Clinical and mutational spectrum of hypoparathyroidism, deafness and renal dysplasia syndrome.

BACKGROUND: Hypoparathyroidism, deafness and renal dysplasia (HDR) syndrome is a rare autosomal dominant disorder, secondary to mutations in the GATA-3 gene. Due to its wide range of penetrance and expressivity, the disease may not always be recognized. We herein describe clinical and genetic features of patients with HDR syndrome, highlighting diagnostic clues. METHODS: Medical records of eight patients from five unrelated families exhibiting GATA-3 mutations were reviewed retrospectively, in conjunction with all previously reported cases. RESULTS: HDR syndrome was diagnosed in eight patients between the ages of 18 and 60 years. Sensorineural deafness was consistently diagnosed, ranging from clinical hearing loss since infancy in seven patients to deafness detected only by audiometry in adulthood in one single patient. Hypoparathyroidism was present in six patients (with hypocalcaemia and inaugural seizures in two out of six). Renal abnormalities observed in six patients were diverse and of dysplastic nature. Three patients displayed nephrotic-range proteinuria and reached end-stage renal disease (ESRD) between the ages of 19 and 61 years, whilst lesions of focal and segmental glomerulosclerosis were histologically demonstrated in one of them. Interestingly, phenotype severity differed significantly between a mother and son within one family. Five new mutations of GATA-3 were identified, including three missense mutations affecting zinc finger motifs [NM_001002295.1: c.856A>G (p.N286D) and c.1017C>G (p.C339W)] or the conserved linker region [c.896G>A (p.R299G)], and two splicing mutations (c.924+4_924+19del and c.1051-2A>G). Review of 115 previously reported cases of GATA-3 mutations showed hypoparathyroidism and deafness in 95% of patients, and renal abnormalities in only 60%. Overall, 10% of patients had reached ESRD. CONCLUSIONS: We herein expand the clinical and mutational spectrum of HDR syndrome, illustrating considerable inter- and intrafamilial phenotypic variability. Diagnosis of HDR should be considered in any patient with hypoparathyroidism and deafness, whether associated with renal abnormalities or not. HDR diagnosis is established through identification of a mutation in the GATA-3 gene.

International Multi-Specialty Delphi Survey: Identification of Diagnostic Criteria for Hepatic and Renal Cyst Infection.

BACKGROUND: Cyst infection is one of the complications of autosomal dominant polycystic kidney disease and polycystic liver disease. The diagnosis is typically made on a mix of clinical, laboratory and imaging abnormalities but the importance of individual items is uncertain. We aimed to perform a Delphi survey amongst physicians to achieve consensus on diagnostic criteria. METHODS: We retrieved diagnostic items from the literature and conducted physician and patient interviews. All items were combined to create the online questionnaire. Participants rated each item during 3 consecutive rounds. Items were rated for diagnostic helpfulness for hepatic and renal cyst infection on a 9-point scale with anchors, from extremely unimportant (n = 1) to extremely important (n = 9). We determined consensus with the disagreement index. The median rating of each item was calculated and categorized into inappropriate (≤3.4), uncertain (3.5-6.4) or appropriate (≥6.5). By combining all items that reached an appropriate consensus rating, we developed a diagnostic algorithm based on expert consensus. RESULTS: We invited 58 physicians to participate in the survey. In total, 35 (60%) responded to round 1 of which 91% (n = 32) and 86% (n = 30) responded to round 2 and 3, respectively. The final panel included 23 nephrologists, 5 hepatologists, a nuclear medicine specialist and an infectious disease physician from 11 countries (male 67%, mean age 47 ± 11 years, median clinical experience 21 years). The panel rated the diagnostic helpfulness of 59 potential items. Ultimately, 22 hepatic and 26 renal items were rated appropriate, including positive blood cultures and fluorodeoxyglucose positron-emission CT imaging. Ultrasonography and absence of intracystic bleeding were amongst those deemed uncertain or inappropriate. Subsequently, by combining items rated appropriate, we developed a clinical tool to diagnose hepatic and renal cyst infection. CONCLUSIONS: We identified diagnostic items for hepatic and renal cyst infection and developed an expert-based diagnostic algorithm, which may aid physicians in the diagnostic work-up. A prospective study is necessary to validate this algorithm.

Complement activation and effect of eculizumab in scleroderma renal crisis.

BACKGROUND: Scleroderma renal crisis (SRC) is a life-threatening complication of systemic sclerosis characterized by abrupt onset of hypertension, thrombotic microangiopathy, and kidney injury. The mechanisms of the disease remain ill-defined, but a growing body of evidence suggests that activation of the complement system may be involved. METHODS: Here, we report the case of a patient presenting with severe SRC and strong evidence of complement activation, both in serum and in the kidney, in the absence of genetic defect of the complement system. RESULTS: Immunofluorescence studies on kidney biopsy showed significant deposits of C1q and C4d in the endothelium of renal arterioles, pointing toward activation of the classical pathway. Because of the dramatic clinical and histological severity, and the lack of response to early treatment with angiotensin-converting enzyme inhibitors, calcium channel blockers and plasma exchange, the patient was treated with the specific C5 blocker eculizumab.Contrarily to conventional treatment, eculizumab efficiently blocked C5b-9 deposition ex vivo and maintained hematological remission. Unfortunately, the patient died from heart failure a few weeks later. Postmortem examination of the heart showed diffuse patchy interstitial fibrosis, the typical lesion of systemic sclerosis-related cardiomyopathy, but normal coronary arteries and myocardial microvasculature. CONCLUSION: SRC may lead to complement system activation through the classical pathway. Early administration of C5 inhibitor eculizumab may have therapeutic potential in patients with life-threatening SRC refractory to conventional treatment using angiotensin-converting enzyme inhibitors.

Calcineurin Inhibitors Downregulate HNF-1ß and May Affect the Outcome of HNF1B Patients After Renal Transplantation.

BACKGROUND: Patients with HNF1B mutations develop progressive chronic renal failure, diabetes mellitus (40-50%), and liver tests abnormalities (40-70%). In HNF1B patients who reach end-stage renal disease, single kidney transplantation (SKT) or combined kidney-pancreas transplantation can be considered. METHODS: A retrospective multicenter study including 18 HNF1B patients receiving SKT or kidney-pancreas transplantation, and in vitro experiments including the characterization of the HNF1B expression after calcineurin inhibitor (CNI) exposure. RESULTS: After SKT, 50% of the HNF1B patients develop early posttransplantation diabetes mellitus, whereas 40% experience new-onset or severe worsening of preexisting abnormalities of liver tests, including severe cholestasis. In liver biopsies, disorders of the cholangiocytes primary cilium and various degrees of bile duct paucity and dysplasia were identified. In vitro studies combining CNI exposure and siRNA-mediated inhibition of NFATc revealed that calcineurin inhibition decreases HNF1B expression in epithelial cells but independent of NFATc. CONCLUSIONS: Because HNF1B-related disease is a heterozygous condition, CNIs used to prevent rejection may induce reduced expression of the nonmutated allele of HNF1B leading to a superimposed defect of HNF-1ß transcriptional activity. Taking into account the specific risk of posttransplantation diabetes mellitus and liver disorders in HNF1B patients, these findings advocate for in-depth characterization of pathways that regulate HNF1B and plead for considering individually tailored graft management that may include a CNI-free immunosuppressive regimen. Interventional studies will have to confirm this individualized approach.

Lanreotide Reduces Liver Volume, But Might Not Improve Muscle Wasting or Weight Loss, in Patients With Symptomatic Polycystic Liver Disease.

BACKGROUND & AIMS: Polycystic liver disease (PCLD) can induce malnutrition owing to extensive hepatomegaly and patients might require liver transplantation. Six months of treatment with the somatostatin analogue lanreotide (120 mg) reduces liver volume. We investigated the efficacy of a lower dose of lanreotide and its effects on nutritional status. METHODS: We performed an 18-month prospective study at 2 tertiary medical centers in Belgium from January 2011 through August 2012. Fifty-nine patients with symptomatic PCLD were given lanreotide (90 mg, every 4 weeks) for 6 months. Patients with reductions in liver volume of more than 100 mL (responders, primary end point) continued to receive lanreotide (90 mg) for an additional year (18 months total). Nonresponders were offered increased doses, up to 120 mg lanreotide, until 18 months. Liver volume and body composition were measured by computed tomography at baseline and at months 6 and 18. Patients also were assessed by the PCLD-specific complaint assessment at these time points. RESULTS: Fifty-three patients completed the study; 21 patients (40%) were responders. Nineteen of the responders (90%) continued as responders until 18 months. At this time point, they had a mean reduction in absolute liver volume of 430 ± 92 mL. In nonresponders (n = 32), liver volume increased by a mean volume of 120 ± 42 mL at 6 months. However, no further increase was observed after dose escalation in the 24 patients who continued to the 18-month end point. All subjects had decreased scores on all subscales of the PCLD-specific complaint assessment, including better food intake (P = .04). Subjects did not have a mean change in subcutaneous or visceral fat mass, but did have decreases in mean body weight (2 kg) and total muscle mass (1.06 cm(2)/h(2)). Subjects also had a significant mean reduction in their level of insulin-like growth factor 1, from 19% below the age-adjusted normal range level at baseline to 50% at 18 months (P = .002). CONCLUSIONS: In a prospective study, we observed that low doses of lanreotide (90 mg every 4 weeks) reduced liver volumes and symptoms in patients with PCLD. However, patients continued to lose weight and muscle mass. The effects of somatostatin analogues on sarcopenia require investigation. Clinicaltrials.gov: NCT01315795.

[Infectious complications in autosomal dominant polycystic kidney disease]. / Complications infectieuses associées à la polykystose rénale autosomique dominante.

Despite advances in the management of autosomal dominant polycystic kidney disease over the past two decades, infection of liver and kidney cysts remains a serious and potentially threatening complication. Kidney cyst infection is the most frequent complication. It is differentiated from hemorrhage by the clinical presentation (mainly the severity and duration of fever), C-reactive protein (CRP) and white blood cells levels, and the density of the suspected cyst on computed tomography. Liver cyst infection occurs more frequently in patients with large cysts volumes. It can be life threatening and has a tendency to recur. In both infections, the best radiological imaging technique is positron emission tomography after intravenous injection of [18F]-fluorodeoxyglucose combined with computed tomography. Treatment with a fluoroquinolone should be continued for 6 weeks. Cyst aspiration is necessary only when cysts are very large and/or when infection is resistant to antibiotic treatment. In patients who are candidates to kidney transplantation, a history of recurrent kidney cyst infection justifies pre-transplant nephrectomy, while a past history of recurrent liver cyst infection or angiocholitis leads to consider liver transplantation. Among extrarenal and extrahepatic complications of polycystic disease, colic diverticulosis is reported to be associated with increased risk of infection in patients on hemodialysis and after kidney transplantation. However, this observation needs to be confirmed.

Building a network of ADPKD reference centres across Europe: the EuroCYST initiative.

BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) is the most common monogenic inherited kidney disease, affecting an estimated 600 000 individuals in Europe. The disease is characterized by age-dependent development of a multiple cysts in the kidneys, ultimately leading to end-stage renal failure and the need of renal replacement therapy in the majority of patients, typically by the fifth or sixth decade of life. The variable disease course, even within the same family, remains largely unexplained. Similarly, assessing disease severity and prognosis in an individual with ADPKD remains difficult. Epidemiological studies are limited due to the fragmentation of ADPKD research in Europe. METHODS: The EuroCYST initiative aims: (i) to harmonize and develop common standards for ADPKD research by starting a collaborative effort to build a network of ADPKD reference centres across Europe and (ii) to establish a multicentric observational cohort of ADPKD patients. This cohort will be used to study factors influencing the rate of disease progression, disease modifiers, disease stage-specific morbidity and mortality, health economic issues and to identify predictive disease progression markers. Overall, 1100 patients will be enrolled in 14 study sites across Europe. Patients will be prospectively followed for at least 3 years. Eligible patients will not have participated in a pharmaceutical clinical trial 1 year before enrollment, have clinically proven ADPKD, an estimated glomerular filtration rate (eGFR) of 30 mL/min/1.73 m(2) and above, and be able to provide written informed consent. The baseline visit will include a physical examination and collection of blood, urine and DNA for biomarker and genetic studies. In addition, all participants will be asked to complete questionnaires detailing self-reported health status, quality of life, socioeconomic status, health-care use and reproductive planning. All subjects will undergo annual follow-up. A magnetic resonance imaging (MRI) scan will be carried out at baseline, and patients are encouraged to undergo a second MRI at 3-year follow-up for qualitative and quantitative kidney and liver assessments. CONCLUSIONS: The ADPKD reference centre network across Europe and the observational cohort study will enable European ADPKD researchers to gain insights into the natural history, heterogeneity and associated complications of the disease as well as how it affects the lives of patients across Europe.

Development and validation of a polycystic liver disease complaint-specific assessment (POLCA).

BACKGROUND & AIMS: Polycystic liver disease (PCLD) may lead to extensive hepatomegaly and invalidating complaints. Therapeutic decisions, including somatostatin-analogues (SAs) and (non)-transplant surgery are besides the existence of hepatomegaly, also guided by the severity of complaints. We developed and validated a self-report instrument to capture the presence and severity of disease specific complaints for PCLD. METHODS: The study population consisted of 129 patients. Items for the PCLD-complaint-specific assessment (POLCA) were developed based on the chart review of symptomatic PCLD patients (n=68) and literature, and discussed during expert-consensus-meetings. 61 patients who needed therapy were asked to complete the POLCA and the short form health survey version 2 (SF36V2) at baseline and after 6 months of SA-treatment. CT-scans were used to calculate liver volumes (LV). Factor analysis was conducted to identify subscales and remove suboptimal items. Reliability was assessed by Cronbach's alpha. Convergent, criterion validity and responsiveness were tested using prespecified hypotheses. RESULTS: In the validation group (n=61), 47 received lanreotide (LAN) and 14 were offered LAN as bridge to liver transplantation (LTx). Factor analysis identified four subscales, which correlated with the physical component summary (PCS). Baseline POLCA scores were significantly higher in LTx-listed patients. In contrast to SF36V2, POLCA-paired observations in 47 patients demonstrated that 2 subscales were lowered significantly and 2 borderline. LV reduction of ⩾ 120 ml resulted in a numerical, more pronounced relative decrease of all scores. CONCLUSIONS: In contrast to SF36V2, the POLCA shows good validity and responsiveness to measure complaint severity in PCLD.

Rituximab for minimal-change nephrotic syndrome in adulthood: predictive factors for response, long-term outcomes and tolerance.

BACKGROUND: Minimal-change nephrotic syndrome (MCNS) is a common cause of steroid sensitive nephrotic syndrome (NS) with frequent relapse. Although steroids and calcineurin inhibitors (CNIs) are the cornerstone treatments, the use of rituximab (RTX), a monoclonal antibody targeting B cells, is an efficient and safe alternative in childhood. METHODS: Because data from adults remain sparse, we conducted a large retrospective and multicentric study that included 41 adults with MCNS and receiving RTX. RESULTS: Complete (NS remission and withdrawal of all immunosuppressants) and partial (NS remission and withdrawal of at least one immunosuppressants) clinical responses were obtained for 25 and 7 patients, respectively (overall response 78%), including 3 patients that only received RTX and had a complete clinical response. After a follow-up time of 39 months (6-71), relapses occurred in 18 responder patients [56%, median time 18 months (3-36)]. Seventeen of these received a second course of RTX and then had a complete (n = 13) or partial (n = 4) clinical response. From multivariate analysis, on-going mycophenolate mofetil (MMF) therapy at the time of RTX was the only predictive factor for RTX failure [HR = 0.07 95% CI (0.01-0.04), P = 0.003]. Interestingly, nine patients were still in remission at 14 months (3-36) after B-cell recovery. No significant early or late adverse event occurred after RTX therapy. CONCLUSIONS: RTX is safe and effective in adult patients with MCNS and could be an alternative to steroids or CNIs in patients with a long history of relapsing MCNS.

Renal transplantation in autosomal dominant polycystic kidney disease.

In patients with autosomal dominant polycystic kidney disease (ADPKD) evaluated for kidney transplantation, issues related to native nephrectomy, cystic liver involvement, screening for intracranial aneurysms and living-related kidney donation deserve special consideration. Prophylactic native nephrectomy is restricted to patients with a history of cyst infection or recurrent haemorrhage or to those in whom space must be made to implant the graft. Patients with liver involvement require pretransplant imaging. Selection of patients for pretransplant screening of intracranial aneurysms should follow the general recommendations for patients with ADPKD. In living related-donor candidates aged <30 years and at-risk of ADPKD, molecular genetic testing should be carried out when ultrasonography and MRI findings are normal or equivocal. After kidney transplantation, patient and graft survival rates are excellent and the volume of native kidneys decreases. However, liver cysts continue to grow and treatment with a somatostatin analogue should be considered in patients with massive cyst involvement. Cerebrovascular events have a marginal effect on post-transplant morbidity and mortality. An increased risk of new-onset diabetes mellitus and nonmelanoma skin cancers has been reported, but several studies have challenged these findings. Finally, no data currently support the preferential use of mammalian target of rapamycin inhibitors as immunosuppressive agents in transplant recipients with ADPKD.

Fabry nephropathy: indications for screening and guidance for diagnosis and treatment by the European Renal Best Practice.

Fabry disease (FD) is an X-linked disorder of glycosphingolipid catabolism resulting in the accumulation of glycolipids including globotriaosylceramide in cells of various tissues resulting in end-organ manifestations. Initially, FD is typically characterized by angiokeratoma and recurrent episodes of neuropathic pain in the extremities occurring during childhood or adolescence. Most affected patients also exhibit a decreased ability to sweat. Later in life, FD results in left ventricular hypertrophy, proteinuria, renal failure and stroke. These later disease manifestations are non-specific and also common in diabetes, hypertension and atheromatosis and thus for most practitioners do not point into the direction of FD. As a consequence, FD is under-diagnosed and screening of high-risk groups is important for case finding, as is a thorough pedigree analysis of affected patients. In the nephrology clinic, we suggest to screen patients for FD when there is unexplained chronic kidney disease in males younger than 50 years and females of any age. In men, this can be performed by measuring α-galactosidase A activity in plasma, white blood cells or dried blood spots. In women, mutation analysis is necessary, as enzyme measurement alone could miss over one-third of female Fabry patients. A multidisciplinary team should closely monitor all known Fabry patients, with the nephrologist screening kidney impairment (glomerular filtration rate and proteinuria) on a regular basis. Transplanted Fabry patients have a higher mortality than the regular transplant population, but have acceptable outcomes, compared with Fabry patients remaining on dialysis. It is unclear whether enzyme replacement therapy (ERT) prevents deterioration of kidney function. In view of the lack of compelling evidence for ERT, and the low likelihood that a sufficiently powered randomized controlled trial on this topic will be performed, data of all patients with FD should be collected in a central registry.

Diagnosis of cyst infection in patients with autosomal dominant polycystic kidney disease: attributes and limitations of the current modalities.

Cyst infection is a diagnostic challenge in patients with autosomal dominant polycystic kidney disease (ADPKD) because of the lack of specific manifestations and limitations of conventional imaging procedures. Still, recent clinical observations and series have highlighted common criteria for this condition. Cyst infection is diagnosed if confirmed by cyst fluid analysis showing bacteria and neutrophils, and as a probable diagnosis if all four of the following criteria are concomitantly met: temperature of >38°C for >3 days, loin or liver tenderness, C-reactive protein plasma level of >5 mg/dL and no evidence for intracystic bleeding on computed tomography (CT). In addition, the elevation of serum carbohydrate antigen 19-9 (CA19-9) has been proposed as a biomarker for hepatic cyst infection. Positron-emission tomography after intravenous injection of 18-fluorodeoxyglucose, combined with CT, proved superior to radiological imaging techniques for the identification and localization of kidney and liver pyocyst. This review summarizes the attributes and limitations of these recent clinical, biological and imaging advances in the diagnosis of cyst infection in patients with ADPKD.

Autosomal dominant polycystic kidney disease is associated with central and nephrogenic defects in osmoregulation.

Autosomal dominant polycystic kidney disease (ADPKD) is associated with a urine-concentrating defect attributed to renal cystic changes. As PKD genes are expressed in the brain, altered central release of arginine vasopressin could also play a role. In order to help determine this we measured central and nephrogenic components of osmoregulation in 10 adults and 10 children with ADPKD, all with normal renal function, and compared them to 20 age- and gender-matched controls. Overnight water deprivation caused a lower rise in urine osmolality in the patients with ADPKD than controls, reflecting an impaired release of vasopressin and a peripheral defect in the patients. The reactivity of plasma vasopressin to water deprivation, as found in controls, was blunted in the patients with the latter showing lower urine osmolality for the same range of plasma vasopressin. The maximal urine osmolality correlated negatively with total kidney volume. Defective osmoregulation was confirmed in the children with ADPKD but was unrelated to number of renal cysts or kidney size. Thus, patients with ADPKD have an early defect in osmoregulation, with a blunted release of arginine vasopressin. This reflects expression of polycystins in hypothalamic nuclei that synthesize vasopressin, and this should be considered when evaluating treatments targeting the vasopressin pathway in ADPKD.

Phenotype and outcome in hereditary tubulointerstitial nephritis secondary to UMOD mutations.

BACKGROUND: UMOD mutations cause familial juvenile hyperuricemic nephropathy (FJHN) and medullary cystic kidney disease (MCKD), although these phenotypes are nonspecific. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We reviewed cases of UMOD mutations diagnosed in the genetic laboratories of Necker Hospital (Paris, France) and of Université Catholique de Louvain (Brussels, Belgium). We also analyzed patients with MCKD/FJHN but no UMOD mutation. To determine thresholds for hyperuricemia and uric-acid excretion fraction (UAEF) according to GFR, these parameters were analyzed in 1097 patients with various renal diseases and renal function levels. RESULTS: Thirty-seven distinct UMOD mutations were found in 109 patients from 45 families, all in exon 4 or 5 except for three novel mutations in exon 8. Median renal survival was 54 years. The type of mutation had a modest effect on renal survival, and intrafamilial variability was high. Detailed data available in 70 patients showed renal cysts in 24 (34.3%) of nonspecific localization in most patients. Uricemia was >75th percentile in 31 (71.4%) of 42 patients not under dialysis or allopurinol therapy. UAEF (n = 27) was <75th percentile in 70.4%. Among 136 probands with MCKD/FJHN phenotype, UMOD mutation was found in 24 (17.8%). Phenotype was not accurately predictive of UMOD mutation. Six probands had HNF1B mutations. CONCLUSIONS: Hyperuricemia disproportionate to renal function represents the hallmark of renal disease caused by UMOD mutation. Renal survival is highly variable in patients with UMOD mutation. Our data also add novel insights into the interpretation of uricemia and UAEF in patients with chronic kidney diseases.

Association of PKD2 (polycystin 2) mutations with left-right laterality defects.

Mutations in the PKD1 (polycystin 1) and PKD2 (polycystin 2) genes cause autosomal dominant polycystic kidney disease (ADPKD). Most Pkd2-null mouse embryos present with left-right laterality defects. For the first time, we report the association of ADPKD resulting from a mutation in PKD2 and left-right asymmetry defects. PKD1 and PKD2 were screened for mutations or large genomic rearrangements in 3 unrelated patients with ADPKD presenting with laterality defects: dextrocardia in one and situs inversus totalis in 2 others. A large gene deletion, a single-exon duplication, and an in-frame duplication respectively, were found in the 3 patients. These polymorphisms were found in all tested relatives with ADPKD, but were absent in unaffected related individuals. No left-right anomalies were found in other members of the 3 families. A possible association between heterotaxia and a PKD2 mutation in our 3 patients is suggested by: (1) the existence of laterality defects in Pkd2-null mouse and zebrafish models and (2) detection of a pathogenic PKD2 mutation in the 3 probands, although PKD2 mutations account for only 15% of ADPKD families. The presence of left-right laterality defects should be systematically screened in larger cohorts of patients with ADPKD harboring PKD2 mutations.

Positron-emission computed tomography in cyst infection diagnosis in patients with autosomal dominant polycystic kidney disease.

BACKGROUND: Cyst infection remains a challenging issue in patients with autosomal dominant polycystic kidney disease (ADPKD). In most patients, conventional imaging techniques are inconclusive. Isolated observations suggest that (18)fluorodeoxyglucose (¹8FDG) positron-emission computed tomography (PET/CT) might help detect cyst infection in ADPKD patients. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Comparative assessment of administrative databases from January 2005 to December 2009 identified 27 PET/CT scans performed in 24 ADPKD patients for suspicion of abdominal infection. Cyst infection was definite if confirmed by cyst fluid analysis. Cyst infection was probable if all four of the following criteria were met: temperature of >38°C for >3 days, loin or liver tenderness, C-reactive protein plasma level of >5 mg/dl, and no CT evidence for intracystic bleeding. Episodes with only two or three criteria were grouped as "fever of unknown origin". RESULTS: Thirteen infectious events in 11 patients met all criteria for kidney (n = 3) or liver (n = 10) cyst infection. CT was contributive in only one patient, whereas PET/CT proved cyst infection in 11 patients (84.6%). In addition, 14 episodes of "fever of unknown origin" in 13 patients were recorded. PET/CT identified the source of infection in nine patients (64.3%), including 2 renal cyst infections. Conversely, PET/CT showed no abnormal ¹8FDG uptake in 5 patients, including 2 intracystic bleeding. The median delay between the onset of symptoms and PET/CT procedure was 9 days. CONCLUSIONS: This retrospective series underscores the usefulness of PET/CT to confirm and locate cyst infection and identify alternative sources of abdominal infection in ADPKD patients.

A homozygous mutation in INVS causing juvenile nephronophthisis with abnormal reactivity of the Wnt/beta-catenin pathway.

Mutations in the INVS gene coding for inversin have been identified in patients with nephronophthisis type 2 (NPHP2), typically causing infantile onset of ESRD and potentially associated with situs inversus. We report a novel family with a homozygous INVS mutation (c.2695 C > T; p.Arg899X) deleting the C-terminus of inversin. Both affected patients had juvenile ESRD and were discordant for situs inversus. The end-stage kidneys showed chronic interstitial nephritis with cysts and abnormal expression of ß-catenin and Dishevelled-1 supporting up-regulated canonical Wnt pathway in tubular cells. This case shows that INVS mutation can cause juvenile nephronophthisis with abnormal reactivity of the Wnt/ß-catenin pathway.

Extrarenal manifestations of autosomal dominant polycystic kidney disease.

Although asymptomatic in most patients, extrarenal manifestations of ADPKD may become more clinically relevant with the increasing life expectancy of affected patients. They mainly encompass cysts in other organs than the kidney (liver: 94%, seminal vesicle: 40%, pancreas: 9%, arachnoid membrane: 8%, and spinal meningeal, 2%) and connective tissue abnormalities (mitral valve prolapse: 25%, intracranial aneurysms: 8%, and abdominal hernia: 10%). Their recognition may spare the patient from other, useless investigations (eg, when an arachnoid cyst is incidentally found) or lead to the implementation of prophylactic or therapeutic measures (eg, screening, sometimes followed by the treatment of an asymptomatic intracranial aneurysm in at-risk patients, or, in the presence of a severe polycystic liver disease, avoidance from estrogens and treatment aimed to slow cyst growth).