Renal disease in Fabry patients

Development and validation of a disease-specific quality of life scale for adult patients with Fabry disease in Japan

Background

Fabry disease is a rare X-linked lysosomal storage disorder. It is associated with physical distress and social challenges that may affect adults differently compared to pediatric patients. However, there is no disease-specific quality of life (QOL) scale that can provide a detailed assessment of QOL for adults with Fabry disease. Therefore, we aimed to determine the factor structure and assess the validity of a scale that was created to assess the QOL of adult patients with Fabry disease. This study was conducted in two phases. First, scale feasibility was confirmed through a questionnaire survey of nine patients. Second, a cross-sectional questionnaire survey of patients (aged ≥ 18 years) diagnosed with Fabry disease was conducted. Item development and refinement were conducted based on guidelines for scale development. Exploratory factor analysis was used to clarify the factor structure and confirm internal consistency. As a measure of QOL, construct validity was of the scale was verified based on its correlations with the Short Form-8 (SF-8) scale.

Results

The newly created Adult Fabry Disease QOL (AFQOL) scale comprises 39 items that cover five factors: “neuropathic pain and abdominal symptoms,” “impact on work and school,” “relationship challenges,” “ophthalmologic and otolaryngologic symptoms,” and “cardiovascular and renal symptoms.” Cronbach’s alpha coefficient for all factors was above 0.8, and the AFQOL total scores were significantly correlated with the physical and mental components of the SF-8 (rs = − 0.508 and − 0.400, respectively).

Conclusions

The AFQOL scale assesses physical symptoms and social difficulties experienced by adult patients with Fabry disease. A strength of the scale is its ability to assess the impact of work and relationships on patients. The scale can be useful in objectively assessing QOL for a group or for individual patients. Future research should explore further aspects of the scale’s validity and reliability.

X Chromosome Inactivation in Carriers of Fabry Disease: Review and Meta-Analysis

Anderson-Fabry disease is an X-linked inborn error of glycosphingolipid catabolism caused by a deficiency of α-galactosidase A. The incidence ranges between 1: 40,000 and 1:117,000 of live male births. In Italy, an estimate of incidence is available only for the north-western Italy, where it is of approximately 1:4000. Clinical symptoms include angiokeratomas, corneal dystrophy, and neurological, cardiac and kidney involvement. The prevalence of symptomatic female carriers is about 70%, and in some cases, they can exhibit a severe phenotype. Previous studies suggest a correlation between skewed X chromosome inactivation and symptoms in carriers of X-linked disease, including Fabry disease. In this review, we briefly summarize the disease, focusing on the clinical symptoms of carriers and analysis of the studies so far published in regards to X chromosome inactivation pattern, and manifesting Fabry carriers. Out of 151 records identified, only five reported the correlation between the analysis of XCI in leukocytes and the related phenotype in Fabry carriers, in particular evaluating the Mainz Severity Score Index or cardiac involvement. The meta-analysis did not show any correlation between MSSI or cardiac involvement and skewed XCI, likely because the analysis of XCI in leukocytes is not useful for predicting the phenotype in Fabry carriers.

Fabry disease-what cardiologists can learn from the nephrologist: a narrative review

Fabry disease (FD) is a rare, X-linked lysosomal storage disorder resulting in decreased or absent activity of the lysosomal enzyme alpha-galactosidase A. Subsequent accumulation of storage material can occur in virtually all cells of the body. Organs and structures affected by storage material deposition include the heart, the kidney, the central and peripheral nervous system and the cornea of the eyes. Progressive cardiac hypertrophy, arrhythmias, cardiac fibrosis, heart failure and cardiac death are common characteristics of cardiac involvement. Renal depositions of glycosphingolipids are already detectable in childhood. An early clinical sign of Fabry renal involvement is albuminuria, often preceding a detectable loss of kidney function. Later in life Fabry patients may exhibit a progressive decline of their kidney function leading to end-stage renal disease (ESRD). The clinical presentation of Fabry patients regarding renal involvement depends on the underlying mutation in the GLA gene. Classically affected males typically show a gradual decrease in kidney function, patients with mild or late onset mutations as well as a subgroup of females may exhibit only little or no renal abnormalities. This review summarizes the characteristics of renal involvement in FD, the diagnostics necessary to evaluate the degree of renal impairment and possible treatment options.

Quantitative Analysis of Conjunctival and Retinal Vessels in Fabry Disease

Fabry Disease (FD) is a rare X-linked lysosomal storage disorder characterized by systemic and ocular involvement. It has been described an increasing in retinal and conjunctival vessel tortuosity and this feature represents an important marker for the disease. Currently, there is not an objective method to measure and quantify this parameter. We tested a new semi-automatic software measuring retinal and conjunctival vessel tortuosity from eye fundus and conjunctival digital images in a group of FD patients. We performed an observational case-control study evaluating three mathematical parameters describing tortuosity (sum of angle metric [SOAM], product of angle distance [PAD], triangular index [I2e]) obtained from fundus and conjunctival pictures of 11 FD patients and 11 age and sex-matched controls. Both eyes were considered. Mann-Whitney test was used to compare the FD group versus the control group and, within the FD group, male versus female patients. Linear regression analysis was performed to evaluate the possible association of retinal and conjunctival vessels tortuosity parameters with age and with specific markers of systemic disease's progression. The tortuosity parameters (SOAM, PAD and I2e) were significantly higher in retinal vessels and in conjunctival nasal vessels in FD patients in comparison with the controls (p=0.003, p=0.002, p=0.001 respectively for retina) (p=0.023, p=0.014, p=0.001 respectively for nasal conjunctiva). No significant association was found between retinal and conjunctival tortuosity parameters and increasing age or systemic involvement markers. Vessel tortuosity represents an important clinical manifestation in FD. A computer-assisted analysis of retinal and conjunctival vasculature demonstrated an increased vessels tortuosity in patients affected by Fabry disease. This non-invasive technique might be useful to help the diagnosis in early stages, to establish disease severity and monitor its progression.

Lysosomal storage disorders affecting the heart: a review

Lysosomal storage disorders (LSD) comprise a group of diseases caused by a deficiency of lysosomal enzymes, membrane transporters or other proteins involved in lysosomal biology. Lysosomal storage disorders result from an accumulation of specific substrates, due to the inability to break them down. The diseases are classified according to the type of material that is accumulated; for example, lipid storage disorders, mucopolysaccharidoses and glycoproteinoses. Cardiac disease is particularly important in lysosomal glycogen storage diseases (Pompe and Danon disease), mucopolysaccharidoses and in glycosphingolipidoses (Anderson-Fabry disease). Various disease manifestations may be observed including hypertrophic and dilated cardiomyopathy, coronary artery disease and valvular diseases. Endomyocardial biopsies can play an important role in the diagnosis of these diseases. Microscopic features along with ancillary tests like special stains and ultrastructural studies help in the diagnosis of these disorders. Diagnosis is further confirmed based upon enzymatic and molecular genetic analysis. Emerging evidence suggests that Enzyme replacement therapy (ERT) substantially improves many of the features of the disease, including some aspects of cardiac involvement. The identification of these disorders is important due to the availability of ERT, the need for family screening, as well as appropriate patient management and counseling.

Elevated Inflammatory Plasma Biomarkers in Patients With Fabry Disease: A Critical Link to Heart Failure With Preserved Ejection Fraction

Background Because systemic inflammation and endothelial dysfunction lead to heart failure with preserved ejection fraction, we characterized plasma levels of inflammatory and cardiac remodeling biomarkers in patients with Fabry disease ( FD ). Methods and Results Plasma biomarkers were studied in multicenter cohorts of patients with FD (n=68) and healthy controls (n=40). Plasma levels of the following markers of inflammation and cardiac remodeling were determined: tumor necrosis factor ( TNF ), TNF receptor 1 ( TNFR 1) and 2 ( TNFR 2), interleukin-6, matrix metalloprotease-2 ( MMP -2), MMP -8, MMP -9, galectin-1, galectin-3, B-type natriuretic peptide ( BNP ), midregional pro-atrial natriuretic peptide ( MR -pro ANP ), and globotriaosylsphingosine. Clinical profile, cardiac magnetic resonance imaging, and echocardiogram were reviewed and correlated with biomarkers. Patients with FD had elevated plasma levels of BNP , MR -pro ANP , MMP -2, MMP -9, TNF , TNFR 1, TNFR 2, interleukin-6, galectin-1, globotriaosylsphingosine, and analogues. Plasma TNFR 2, TNF , interleukin-6, MMP -2, and globotriaosylsphingosine were elevated in FD patients with left ventricular hypertrophy, whereas diastolic dysfunction correlated with higher BNP , MR -pro ANP , and MMP -2 levels. Patients with late gadolinium enhancement on cardiac magnetic resonance imaging had greater levels of BNP , MR -pro ANP , TNFR 1, TNFR 2, and MMP -2. Plasma BNP , MR -pro ANP , MMP -2, MMP -8, TNF , TNFR 1, TNFR 2, galectin-1, and galectin-3 were elevated in patients with renal dysfunction. Patients undergoing enzyme replacement therapy who have more severe disease had higher MMP -2, TNF , TNFR 1, TNFR 2, and globotriaosylsphingosine analogue levels. Conclusions Inflammatory and cardiac remodeling biomarkers are elevated in FD patients and correlate with disease progression. These features are consistent with a phenotype dominated by heart failure with preserved ejection fraction and suggest a key pathogenic role of systemic inflammation in FD .

[Combined heart and kidney transplantation in Fabry's disease: Long-term outcomes in two patients]

INTRODUCTION

Fabry disease is a lysosomal storage disorder linked to an alpha-galactosidase A deficiency that can lead to heart and kidney failure. There is little data about the prognosis of patients who undergo a combined heart and kidney transplantation.

CASE REPORTS

Two brothers who were diagnosed with Fabry disease after the age of 30 years underwent a combined heart and kidney transplantation at respectively 49 and 42 years of age because of a severe hypertrophic cardiomyopathy with end stage renal failure. They are alive respectively 4 and 9 years after the transplantation. No recurrence of the disease in the transplanted organs has been found.

CONCLUSION

Combined heart and kidney transplantation in Fabry disease is an efficient therapy for the cardiomyopathy and kidney failure. Its prognosis can be good when the patients are carefully selected. However, an early diagnosis is critical in order to avoid a procedure associated with a high perioperative mortality.

Prevalence of Fabry disease in dialysis patients: Japan Fabry disease screening study (J-FAST)

BACKGROUND

In Fabry disease, progressive glycolipid accumulation leads to damage in kidney and other organs. This study was designed to determine the prevalence rate of Fabry disease in Japanese dialysis patients.

METHODS

All dialysis patients agreeing to Japan Fabry disease screening study (J-FAST) with informed consent were selected except for Fabry disease. The screening was performed by a method of measuring plasma and/or leukocytes lysosomal α-galactosidase A protein level and α-galactosidase A activity. If positive, genetic analysis was carried out upon patient's agreement.

RESULTS

J-FAST dealt with 8547 patients (male 5408, female 3139). At the tertiary examination, 26 out of 8547 patients were found to be positive. Six out of 26 patients could not accept genetic analysis because of death. Remaining 20 patients agreed with genetic analysis; then 2 patients (male 2, female 0) had a variation of the α-Gal gene and 11 patients showed E66Q variations. Therefore, the frequency of Fabry disease in J-FAST was 0.04 % (2/5408) in males and 0 % (0/3139) in females, and then 0.02 % (2/8547) in all patients. The presumptive clinical diagnoses of end-stage kidney disease (ESKD) were 10 chronic glomerulonephritis, 7 diabetic nephropathy, 3 unknown etiology, 3 nephrosclerosis, 1 gouty nephropathy, 1 autosomal dominant polycystic kidney disease and 1 renal tuberculosis among 26 tertiary positive patients. Two male Fabry patients were initially diagnosed as nephrosclerosis and chronic glomerulonephritis.

CONCLUSIONS

The prevalence rate of Fabry disease in J-FAST was 0.02 %. Moreover, Fabry disease could not be ruled out as the clinical diagnosis of ESKD.

Anderson-Fabry cardiomyopathy: prevalence, pathophysiology, diagnosis and treatment

Anderson-Fabry disease (AFD) is a lysosomal storage disease caused by the inappropriate accumulation of globotriaosylceramide in tissues due to a deficiency in the enzyme α-galactosidase A (α-Gal A). Anderson-Fabry cardiomyopathy is characterized by structural, valvular, vascular and conduction abnormalities, and is now the most common cause of mortality in patients with AFD. Large-scale metabolic and genetic screening studies have revealed AFD to be prevalent in populations of diverse ethnic origins, and the variant form of AFD represents an unrecognized health burden. Anderson-Fabry disease is an X-linked disorder, and genetic testing is critical for the diagnosis of AFD in women. Echocardiography with strain imaging and cardiac magnetic resonance imaging using late enhancement and T1 mapping are important imaging tools. The current therapy for AFD is enzyme replacement therapy (ERT), which can reverse or prevent AFD progression, while gene therapy and the use of molecular chaperones represent promising novel therapies for AFD. Anderson-Fabry cardiomyopathy is an important and potentially reversible cause of heart failure that involves LVH, increased susceptibility to arrhythmias and valvular regurgitation. Genetic testing and cardiac MRI are important diagnostic tools, and AFD cardiomyopathy is treatable if ERT is introduced early.

A missense mutation of the α-galactosidase A gene in a Chinese family of Fabry disease with renal failure

BACKGROUND

Fabry disease (FD) is a rare disease due to an X-linked recessive inborn error of glycosphingolipid metabolism resulting from the mutations of the α-galactosidase A (α-gal A) gene. FD is rare in Chinese and the data on clinic and genetic features of FD is still limited.

METHODS

In this study, the α-gal A gene of a Chinese family diagnosed with FD was analyzed for mutations and the genetic features of FD in this family were presented.

RESULTS

The α-gal A activity of the proband in this family was 0.03 nmol/ml/h in the whole blood. By PCR amplification and sequencing of the α-gal A gene exons, a single C-to-T transition was identified in codon 112 of exon 2. This C-to-T transition, mapping to position 334 in the cDNA of the α-gal A gene, was a missense mutation predicting a substitution of arginine to cysteine (p.R112C), which disrupts the normal activity of α-gal A enzyme. No further mutations were found in other exons of the α-gal A gene. In contrast to previous reports, in this family, all of the five male patients developed end-stage renal failure due to this missense mutation.

CONCLUSIONS

These findings suggest that the missense mutation, p.R112C, in α-gal A gene ablates its activity and results in the development of FD with the renal damage.

Electron microscopy in end stage renal disease: a case of Fabry's disease

Fabry's disease is an X-linked error of metabolism with deficiency of the enzyme α-glycosidase A, and glycosphingolipid accumulation in multiple tissues. Patients may be asymptomatic and present with advanced disease. We report a case of a 38 year old white male who presented with end stage renal disease of unknown etiology. He received a living-related donor kidney transplant (mother), but lost the graft after 10 years to multiple episodes of rejection. Review of the native renal biopsy with added ultrastructural studies established the diagnosis of Fabry's disease. Evaluation of renal biopsies showing advanced chronic injury should include electron microscopic studies, which may reveal characteristic diagnostic features, as seen in this case of Fabry's disease. Identification of hereditary disorders involving the kidney is important for appropriate treatment and prevention of disease recurrence. Potential living related donors should be screened for genetic involvement.

Fabry disease: progression of nephropathy, and prevalence of cardiac and cerebrovascular events before enzyme replacement therapy

Background. In Fabry disease, progressive glycolipid accumulation leads to organ damage and early demise, but the incidence of renal, cardiac and cerebrovascular events has not been well characterized.

Methods. We conducted a retrospective chart review of 279 affected males and 168 females from 27 sites (USA, Canada, Europe). The pre-defined study endpoints included progression of renal, cardiac and cerebrovascular involvement and/or death before the initiation of enzyme replacement therapy.

Results. The mean rate of estimated glomerular filtration rate (eGFR) decline for patients was −2.93 for males, and −1.02 ml/min/1.73 m²/year for females. Prevalence and severity of proteinuria, baseline eGFR <60 ml/min/1.73 m² and hypertension were associated with more rapid loss of eGFR. Advanced Fabry nephropathy was more prevalent and occurred earlier among males than females. Cardiac events (mainly arrhythmias), strokes and transient ischaemic attacks occurred in 49, 11, 6% of males, and in 35, 8, 4% of females, respectively. The mean age at death for 20 male patients was 49.9 years.

Conclusions. Baseline proteinuria, reduced baseline eGFR, hypertension and male gender were associated with more rapid progression of Fabry nephropathy. The eGFR progression rate may increase with advancing nephropathy, and may differ between subgroups of patients with Fabry disease.

Combined heart and kidney transplantation in a patient with Fabry disease in the enzyme replacement therapy era

Fabry disease (FD) is an X-linked genetic disease, resulting from the deficiency of alpha-galactosidase A, a lysosomal enzyme responsible for the cleavage of glycosphingolipids. In absence of enzyme replacement therapy (ERT), globotriaosylceramide (Gb3) accumulates in tissue, leading to progressive organ damage with severe renal, cardiac and central nervous system complications. We herein describe the first case of successful combined and simultaneous heart and kidney transplantation in a young male patient with FD complicated by end-stage renal disease and severe heart failure not responding to late-onset ERT. Combined heart and kidney transplantation can be recommended for Fabry patients with end-stage renal disease and overt hypertrophic cardiomyopathy, severe ischemic or valvular heart disease.

Monogenic vessel diseases related to ischemic stroke: a clinical approach

The identification of stroke cases caused by monogenic disorders is important both for therapeutic decisions and genetic counselling, although they represent less than 1% of all stroke patients. The purpose of this review is to summarize genetic, pathological, and clinical features of single-gene disorders related to ischemic stroke. The following monogenic disorders are considered: cerebral autosomal-dominant arteriopathy with subcortical infarcts and leukoencephalopathy, cerebral autosomal-recessive arteriosclerosis with subcortical infarcts and leukoencephalopathy, hereditary endotheliopathy with retinopathy, nephropathy, and stroke, Fabry disease, pseudoxanthoma elasticum, Neurofibromatosis type 1, familial MoyaMoya disease, Ehlers-Danlos syndrome type IV, Marfan syndrome. For each monogenic disorder, mode of inheritance, pathophysiological aspects, clinical phenotype, and diagnostic tools are carefully described. Furthermore, the classification of monogenetic disorders is presented according to stroke mechanisms, which include small vessel diseases, large artery diseases, and arterial dissections. This review could be useful to identify specific diagnostic pathways for patients with a suspicion of monogenic disease.

Diagnosis and management of kidney involvement in Fabry disease

Interest in the diagnosis and treatment of Fabry disease has been greatly stimulated by the availability of Food and Drug Administration-approved, effective enzyme replacement therapy. This review will update the progress in this area since enzyme replacement therapy has become available. Fabry disease is often associated with proteinuric chronic kidney disease (CKD), and it appears that the treatment paradigms that have proven to be so effective in diabetes mellitus and other forms of proteinuric kidney disease are also effective in conjunction with enzyme replacement therapy for treating the kidney manifestations of Fabry disease. As such, Fabry disease represents an interesting example of progressive proteinuric kidney disease in which the usual blood pressure is lower than in other forms of CKD. This makes the use of effective antiproteinuric therapy challenging, especially considering the autonomic dysfunction that appears to be part of the disease. Comprehensive therapy for Fabry disease includes enzyme replacement therapy and all of the adjunctive therapies that are currently used to treat all forms of proteinuric CKD. It is anticipated that this approach will preserve kidney function and also benefit the cardiac and cerebrovascular systems in patients with Fabry disease.

Effects of enzyme replacement therapy on pain and health related quality of life in patients with Fabry disease: data from FOS (Fabry Outcome Survey)

BACKGROUND

Fabry disease is an X linked lysosomal storage disease caused by deficiency of the lysosomal enzyme alpha-galactosidase A. This leads to accumulation of globotriaosylceramide in nearly all tissues, including the blood vessels, kidney, myocardium, and nervous system. Symptoms often begin in childhood and include acroparaesthesia, with burning or tingling pain that spreads from the extremities to more proximal sites.

AIMS

This study set out to evaluate pain and its influence on quality of life in patients with Fabry disease receiving enzyme replacement therapy (ERT) with agalsidase alfa.

METHODS

Data were obtained from the Fabry Outcome Survey. Pain was measured using the Brief Pain Inventory (BPI), and health-related quality of life (HRQoL) was documented with the European Quality of Life Questionnaire (EQ-5D).

RESULTS

The mean (SD) score for "pain at its worst" on the BPI prior to ERT was 5.1 (2.7). One year after commencement of ERT, this had improved by 0.5, and improved by a further 0.6 after 2 years (p<0.05). Similar statistically significant improvements were seen for "pain on average" and "pain now" after 2 years of ERT. The mean HRQoL utility score prior to ERT was 0.66 (0.32). After 12 months of treatment with agalsidase alfa, this had improved to 0.74 (0.26; p<0.05); this improvement was maintained after 2 years.

CONCLUSIONS

ERT with agalsidase alfa significantly reduces pain and improves quality of life in patients with Fabry disease.

A Comprehensive Assessment of Renal Function in Patients With Gaucher Disease

BACKGROUND

Gaucher disease (GD) is caused by deficiency of acid beta-glucocerebrosidase and is the most common lysosomal storage disease. Patients may have massive hepatosplenomegaly, severe bone disease, and, occasionally, pulmonary or neurological involvement. Although other storage diseases, such as Fabry disease, frequently affect the kidneys, reports of renal abnormalities in patients with GD are limited to case reports. Our aim was to perform a comprehensive evaluation of renal function in patients with GD.

METHODS

Evaluation was performed at routine clinic visits and included blood pressure recording and renal ultrasound. Serum chemistries, urinalysis, urine electrolytes, total protein, and tubular proteinuria were assessed, and estimated glomerular filtration rate (GFR) was calculated.

RESULTS

One hundred sixty-one patients underwent evaluation, including 26 children. GFR was significantly greater in patients with GD than in age- and sex-matched healthy controls (P = 0.01 in men, P < 0.001 in women, P = 0.003 in children). Subgroups of patients with markers of more severe disease had a greater GFR than other patients. No patient had decreased renal function. Significant proteinuria was found only in patients with such comorbidities as diabetes mellitus or multiple myeloma. No evidence of renal tubular abnormalities was found, and kidney sonographic appearance and size were normal.

CONCLUSION

Despite the multiorgan nature of the disease, a systematic evaluation did not find renal abnormalities in patients with GD. Glomerular hyperfiltration was observed in a proportion of patients, particularly those with markers of more severe disease. This phenomenon does not seem to be associated with a subsequent decline in renal function.