Restless legs syndrome is contributing to fatigue and low quality of life levels in hemodialysis patients

AIM: To examine whether hemodialysis (HD) patients with restless legs syndrome (RLS) are subjects of greater fatigue and impaired quality of life (QoL) compared to HD patients without RLS. METHODS: Eighty five stable HD patients participated in this study. According to their RLS status, the patients were divided into the RLS group (n = 23) and the non-RLS group (n = 62). QoL, fatigue, sleep quality, daily sleepiness and depression symptoms were assessed by using various questionnaires. Finally, biochemical parameters including iron, ferritin, hemoglobin, hematocrit and parathormone were assessed. RESULTS: The HD patients with RLS scored worse in all the questionnaires used in the study (P < 0.05). The patients with RLS were more likely to receive the HD therapy on the morning shift, whilst 43.5% of the RLS patients reported to experience the RLS symptoms also during HD. The severity of RLS was correlated with fatigue, depression score and sleep quality (P < 0.05). CONCLUSION: HD patients with RLS are subject to lower QoL related parameters and greater fatigue compared to HD patients without RLS. RLS should be successfully managed in order to improve the QoL of the sufferers

Familial focal segmental glomerulosclerosis clinical and molecular study

The familial background in kidney diseases is under investigation since 19th century. Although speculated, the genetic involvement in the development of kidney diseases only recently became real by progress in molecular genetics. Nowadays correlation of kidney diseases to special DNA loci is possible. There have been recognized genes encoding glomerular proteins in podocyte cytoskeleton and slit diaphragm. Mutations of these genes result in the familial forms of nephrotic syndrome in general and especially FSGS. The inheritance of these diseases may be transmitted in autosomal dominant or recessive way. Genes appearing to be responsible for the familial forms of FSGS and nephrotic syndrome are ACTN4, encoding a-actinin-4 an important structural component of the podocyte cytoskeleton, TRPC6, a cation-selective ion-channel protein that mediates calcium signals, CD2AP, an immunoglobulin-like protein that is involved in nephrin integration with the podocyte cytoskeleton, and NPHS1 and NPHS2 encoding nephrin and podocin respectively. Mutations in the COL4A3/COL4A4 genes of the type IV collagen component of glomerular basement membranes (GBM) have been found in ~ 40% of cases of Thin Basement Membrane Nephropathy (TBMN) which is considered of excellent prognosis, rarely leading to proteinuria and chronic renal failure (CRF). Occasionally it has been associated with other glomerulopathies such as focal segmental glomerulosclerosis (FSGS). Here we report on 11 Cypriot families with 303 subjects, 118 of whom were clinically diagnosed to be affected. All families came to our attention because of the diagnosis of FSGS in renal biopsies while they all segregated asymptomatic isolated microscopic hematuria, proteinuria and variable degrees of renal impairment leading to ESRD and the need for renal replacement therapy or kidney transplantation, in the absence of IgA or other nephropathies. To this end, we performed genetic linkage analysis at three genetic loci 19q13 (ACTN-4), 11q21q22 (TRPC6) and 6p12 (CD2AP) associated with primary FSGS. There was no linkage between the disease and these DNA loci. We move our effort at locus 2q36 (COL4A3, COL4A4) that is linked with TBMN since the observation of renal biopsies showed uniform thinning of GBM <250 nm. We found positive linkage at locus 2q36 and subsequent DNA sequencing identified founder mutations in both, the COL4A3 and COL4A4 genes in 11 families that support the pathology of TBMN. In our cohort, of a total of 127 patients in eleven families who carried pathogenic COL4A3/COL4A4 mutations in heterozygosity, on whom we had detailed clinical information, 42 patients (33.1%) had progressed to chronic renal failure, while 18 of them (14.2%) had progressed to end-stage nephropathy that required renal replacement therapy. All renal biopsies showed FSGS. It is reasonable to hypothesize that COL4A3/COL4A4 mutations and TBMN either predispose patients to FSGS and CRF or sometimes TBMN coexists with another inherited factor (modifier genes) that is responsible for FSGS pathology and the progressive development of renal failure. At the same time, the effect of environmental factors that may selectively facilitate the progression of the disease remain unidentified and need further investigation. There are a lot of persons sharing the same mutation that could be investigated in the future for modifier genes. In this study the findings do not conform to the term “benign familial microscopic hematuria” and TBMN does not fulfil the long term renal prognosis that is written in the relevant literature.Το κληρονομικό υπόβαθρο των νεφρικών παθήσεων συζητάται από το 19ο αιώνα. Με την πρόοδο στη μοριακή γενετική έγινε δυνατή η χαρτογράφηση κάποιων νεφρικών παθήσεων στο ανθρώπινο γονιδίωμα. Για το νεφρωσικό σύνδρομο γενικά αλλά και την ΕΤΣΣ έχουν βρεθεί υπεύθυνα γονίδια που κωδικοποιούν πρωτεΐνες του σπειράματος (των ποδοκυττάρων και των μεταξύ τους διαφραγμάτων), μεταλλάξεις δε αυτών ευθύνονται για την εμφάνιση της νόσου με κληρονομική κατανομή. Η νόσος μεταβιβάζεται με αυτόσωμο επικρατούντα ή υπολειπόμενο χαρακτήρα καθώς και στο πλαίσιο συγγενών συνδρόμων. Γνωστά γονίδια είναι το ACTN4 που κωδικοποιεί την α-ακτινίνη-4, το TRPC6 που κωδικοποιεί ένα κανάλι κατιόντων στη μεμβράνη του ποδοκυττάρου, το CD2AP που κωδικοποιεί την πρωτεΐνη που σχετίζεται με το CD2 και τα NPHS1 και NPHS2 που κωδικοποιούν την νεφρίνη και την ποδοσίνη αντίστοιχα. Μεταλλάξεις στα γονίδια COL4A3/COL4A4 του κολλαγόνου IV, συστατικού των σπειραματικών βασικών μεμβρανών, έχουν βρεθεί περίπου στο 40% των περιπτώσεων της νεφροπάθειας της λεπτής μεμβράνης - thin membrane disease - (ΝΛΒΜ) που χαρακτηρίζεται από πολύ καλή πρόγνωση, οδηγώντας σπάνια σε σοβαρή λευκωματουρία και χρόνια νεφρική ανεπάρκεια (ΧΝΑ). Υπάρχουν όμως κάποιες αναφορές που συνδέουν τη ΝΛΒΜ με άλλες σπειραματοπάθειες, όπως η εστιακή τμηματική σπειραματοσκλήρυνση (ΕΤΣΣ) και η IgA νεφροπάθεια. Στη μελέτη αυτή ελέγχθηκαν 303 άτομα, μέλη 11 οικογενειών εκ των οποίων οι 118 εμφανίζουν κλινικά συμπτώματα ή εργαστηριακά ευρήματα της ΕΤΣΣ. Πολλά μέλη των οικογενειών αυτών εμφάνιζαν αιματουρία, ήπια ή σοβαρή λευκωματουρία και νεφρική ανεπάρκεια σε διάφορα στάδια ΧΝΝ, αποκλείοντας την IgA ή άλλη νεφροπάθεια. Παράλληλα μέλη αυτών των οικογενειών που είχαν υποβληθεί σε βιοψία νεφρού είχαν σαν σταθερό ιστολογικό εύρημα την ΕΤΣΣ. Πραγματοποιήθηκε γενετικός έλεγχος με τη μέθοδο της ανάλυσης σύνδεσης. Αυτό έγινε αρχικά για τις τρεις γενετικές περιοχές (19q13, 11q21q22, 6p12) που σύμφωνα με τη βιβλιογραφία η εμφάνιση μεταλλάξεων τους ευθύνεται για την οικογενή μορφή ΕΤΣΣ. Δεν αποδείχθηκε θετική συσχέτιση. Στη συνέχεια το ενδιαφέρον στράφηκε στη γενετική περιοχή 2q36q37 που συνδέεται με τη λεγόμενη «καλοήθη αιματουρία» η οποία έχει δειχθεί σε μικρό αριθμό περιστατικών να συνοδεύεται από εστιακή τμηματική σπειραματοσκλήρυνση. Μεταγενέστερη προσεκτική παρατήρηση των βιοψιών των ασθενών στο ηλεκτρονικό μικροσκόπιο υποστήριξε αυτή τη διάγνωση (πάχος μεμβράνης <250 nm). Παρατηρήθηκε ότι στις περισσότερες οικογένειες υπήρχε σύνδεση με την τελευταία γενετική περιοχή στο χρωμόσωμα 2q36q37, περιοχή που περιλαμβάνει τα γονίδια COL4A3 και COL4A4 που κωδικοποιούν τις αντίστοιχες αλυσίδες κολλαγόνου IV, α3 και α4. Η έρευνα επεκτάθηκε στην ανίχνευση μεταλλάξεων στα γονίδια αυτά, και εντοπίστηκαν τρεις μεταλλάξεις σε ετεροζυγία, γεγονός που συνάδει με τη διάγνωση της Νεφροπάθειας της Λεπτής Βασικής Μεμβράνης

COL4A3/COL4A4 Mutations Producing Focal Segmental Glomerulosclerosis and Renal Failure in Thin Basement Membrane Nephropathy

&lt;p&gt;Mutations in the COL4A3/COL4A4 genes of type IV collagen have been found in ~40% of cases of thin basement membrane nephropathy, which is characterized by microscopic hematuria and is classically thought to cause proteinuria and chronic renal failure rarely. Here we report our observations of 116 subjects from 13 Cypriot families clinically affected with thin basement membrane nephropathy. These families first came to our attention because they segregated microscopic hematuria, mild proteinuria, and variable degrees of renal impairment, but a dual diagnosis of focal segmental glomerulosclerosis (FSGS) and thin basement membrane nephropathy was made in 20 biopsied cases. Molecular studies identified founder mutations in both COL4A3 and COL4A4 genes in 10 families. None of 82 heterozygous patients had any extrarenal manifestations, supporting the diagnosis of thin basement membrane nephropathy. During follow-up of up to three decades, 31 of these 82 patients (37.8%) developed chronic renal failure and 16 (19.5%) reached end-stage renal disease. Mutations G1334E and G871C were detected in seven and three families, respectively, and were probably introduced by founders. We conclude that these particular COL4A3/COL4A4 mutations either predispose some patients to FSGS and chronic renal failure, or that thin basement membrane nephropathy sometimes coexists with another genetic modifier that is responsible for FSGS and progressive renal failure. The findings presented here do not justify the labelling of thin basement membrane nephropathy as a benign condition with excellent prognosis.&lt;/p&gt

Clinico-pathological correlations in 127 patients in 11 large pedigrees, segregating one of three heterozygous mutations in the COL4A3/ COL4A4 genes associated with familial haematuria and significant late progression to proteinuria and chronic kidney disease from focal segmental glomerulosclerosis

&lt;p&gt;&lt;strong&gt;Background.&lt;/strong&gt; Heterozygous mutations in the &lt;i&gt;COL4A3/ COL4A4&lt;/i&gt; genes are currently thought to be responsible for familial benign microscopic haematuria and maintenance of normal long-term kidney function.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Methods.&lt;/strong&gt; We report on 11 large Cypriot pedigrees with three such mutations. A total of 236 at-risk family members were genetically studied, and 127 (53.8%) carried a heterozygous mutation. Clinico-pathological correlations were available in all of these patients. Renal biopsies in 21 of these patients all showed various stages of focal, segmental glomerulosclerosis (FSGS). Thirteen of these biopsies were also studied with EM and showed thinning of the glomerular basement membrane.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results.&lt;/strong&gt; Mutation G1334E (&lt;i&gt;COL4A3&lt;/i&gt;) was found in six pedigrees, mutation G871C (&lt;i&gt;COL4A3&lt;/i&gt;) in four and mutation 3854delG (&lt;i&gt;COL4A4&lt;/i&gt;) in one pedigree. Clinical and laboratory correlations in all 127 mutation carriers (MC) showed that microscopic haematuria was the only urinary finding in patients under age 30. The prevalence of 'haematuria alone' fell to 66% between 31 and 50 years, to 30% between 51 and 70 and to 23% over age 71. Proteinuria with CRF developed on top of haematuria in 8% of all MC between 31 and 50 years, to 25% between 51 and 70 years and to 50% over 71 years. Altogether 18 of these 127 MC (14%) developed ESRD at a mean age of 60 years. Two members with different mutations married, and two of their children inherited both mutations and developed adolescent, autosomal recessive Alport syndrome (ATS), confirming that these mutations are pathogenic.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Conclusions.&lt;/strong&gt; Our data confirm for the first time a definite association of heterozygous &lt;i&gt;COL4A3/COL4A4&lt;/i&gt; mutations with familial microscopic haematuria, thin basement membrane nephropathy and the late development of familial proteinuria, CRF, and ESRD, due to FSGS, indicating that the term 'benign familial haematuria' is a misnomer, at least in this cohort. A strong hypothesis for a causal relationship between these mutations and FSGS is also made. Benign familial haematuria may not be so benign as commonly thought.&lt;/p&gt

Familial C3 Glomerulopathy Associated with CFHR5 Mutations: Clinical Characteristics of 91 Patients in 16 Pedigrees

Background and objectives Complement factor H and related proteins (CFHR) are key regulators of the alternative complement pathway, where loss of function mutations lead to a glomerulopathy with isolated mesangial C3 deposits without immunoglobulins. Gale et al. (12) reported on 26 patients with the first familial, hematuric glomerulopathy caused by a founder mutation in the CFHR5 gene in patients of Cypriot descent living in the United Kingdom. CFHR5 nephropathy is clinically characterized by continuous microscopic hematuria whereas some patients present with additional episodes of synpharyngitic macrohematuria, associated with infection and pyrexia. A subgroup of patients, particularly men, develop additional proteinuria, hypertension, and chronic renal disease or ESRD.Design, setting, participants, & measurements We herewith expand significantly on the study by Gale et al., reporting on histologic, molecular, and clinical findings in 91 patients from 16 families with the same founder mutation.Results Eighty-two patients (90%) exhibited microscopic hematuria; 51(62%), exhibited only microscopic hematuria, whereas the remaining 31 additionally had proteinuria (38%); 28 proteinuric patients developed chronic renal failure (CRF). Among carriers of CFHR5 mutation aged >50 years, 80% of the men and 21% of the women developed CRF; 18 developed ESRD (14 men [78%], 4 women [22%]).Conclusions The diagnosis of CFHR5-related, isolated C3 glomerulopathy was established in 2009 using newly described mutation analysis after decades of follow-up with unclear diagnoses, occasionally confused with IgA nephropathy. This larger patient cohort establishes the clinical course, significant variable expressivity, and marked gender difference regarding the development of CRF and ESRD. Clin J Am Soc Nephrol 6: 1436-1446, 2011. doi: 10.2215/CJN.0954101

Frequency of COL4A3/COL4A4 mutations amongst families segregating glomerular microscopic hematuria and evidence for activation of the unfolded protein response. Focal and segmental glomerulosclerosis is a frequent development during ageing.

Familial glomerular hematuria(s) comprise a genetically heterogeneous group of conditions which include Alport Syndrome (AS) and thin basement membrane nephropathy (TBMN). Here we investigated 57 Greek-Cypriot families presenting glomerular microscopic hematuria (GMH), with or without proteinuria or chronic kidney function decline, but excluded classical AS. We specifically searched the COL4A3/A4 genes and identified 8 heterozygous mutations in 16 families (28,1%). Eight non-related families featured the founder mutation COL4A3-p.(G1334E). Renal biopsies from 8 patients showed TBMN and focal segmental glomerulosclerosis (FSGS). Ten patients (11.5%) reached end-stage kidney disease (ESKD) at ages ranging from 37-69-yo (mean 50,1-yo). Next generation sequencing of the patients who progressed to ESKD failed to reveal a second mutation in any of the COL4A3/A4/A5 genes, supporting that true heterozygosity for COL4A3/A4 mutations predisposes to CRF/ESKD. Although this could be viewed as a milder and late-onset form of autosomal dominant AS, we had no evidence of ultrastructural features or extrarenal manifestations that would justify this diagnosis. Functional studies in cultured podocytes transfected with wild type or mutant COL4A3 chains showed retention of mutant collagens and differential activation of the unfolded protein response (UPR) cascade. This signifies the potential role of the UPR cascade in modulating the final phenotype in patients with collagen IV nephropathies

Clinical, pathologic and mutational analysis results for the families that mutations were found in the present patient cohort.

<p>Clinical, pathologic and mutational analysis results for the families that mutations were found in the present patient cohort.</p

Details of mutagenic primers used in this work for introducing mutations in cDNA constructs that were transiently transfected into cultured podocytes AB8/13.

<p>Details of mutagenic primers used in this work for introducing mutations in cDNA constructs that were transiently transfected into cultured podocytes AB8/13.</p

Mutant <i>COL4A3</i> chains expressed in AB8/13 cultured podocytes demonstrate a trend for increased intracellular retention.

<p>(a) AB8/13 cells were transiently transfected with expression vectors containing wild-type <i>COL4A3</i>-WT or the mutant <i>COL4A3</i> (p.G1334E, p.G871C, p.G484R, p.A587G) cDNAs that included a HA epitope at C-terminus. Single chain expression was measured via Western blot analysis of the cell lysate, 48 h after transfection. No HA antigen was detected in AB8/13 cells transfected with a construct expressing the empty vectors. Shown is a representative Western blot of proteins in cell lysates. (b) All mutant chains show a trend towards increased intracellular retention as compared to the wild type chain, although not reaching significance at the 48 h time point. Shown is densitometry analysis data normalized to tubulin expression. Data are represented as means ± SEM of n≥3 independent experiments.</p

Mutations detected in <i>COL4A3</i> and <i>COL4A4</i> genes.

<p>*these mutations tested negative in an additional collection of 52 patients with chronic kidney disease.</p><p>**this mutation was detected only in a single patient during screening of 153 patient samples. It was subsequently detected in six of 120 Cypriot controls. It is a suspect founder mutation and is under further investigation.</p>+<p>these mutations tested negative in an additional collection of 40 patients with glomerulonephritis of unknown aetiology CY, Cypriot samples; RO, Romanian sample; ND: Not Done; NA: Not applicable.</p><p>Mutations detected in <i>COL4A3</i> and <i>COL4A4</i> genes.</p