Fabry's disease: a multidisciplinary disorder

Fabry's Disease: The Utility of a Multidisciplinary Screening Approach

(1) Background: As a lysosomal storage disorder, Fabry’s disease (FD) shows variable clinical manifestations. We applied our multidisciplinary approach to identify any organ damage in a sample of adult patients with different pathogenic variants. (2) Methods: 49 participants (mean age 44.3 ± 14.2 years; 37 females), underwent a multidimensional clinical and instrumental assessment. (3) Results: At diagnosis, mean enzymatic activity was 5.2 ± 4.6 nM/mL/h in females and 1.4 ± 0.5 nM/mL/h in males (normal values > 3.0), whereas globotriaosylsphingosine was 2.3 ± 2.1 nM/L in females and 28.7 ± 3.5 nM/L in males (normal values < 2.0). Overall, cardiovascular, neurological, and audiological systems were the most involved, regardless of the variant detected. Patients with classic variants (10) showed typical multiorgan involvement and, in some cases, prevalent organ damage (cardiovascular, neurological, renal, and ocular). Those with late-onset variants (39) exhibited lower occurrence of multiorgan impairment, although some of them affected the cardiovascular and neurological systems more. In patients with lower enzymatic activity, the most frequent involvement was neurological, followed by peripheral vascular disease. (4) Conclusions: FD patients exhibited wide phenotypic variability, even at single-organ level, likely due to the individual genetic mutation, although other factors may contribute. Compared to the conventional management, a multidisciplinary approach, as that prompted at our Center, allows one to achieve early clinical detection and management.

Long time enzyme replacement therapy stabilizes obstructive lung disease and alters peripheral immune cell subsets in Fabry patients

BACKGROUND

Fabry disease is an X-linked lysosomal storage disorder, causing accumulation of globotriaosylceramid in different organs. Glycolipids are activators of different immune cell subsets the resulting inflammation is responsible for organ damage. Pulmonary involvement leads to airway inflammation; however, data on severity, as well as the effect of enzyme replacement therapy on lung function parameters and changes in peripheral immune cell subsets on lung involvement are sparse.

METHODS

Seven Fabry patients and four carriers underwent detailed clinical examinations screening for pulmonary manifestations. Repetitive measurements were performed on five patients on ERT (average follow-up 5 years). Patients with Fabry disease and control volunteers were included into peripheral blood cell measurements.

RESULTS

Lung involvement was present in all patients. Symptoms suggestive for lung disease were mild, however, obstructive ventilatory disorder, dominantly affecting small airways accompanied by hyperinflation was demonstrated in all affected patients. ERT resulted in small improvement of FEV1 in most treated patients. Decreased ratio of myeloid DC, Th17 cells while increase in T helper (Th)1 cells, and no change in Th2 and regulatory T (Treg) cells were detected in Fabry patients.

CONCLUSIONS

Fabry disease results mainly in mild symptoms related to lung involvement, characterized by moderate non-reversible obstructive ventilatory disorder. Stabilization of airway obstruction during follow-up was observed using ERT in most patients, emphasizing the importance of this treatment in respect of pulmonary manifestations. Changes of immune cell subsets in the peripheral blood might play a role in inflammatory process, including small airways in Fabry patient's lung.

Effects of a chemical chaperone on genetic mutations in alpha-galactosidase A in Korean patients with Fabry disease

Fabry disease is an X-linked inborn error of glycosphingolipid catabolism that results from mutations in the gene encoding the alpha-galactosidase A (GLA) enzyme. We have identified 15 distinct mutations in the GLA gene in 13 unrelated patients with classic Fabry disease and 2 unrelated patients with atypical Fabry disease. Two of the identified mutations were novel (i.e., the D231G missense mutation and the L268delfsX1 deletion mutation). This study evaluated the effects of the chemical chaperones 1-deoxygalactonojirimycin (DGJ) on the function of GLA in vitro, in cells containing missense mutations in the GLA gene. Nine missense and a nonsense mutations, including one novel mutation were cloned into mammalian expression vectors. After transient expression in COS-7 cells, GLA enzyme activity and protein expression were analyzed using fluorescence spectrophotometry and Western blot analysis, respectively. DGJ enhanced GLA enzyme activity in the M42V, I91T, R112C and F113L mutants. Interestingly, the I91T and F113L mutations are associated with the atypical form of Fabry disease. However, DGJ treatment did not have any significant effect on the GLA enzyme activity and protein expression of other mutants, including C142W, D231G, D266N, and S297F. Of note, GLA enzyme activity was not detected in the novel mutant (i.e., D231G), although protein expression was similar to the wild type. In the absence of DGJ, the E66Q mutant had wild-type levels of GLA protein expression and approximately 40% GLA activity, indicating that E66Q is either a mild mutation or a functional single nucleotide polymorphism (SNP). Thus, the results of this study suggest that the chemical chaperone DGJ enhances GLA enzyme activity and protein expression in milder mutations associated with the atypical form of Fabry disease.

Pulmonary Langerhans cell histiocytosis and other pulmonary histiocytic diseases: a review

CONTEXT

Pulmonary Langerhans cell histiocytosis is the most common and best known pulmonary histiocytic lesion; however, the realm of pulmonary histiocytic lesions also includes an assortment of uncommon diseases that may exhibit pulmonary involvement.

OBJECTIVE

To review pulmonary Langerhans cell histiocytosis and other pulmonary histiocytoses to better ensure correct diagnosis and optimal assessment of prognosis and treatment.

DATA SOURCES

Literature review and primary material from the author's institution.

CONCLUSIONS

This review discusses the most common pulmonary histiocytosis, pulmonary Langerhans cell histiocytosis, and also reviews the uncommon pulmonary histiocytic lesions, which are distinct from pulmonary Langerhans cell histiocytosis.

Short-term efficacy of enzyme replacement therapy in Korean patients with Fabry disease

Fabrazyme has been widely used for treatment of Fabry disease since its approval by the U.S. Food and Drug Administration in 2003. This study was undertaken to assess the short-term efficacy and safety of enzyme replacement therapy (ERT) for Fabry disease in Korea. Eight male patients and three female symptomatic carriers aged 13 to 48 yr were included. Fabrazyme was administered by intravenous infusion at a dose of 1 mg/kg every 2 weeks. Plasma and urine globotriaosylceramide (GL-3) levels, serum creatinine, creatinine clearance, and 24-hr urine protein levels were measured every 3 months. Kidney biopsies, ophthalmologic exams, and pure tone audiometry were performed before and 1 yr after ERT. Kidney function, including serum creatinine, creatinine clearance, and the 24-hr urine protein level, remained stable during ERT. Plasma and urine GL-3 levels were reduced within 3 to 6 months of ERT initiation. Microvascular endothelial deposits of GL-3 were decreased from renal biopsy specimens after 1 yr of treatment. The severity of sensorineural hearing loss and tinnitus did not improve after ERT. ERT is safe and effective in stabilizing renal function and clearing microvascular endothelial GL-3 from kidney biopsy specimen in Korean patients with Fabry disease.

Fabry disease: an ultrastructural comparative study of skin in hemizygous and heterozygous patients

Fabry disease is a rare X-linked lysosomal storage disorder due to alpha galactosidase A deficiency, better known after the advent of a promising treatment, a periodical enzyme replacement. As other hereditary X-linked disorders, females have historically been considered non-affected carriers, although they are, actually, clinically and pathologically affected to a variable degree. Some women are asymptomatic, but the majority present milder forms of the disease and later onset. This wide range of disease expression is supposed to be related to the levels of enzymatic activity, probably in accordance with a skewing of X inactivation. Lysosomal deposits of ceramide trihexoside have been repeatedly documented in a wide range of tissues, including those found in angiokeratoma, the characteristic cutaneous lesion which allowed the definition of Fabry disease. The aim of this study was to investigate whether there was any difference in the amount of dermal lysosomal storage in males and females, thus accounting for the difference in clinical severity of both groups. For that purpose, with electron microscopy and quantitative methods, we studied the extent of lysosomal deposits in dermal fibroblasts of normal-appearing skin in six females and nine men, enzymatically and genetically proven as to have Fabry disease, and results were compared. Our results indicate a statistically significant difference between the two groups regarding both the percentage of dermal fibroblasts bearing stored material, and the storage surface occupied in 100 fibroblasts per case. We suggest that periodical ultrastructural examination of normal-appearing skin could be an indicator of the efficacy of enzyme replacement therapy and could help to evaluate results.

Optimisation of the separation of four major neutral glycosphingolipids: application to a rapid and simple detection of urinary globotriaosylceramide in Fabry disease

A simple method for the separation of the four major neutral glycosphingolipids, present in all human tissue, was developed. This gradient normal phase-HPLC method utilises a polyvinyl alcohol bonded stationary phase and an evaporative light-scattering detection (ELSD). Screening pure solvents in a binary gradient elution mode allowed, in a first step, to assess the behaviour of the studied solutes and to select the solvents for further mobile phase optimisation. The proportion of the remaining solvents was defined to reach a maximal resolution. The reduction of the analysis time and the enhancement of the signal were obtained by optimising the gradient slope and the flow-rate. Optimal levels of triethylamine and formic acid (TEA-FA) for the enhancement of the evaporative light scattering detector response were established at 0.1% (v/v). Thus, the optimal conditions for the separation of the four glycosphingolipids was obtained with a gradient elution from a 100% chloroform to a 100% acetone:methanol (90:10 (v/v)) mobile phase at 0.2 ml min-1, using a 10% min-1 gradient slope. Finally, this method was applied to detect the excess of one of the neutral sphingolipids, namely globotriaosylceramide (Gb3) in the urine of patients affected with Fabry disease. A liquid-liquid extraction of the sediments obtained from an aliquot of only ten ml of urine proved sufficient to detect the excess of Gb3 present in both hemizygote and heterozygote patients. In all, the ability of our method to detect abnormal amounts of Gb3 in urinary sediments could allow the diagnosis of weakly symptomatic Fabry patients in large screening programs

Monitoring enzyme replacement therapy in Fabry disease--role of urine globotriaosylceramide

Anderson-Fabry disease (referred to as Fabry disease) is an X-linked disorder characterized by a deficiency of the lysosomal enzyme alpha-galactosidase A and the subsequent accumulation in various tissues of globotriaosylceramide (Gb(3)), the main substrate of the defective enzyme. Enzyme replacement therapy (ERT) offers a specific treatment for patients with Fabry disease, though monitoring of treatment is hampered by a lack of surrogate markers of response. In this study, the efficacy of long-term ERT in six Fabry hemizygotes and two symptomatic heterozygotes has been evaluated. Patients were administered recombinant alpha-galactosidase A every 2 weeks for up to a year. The efficacy of ERT was assessed by monitoring symptomatology and renal function. Urinary glycolipid concentration was estimated by a novel tandem mass spectrometric method. Urine glycolipid (Gb(3)) was elevated at baseline and fell impressively on ERT where patients were hemizygotes and in the absence of renal transplantation. In heterozygotes and in a recipient of a renal allograft, elevations and changes in urine glycolipids were less pronounced. In one patient, after several months of ERT, there was a transient increase in Gb(3) concentrations to baseline (pre-ERT) levels, associated with the presence of antibodies to the recombinant alpha-galactosidase A. The marked decline in urine Gb(3) on ERT, and its subsequent increase in association with an inhibitory antibody response, suggest that this analyte deserves further investigation as a potential marker of disease severity and response to treatment.

Progress in molecular genetics of heritable skin diseases: the paradigms of epidermolysis bullosa and pseudoxanthoma elasticum

The 42nd Annual Symposium on the Biology of the Skin, entitled "The Genetics of Skin Disease", was held in Snowmass Village, Colorado, in July 1993. That meeting presented the opportunity to discuss how modern approaches to molecular genetics and molecular biology could be applied to understanding the mechanisms of skin diseases. The published proceedings of this meeting stated that "It is an opportune time to examine the genetics of skin disease" (Norris et al, 1994). Indeed, this meeting just caught the wave of early pioneering studies that have helped us to understand the molecular basis of a large number of genodermatoses. This overview presented in the 50th Annual Symposium on the biology of the skin, highlights the progress made in the molecular genetics of heritable skin diseases over the past decade.

Fabry disease in genetic counseling practice: recommendations of the National Society of Genetic Counselors

The objective of this document is to provide health care professionals with recommendations for genetic counseling and testing of individuals with a suspected or confirmed diagnosis of Fabry disease, with a family history of Fabry disease, and those identified as female carriers of Fabry disease. These recommendations are the opinions of a multicenter working group of genetic counselors, medical geneticists, and other health professionals with expertise in Fabry disease counseling, as well as an individual with Fabry disease who is a founder of a Fabry disease patient advocacy group in the United States. The recommendations are U.S. Preventive Task Force Class III, and they are based on clinical experience, a review of pertinent English-language articles, and reports of expert committees. This document reviews the genetics of Fabry disease, the indications for genetic testing and interpretation of results, psychosocial considerations, and references for professional and patient resources. These recommendations should not be construed as dictating an exclusive course of management, nor does use of such recommendations guarantee a particular outcome. The professional judgment of a healthcare provider, familiar with the facts and circumstances of a specific case, will always supersede these recommendations.

Advances in the management of Anderson-Fabry disease: enzyme replacement therapy

Anderson-Fabry disease (AFD) is a lysosomal storage disorder (LSD) due to alpha-galactosidase A (alpha-Gal A) deficiency and the resultant accumulation of incompletely metabolised glycosphingolipids (GSLs), primarily globotriosylceramide (Gb(3)), within various tissues. It is an X-linked multisystem disorder characterised by progressive renal insufficiency, with added morbidity from cardio- and cerebrovascular involvement, and associated with significant impact on quality of life and diminished lifespan. The disease manifests primarily in hemizygous males; however, there is increasing recognition that heterozygous (carrier) females may also develop disease-related complications, although onset among affected women may be delayed. Until recently, treatment has been limited to symptomatic management of pain and other measures to alleviate the problems associated with end-stage complications from renal, cardiac and nervous system involvement. The availability of the recombinant enzyme offers the potential of a safe and effective targeted treatment approach. At the moment, two distinct enzyme formulations are approved in Europe (and in other countries) and both continue to undergo FDA evaluation in the US. Increasing knowledge of the natural history of AFD and greater experience with enzyme therapy should enable optimal patient care. The relative rarity and complexity of AFD necessitates a multi-disciplinary team approach that may be facilitated by a centralised registry.

The genodermatoses: candidate diseases for gene therapy

Tremendous progress has been made in understanding the genetic basis of different forms of genodermatoses, a group of heritable diseases displaying a spectrum of phenotypic manifestations and clinical severity. The information about the underlying mutations in the candidate gene/protein systems has provided the basis for initial development of cutaneous gene therapy, and these heritable conditions appear to serve as appropriate candidate diseases for such efforts. Because of its accessibility and the fact that resident skin cells, such as epidermal keratinocytes and dermal fibroblasts, can be readily propagated in culture, skin serves as an appropriate target tissue for gene therapy. Various strategic considerations, including the use of in vivo or ex vivo approaches, gene replacement versus gene repair, utilization of different delivery systems, etc., require careful prioritization depending on the type of mutations and their pathogenetic consequences at the mRNA and protein levels.

Cutaneous gene therapy. Principles and prospects

As investigators continue to close the gap between basic research and clinical science, gene therapy is becoming of increasing interest to the dermatologist. Most notably, recent advances in gene-based cancer therapy, DNA vaccination, and molecular pharmacology have opened new avenues for investigation beyond those of the traditional gene replacement applications. Different gene delivery systems are currently being tested, each with specific advantages and disadvantages. This article summarizes some of the principles of gene therapy and its applications to cutaneous diseases.