The P274S Mutation of Lecithin-Cholesterol Acyltransferase (LCAT) and Its Clinical Manifestations in a Large Kindred.

RATIONALE & OBJECTIVE: Lecithin-cholesterol acyltransferase (LCAT) catalyzes the maturation of high-density lipoprotein. Homozygosity for loss-of-function mutations causes familial LCAT deficiency (FLD), characterized by corneal opacities, anemia, and renal involvement. This study sought to characterize kidney biopsy findings and clinical outcomes in a family with FLD. STUDY DESIGN: Prospective observational study. SETTING & PARTICIPANTS: 2 (related) index patients with clinically apparent FLD were initially identified. 110 of 122 family members who consented to genetic analysis were also studied. PREDICTORS: Demographic and laboratory parameters (including lipid profiles and LCAT activity) and full sequence analysis of the LCAT gene. Kidney histologic examination was performed with samples from 6 participants. OUTCOMES: Cardiovascular and renal events during a median follow-up of 12 years. Estimation of annual rate of decline in glomerular filtration rate. ANALYTICAL APPROACH: Analysis of variance, linear regression analysis, and Fine-Gray competing-risk survival analysis. RESULTS: 9 homozygous, 57 heterozygous, and 44 unaffected family members were identified. In all affected individuals, full sequence analysis of the LCAT gene revealed a mutation (c.820C>T) predicted to cause a proline to serine substitution at amino acid 274 (P274S). Homozygosity caused a complete loss of LCAT activity. Kidney biopsy findings demonstrated lipid deposition causing glomerular basement membrane thickening, mesangial expansion, and "foam-cell" infiltration of kidney tissue. Tubular atrophy, glomerular sclerosis, and complement fixation were associated with worse kidney outcomes. Estimated glomerular filtration rate deteriorated among homozygous family members at an average annual rate of 3.56 mL/min/1.73 m2. The incidence of cardiovascular and renal complications was higher among homozygous family members compared with heterozygous and unaffected members. Mild thrombocytopenia was a common finding among homozygous participants. LIMITATIONS: The presence of cardiovascular disease was mainly based on medical history. CONCLUSIONS: The P274S LCAT mutation was found to cause FLD with renal involvement. Tubular atrophy, glomerular sclerosis, and complement fixation were associated with a worse renal prognosis.

Histological grading in primary membranous nephropathy is essential for clinical management and predicts outcome of patients.

AIMS: Diagnosis of primary membranous nephropathy (PMN) is mainly based on immunofluorescence/immunohistochemistry findings. However, assessment of specific features on optical microscopy can help to estimate the severity of the disease, guide treatment and predict the response. The aim of this study was to identify, classify and grade the precise histological findings in PMN to predict renal function outcome and guide treatment. METHODS AND RESULTS: Histological parameters, including focal segmental sclerosis (FSGS), tubular atrophy (TA), interstitial fibrosis (IF) and vascular hyalinosis (VH), were re-evaluated in 752 patients with PMN. Their predictive value was estimated separately, and also in a combination score (FSTIV) graded from 0 to 4. Finally, the impact of histology was assessed in the response to immunosuppressive treatment. Mean age of patients was 53.3 (15-85) years and most presented with nephrotic syndrome. FSGS was present in 32% and VH in 51% of the patients, while TA and IF were graded as stage ≥1 in 52% and 51.4%, respectively. The follow-up period was 122.3 (112-376) months. FSGS, TA and IF and VH were associated with impaired renal function at diagnosis (P = 0.02, P < 0.0001, P = 0.001 and P = 0.02, respectively) and at the end of follow-up (P = 0.004, P < 0.0001, P < 0.0001 and P = 0.04, respectively). In multiple regression and binary logistic analysis, the presence of FSGS and degree of TA were the most significant parameters predicting renal function outcome, defined either by eGFR (end), FSGS (r = 0.6, P < 0.0001) and TA (r = 0.6, P < 0.0001), or by the endpoint of >50% eGFR reduction, FSGS (P = 0.001) and TA (P = 0.02). Also, patients presented with FSGS, IF, VH and/or with FSTIV > 1 could benefit from immunosuppression, regardless of clinical presentation. CONCLUSIONS: The presence and degree of four histological indices, FSGS, VH, TA and IF, assessed separately or in combination, and FSTIV score not only predict renal function outcome after long-term follow-up, but can also help in the choice of appropriate treatment. Decisions concerning immunosuppressive treatment can be guided by pathology regardless of clinical findings.

The Effect of Natural LCAT Mutations on the Biogenesis of HDL.

We have investigated how the natural LCAT[T147I] and LCAT[P274S] mutations affect the pathway of biogenesis of HDL. Gene transfer of WT LCAT in LCAT(-/-) mice increased 11.8-fold the plasma cholesterol, whereas the LCAT[T147I] and LCAT[P274S] mutants caused a 5.2- and 2.9-fold increase, respectively. The LCAT[P274S] and the WT LCAT caused a monophasic distribution of cholesterol in the HDL region, whereas the LCAT[T147I] caused a biphasic distribution of cholesterol in the LDL and HDL region. Fractionation of plasma showed that the expression of WT LCAT increased plasma apoE and apoA-IV levels and shifted the distribution of apoA-I to lower densities. The LCAT[T147I] and LCAT[P274S] mutants restored partially apoA-I in the HDL3 fraction and LCAT[T147I] increased apoE in the VLD/IDL/LDL fractions. The in vivo functionality of LCAT was further assessed based on is its ability to correct the aberrant HDL phenotype that was caused by the apoA-I[L159R]FIN mutation. Co-infection of apoA-I(-/-) mice with this apoA-I mutant and either of the two mutant LCAT forms restored only partially the HDL biogenesis defect that was caused by the apoA-I[L159R]FIN and generated a distinct aberrant HDL phenotype.

Immunosuppressive regimens based on Cyclophospamide or Calcineurin inhibitors: Comparison of their effect in the long term outcome of Primary Membranous Nephropathy.

INTRODUCTION: Management of the Primary Membranous Nephropathy (PMN) usually involves administration of immunosuppressives. Cyclophosphamide (Cyclo) and Calcineurin Inhibitors (CNIs) are both widely used but only limited data exist to compare their efficacy in long term follow-up. AIM: The aim of the present study was to estimate and compare long term effects of Cyclo and CNIs in patients with PMN. PATIENTS-METHODS: Clinical data, histologic findings and long term outcome were retrospectively studied. The response to treatment and rate of relapse was compared between patients treated with CNIs or Cyclo based immunosuppressive regimens. RESULTS: Twenty three centers participated in the study, with 752 PMN patients (Mean age 53.4(14-87) yrs, M/F 467/285), followed for 10.1±5.7 years. All patients were initially treated with Renin Angiotensin Aldosterone System inhibitors (RAASi) for at least 6 months. Based on their response and tolerance to initial treatment, patients were divided into 3 groups, group I with spontaneous remission, who had no further treatment, group II, continued on RAASi only, and group III on RAASi+immunosuppression. Immunosuppressive regimes were mainly based on CNIs or Cyclo. Frequent relapses and failure to treatment were more common between patients who had started on CNIs (n = 381) compared to those initially treated with Cyclo (n = 110), relapse rate: 25.2% vs. 6.4%, p<0.0001, and no response rate: 22.5% vs. 13.6%, p = 0.04, respectively. CONCLUSIONS: Long term follow up showed that administration of Cyclo in PMN is followed by better preservation of renal function, increased response rate and less frequent relapses, compared to CNIs.

Multicenter epidemiological study to assess the population of CKD patients in Greece: results from the PRESTAR study.

BACKGROUND: Chronic Kidney Disease (CKD) is a relatively common condition not only associated with increased morbidity and mortality but also fuelling End Stage Renal Disease (ESRD). Among developed nations, Greece has one of the highest ESRD incidence rates, yet there is limited understanding of the epidemiology of earlier stages of CKD. METHODS: Cross-sectional survey of pre-dialysis CKD outpatients in nephrology clinics in the National Health Care system between October 2009 and October 2010. Demographics, cause of CKD, blood pressure, level of renal function, duration of CKD and nephrology care, and specialty of referral physician were collected and analyzed. Different methods for estimating renal function (Cockroft-Gault [CG], CKD-Epi and MDRD) and staging CKD were assessed for agreement. RESULTS: A total of 1,501 patients in 9 centers were enrolled. Diabetic nephropathy was the most common nephrologist assigned cause of CKD (29.7%). In total, 36.5% of patients had self-referred to the nephrologist; patients with diabetes or serum creatinine above 220 µmol/l (eGFR<40 ml/min/1.73 m2) were more likely to have been referred by a physician. Agreement between MDRD and CKD-Epi, but not between CG, the other estimating equations, was excellent. There was substantial heterogeneity with respect to renal diagnoses, referral patterns and blood pressure among participating centers. CONCLUSIONS: In this first epidemiologic assessment of CKD in Greece, we documented delayed referral and high rates of self-referral among patients with CKD. eGFR reporting, currently offered by a limited number of laboratories, may facilitate detection of CKD at an earlier, more treatable stage.

Hematological abnormalities in inborn errors of metabolism--how frequent are they? The Cretan experience.

This study aimed to ascertain the frequency and type of hematological findings in a defined group of patients with inborn errors on Crete. The key role of these hematological findings in the diagnosis of the inborn errors in daily practice was explored. A variety of hematological findings were obtained from 31 of the 132 subjects who had been referred to the University Hospital of Heraklion. A diagnosis of inborn errors of metabolism (IEM) was confirmed in 21 subjects, but in 12 of them the diagnosis was combined with hematological findings. The hematological findings consist of a neglected area in the diagnosis of the IEM, and cooperation of primary care physicians and neurologists could help hematologists in the management of people with unexplained hematological symptoms and signs.