Prevalence of chronic kidney disease in fabry disease patients: Multicenter cross sectional study in Argentina

Baseline Characteristics of Fabry Disease "Amenable" Migalastat Patients in Argentinian Cohort

Fabry disease (FD) is a multisystem lysosomal storage disorder induced by genetic variants in the alpha-galactosidase A (αGalA) gene. Some FD patients have GLA variants with a reduction in overall αGalA enzymatic activity due to mutated proteins with reduced stability, caused by protein misfolding and premature degradation, but the αGalA catalytic activity remains conserved ("amenable" genetic variants). To correct this misfolding and to prevent premature degradation, migalastat, a small iminosugar molecule was developed. We report the clinical characteristics of FD "amenable" cohort patients from Argentina, prior to starting treatment with migalastat. Seventeen Fabry adult patients were recruited from 13 Argentinian Centers; 8 males (47.1%) and 9 females (52.9%) were included. All genotypes included were missense-type "amenables" mutations. Some classic FD typical early manifestations were more frequent in patients with "classic" versus "late-onset" FD phenotype (pain, p=0.002; cornea verticillata, p=0.019). There was a statistically significant difference in estimated glomerular filtration rate in the "classic" versus "late-onset" phenotype (p=0.026) but no difference between genders (p=0.695). Left ventricular mass was similar between genders (p=0.145) and phenotypes (p=0.303). Cardiovascular risk factors were present among "late-onset" females (obesity 50% and smoke 25%). In patients who started "de novo" migalastat, the main indications were (i) heart disease, (ii) kidney damage, and (iii) pain, while in "switched from prior enzyme replacement therapy" patients, the most frequent indication was "patient decision;" this coincides with publications by other authors.

Biomarkers for Monitoring Renal Damage Due to Fabry Disease in Patients Treated with Migalastat: A Review for Nephrologists

Nephropathy is a major Fabry disease complication. Kidney biopsies reveal glomerulosclerosis even in pediatric patients. The main manifestations of Fabry nephropathy include reduced glomerular filtration rate and proteinuria. In 2016, an oral pharmacological Chaperone was approved to treat Fabry patients with “amenable” mutations. Because (i) Fabry disease is a rare disorder that frequently causes kidney damage, and (ii) a new therapeutic is currently available, it is necessary to review wich biomarkers are useful for nephropathy follow-up among Fabry “amenable” patients receiving migalastat. The literature search was conducted in MEDLINE, EMBASE, SCOPUS, Cochrane, and Google academic. Prospective studies in which renal biomarkers were the dependent variable or criterion, with at least 6 months of follow-up, were included. Finally, we recorded relevant information in an ad hoc database and summarized the main results. To date, the main useful biomarker for nephropathy monitoring among Fabry “amenable” patients receiving migalastat is glomerular filtration rate estimated by equations that include serum creatinine.

Arrhythmias in Chronic Kidney Disease

Arrhythmias cause disability and an increased risk of premature death in the general population but far more so in patients with renal failure. The association between the cardiac and renal systems is complex and derives in part from common causality of renal and myocardial injury from conditions including hypertension and diabetes. In many cases, there is a causal relationship, with renal dysfunction promoting arrhythmias and arrhythmias exacerbating renal dysfunction. In this review, the authors expand on the challenges faced by cardiologists in treating common and uncommon arrhythmias in patients with renal failure using pharmacological interventions, ablation and cardiac implantable device therapies. They explore the most important interactions between heart rhythm disorders and renal dysfunction while evaluating the ways in which the coexistence of renal dysfunction and cardiac arrhythmia influences the management of both.

Atherosclerosis in Fabry Disease-A Contemporary Review

Fabry disease (FD) is a lysosomal storage disorder characterised by a deficiency in the enzyme α-galactosidase A resulting in sphingolipid deposition which causes progressive cardiac, renal, and cerebral manifestations. The case illustrates a patient with FD who died suddenly, and medical examination demonstrated myocardial scarring and prior infarction. Angina is a frequent symptom in FD. Our own data are consistent with registry data indicating a high prevalence of risk factors for coronary artery disease (CAD) in FD that may accelerate conventional atherosclerosis. Patients with FD also have a higher high-density lipoprotein (HDL)/total cholesterol (T-Chol) ratio which may further accelerate atherosclerosis through expression of early atherosclerotic markers. Patients with FD may develop CAD both via classical atherosclerosis and through formation of thickened fibrocellular intima containing fibroblasts with storage of sphingolipids. Both mechanisms occurring together may accelerate coronary stenosis, as well as alter myocardial blood flow. Our data supports limited data that, although coronary flow may be reduced, the prevalence of epicardial coronary stenosis is low in FD. Microvascular dysfunction and arterial wall stress from sphingolipid deposition may form reactive oxygen species (ROS) and myeloperoxidase (MPO), key atherosclerotic mediators. Reduced myocardial blood flow in FD has also been demonstrated using numerous imaging modalities suggesting perfusion mismatch. This review describes the above mechanisms in detail, highlighting the importance of modifying cardiovascular risk factors in FD patients who likely develop accelerated atherosclerosis compared to the general population.

Severe manifestations and treatment of COVID-19 in a transplanted patient with Fabry disease

Fabry disease is an X linked disease caused by pathogenic variants in the GLA gene. The cardiovascular and renal systems are most affected in Fabry patients and may require heart or kidney transplants in the late stages of the disease depending on severity of manifestations. Enzyme replacement therapy (ERT) has proven to delay progression of Fabry disease considerably, especially when started early in life. Current research has shown that individuals who have received cardiac or renal transplants or are currently on dialysis have the greatest probability of developing severe manifestations of COVID-19. It has also been shown that people who contract COVID-19 experience a rapid increase in cytokine levels which can lead to a prothrombotic state and have a greater risk in the presence of comorbidities. A history of cardiac or renal transplants as well as the naturally elevated cytokine levels in Fabry disease make it likely that COVID-19 could have a greater impact on the health of these patients. We report the case of a 67-year-old male with diabetes mellitus, history of kidney transplant, and Fabry disease treated late in progression of the disease first with agalsidase beta ERT, then oral migalastat who developed severe manifestations of COVID-19. The autopsy findings showed acute and organizing hyaline membrane disease consistent with COVID-19 pneumonia and secondary invasive bronchopulmonary aspergillosis with cavitary lesion formation. The sections of the heart showed scattered subendocardial fibrosis, and the transplanted kidneys showed thyroidization and interstitial nephritis potentially secondary to COVID-19, in addition to his long-standing renal disease. This case report serves to chronicle complications in a complex patient with late stage Fabry disease and multiple COVID-19 related complications who succumbed from respiratory failure despite the advanced management for the COVID-19 infection.

Variable clinical features of patients with Fabry disease and outcome of enzyme replacement therapy

Fabry disease (FD) is an X-linked lysosomal storage disorder caused by a deficiency in the enzyme α-galactosidase A due to mutations in the GLA gene. This leads to an accumulation of globotriaosylceramide (GL-3) in many tissues, which results in progressive damage to the kidneys, heart, and nervous system. We present the molecular and clinical characteristics and long-term outcomes of FD patients from a multidisciplinary clinic at the University of California, Irvine treated with agalsidase beta enzyme replacement therapy (ERT) for 2-20 years. This cohort comprised 24 adults (11 males, 13 females) and two male children (median age 45; range 10-68 years). Of the 26 patients in this cohort, 20 were on ERT (12 males, 8 females). We describe one novel variant not previously reported in the literature in a patient with features of 'classic' FD. The vast majority of patients in this cohort presented with symptoms of 'classic' FD including peripheral neuropathic pain, some form of cardiac involvement, angiokeratomas, corneal verticillata, hypohidrosis, tinnitus, and gastrointestinal symptoms, primarily abdominal pain. The majority of males had clinically evident renal involvement. An annual eGFR reduction of -1.88 mL/min/1.73 m²/yr during the course of ERT was seen in this cohort. The most common renal presentation was proteinuria, and one individual required a renal transplant. Other common findings were pulmonary involvement, lymphedema, hearing loss, and significantly, three patients had strokes. Notably, there was a high prevalence of endocrine dysfunction and low bone mineral density, including several with osteoporosis. While enzyme replacement therapy (ERT) cleared plasma GL-3 in this cohort, there was limited improvement in renal function or health-related quality of life based on the patient-reported SF-36 Health Survey. Physical functioning significantly declined over the course of ERT treatment, which may be, in part, due to the late initiation of ERT in several patients. Further delineation of the phenotypic and genotypic spectrum in patients with FD and the long-term outcome of ERT will help improve management and treatment options for this disease.

Variables Associated with Glomerular Hyperfiltration in Fabry Disease Patients

Background: Fabry disease is a genetic disorder caused by the deficiency of the lysosomal α-galactosidase A enzyme. This failure generates the storage of globotriaosylceramide in different cells with a progressive multi-organ involvement. Objectives: To report the prevalence of glomerular hyperfiltration in Fabry disease patients and the association with clinical variables. Methods: Adult patients (≥ 18 years) at the moment of FD diagnosis were evaluated. The variables studied were: central and peripheral nervous system compromise, presence of arterial hypertension, cardiac arrhythmia, left ventricular hypertrophy, albuminuria/proteinuria, cornea verticillata, gastrointestinal involvement, treatment with inhibitors of the renin-angiotensin-aldosterone system, deafness, and presence of angiokeratomas. Results: Forty-eight adults with Fabry disease (35.9 ± 11.7 years), 28 women (58.3%), and 20 men (41.7%) were analyzed. Nine (18.8%) patients with glomerular hyperfiltration, including six females and three males (mean age: 28.8 years), were detected. A significant association between and central nervous system (P = 0.021) and peripheral nervous system (P = 0.001) compromise, cardiac arrhythmia (P = 0.001), cornea verticillata (P = 0.009), and gastrointestinal involvement (P = 0.009) was observed. However, no association was found between glomerular hyperfiltration and proteinuria or treatment with inhibitors of the renin-angiotensin-aldosterone system. Conclusions: This research showed a higher prevalence of glomerular hyperfiltration in the younger group and a significant association between glomerular hyperfiltration and some typical manifestations of classic Fabry patients. Although more studies are needed, it is concluded that other mechanisms than glomerular hyperfiltration, like injury by glycosphingolipids deposit into the filtration barrier, might influence the protein loss in Fabry nephropathy.

Screening for Fabry disease among 619 hemodialysis patients in Saudi Arabia

Objectives:

To determine the prevalence of Fabry disease (FD) among Saudi patients on hemodialysis.

Methods:

This prospective study was conducted in 3 major hospitals in the. All adult patients (>18 years old) attending the dialysis unit who have end-stage renal disease (ESRD) and on hemodialysis were included. Known patients with FD and those who refused to participate in the study were excluded. All eligible patients were screened for FD using dry blood spot (DBS) for alpha-galactosidase A (α-Gal A). A positive DBS (enzyme activity <40%) was followed by another confirmatory enzyme assay. When the second DBS sample was also positive (enzyme activity <40%), a Sanger sequencing of the GLA gene was performed.

Results:

A total of 619 patients with ESRD and on hemodialysis were screened for FD using DBS for α-Gal A enzyme level. Enzymatic activity was below 40% in 11 samples. On retesting, 3 females had <20% enzymatic activity suggesting FD. Sanger sequencing of these 3 females showed the variant c.1055C>G (p.Ala352Gly) confirming the diagnosis of FD. Family screening of one of these 3 patients revealed one asymptomatic female carrying the same variant.

Conclusion:

The prevalence of FD in this cohort was 4.8 per 1000 patients. Screening of Fabry patients with ESRD seems to be a cost-effective strategy. Furthermore, relatives of the patients identified by screening enhances this screening strategy.

Direct Correlation between Age at Diagnosis and Severity of Nephropathy in Fabry Disease Patients

INTRODUCTION

Nephropathy is one of the major complications of Fabry disease and mainly includes reduced glomerular filtration rate and proteinuria. Affected patients show different degrees of annual loss of renal function according to the magnitude of proteinuria and decrease in estimated glomerular filtration rate (eGFR) at the baseline.

OBJETIVE

To analyze the relationship between age at diagnosis and severity of nephropathy in a Fabry disease population.

METHODS

Cross-sectional design with retrospective data collection.

RESULTS

Seventy-two patients were studied with mean age of 26.26 ± 16.48 years and 30 men (41.6%). Twenty-seven paediatric patients and 45 adults were included. Thirteen genotypes were found: E398X, L415P, c886A>G, L106R, c.680G>A, A292T, c. 448.delG, R363H, C382Y, R301Q, D109G, del 3 and 4 exons, W81X, all pathogenic mutations of GLA gene. The mean eGFR in paediatric population was 115.81 ± 20.87 ml/min/1.73 m2 and in adults was 80.63 ± 42.22 ml/min/1.73 m2. The Pearson's bilateral correlation coefficient test (value = -0.462) between the age at diagnosis and eGFR indicates inverse correlation between both variables with a strong statistical significance (P = < 0.01). Spearman's bilateral correlation coefficient (value = +0.385) between the variables at diagnosis and the degree of proteinuria indicates direct correlation between both variables with a strong statistical significance (P = <0.01).

CONCLUSIONS

Diagnosis of Fabry disease patients at a younger age could be a key to improve the nephropathy prognosis and allow early and effective interventions.

Fabry nephropathy. Role of nephrologist and clinical variables associated with the diagnosis

BACKGROUND

The early detection of Fabry nephropathy is of interest to us. Its treatment is more effective in early stages. It has been studied by analysing molecular and tissue biomarkers. These have certain disadvantages that hinder its routine use. The aim of this study is to describe the role of the nephrologist in the diagnosis of the disease, and to describe the clinical variables associated with nephropathy in affected patients.

MATERIAL AND METHODS

Cross-sectional study. Patients were included from three reference centres in Argentina.

RESULTS

Seventy two patients were studied (26.26±16.48years): 30 of which (41.6%) were men and 42 of which (58.4%) were women; 27 paediatric patients and 45 adults. Fourteen "index cases" were detected, 50% of which were diagnosed by nephrologists. Nephropathy was found in 44 patients (61%): 6 paediatric patients and 38 adults. Two types of clinical variables were associated with nephropathy: (i)peripheral nervous system compromise (P≤.001), angiokeratomas (P≤.001) and auditory compromise (P=.01-.001), with these being early clinical manifestations of the most severe disease phenotype, and (ii)structural heart disease (P=.01-.001) and central nervous system compromise (P=.05-.01), which are major and late complications, responsible for increased morbidity and mortality and lower life expectancy.

CONCLUSION

The nephrologist plays an important role in the diagnosis of Fabry nephropathy, although the detection thereof owing to its renal involvement would represent a late diagnosis, because nephropathy is associated with late complications of the most severe disease phenotype.

High Lyso-Gb3 Plasma Levels Associated with Decreased miR-29 and miR-200 Urinary Excretion in Young Non-Albuminuric Male Patient with Classic Fabry Disease

Renal involvement is associated with a greater morbidity and mortality in Fabry disease. Pathological albuminuria, the first Fabry nephropathy clinical manifestation, can occur from early childhood, although histological lesions such as tubulo-interstitial fibrosis and glomerulosclerosis are present or may precede the onset of pathological albuminuria. In renal cells, exposure to Lyso-Gb3 is correlated with increased expression of Transforming Growth Factor-βeta (TGF-β). miR-21, miR-192, and miR-433 that promote fibrosis are activated by TGF-β, and miR-29 and miR-200 that suppress fibrosis are inhibited by TGF-β. A 23-year-old male was diagnosed with FD. αGalA decreased enzyme activity: 0.1 nmol/hour/liter; genotype: [c.317T>G (p.L106R)]; GFR: 104.4 mL/min/m²; urinary albumin excretion: 6.00 mg/day; plasma Lyso-Gb3: 124.5 nmol/L. A decrease urinary excretion of miR-29 and miR-200 was found (p <0.005) compared to controls. In addition to its usefulness as a phenotype marker, Lyso-Gb3 has been proposed as an indicator of therapeutic response. We detect an association of high Lyso-Gb3 plasma values with decreased urinary excretion of miRNAs with known antifibrotic effect (miR-29 and miR-200). Although the present work is a case report, it could be hypothesized that one of the harmful Lyso-Gb3 effects could be the miRNAs regulation through changes in TGF-β expression.

Major Organic Involvement in Women with Fabry Disease in Argentina

Fabry disease (FD) is an X-linked lysosomal storage disorder resulting from the deficiency or absence of the alpha galactosidase A enzyme. Organic involvement in men is well known, but in women it is controversial, partly due to the random X-chromosomes inactivation (Lyon hypothesis). The aim of this study was to describe the organic involvement in women at the time of FD diagnosis. A descriptive, cross-sectional and multicenter study was carried out. Thirty-five women with FD from three reference centers in Argentina were evaluated. The mean age of the whole group (n = 35) was 26.6 ± 16.9 years; 22 were adult (over 18) and 13 were paediatric patients. Enzymatic activity was performed in 29/35 patients, which was normal in 24/29 (82.8%). Seven different mutations of the GLA gene were found. The results showed urinary protein loss (45.7%) and decreased glomerular filtration rate (31.4%), mainly in adults. And also, cornea verticillata (56.5%), peripheral neuropathy (51.4%), cardiovascular manifestations (31.4%), hearing loss (20%), angiokeratomas (20%), central nervous system (17.1%), and gastrointestinal involvement (14.3%). Organic compromise in females with FD may be as severe as in men. This analysis has demonstrated a significant proportion of women with signs, symptoms, and major organic involvement at FD diagnosis.

Early Renal Involvement in a Girl with Classic Fabry Disease

Fabry disease is an X-linked lysosomal storage disorder resulting from the deficiency or absence of the enzyme alpha galactosidase A; this defect leads to the systemic accumulation of globotriaosylceramide and its metabolites. Organic involvement in men is well known, but in women it is controversial, mainly due to the random X-chromosome inactivation in each of their cells (Lyon hypothesis). This would explain why women (heterozygotes) present a wide variability in the severity of their phenotype. The manifestations are multisystemic and begin in early childhood, reaching a severe compromise in adulthood. Typical acroparesthesia in hands and feet, gastrointestinal symptoms, angiokeratomas, dyshidrosis, hearing loss, arrhythmias, hypertrophic cardiomyopathy, cerebrovascular accidents, and renal failure can be observed. Nephropathy is one of the major complications of Fabry disease. Glomerular and vascular changes are present before progression to overt proteinuria and decreased glomerular filtration rate, even in pediatric patients. A case of incipient renal involvement in a girl with classic Fabry disease is reported.