Fabry病肾病临床病理分析

目的阐明具有肾脏损害的Fabry病的临床病理特点。方法回顾性分析3例具有肾损害的Fabry病患者的临床表现,并对其肾活检组织进行免疫荧光、光镜及超微结构观察。结果3例患者均出现血尿、蛋白尿;光镜下肾小球足细胞体积增大,空泡变性,肾小管上皮也可出现上述改变;电镜下肾小球足细胞胞质内可见大量嗜锇性髓鞘样包涵体—圆形或卵圆形,明暗相间呈板层状,大小为0.3～10μm,外有单位膜包绕。结论具有肾脏损害的Fabry病患者临床上可出现蛋白尿、血尿,晚期常发展为肾功能衰竭。肾小球足细胞胞质内出现嗜锇性髓鞘样包涵体是Fabry病肾病特征性的形态学改变。     

Natural history of Fabry disease in females in the Fabry Outcome Survey

Background

Fabry disease is a rare X linked lysosomal storage disorder resulting from deficiency of α‐galactosidase A activity. Although the severity of clinical features in male patients is well described, only recently have studies reported the high prevalence of disabling clinical features in heterozygous females.

Aims

This study sets out to examine the clinical features and natural history of Fabry disease in further detail in a large group of female patients.

Methods

Data were obtained from 303 females enrolled in the Fabry Outcome Survey. Pain was assessed using the Brief Pain Inventory, and health related quality of life (HRQoL) was assessed using the European Quality of Life Questionnaire. A modified version of the Mainz Severity Score Index was also applied. Data on left ventricular mass (LVM) index, mean ventricular wall thickness, and glomerular filtration rate (GFR) were used to assess cardiac and renal involvement.

Results

The most commonly reported clinical features in females were neurological (77%) and cardiac (59%). A history of renal involvement was recorded in 40% of cases. Neurological features were the earliest to develop (mean age: 16 years), whereas cardiac (mean age: 33.5 years) and renal (mean age: 37.3 years) features developed later. LVM index increased exponentially with age. In addition, age was negatively correlated with estimated GFR and HRQoL.

Conclusions

Females with Fabry disease report important age related clinical features and clinical investigation demonstrates evidence of disease progression. This study highlights the importance of careful and longitudinal assessment of female heterozygote patients with Fabry disease.     

Cardiac and skeletal myopathy in Fabry disease: a clinicopathologic correlative study

Skeletal muscle disturbances are commonly reported in patients with Fabry disease. Whether they derive from cardiac dysfunction or direct muscle involvement is still unclear. Clinical, noninvasive, and invasive cardiac and muscle studies, including an endomyocardial and muscle biopsy, were obtained in 12 patients (mean age, 42.1 ± 12.6 years; range, 24-58 years) with Fabry disease. In the youngest patients (group A, 4 men aged <35 years), results of cardiac and skeletal noninvasive studies were normal, except for reduced velocities in tissue Doppler imaging. Histologic examination indicated that muscle myocytes were unaffected, whereas muscle vessels showed the presence of mild glycosphingolipid accumulation in endothelial and smooth muscle cells. In the heart, cardiomyocytes and endothelial and smooth muscle cells of intramural cardiac vessels were involved by the disease. The oldest patients (group B, 6 men and 2 women aged >35 years) showed ultrasound muscle disarray and electromyography signs of myopathy, increased left ventricular mass, and normal cardiac function. Histologic examination showed that muscle myocytes contained mild glycosphingolipid accumulation compared with severe engulfment of cardiomyocytes. Moreover, similar infiltration of myocardial and muscle intramural vessels, causing lumen narrowing and fibrofatty tissue replacement, was observed. Direct muscle involvement occurs in patients with Fabry disease. It is milder and delayed compared with that in the heart. The difference in organ function and the need of residual α-galactosidase A activity are the likely causes.     

Fabry disease: polymorphic haplotypes and a novel missense mutation in the GLA gene

Fabry disease: polymorphic haplotypes and a novel missense mutation in the GLA gene. Fabry disease (FD) is an X-linked lysosomal storage disorder with a heterogeneous spectrum of clinical manifestations that are caused by the deficiency of α-galactosidase A (α-Gal-A) activity. Although useful for diagnosis in males, enzyme activity is not a reliable biochemical marker in heterozygous females due to random X-chromosome inactivation, thus rendering DNA sequencing of the α-Gal-A gene, alpha-galactosidase gene (GLA), the most reliable test for the confirmation of diagnosis in females. The spectrum of GLA mutations is highly heterogeneous. Many polymorphic GLA variants have been described, but it is unclear if haplotypes formed by combinations of such variants correlate with FD, thus complicating molecular diagnosis in females with normal α-Gal-A activity. We tested 67 female probands with clinical manifestations that may be associated with FD and 110 control males with normal α-Gal-A activity. Five different combinations of GLA polymorphic variants were identified in 14 of the 67 females, whereas clearcut pathogenetic alterations, p.Met51Ile and p.Met290Leu, were identified in two cases. The latter has not been reported so far, and both mutant forms were found to be responsive to the pharmacological chaperone deoxygalactonojirimycin (DGJ; migalastat hydrochloride). Analysis of the male control population, as well as male relatives of a suspected FD female proband, permitted the identification of seven different GLA gene haplotypes in strong linkage disequilibrium. The identification of haplotypes in control males provides evidence against their involvement in the development of FD phenotypic manifestations.     

Fabry disease in children and response to enzyme replacement therapy: results from the Fabry Outcome Survey

The Fabry Outcome Survey (FOS) was established to extend the knowledge of the natural history of Fabry disease and to assess the effects of enzyme replacement therapy (ERT) with agalsidase alfa. As of March 2009, 64 boys and 34 girls with Fabry disease had enrolled in the FOS and been treated with agalsidase alfa for at least 6 months. The prevalence of symptoms tended to be reduced after 12 and 24 months of ERT in patients who experienced symptoms at baseline. In the entire population, non-significant decreases in the prevalence of gastrointestinal problems in boys and pain crises in girls were observed after 12-24 months. Kidney function and left ventricular mass indexed to height remained stable. Fifty-eight treatment-related adverse events were reported in 23 patients (21 boys and 2 girls), including 55 infusion reactions. Anti-agalsidase alfa IgG antibodies were found in two boys. No IgE antibodies were reported. This study represents the largest observational study of paediatric Fabry disease patients treated with ERT and indicates continued safety of long-term ERT in children. Continued long-term follow-up is recommended to determine early initiation of ERT, which could potentially slow or prevent the progression of serious morbidities of Fabry disease.     

Fabry disease: a functional and anatomical study of cardiac manifestations in 20 hemizygous male patients

Fabry disease (FD, OMIM 301500) is an X-linked disorder of glycosphingolipid metabolism resulting from the deficient activity of alpha-galactosidase A, a lysosomal acid hydrolase, leading to progressive lysosomal accumulation of incompletely metabolized neutral glycosphingolipids. Cardiac involvement is frequent. The objective of this study was to characterize the cardiac abnormalities in male patients affected with classic Fabry disease and define the context in which the clinicians were able to make the diagnosis. Clinical evaluation, laboratory tests, electrocardiography (ECG) and echocardiography were performed in 20 hemizygous men (mean age 39 years, range 12-65 years). The context of diagnosis was obtained by review of patients' charts. Left ventricular hypertrophy (LVH) and/or concentric remodeling were found in 12 patients (60%). Structural changes in mitral and aortic valves were found in 25% and 10% of cases, respectively. The sensitivity of the ECG Romhilt-Estes score for LVH was high (80%). Short PR interval (40%), ST segment abnormalities and conduction delay were frequent on ECG. Left ventricular mass index, ECG scores for LVH and systolic pulmonary pressure correlated positively with age. There was no relation between classic vascular risk factors and coronary artery disease, transient ischemic attack (TIA) or stroke. Diagnosis of Fabry disease was frequently suggested by nephrologists, dermatologists or geneticists. Echocardiograph and ECG abnormalities are frequently observed in patients with Fabry disease. Cardiologists should be aware of the diagnosis of Fabry disease in patients presenting with LVH, concentric remodeling, mitral and aortic valve thickening on echocardiography, short PR interval and conduction defects on ECG.     

Fabry Disease and the Effectiveness of Enzyme Replacement Therapy (ERT) in Left Ventricular Hypertrophy (LVH) Improvement: A Review and Meta-Analysis

Background: Fabry disease is an inherited lysosomal storage disease affecting multiple organs with complications, including cardiomyopathy such as left ventricular hypertrophy (LVH). Enzyme replacement therapy (ERT) has been the main treatment for Fabry patients since 2001. However, the indications of ERT are not clearly defined. We performed a meta-analysis according to previous studies to review the benefit of ERT for LVH improvement in Fabry patients.Methods: We performed a literature search from the National Center for Biotechnology Information (NCBI) and PubMed database without restriction of years for systematic review purposes. We performed a systematic review of clinical cohort studies and trials using a pooled analysis of proportions. We calculated the pooled proportions and the confidence intervals (CI) for left ventricular mass index (LVMI) for both ERT treatment and ERT treatment-naïve groups. The results for before ERT treatment and after ERT treatment are also investigated.Results: A total of 5 cohort studies and 2 randomized controlled trials (RCTs), involving a total of 552 participants (267 on ERT treatment versus 285 on naïve treatment), met the inclusion criteria. The pooled proportions analysis showed that the difference in means of LVMI between the ERT treatment group and the ERT treatment-naïve group was -0.149 [95% CI: -0.431, 0.132]. Effect differences favored the ERT treatment group over the ERT treatment-naïve group (p = 0.034). Another analysis included 3 cohort studies and 1 RCT with 442 participants (228 on before ERT and 214 on 4 years after ERT). The pooled proportions analysis showed that the difference in means of LVMI between the before ERT treatment group and the after ERT treatment group was -0.448 [95% CI: -0.787, -0.108]. It favored the 4 years after ERT group over the before ERT group (p = 0.037).Conclusions: Based on the currently available data, our meta-analysis showed that there are beneficial effects on LVH improvement with ERT in Fabry disease patients. It is better to start ERT as soon as we have diagnoses in female carriers and atypically affected males. Further research is needed to investigate the role of ERT in LVH improvement.     

Inner ear involvement in Fabry disease: Clinical and audiometric evaluation of a large cohort of patients followed in a reference centre

Background

Fabry disease (FD) is a lysosomal storage disorder (LSD) that involves the cochleovestibular system. Tinnitus and progressive sensorineural hearing loss are frequent complains. A stabilization of hearing function has been reported with enzyme replacement therapy (ERT). This study aims to characterize the inner ear involvement, identify factors associated to hearing loss and evaluate the effect of ERT on the hearing function of FD patients.

Brachial-Ankle Pulse Wave Velocity Predicts Decline in Renal Function and Cardiovascular Events in Early Stages of Chronic Kidney Disease

Objective: In this study, we investigated the predictive capacity of the brachial-ankle aortic pulse wave velocity (baPWV), a marker of arterial stiffness, for the decline in renal function and for cardiovascular events in the early stages of chronic kidney disease (CKD).Method: Two hundred forty-one patients who underwent a comprehensive check-up were included and were divided into two groups according to their estimated glomerular filtration rates (eGFR): patients with CKD categories G2, G3a and G3b (30 ≤ eGFR < 90 ml/min/1.73m², eGFR < 90 group; n=117) and those with eGFR ≥ 90 ml/min/1.73 m² (eGFR ≥ 90 group; n=124). The change in renal function, the eGFR change, was determined by the slope of eGFR against time. We analysed whether baPWV was associated with eGFR change or predicted cardiovascular events.Results: baPWV was independently associated with eGFR change in a multivariate analysis of the total patients (β=-0.011, p=0.011) and remained significantly associated with eGFR change in a subgroup analysis of the eGFR < 90 group (β=-0.015, p=0.035). baPWV was independently associated with cardiovascular events (odds ratio=1.002, p=0.048) in the eGFR < 90 group, but not in the eGFR ≥ 90 group. The receiver operative characteristic curve analysis showed that 1,568 cm/sec was the cut-off value of baPWV for predicting CV events in the eGFR < 90 group (area under curve=0.691, p=0.03)Conclusions: In patients with early stages of CKD, baPWV was independently associated with the decline in renal function and short-term cardiovascular events.     

Newborn screening for Fabry disease in Oregon: Approaching the iceberg of A143T and variants of uncertain significance

Fabry disease newborn screening (NBS) has been ongoing in Oregon for over 41 months by first-tier enzyme quantitation and second-tier DNA testing. During that period the majority of abnormal referrals received (34/60) were for the presence of the controversial c.427G > A (p.Ala143Thr) aka A143T and the majority of non-A143T referrals were for other variants of uncertain significance (17/60) resulting in at least 32 infants with an inconclusive case outcome even after clinical evaluation and/or diagnostic testing. To date there has been no significant family history or onset of symptoms in individuals with an inconclusive outcome. Based on our experience, we have developed a framework for approaching A143T and other variants of uncertain clinical significance in an attempt to balance sensitivity with the unnecessary medicalization of healthy infants.     

Functional and Clinical Consequences of Novel α‐Galactosidase A Mutations in Fabry Disease

Fabry disease (FD) is a rare metabolic disorder of glycosphingolipid storage caused by mutations in the GLA gene encoding lysosomal hydrolase α‐galactosidase A (α‐gal A). Recently, the diagnostic procedure for FD has advanced in several ways, through the development of a specific biomarker (lyso‐Gb3) and the implementation of newborn screenings, which acted as a catalyst to augment general awareness of the disease. Heterologous over‐expression of α‐gal A variants and subsequent in vitro measurement of enzyme activity provided molecular data to elucidate the relationship between mutation, enzyme damage, lyso‐Gb3 biomarker levels, and clinical phenotype. This knowledge is the foundation for improved counseling with regard to prognosis and therapeutic decisions. Herein, we resume the approach of in vitro characterization, with a further 73 mainly novel GLA gene mutations. Patient lyso‐Gb3 data were available for most of the mutations. All mutations were tested for responsiveness to pharmacological chaperone treatment and phenotypic data for 61 hemizygous male and 116 heterozygous female patients carrying a mutation associated with ≥20% residual activity, formerly classified as “mild” variant, were collected in order to evaluate the pathogenicity. We conclude that a mild GLA variant is typically characterized by high residual enzyme activity and normal biomarker levels. We found evidence that these variants can still be classified as a distinctive, but milder, sub‐type of FD.     

Fabry disease 'The New Great Imposter': results of the French Observatoire in Internal Medicine Departments (FIMeD)

Fabry disease (FD) is an X-linked lysosomal storage disorder due to α-galactosidase A deficiency. It is associated with a broad range of clinical symptoms, resulting in frequent misdiagnosis and diagnostic delay, which may impact on patient outcomes. This retrospective observational study of 58 FD patients referred to 10 internal medicine departments in France aimed to review differential diagnoses received prior to diagnosis and examines diagnostic delay. The average age at the time of diagnosis was 27.6 years (range: 10-60) and 42.2 years (range: 9-77) among the 23 males and 35 females analyzed, respectively. Most common symptoms that led to FD diagnosis were family history of FD (12 males and 27 females), followed by pain in extremities (10 males and 5 females), and angiokeratoma (8 males and 4 females). Eighteen patients had received alternative diagnoses prior to FD diagnosis, including a female patient with four previous diagnoses. Four case reports are presented, which illustrate the diagnostic 'odyssey' and delayed diagnosis often experienced by patients. Clinicians should consider a diagnosis of FD when presented with a wide range of symptoms, thus helping to shorten the diagnostic delay and facilitating early therapy with enzyme replacement therapy to improve patient outcomes.     

Identification of a novel point mutation (S65T) in α-galactosidase A gene in Chinese patients with Fabry disease

Fabry disease is an X-linked inborn error of sphingolipid catabolism resulting from deficient enzyme activity of α-galactosidase A. The molecular defects of human α-galactosidase A gene causing Fabry disease have been characterized, including gene rearrangement and point mutations, which show the genetic heterogeneity in Fabry disease. To characterize the molecular defects of these patients, each exon of α-galactosidase A gene including intron-exon junctions were PCR amplified using biotin-labelled primer and sequenced using magnetic beads solid-phase sequencing. A G to C transversion was identified in the last nucleotide of exon 1 in two unrelated Chinese patients. This mutation obliterates an EcoN1 restriction site. Family studies show close linkage with the affected family members. Screening of 100 alleles (22 males, 39 females) of unrelated normal Chinese can not find this mutation. This mutation not only changes the amino acid from serine to threonine, but also likely cause splicing defects. To our knowledge, this is the first report of mutation in Chinese patients with Fabry disease, and a novel mutation causing Fabry disease not reported in literature previously. Hum Mutat 11:328–330, 1998. © 1998 Wiley-Liss, Inc.     

Long-term effectiveness of enzyme replacement therapy in Fabry disease with the p.Arg227Ter variant: Fabry disease in Ostrobothnia (FAST) study

Fabry disease (FD) is an X chromosome-linked, life-threatening lysosomal disease caused by one of more than 1000 currently known variants in the α-galactosidase A (GLA) gene. The follow-up part of the Fabry Disease in Ostrobothnia (FAST) study reports the long-term effect of enzyme replacement therapy (ERT) on a prospectively collected cohort of 12 patients, 4 males and 8 females, mean age 46 years (SD 16), with the classical variant c.679C > T p.Arg227Ter, which is one of the most common FD variants worldwide. In the natural history period of the FAST study, half of the patients in both sexes had at least one major event, of which 80% were of cardiac origin. During 5 years of ERT, four patients had a total of six major clinical events consisting of one silent ischemic stroke, three ventricular tachycardias and two increased left ventricular mass indexes. In addition, four patients developed minor cardiac events, four patients minor renal events, and one patient a minor neurological event. ERTs may delay but not prevent the progression of the disease in most patients with the variant Arg227Ter. This variant might be suitable for investigating the efficacy of second-generation ERTs compared to the currently used ERTs regardless of sex.     

Histologic abnormalities of placental tissues in Fabry disease: a case report and review of the literature

Fabry disease is an X-linked lysosomal storage disease caused by deficiency of α-galactosidase A, resulting in the accumulation of globotriaosylceramide. Many women experience symptoms, but the understanding of placental and fetal aspects of the disease is limited. We report the pregnancy outcome in and placental pathology of a 37-year-old woman with Fabry disease. She became pregnant 2 years after starting enzyme replacement therapy and continued therapy throughout her pregnancy. At 38 weeks' gestation, she gave birth to a healthy boy with the same maternal Fabry mutation. The present case describes more extensive placental involvement by Fabry disease than has been previously reported. Globotriaosylceramide deposits were found within multiple cell types of the placenta, cord, and membranes. Because of the small numbers of cases described in the literature for comparison, it remains unclear if placental tissues are also targeted by enzyme replacement therapy.     

Role of Electron Microscopy in the Diagnosis of Nonneoplastic Renal Disease in Children

To assess the role of electron microscopy in the evaluation of pediatric renal biopsies, all native kidney biopsies performed in children for nonneoplastic renal disease over a 2-year period were reviewed. Of 80 biopsies, the role of electron microscopy was classified as “essential” in 50 (63%), “supportive or confirmatory” in 18 (23%), and “noncontributory” in 9 (11%), with no glomeruli available for study in 3 (4%). The role of electron microscopy with respect to indication for biopsy and final diagnosis is discussed. This study confirms the continued importance of electron microscopy in the evaluation of pediatric renal biopsies.     

Compliance Index,a Marker of Peripheral Arterial Stiffness,may Predict Renal Function Decline in Patients with Chronic Kidney Disease

Background: Compliance index derived from digital volume pulse (CI-DVP), measuring the relationship between volume and pressure changes in fingertip, is a surrogate marker of peripheral arterial stiffness. This study investigated if CI-DVP can predict renal function deterioration, cardiovascular events and mortality in patients with chronic kidney disease (CKD).Methods: In this prospective observational study, 149 CKD patients were included for final analysis. CI-DVP and brachial-ankle pulse wave velocity (baPWV) were measured, decline in renal function was assessed by the estimated glomerular filtration rate (eGFR) slope. Composite renal and cardiovascular outcomes were evaluated, including ≥50% eGFR decline, start of renal replacement therapy, and major adverse events.Results: Patients in CKD stages 3b to 5 had higher baPWV and lower CI-DVP values than those in patients with CKD stages 1 to 3a. Stepwise multivariate linear regression analysis showed that lower CI-DVP (p =0.0001) and greater proteinuria (p =0.0023) were independent determinants of higher eGFR decline rate. Multivariate Cox regression analysis revealed that CI-DVP (HR 0.68, 95% CI 0.46-1.00), baseline eGFR (HR 0.96, 95% CI 0.94-0.98) and serum albumin (HR 0.17, 95% CI 0.07-0.42) were independent predictors for composite renal and cardiovascular outcomes.Conclusions: Compliance index, CI-DVP, was significantly associated with renal function decline in patients with CKD. A higher CI-DVP may have independent prognostic value in slower renal function decline and better composite renal and cardiovascular outcomes in CKD patients.     

Methotrexate reduces antibody responses to recombinant human alpha-galactosidase A therapy in a mouse model of Fabry disease

Therapeutic enzymes are often recognized as foreign by the immune system of patients undergoing enzyme replacement therapy. The antibodies that develop may alter pharmacokinetics and biodistribution of the therapeutic protein, may be able to neutralize the activity of the enzyme, or may cause immune reactions in certain patients. We have explored treatment regimens to reduce the antibody response to human alpha-galactosidase A (r-halphaGAL) in Fabry (alphaGAL knock-out) and normal BALB/c mice. A wide variety of treatment modalities were tested, including high dose tolerance induction, increased frequency of therapeutic doses and immunosuppressive drugs in combination with administration of enzyme. The most substantial effects were observed in mice injected intravenously with r-halphaGAL in combination with methotrexate (MTX), which significantly lowered r-halphaGAL-specific serum antibody levels. A short course of treatment with MTX was able to reduce antibody and spleen cell proliferative responses to long-term r-halphaGAL treatment. MTX was able to suppress the development of r-halphaGAL-specific IgG in antigen-primed mice. However, MTX was not effective in dampening robust ongoing antibody responses. These experiments provide a framework for the design of clinical protocols to prevent the drug-specific antibody responses of patients undergoing enzyme replacement therapy.     

Screening of Fabry disease in patients with end-stage renal disease of unknown etiology: the first Thailand study

We aimed to explore the prevalence of Fabry disease in Thai patients who were diagnosed with end-stage renal disease (ESRD) of an unknown origin. Venous blood samples were collected from ESRD patients for biochemical and molecular studies. Alpha-galactosidase A (α-GAL A) screening was performed from dried-blood spots using fluorometry. Molecular confirmation was performed using DNA sequencing of the GLA gene. A total of 142 male and female patients were included in this study. Ten patients (7.04%) exhibited a significant decrease in α-GAL A activity. There were no definitive pathogenic mutations observed in the molecular study. However, four patients revealed a novel nucleotide variant at c.1 -10 C>T, which was identified as a benign variant following screening in the normal population. In conclusion, the α-GAL A assay utilizing dried-blood spots revealed a significant false positive rate. There was no definitive Fabry disease confirmed in Thai patients diagnosed with ESRD of unknown etiology.     

Fabry disease: ultrastructural lectin histochemical analyses of lysosomal deposits

Fabry disease is an X-linked inborn error of glycosphingolipid catabolism resulting from a deficiency of lysosomal α-galactosidase activity. Globotriaosylceramide accumulates predominantly in lysosomes of various tissues. Former studies have clarified the nature of this disease, and the accumulated materials in the lysosomes have been analyzed using biochemical techniques. In the present study, transmission electron microscopy was used to reveal the fine structure of these lysosomal deposits, and sugar residues in the lysosomal deposits in Fabry disease were examined by lectin histochemistry combined with enzyme digestion. This is the first report to describe the lysosomal sugar residues in Fabry disease analyzed using lectin histochemistry at the ultrastructural level. With these techniques, we were able to detect α-galactosyl, β-galactosyl and glucosyl sugar residues in the lysosomal deposits. The experimental procedures used in this study have considerable potential for use in investigations of glycolipid and glycoprotein storage diseases without the need for complex methodology and expensive materials. Received: 17 March 1999 / Accepted: 2 June 1999