair from podocytes had almost no effect on kidney structure, function or ultrastructure. Glomerular HOTAIR expression was found to be increased in human DKD, in the kidneys of mice with streptozotocin-induced diabetes and in the kidneys of db/db mice. Likewise, exposure of cultured mouse podocytes to high glucose caused upregulation of Hotair expression, which occurred in a p65-dependent manner. Although HOTAIR expression was upregulated in DKD and in high glucose-exposed podocytes, its knockout did not alter the development of kidney damage in diabetic mice. Rather, in a bioinformatic analysis of human kidney tissue, HOTAIR expression closely paralleled the expression of its genic neighbour, HOXC11, which is important to developmental patterning but which has an uncertain role in the adult kidney. CONCLUSIONS/INTERPRETATION: Many lncRNAs have been found to bind to the same chromatin modifying complexes. Thus, there is likely to exist sufficient redundancy in the system that the biological effects of dysregulated lncRNAs in kidney disease may often be inconsequential. The example of the archetypal scaffold lncRNA, HOTAIR, illustrates how lncRNA dysregulation may be a bystander in DKD without necessarily contributing to the pathogenesis of the condition. In the absence of in vivo validation, caution should be taken before ascribing major functional roles to single lncRNAs in the pathogenesis of chronic diseases.

Establishing an effective clinical data collecting tool for optimal evaluation of native and allograft renal biopsies.

Introduction: Percutaneous kidney biopsy is the gold standard method to reach a precise diagnosis in most medical kidney diseases, which positively impacts patient care by personalizing the treatment. Accurate diagnosis in the pathology report for medical kidney diseases requires clinicopathological correlation, and clinical data is not always reachable to the nephropathologist. This study aimed to create a standardized, paperless requisition form compatible with medical renal biopsies. Methods: An initial form was prepared for native and allograft renal biopsies according to the current classification of medical kidney diseases. We invited 33 nephropathologists working in Canadian healthcare institutions to answer survey questions about the need to include a particular aspect of clinical information. According to the responses, we modified the experimental form. Eighty nephrologists were asked to complete a clinical data-collecting form given out as PDF files. The time for completing the form and clinicians' satisfaction were assessed. Results: The experimental form survey was answered by 20 out of 33 nephropathologists (61%) from 14 Canadian healthcare centers. The agreement rate on the questions was from 38.89% to 100.00% (average 83.33% and 77.14% for the native and the allograft section, respectively). Seventeen out of 80 nephrologists and their assistants (21%) responded by completing 22 PDF forms. The time required to finish a PDF form was 10.4 min on average. Nephrologists considered the form time-consuming and suggested making it more clinically relevant. Only seven nephrologists responded to the satisfaction survey; four (57%) were satisfied. Conclusions: Medical information is critical in renal pathology diagnoses. A uniform paperless clinical data requisition form was evolved through an agreement by Canadian nephropathologists.

Single cell G-protein coupled receptor profiling of activated kidney fibroblasts expressing transcription factor 21.

BACKGROUND AND PURPOSE: Activated fibroblasts deposit fibrotic matrix in chronic kidney disease (CKD) and G-protein coupled receptors (GPCRs) are the most druggable therapeutic targets. Here, we set out to establish a transcriptional profile that identifies activated kidney fibroblasts and the GPCRs that they express. EXPERIMENTAL APPROACH: RNA sequencing and single cell qRT-PCR were performed on mouse kidneys after unilateral ureteral obstruction (UUO). Candidate expression was evaluated in mice with UUO or diabetes or injected with adriamycin or folic acid. Intervention studies were conducted in mice with diabetes or UUO. Correlative histology was performed in human kidney tissue. KEY RESULTS: Transcription factor 21 (Tcf21)+ cells that expressed 2 or 3 of Postn, Acta2 and Pdgfra were highly enriched for fibrogenic genes and were defined as activated kidney fibroblasts. Tcf21+ α-smooth muscle actin (α-SMA)+ interstitial cells accumulated in kidneys of mice with UUO or diabetes or injected with adriamycin or folic acid, whereas renin-angiotensin system blockade attenuated increases in Tcf21 in diabetic mice. Fifty-six GPCRs were up-regulated in single Tcf21+ kidney fibroblasts, the most up-regulated being Adgra2 and S1pr3. Adenosine receptors, Adora2a/2b, were up-regulated in Tcf21+ fibroblasts and the adenosine receptor antagonist, caffeine decreased Tcf21 upregulation and kidney fibrosis in UUO mice. TCF21, ADGRA2, S1PR3 and ADORA2A/2B were each detectable in α-SMA+ interstitial cells in human kidney samples. CONCLUSION AND IMPLICATIONS: Tcf21 is a marker of kidney fibroblasts that are enriched for fibrogenic genes in CKD. Further analysis of the GPCRs expressed by these cells may identify new targets for treating CKD. LINKED ARTICLES: This article is part of a themed issue on Translational Advances in Fibrosis as a Therapeutic Target. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v180.22/issuetoc.

Q-uestioning the Diagnosis: An Educational Case Report.

Rationale: Q fever is a zoonotic infection that may lead to acute or long-term renal injury. Given its rare incidence, Q fever is not often considered on the initial differential diagnosis for glomerular disease which can lead to delays in treatment. This case highlights the importance of avoiding early diagnostic closure and revisiting the differential diagnosis in the setting of an atypical clinical presentation or response to treatment. Presenting Concerns: A 52-year-old female was referred for assessment of possible glomerulonephritis. She described a 3-month history of bilateral lower extremity rash, intermittent knee pain with swelling, and a 2-year history of subjective fevers. Urinalysis showed persistent microscopic hematuria, and her creatinine was elevated at 94 umol/L (baseline 59 umol/L). Her initial investigations included an elevated C-reactive protein (CRP) and rheumatoid factor with a weakly positive anti nuclear antibody (ANA). Diagnoses: Kidney biopsy was consistent with an immune complex mesangial proliferative glomerulonephritis. Light microscopy showed diffuse global mesangial hypercellularity. Immunofluorescence was positive for trace mesangial IgG and kappa, 1+ IgM, lambda and C1q, and 2+ C3. Electron microscopy showed mesangial electron dense deposits. These findings were felt to be most in keeping with mesangial proliferative lupus nephritis; however, it was acknowledged that clinical and laboratory findings supporting this diagnosis were lacking. Interventions: Following treatment with oral prednisone her symptoms resolved, and renal function improved. However, she was unable to taper off prednisone completely without her symptoms returning. Additional immunosuppressive therapies were trialed, but she remained steroid dependent with disease flares related to prednisone tapers. Her atypical response to treatment led to consideration of alternative diagnoses, and further investigation revealed positive Q fever serology (phase-I IgG 1:1892, phase II IgG 1:8192, phase-I and -II IgM < 1:16). She was diagnosed with long-term Q fever and was treated with doxycycline and hydroxychloroquine. Outcomes: She remained on treatment for 2 years. During this time, her symptoms resolved, hematuria disappeared, and her creatinine returned to baseline. Following cessation of therapy, her Q fever IgM titres rose, and she was restarted on doxycycline and hydroxychloroquine indefinitely. Teaching Points: (1) Keeping a broad differential diagnosis in the setting of atypical clinical features or unexpected response to therapy is important for ensuring accurate diagnosis and appropriate treatment. (2) Clinical improvement in relation to immunosuppressive therapy does not preclude an infectious cause of glomerular disease.

Justification: La fièvre Q est une infection zoonotique qui peut entraîner l'insuffisance rénale aiguë ou chronique. D'incidence rare, la fièvre Q n'est généralement pas considérée dans le diagnostic différentiel initial de la glomérulonéphrite, ce qui peut retarder le traitement. Ce cas souligne l'importance d'éviter de poser un diagnostic précoce et d'envisager un diagnostic différentiel lors d'une présentation clinique atypique ou d'une réponse inattendue au traitement. Présentation du cas: Une femme de 52 ans envoyée pour l'évaluation d'une possible glomérulonéphrite. La patiente disait avoir une éruption cutanée bilatérale des membres inférieurs et une douleur intermittente au genou avec enflure depuis trois mois, ainsi que des épisodes de fièvre subjective au cours des deux dernières années. L'analyze d'urine a révélé une hématurie microscopique persistante et un taux de créatinine élevé à 94 umol/L (59 umol/L initialement). Ses premiers examens ont montré une élévation de la CRP et du facteur rhumatoïde, ainsi qu'un titer d'ANA faiblement positif. Diagnostic: La biopsie rénale était compatible avec une glomérulonéphrite mésangiale proliférative à complexe immun. La microscopie optique a démontré une hypercellularité mésangiale diffuse globale. L'immunofluorescence des cellules mésangiales a révélé des traces d'IgG, de kappa, d'IgM, de chaînes lambda et de fragments C1q 1+ et de C3 2+. La microscopie électronique a montré des dépôts denses aux électrons en localization mésangiale. Ces résultats ont été jugés comme plus conformes à la néphrite lupique mésangiale proliférative; on a toutefois reconnu que des résultats cliniques et de laboratoire appuyant ce diagnostic faisaient défaut. Intervention: Après un traitement par prednisone orale, les symptômes de la patiente se sont résorbés et sa fonction rénale s'est améliorée. Il ne lui a toutefois pas été possible de cesser complètement la prednisone sans une réapparition de ses symptômes. D'autres traitements immunosuppresseurs ont été mis à l'essai, mais la patiente est restée dépendante des stéroïdes en raison de poussées de la maladie liées aux réductions de la dose de prednisone. Cette réponse atypique au traitement a mené l'équipe soignante à envisager d'autres diagnostics. Des examens supplémentaires ont révélé une sérologie positive pour la fièvre Q (IgG phase I 1:1892; IgG phase II 1:8192; IgM phase I et II <1:16). La patiente a reçu un diagnostic de fièvre Q chronique et a été traitée avec de la doxycycline et de l'hydroxychloroquine. Résultats: La patiente a reçu le traitement pendant deux ans au cours desquels ses symptômes se sont résorbés, son taux de créatinine est revenu à la valeur initiale et l'hématurie est disparue. Après l'arrêt du traitement, ses titres d'IgM de fièvre Q ont augmenté et la patiente a dû reprendre indéfiniment le traitement par doxycycline et hydroxychloroquine. Enseignements tirés: (1) Pour garantir un diagnostic précis et le traitement approprié, il est important d'envisager un diagnostic différentiel étendu en présence de caractéristiques cliniques atypiques ou d'une réponse inattendue au traitement. (2) L'amélioration clinique liée au traitement immunosuppresseur n'exclut pas une étiologie infectieuse de la glomérulonéphrite.

Lung-Protective Ventilation Attenuates Mechanical Injury While Hypercapnia Attenuates Biological Injury in a Rat Model of Ventilator-Associated Lung Injury.

Background and Objective: Lung-protective mechanical ventilation is known to attenuate ventilator-associated lung injury (VALI), but often at the expense of hypoventilation and hypercapnia. It remains unclear whether the main mechanism by which VALI is attenuated is a product of limiting mechanical forces to the lung during ventilation, or a direct biological effect of hypercapnia. Methods: Acute lung injury (ALI) was induced in 60 anesthetized rats by the instillation of 1.25 M HCl into the lungs via tracheostomy. Ten rats each were randomly assigned to one of six experimental groups and ventilated for 4 h with: 1) Conventional HighV E Normocapnia (high VT, high minute ventilation, normocapnia), 2) Conventional Normocapnia (high VT, normocapnia), 3) Protective Normocapnia (VT 8 ml/kg, high RR), 4) Conventional iCO 2 Hypercapnia (high VT, low RR, inhaled CO2), 5) Protective iCO 2 Hypercapnia (VT 8 ml/kg, high RR, added CO2), 6) Protective endogenous Hypercapnia (VT 8 ml/kg, low RR). Blood gasses, broncho-alveolar lavage fluid (BALF), and tissue specimens were collected and analyzed for histologic and biologic lung injury assessment. Results: Mild ALI was achieved in all groups characterized by a decreased mean PaO2/FiO2 ratio from 428 to 242 mmHg (p < 0.05), and an increased mean elastance from 2.46 to 4.32 cmH2O/L (p < 0.0001). There were no differences in gas exchange among groups. Wet-to-dry ratios and formation of hyaline membranes were significantly lower in low VT groups compared to conventional tidal volumes. Hypercapnia reduced diffuse alveolar damage and IL-6 levels in the BALF, which was also true when CO2 was added to conventional VT. In low VT groups, hypercapnia did not induce any further protective effect except increasing pulmonary IL-10 in the BALF. No differences in lung injury were observed when hypercapnia was induced by adding CO2 or decreasing minute ventilation, although permissive hypercapnia decreased the pH significantly and decreased liver histologic injury. Conclusion: Our findings suggest that low tidal volume ventilation likely attenuates VALI by limiting mechanical damage to the lung, while hypercapnia attenuates VALI by limiting pro-inflammatory and biochemical mechanisms of injury. When combined, both lung-protective ventilation and hypercapnia have the potential to exert an synergistic effect for the prevention of VALI.

Serum Amyloid A Protein-Associated Kidney Disease: Presentation, Diagnosis, and Management.

Serum amyloid A protein (AA) amyloidosis, also known as secondary amyloidosis, is a known consequence of chronic inflammation and results from several conditions including inflammatory arthritis, periodic fever syndromes, and chronic infection. AA amyloidosis can lead to multiorgan dysfunction, including changes in glomerular filtration rate and proteinuria. Definitive diagnosis requires tissue biopsy, and management of AA amyloid kidney disease is primarily focused on treating the underlying inflammatory condition to stabilize glomerular filtration rate, reduce proteinuria, and slow potential progression to kidney failure. In this narrative review, we describe the causes, pathophysiology, presentation, and pathologic diagnosis of AA amyloid kidney disease using an illustrative case of biopsy-proven AA amyloid kidney disease in a patient with long-standing rheumatoid arthritis who had a favorable response to interleukin 6 inhibition. We conclude the review with a description of established and more novel therapies for AA amyloidosis including published cases of use of tocilizumab (an interleukin 6 inhibitor) in biopsy-proven AA amyloid kidney disease.

Margin Sampling and Survival Outcomes in Oral Cavity and p16-Positive Oropharyngeal Squamous Cell Carcinoma.

Objective: To compare the association of margin sampling technique on survival outcomes in surgically treated cT1-2 oral cavity and oropharyngeal squamous cell carcinoma. Study Design: A prospective longitudinal cohort study. Setting: Tertiary care academic teaching hospital in Halifax, Nova Scotia. Methods: All cases of surgically treated cT1-2 oral cavity and oropharyngeal cancer undergoing specimen-oriented margin analysis between January 1, 2017, and December 31, 2018 were analyzed. The specimen-oriented cohort was compared with a cohort of patients from January 1, 2009, to December 31, 2014, where a defect-oriented margin sampling protocol was used. Kaplan-Meier survival curves were used to estimate 2-year overall survival, disease-specific survival, local control, and recurrence-free survival rates in oral cavity and p16-positive oropharyngeal squamous cell carcinoma. Cox proportional hazards models were used to assess the effect of margin sampling method on disease-specific survival and local control. Results: There was no significant association between margin sampling technique and 2-year survival outcomes for surgically treated cT1-2 oral cavity and oropharyngeal squamous cell carcinoma. In the multivariate Cox proportional hazard model, the hazard ratio (HR) of specimen-oriented sampling was not significantly different for disease-specific survival (HR, 1.32; 95% CI, 0.3032-5.727; P = .713) or local control (HR, 0.4087; 95% CI, 0.0795-2.099; P = .284). Conclusion: Intraoperative margin sampling method was not associated with a significant change in 2-year survival outcomes. Despite no effect on survival outcomes, implementation of a specimen-oriented sampling method has potential for cost avoidance by decreasing the number of re-resections for positive or close margins.

Predictors of an unsatisfactory conventional cervical cytology smear.

OBJECTIVES: Cervical cytology smears reported as unsatisfactory for interpretation represent an unrealized screening opportunity and may have significant laboratory and patient costs. Identifying patients at higher risk for an unsatisfactory smear could alert clinicians to take extra care in the acquisition of the smear. Few studies have examined patient characteristics that could predict an unsatisfactory cervical cytology smear. The purpose of this study was to determine the effect of patient age, day of the menstrual cycle, postmenopausal status, postpartum status, and the use of oral contraceptives on the rate of unsatisfactory cervical cytology smears. METHODS: We performed a case-control study of all unsatisfactory cervical cytology smears at a large tertiary care teaching hospital over one year compared with a random sample of smears that were satisfactory for interpretation. Data were obtained from the cytology requisitions. Continuous variables were tested with unpaired t tests, and dichotomous variables were analyzed with chi-square tests. Multivariate significance was tested with binary logistic regression analysis. RESULTS: Of all cervical cytology smears, 1.1% were reported as unsatisfactory. In univariate analyses increased age, earlier date in the menstrual cycle, and postpartum status were associated with unsatisfactory smears. However, following Bonferroni correction for multiple comparisons and multivariate regression analysis, only increased age remained a significant predictor of an unsatisfactory cervical cytology smear. CONCLUSION: Older women are at greater risk of having an unsatisfactory cervical cytology smear. Clinicians and public health officials must be aware of this risk and must encourage optimal collection techniques for women in this demographic group.

Primary Hyperoxaluria Type 1 (PH1) Presenting With End-Stage Kidney Disease and Cutaneous Manifestations in Adulthood: A Case Report.

RATIONALE: Primary hyperoxaluria (PH) is a rare autosomal recessive disorder more commonly diagnosed in children or adolescents. Owing to its rarity and heterogeneous phenotype, it is often underrecognized, resulting in delayed diagnosis, including diagnosis after end-stage kidney disease (ESKD) has occurred or recurrence after kidney-only transplantation. CASE PRESENTATION: A 40-year-old Caucasian Canadian woman with a history of recurrent nephrolithiasis since age 19 presented with ESKD and cutaneous symptoms. She had no known prior kidney disease and no family history of kidney disease or nephrolithiasis. DIAGNOSIS: A diagnosis of primary hyperoxaluria type 1 (PH1) due to homozygous splice donor mutation (AGXT c.680+1G>A) was made with kidney and cutaneous pathology demonstrating calcium oxalate deposition and ultrasound suggestive of nephrocalcinosis. INTERVENTIONS: She was initiated on frequent, high-efficiency, high-flux conventional hemodialysis and oral pyridoxine. Lumasiran was added 11 months later, after she developed bilateral swan-neck deformities. OUTCOMES: After 14 months of high-intensity dialysis and 3 months of lumasiran, there have been no signs of renal recovery, and extra-renal involvement has increased with progressive swan-neck deformities, reduced cardiac systolic function, and pulmonary hypertension. The patient has been waitlisted for kidney-liver transplantation. TEACHING POINTS: This case report describes an adult presentation of PH1. The case highlights the importance of timely workup of metabolic causes of recurrent nephrolithiasis or nephrocalcinosis in adults which can be a presenting sign of PH and genetic testing for PH to facilitate early diagnosis and treatment especially in the era of novel therapeutics that may alter disease course and outcomes. The case also demonstrates the value of testing for PH in adults presenting with unexplained ESKD and a history of recurrent nephrolithiasis or nephrocalcinosis due to implications for organ transplantation strategy and presymptomatic family screening.

JUSTIFICATION: L'hyperoxalurie primaire (HP) est un trouble récessif autosomique rare plus souvent rencontré chez les enfants ou les adolescents. En raison de sa rareté et de son phénotype hétérogène, cette affection est fréquemment sous-reconnue, ce qui entraîne un retard dans le diagnostic, et ce, même après l'apparition d'une insuffisance rénale terminale (IRT) ou une récidive suivant une greffe simple de rein. PRÉSENTATION DU CAS: Nous présentons le cas d'une Canadienne de race blanche âgée de 40 ans avec des antécédents de néphrolithiase récurrente depuis l'âge de 19 ans. La patiente était atteinte d'IRT et présentait des symptômes cutanés. Elle n'avait aucun antécédent connu de maladie rénale ou antécédent familial de maladie rénale ou de néphrolithiase. DIAGNOSTIC: Une pathologie rénale et cutanée montrant des dépôts d'oxalate de calcium et une échographie suggérant une néphrocalcinose ont permis de poser un diagnostic d'hyperoxalurie primaire de type 1 (HP1) due à une mutation de donneur d'épissage homozygote (AGXT c.680+1G>A). INTERVENTIONS: La patiente a amorcé des traitements d'hémodialyse conventionnelle à grande fréquence, à haut rendement et à flux élevé, et a reçu de la pyridoxine par voie orale. Un traitement par lumasiran a été ajouté 11 mois plus tard, après le développement de déformations bilatérales en col de cygne. RÉSULTATS: Après quatorze mois de dialyze à haute intensité et trois mois de lumasiran, aucun signe de récupération rénale n'a été observé. L'intervention d'épuration extra-rénale a été augmentée en raison de déformations progressives en col de cygne, d'une réduction de la fonction cardiaque systolique et d'une hypertension pulmonaire. La patiente a été placée sur la liste d'attente pour une transplantation rénale et hépatique. ENSEIGNEMENTS TIRÉS: Ce rapport de cas décrit une présentation adulte d'HP1. Ce cas souligne l'importance de traiter rapidement les causes métaboliques de la néphrolithiase ou de la néphrocalcinose récidivante chez les adultes, car celles-ci peuvent être des signes d'hyperoxalurie primaire (HP). Ce cas souligne en outre l'importance de procéder à des tests génétiques pour l'HP afin de permettre le diagnostic et le traitement précoces, en particulier à l'ère de nouveaux traitements susceptibles d'infléchir l'évolution et les résultats de la maladie. Enfin, il démontre la valeur du dépistage de l'HP chez les adultes présentant une IRT inexpliquée et des antécédents de néphrolithiase ou de néphrocalcinose récidivante, en raison de ses implications sur la stratégie de transplantation d'organes et sur le dépistage pré-symptomatique de la famille.

Scoring system for renal pathology in Fabry disease: report of the International Study Group of Fabry Nephropathy (ISGFN).

BACKGROUND: In Fabry nephropathy, alpha-galactosidase deficiency leads to accumulation of glycosphingolipids in all kidney cell types, proteinuria and progressive loss of kidney function. METHODS: An international working group of nephrologists from 11 Fabry centres identified adult Fabry patients, and pathologists scored histologic changes on renal biopsies. A standardized scoring system was developed with a modified Delphi technique assessing 59 Fabry nephropathy cases. Each case was scored independently of clinical information by at least three pathologists with an average final score reported. RESULTS: We assessed 35 males (mean age 36.4 years) and 24 females (43.9 years) who mostly had clinically mild Fabry nephropathy. The average serum creatinine was 1.3 mg/dl (114.9 micromol/l); estimated glomerular filtration rate was 81.7 ml/min/1.73 m(2) and urine protein to creatinine ratio was 1.08 g/g (122.0 mg/mmol). Males had greater podocyte vacuolization on light microscopy (mean score) and glycosphingolipid inclusions on semi-thin sections than females. Males also had significantly more proximal tubule, peritubular capillary and vascular intimal inclusions. Arteriolar hyalinosis was similar, but females had significantly more arterial hyalinosis. Chronic kidney disease stage correlated with arterial and glomerular sclerosis scores. Significant changes, including segmental and global sclerosis, and interstitial fibrosis were seen even in patients with stage 1-2 chronic kidney disease with minimal proteinuria. CONCLUSIONS: The development of a standardized scoring system of both disease-specific lesions, i.e. lipid deposition related, and general lesions of progression, i.e. fibrosis and sclerosis, showed a spectrum of histologic appearances even in early clinical stage of Fabry nephropathy. These findings support the role of kidney biopsy in the baseline evaluation of Fabry nephropathy, even with mild clinical disease. The scoring system will be useful for longitudinal assessment of prognosis and responses to therapy for Fabry nephropathy.

Renal-Limited Antiglomerular Basement Membrane Disease Related To Alemtuzumab: A Case Report.

RATIONALE: Alemtuzumab is a monoclonal antibody approved for the treatment of relapsing-remitting multiple sclerosis (RRMS). Many autoimmune-mediated adverse events have been associated with alemtuzumab, including renal-limited anti-glomerular basement membrane (GBM) disease. PRESENTING CONCERN: A 52-year-old female with RRMS presented with acute kidney injury 39 months after receiving 1 cycle of alemtuzumab. She had a history of alemtuzumab-associated hypothyroidism and thrombocytopenia, urinary tract infections, and chronically abnormal urinalyses. DIAGNOSIS: A diagnosis of renal-limited anti-GBM disease was made based on renal biopsy and positive anti-GBM serology. Alemtuzumab was thought to be the trigger of the anti-GBM disease as there were no other exposures or serologic findings suggesting other causes. INTERVENTIONS: She was treated with corticosteroids, cyclophosphamide, and plasmapheresis. She required hemodialysis for acute renal failure. OUTCOMES: Despite treatment, the patient's renal function did not recover. She remained dialysis-dependent and anti-GBM antibody titers remained elevated 6 months after presentation. TEACHING POINTS: Anti-GBM disease is a life-altering adverse event that can be associated with alemtuzumab. Our case highlights the limitations of monitoring urinalyses as a trigger for anti-GBM antibody testing in patients who have received alemtuzumab and have baseline abnormal urinalyses; such patients may require further protocolized anti-GBM antibody testing, although the optimal frequency of such antibody screening remains unclear.

JUSTIFICATION: L'alemtuzumab est un anticorps monoclonal approuvé pour le traitement de la sclérose en plaque récurrente-rémittente (SPRR). De nombreux événements indésirables à médiation auto-immune ont été associés à ce traitement, notamment la glomérulonéphrite auto-immune (maladie anti-MBG). PRÉSENTATION DU CAS: Une femme de 52 ans atteinte de SPRR présentant une insuffisance rénale aiguë 39 mois après avoir reçu un cycle d'alemtuzumab. La patiente avait des antécédents d'hypothyroïdie et de thrombocytopénie liées à la prise d'alemtuzumab, en plus de présenter des tests urinaires anormaux et de souffrir d'infections des voies urinaires de façon chronique. DIAGNOSTIC: Un diagnostic de glomérulonéphrite auto-immune a été établi sur la base d'une biopsie rénale et d'une sérologie anti-MBG positive. On a suspecté l'alemtuzumab d'être à l'origine de la glomérulonéphrite auto-immune puisqu'aucun résultat sérologique ou exposition ne suggérait d'autres causes. INTERVENTIONS: La patiente a été traitée aux corticostéroïdes, au cyclophosphamide et par plasmaphérèse. L'insuffisance rénale aiguë a requis un traitement d'hémodialyse. RÉSULTATS: Malgré le traitement, la fonction rénale de la patiente ne s'est pas rétablie. La patiente a dû poursuivre les traitements de dialyse et ses titres d'anticorps demeuraient élevés six mois après la présentation des symptômes. LEÇONS TIRÉES: La glomérulonéphrite auto-immune est un événement indésirable aux conséquences dévastatrices et cette affection peut être associée à la prise d'alemtuzumab. Notre cas met en lumière les limites du suivi des analyses urinaires comme critère de dépistage des anticorps anti-MBG chez les patients ayant reçu de l'alemtuzumab et dont les analyses urinaires préalables sont anormales. Ces patients pourraient nécessiter des tests de détection des anticorps anti-MBG supplémentaires, bien que leur fréquence optimale demeure incertaine.

A common glomerular transcriptomic signature distinguishes diabetic kidney disease from other kidney diseases in humans and mice.

BACKGROUND: Current uncertainties about the similarity between human diseases and their experimental models are hampering the development of new therapies. This is especially the case for diabetic kidney disease (DKD), the most common cause of end-stage kidney disease. To better understand the nature of the commonality between humans and their mouse models, we posed the question: in diabetic kidney disease are transcriptional profiles primarily disease-specific or species-specific? METHODS: We performed a meta-comparison of the glomerular transcriptomic characteristics of 133 human and 66 mouse samples including five human kidney diseases and five mouse models, validating expression patterns of a central node by immunohistochemistry. FINDINGS: Principal component analysis controlled for mouse background, revealed that gene expression changes in glomeruli from humans with DKD are more similar to those of diabetic mice than they are to other human glomerular diseases. This similarity enabled the construction of a discriminatory classifier that distinguishes diabetic glomeruli from other glomerular phenotypes regardless of their species of origin. To identify where the commonality between mice and humans with diabetes lies, networks of maximally perturbed protein interactions were examined, identifying a central role for the epidermal growth factor receptor (EGFR). By immunohistochemical staining, we found EGFR to be approximately doubled in its glomerular expression in both humans and mice. INTERPRETATION: These findings indicate that diabetic mouse models do mimic some of the features of human kidney disease, at least with respect to their glomerular transcriptomic signatures, and they identify EGFR as being a central player in this inter-species overlap.

Regulation of CDX2 expression in esophageal adenocarcinoma.

Reflux of acidic gastric contents and bile acids into the lower esophagus has been identified to have a central role in esophageal malignancy and is reported to upregulate caudal-related homologue 2 (CDX2), a regulatory gene involved in embryonic development and axial patterning of the alimentary tract. The aim of this study was to characterize the expression of CDX2 in a well-defined series of human esophageal tissues, comprising reflux-induced esophagitis, premalignant Barrett esophagus (BE), and primary esophageal adenocarcinoma (EADC). To explore potential molecular regulatory mechanisms, we also studied the expression of beta-catenin, SOX9, and CDX2 promoter methylation in esophageal tissues, in addition to the effect of bile acids and nitric oxide (NO) on CDX2 expression in the normal human esophageal cell line Het1A. Relative to matched normal esophageal epithelia, CDX2 was overexpressed in esophagitis (37% for RNA; cytoplasmic immunoreactivity in 48% of tissues), a high proportion (91%) of BE tissues, and in EADC (57% for RNA; cell nuclear immunopositivity in 80%). An association with beta-catenin expression was seen, but not with SOX9 or CDX2 promoter methylation. In Het1A cells, CDX2 was upregulated following exposure to bile acids and NO, alone and in combination. These results further implicate CDX2 and beta-catenin in the molecular pathogenesis of human EADC. The observed synergistic effect of NO on the efficacy of bile acid-induction of CDX2 suggests a novel role for NO in modulating the development of the Barrett phenotype and esophageal adenocarcinogenesis.

Fit-For-Purpose PD-L1 Biomarker Testing For Patient Selection in Immuno-Oncology: Guidelines For Clinical Laboratories From the Canadian Association of Pathologists-Association Canadienne Des Pathologistes (CAP-ACP).

Since 2014, programmed cell death protein 1 (PD-1)/programmed cell death ligand 1 (PD-L1) checkpoint inhibitors have been approved by various regulatory agencies for the treatment of multiple cancers including melanoma, lung cancer, urothelial carcinoma, renal cell carcinoma, head and neck cancer, classical Hodgkin lymphoma, colorectal cancer, gastroesophageal cancer, hepatocellular cancer, and other solid tumors. Of these approved drug/disease combinations, a subset also has regulatory agency-approved, commercially available companion/complementary diagnostic assays that were clinically validated using data from their corresponding clinical trials. The objective of this document is to provide evidence-based guidance to assist clinical laboratories in establishing fit-for-purpose PD-L1 biomarker assays that can accurately identify patients with specific tumor types who may respond to specific approved immuno-oncology therapies targeting the PD-1/PD-L1 checkpoint. These recommendations are issued as 38 Guideline Statements that address (i) assay development for surgical pathology and cytopathology specimens, (ii) reporting elements, and (iii) quality assurance (including validation/verification, internal quality assurance, and external quality assurance). The intent of this work is to provide recommendations that are relevant to any tumor type, are universally applicable and can be implemented by any clinical immunohistochemistry laboratory performing predictive PD-L1 immunohistochemistry testing.

The pesticide adjuvant, Toximul, alters hepatic metabolism through effects on downstream targets of PPARalpha.

Previous studies demonstrated that chronic dermal exposure to the pesticide adjuvant (surfactant), Toximul (Tox), has significant detrimental effects on hepatic lipid metabolism. This study demonstrated that young mice dermally exposed to Tox for 12 days have significant increases in expression of peroxisomal acyl-CoA oxidase (mRNA and protein), bifunctional enzyme (mRNA) and thiolase (mRNA), as well as the P450 oxidizing enzymes Cyp4A10 and Cyp4A14 (mRNA and protein). Tox produced a similar pattern of increases in wild type adult female mice but did not induce these responses in PPARalpha-null mice. These data support the hypothesis that Tox, a heterogeneous blend of nonionic and anionic surfactants, modulates hepatic metabolism at least in part through activation of PPARalpha. Notably, all three groups of Tox-treated mice had increased relative liver weights due to significant accumulation of lipid. This could be endogenous in nature and/or a component(s) of Tox or a metabolite thereof. The ability of Tox and other hydrocarbon pollutants to induce fatty liver despite being PPARalpha agonists indicates a novel consequence of exposure to this class of chemicals, and may provide a new understanding of fatty liver in populations with industrial exposure.

Alternative splicing and differential subcellular localization of the rat FGF antisense gene product.

BACKGROUND: GFG/NUDT is a nudix hydrolase originally identified as the product of the fibroblast growth factor-2 antisense (FGF-AS) gene. While the FGF-AS RNA has been implicated as an antisense regulator of FGF-2 expression, the expression and function of the encoded GFG protein is largely unknown. Alternative splicing of the primary FGF-AS mRNA transcript predicts multiple GFG isoforms in many species including rat. In the present study we focused on elucidating the expression and subcellular distribution of alternatively spliced rat GFG isoforms. RESULTS: RT-PCR and immunohistochemistry revealed tissue-specific GFG mRNA isoform expression and subcellular distribution of GFG immunoreactivity in cytoplasm and nuclei of a wide range of normal rat tissues. FGF-2 and GFG immunoreactivity were co-localized in some, but not all, tissues examined. Computational analysis identified a mitochondrial targeting sequence (MTS) in the N-terminus of three previously described rGFG isoforms. Confocal laser scanning microscopy and subcellular fractionation analysis revealed that all rGFG isoforms bearing the MTS were specifically targeted to mitochondria whereas isoforms and deletion mutants lacking the MTS were localized in the cytoplasm and nucleus. Mutation and deletion analysis confirmed that the predicted MTS was necessary and sufficient for mitochondrial compartmentalization. CONCLUSION: Previous findings strongly support a role for the FGF antisense RNA as a regulator of FGF2 expression. The present study demonstrates that the antisense RNA itself is translated, and that protein isoforms resulting form alternative RNA splicing are sorted to different subcellular compartments. FGF-2 and its antisense protein are co-expressed in many tissues and in some cases in the same cells. The strong conservation of sequence and genomic organization across animal species suggests important functional significance to the physical association of these transcript pairs.

Inducible nitric oxide synthase, nitrotyrosine and p53 mutations in the molecular pathogenesis of Barrett's esophagus and esophageal adenocarcinoma.

Nitric oxide (NO) has been implicated as a potential causative factor for endogenous p53 mutations in gastrointestinal malignancy. To investigate the role of NO in esophageal adenocarcinoma (EADC), we studied patterns of p53 mutations, expression of inducible nitric oxide synthase (iNOS) and the tissue accumulation of nitrotyrosine (NTS), a stable reaction product of NO and a marker for cellular protein damage, in human premalignant and malignant esophageal epithelia. Tissues were obtained from patients with gastroesophageal reflux disease (GERD)-induced esophagitis (n = 76), Barrett's esophagus (BE; n = 119) and primary EADC (n = 54). DNA sequencing was used to characterize p53 mutations, RT-PCR to study iNOS mRNA expression, and immunohistochemistry to study NTS. Relative to self-matched normal epithelia, a progressive increase in iNOS mRNA expression was seen in GERD (30%; 23/76), BE (48%; 57/119), and EADC (63%; 34/54) tissues (P < 0.001). Among patients with EADC, elevated levels of NTS immunoreactivity were more frequent in tumors with p53 mutations (11/21; 52%) compared with tumors with wild-type p53 (9/33; 27%; P = 0.063), and specifically in tumors with p53 mutations at CpG dinucleotides (10/12; 83%) compared with non-CpG p53 mutations (1/9; 11%; P = 0.008). The increasing frequency of iNOS (mRNA) overexpression in GERD, BE and EADC supports the hypothesis that an active inflammatory process, most likely a consequence of GERD, underlies molecular progression to EADC. The highly significant association between NTS, reflecting chronic NO-induced cellular protein damage, and endogenous p53 mutations at CpG dinucleotides, provides further evidence for a molecular link between chronic inflammation and esophageal malignancy.