Anderson-Fabry disease: long-term echocardiographic follow-up under enzyme replacement therapy.

AIMS: Anderson-Fabry disease affects various organ systems due to glycosphingolipid accumulation. Enzyme replacement therapy (ERT) has been reported to decrease left ventricular wall thickening (LVWT) and to improve diastolic dysfunction. METHODS AND RESULTS: This prospective study included 29 patients (patients; mean age 37 +/- 13 years) with genetically, enzymatically and/or biopsy-proven Anderson-Fabry disease and long-time ERT. Data on symptoms, cardiac medications and history of hypertension were collected and all patients had comprehensive echocardiographic examination prior to ERT and at follow-up. Disease was at an early stage with a total mean Mainz severity score index of only 18.6 +/- 13.0. Prior to ERT, 79% of patients reported acroparesthesia. The median creatinine level was 121 +/- 108 mcmol/L and LVWT was present in nine patients (31%). Binary appearance of the interventricular septum was found in 20% and posterobasal fibrosis in 83%. At median follow-up of 37 months, acroparesthesia decreased to 55% (P = 0.016). There was no change in creatinine levels. The incidence of LVWT was unchanged, only an increase in interventricular septal wall thickness from 11.7 +/- 0.4 to 12.5 +/- 0.5 was observed (P = 0.009). Left atrial size and the percentage of patients with binary appearance and posterobasal fibrosis were unchanged. There was a small improvement in diastolic function (29% decrease of E/Ea; P < 0.002). CONCLUSION: Our Anderson-Fabry cohort had successful long-time ERT with impressive amelioration of subjective symptoms. Although there was not much improvement in cardiac changes apart from a slight improvement of diastolic function, at least, there was no progression of cardiac disease. For complete reversibility of cardiac changes in Anderson-Fabry disease, ERT might have to be started earlier in life and/or prescribed for a longer time.

Vestibular and auditory deficits in Fabry disease and their response to enzyme replacement therapy.

Progressive hearing (pHL) and vestibular (pVL) loss are frequent deficits in Fabry disease (FD). Recently, enzyme replacement therapy (ERT) with human alpha-galactosidase A has become available. Here, we investigate the association between pHL and pVL in FD and their ERT responses. Pure tone audiometry (PTA) and head impulse testing (HIT) were administered at baseline in 47 patients (25 male, 18-60 y; 22 female, 17-74 y), of whom 24 also received caloric irrigation (CI). Of the 47 patients, 38 (24 male) were tested both before and during ERT (follow- up < or = 60 months). ERT consisted of agalsidase alfa infusions. At baseline, pHL was present in 88% of males and 86% of females. Over all tested frequencies (range: 0.5-6 kHz), pHL was significantly (two-way ANOVA: p < 0.05) greater at higher age and in males,with largest deficits at high frequencies. When assessed with HIT, 80% of males and 77% of females had pVL. pVL was significantly greater at higher age and in males. Tested with CI, 21% of males and 0% of females had pVL. No associations among individual semicircular canal (SCC) deficits, as tested by HIT, and hearing was observed in individual ears. After > or = 18 months of ERT, pVL was significantly smaller than at baseline (ANOVA for HIT: p < 0.01). In contrast, pHL remained unchanged by ERT over 60 months (p > 0.05). We conclude that pHL and pVL prevalences are similar in FD. To detect pVL, HIT is more sensitive than CI. We speculate that pHL and pVL emerge from lesions within the vestibulocochlear labyrinth, because no specific patterns of vestibulo-cochlear deficits were observed, as expected if lesions were more proximal along the inferior or superior branch of the vestibulo-cochlear nerve or labyrinthine artery. Finally, ERT stabilizes auditory and even improves vestibular function.

Impact of cardio-renal syndrome on adverse outcomes in patients with Fabry disease in a long-term follow-up.

AIMS: Fabry disease (FD) is a rare X-linked lysosomal storage disease with a deficiency of α-galactosidase A leading to progressive sphingolipid accumulation in different organs, among them heart and kidney. We evaluated the impact of cardio-renal syndrome (CRS) on the incidence of major cardiovascular complications and death in a prospective FD cohort. METHODS AND RESULTS: A total of 104 genetically proven FD patients were annually followed at the University Hospitals Zurich and Bern. The main outcome was a composite of incident renal replacement therapy (RRT), hospitalisation due to decompensated Heart Failure, new onset atrial fibrillation, pacemaker/ICD implantation, stroke/TIA and death. Estimated glomerular filtration rate (eGFR) and left ventricular myocardial mass index (LVMMI) where explored as the primary exposure variables. During the median follow-up of 103 [59-155] months, events occurred in 27 patients. In a Cox regression analysis, both higher LVMMI and lower eGFR were independently associated with a greater risk of developing adverse events after adjustment for multiple confounders (HR 1.67 [1.04-2.73] P=0.03 per SD increase in LVMMI, HR 0.45 [0.25-0.83], P=0.01 per SD decrease in eGFR). In patients with CRS, the risk to develop events was significantly increased if adjusted for demographics and RRT (HR 4.46 [1.07-18.62], P=0.04), approaching significance if additionally adjusted for hypertension (HR 4.05 [0.95-17.29], P=0.06). In Kaplan-Meier-Analysis, the poorest event-free survival was observed among patients with CRS. CONCLUSIONS: CRS was associated with a high risk to develop cardiovascular complications and death, emphasizing the importance of its prevention and early recognition. A focus on cardio-reno-protective therapies is crucial.

Simple criteria for differentiation of Fabry disease from amyloid heart disease and other causes of left ventricular hypertrophy.

AIMS: Fabry disease may be difficult to differentiate from other causes of left ventricular hypertrophy such as other myocardial storage diseases (including amyloidosis), hypertrophic cardiomyopathy (HCM), or hypertensive heart disease (HHD). We sought to determine simple criteria to best differentiate the above mentioned cardiac diseases. METHODS AND RESULTS: All patients in a six-year time period with left ventricular hypertrophy due to Fabry disease (13 patients), biopsy proven cardiac amyloidosis (16 patients), non-obstructive HCM (17 patients), and 22 randomly selected patients with advanced HHD were compared. Retrospective analysis of clinical characteristics, findings of electrocardiogram (ECG) and echocardiography by blind review was performed. RESULTS: No single clinical characteristic or findings of ECG or echocardiography could reliably differentiate between the various diseases. Increased echogenicity/granular sparkling, valvular abnormalities, abnormal renal function, and diastolic function were not helpful discriminators. In a univariate analysis, four criteria (acroparesthesia, anhydrosis, absence of hypertension and presence of Sokolow criteria for left ventricular hypertrophy in the ECG) were significant for Fabry disease. By logistic regression analysis, the following most suitable discriminative parameters were identified: hypertension in HHD (specificity 82%), orthostasis and/or pericardial effusion for amyloidosis (specificity 93%), papillary muscle anomaly in non-obstructive HCM (specificity 92%), and Fabry disease if neither hypertension orthostatis, pericardial effusion nor a papillary muscle anomaly was present (specificity 87%). CONCLUSION: A combination of symptoms, echocardiographic findings and ECG in unexplained left ventricular hypertrophy may help to differentiate amyloidosis, non-obstructive HCM and hypertensive heart disease from Fabry disease. The results of this preliminary study will have to be confirmed in a prospective study.

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.

Lethal autoimmune myocarditis in interferon-gamma receptor-deficient mice: enhanced disease severity by impaired inducible nitric oxide synthase induction.

BACKGROUND: Interferon-gamma (IFN-gamma) is an essential cytokine in the regulation of inflammatory responses in autoimmune diseases. Little is known about its role in inflammatory heart disease. METHODS AND RESULTS: We showed that IFN-gamma receptor-deficient mice (IFN-gammaR(-/-)) on a BALB/c background immunized with a peptide derived from cardiac alpha-myosin heavy chain develop severe myocarditis with high mortality. Although myocarditis subsided in wild-type mice after 3 weeks, IFN-gammaR(-/-) mice showed persistent disease. The persistent inflammation was accompanied by vigorous in vitro CD4 T-cell responses and impaired inducible nitric oxide synthase expression, together with evidence of impaired nitric oxide production in IFN-gammaR(-/-) hearts. Treatment of wild-type mice with the nitric oxide synthetase inhibitor N:-nitro-l-arginine-methyl-ester enhanced in vitro CD4 T-cell proliferation and prevented healing of myocarditis. CONCLUSIONS: Our data provide evidence that IFN-gamma protects mice from lethal autoimmune myocarditis by inducing the expression of inducible nitric oxide synthase followed by the downregulation of T-cell responses.

Haemolytic uraemic syndrome and mutations of the factor H gene: a registry-based study of German speaking countries.

BACKGROUND: The aetiology of atypical haemolytic uraemic syndrome (aHUS) is, in contrast to classical, Shiga-like toxin induced HUS in children, largely unknown. Deficiency of human complement factor H and familial occurrence led to identification of the factor H gene (FH1) as the susceptibility gene, but the frequency and relevance of FH1 mutations are unknown. METHODS: We established a German registry for aHUS and analysed in all patients and 100 controls the complete FH1 gene by single strand confirmational polymorphism and DNA sequencing. In addition, complement C3 and factor H serum levels were assayed. Demographic data at onset of aHUS and follow up were compared for the mutation positive and negative groups. RESULTS: Of 111 patients with aHUS (68 female, 43 male, mean age 33 years) 14% had FH1 germline mutations, including two of eight patients with familial aHUS. For each of these eight patients, both parents were tested, and we were able to trace the mutation for five cases. In the other three cases (one with the mutation 3749 C/T, one with 3200 T/C, and one with 3566+1 G/A), we could not detect the mutation in either parent, although paternity was proven by genetic fingerprinting, suggesting that these subjects have new mutations. C3 was decreased in five mutation carriers but also in two non-carriers, and factor H was decreased in none of the carriers, but elevated in six carriers and 15 non-carriers. Clinical parameters including associated medications and diseases, and outcome of aHUS and of post-aHUS kidney transplantation were similar in the mutation positive and negative groups. CONCLUSION: FH1 germline mutations occur with considerable frequency in patients with aHUS. Hypocomplementaemia is not regularly associated with a germline mutation, and factor H serum levels can even be elevated. Screening for FH1 mutations contributes to the classification of aHUS.

Is extrapancreatic tumor hypoglycemia associated with elevated levels of insulin-like growth factor II?

We have tried to answer the still controversial question of whether or not extrapancreatic tumor hypoglycemia is associated with elevated levels of insulin-like growth factor II (IGF II), keeping in mind that controversial results may be due to methodological differences. Serum levels of IGF II were determined by a rat liver membrane radioreceptor assay and by RIA. Serum samples were gel filtered at acidic pH, and some sera were also tested after acid-ethanol extraction as an alternative method for dissociating and separating IGF from the IGF carrier protein. Additionally, the radioreceptor assay was performed with a labeled partially purified IGF preparation [nonsuppressible insulin-like activity soluble in acid-ethanol (NSILA-s "70")] that was used by a group reporting elevated NSILA-s levels in about 40% of their patients with tumor hypoglycemia. Mean serum levels of receptor-reactive IGF II and immunoreactive IGF II (+/- SD) were 436 +/- 169 and 540 +/- 256 ng/ml in 22 patients with tumor hypoglycemia, as compared with 578 +/- 155 and 647 +/- 217 ng/ml in 28 normal adults. This pattern of slightly, but not significantly lower mean IGF II values in tumor hypoglycemia was unchanged when a less pure IGF preparation (NSILA-s 70) was used as a tracer or when the sera were extracted with acid-ethanol. Thus, hypoglycemia resulting from extrapancreatic tumors is not likely to be associated with increased receptorreactive or immunoreactive IGF II levels.

Novel agonists of 5HT2C receptors. Synthesis and biological evaluation of substituted 2-(indol-1-yl)-1-methylethylamines and 2-(indeno[1,2-b]pyrrol-1-yl)-1-methylethylamines. Improved therapeutics for obsessive compulsive disorder.

The syntheses of a series of substituted 2-(indol-1-yl)-1-methylethylamines and 2-(indeno[1,2- b]pyrrol-1-yl)-1-methylethylamines are reported. The binding affinities of the compounds at 5HT2C and 5HT2A receptors (79% homology in the transmembrane domain) were determined. The ligands displayed selectivity for 5HT2C receptors relative to 5HT2A receptors. Compounds were functionally characterized both in vitro and in vivo as 5HT2C receptor agonists. 5f, 5l, 5n, 5o, 5q, 14c, 14f, 14k, and 14m exhibited anticompulsive activity in an animal model of obsessive compulsive disorder.

A non peptidic corticotropin releasing factor receptor antagonist attenuates fever and exhibits anxiolytic-like activity.

The multiple actions of corticotropin-releasing factor (CRF) on neuroendocrine and behavioural functions can now be examined using new, high affinity, non peptidic antagonists which exhibit central activity upon systemic application. We have shown that compound CP 154,526 (butyl-ethyl-[2,5-dimethyl-7-(2,4,6-trimethylphenyl)-7H-pyrrolo [2,3-d]pyrimidin-4-yl]amine) displaces [125I][Tyr0]CRF from rat hippocampal CRF receptors (IC50 = 0.5 nM) and from pituitary CRF receptors (IC50 = 0.04 nM). The same compound inhibits in a concentration-dependent manner the ovine CRF (0.1 microM)-stimulated adenylate cyclase activity in membranes of a mouse pituitary adenoma cell line, AtT20, with an IC50 value of 50 nM. Systemic application of the CRF receptor antagonist (0.16 mg/kg i.p.) blocked recombinant human interleukin-1 beta 5 micrograms/kg i.p.) induced fever in rats. The CRF receptor antagonist CP 154,526 (1 mg/kg i.p.) also exhibited signs of anxiolytic-like activity in the elevated plus-maze test in rats.

Behavioral profile of the 5HT1A receptor antagonist (S)-UH-301 in rodents and monkeys.

The effects of the new 5HT1A receptor antagonist (S)-UH-301 were investigated in several neurological and behavioral tests in rodents and monkeys. By itself, (S)-UH-301 was found to decrease palatable food consumption in rats, to exhibit anticonvulsant activity in mice, and anxiolytic-like properties in two rodent models of anxiety (light-dark test and elevated plus-maze test). (S)-UH-301 antagonized various symptoms and behaviors induced by the selective 5HT1A receptor agonist 8-OH-DPAT, such as lower lip retraction and flat body posture in rats, hyperphagia for palatable food in rats, and displacement activities (considered as indices of anxiety) in squirrel monkeys. These results further characterize (S)-UH-301 as an in vivo active 5HT1A receptor antagonist and suggest that this antagonistic activity might confer the compound with anxiolytic-like properties.

Efficacy of enzyme replacement therapy in Fabry disease.

Enzyme replacement therapy has recently been introduced to treat Fabry disease, a rare X-linked lysosomal storage disorder. The disease occurs due to deficient activity of alpha-galactosidase A, leading to progressive accumulation of globotriaosylceramide in multiple organs and tissues. Renal, cardiac and cerebrovascular manifestations of the disease result in premature death in both hemizygous males and heterozygous females. This paper outlines the clinical signs, symptoms and diagnosis of Fabry disease, and the development of the two available enzyme replacement therapies -- agalsidase alfa and agalsidase beta. Agalsidase alfa and agalsidase beta are produced in a human cell line and in Chinese hamster ovary cells, respectively, resulting in products with the same amino acid sequence as the native human enzyme, but with different patterns of glycosylation. Correct post-translational glycosylation is important in terms of the pharmacokinetics, biodistribution, clinical efficacy and tolerability of genetically engineered protein therapeutics. Differences in glycosylation, which may affect immunogenicity and mannose-6-phosphate receptor-mediated cellular internalisation of administered enzyme, possibly account for the differences in dosing, clinical effects and safety profiles reported for agalsidase alfa and agalsidase beta.

Phototoxicity and photogenotoxicity of nine pyridone derivatives.

Nine structurally related pyridone derivatives were assayed for photogenotoxicity and phototoxicity in the Ames test, the chromosomal aberration test in V79 cells and the neutral red uptake (NRU) test in 3T3 cells. All nine compounds absorb light to a comparable degree at wavelengths between 380 and 430 nm. Seven of the nine compounds were found to produce high quantities of singlet oxygen (1O(2)) upon irradiation in the presence of oxygen. These seven compounds were highly phototoxic in the NRU test, three were clearly and two were marginally photomutagenic in the Ames test, five were assessed as clearly and two as equivocally photoclastogenic in the chromosomal aberration test. Two compounds showed substantially lower 1O(2) yields. The pyridone ring of these two compounds is attached to a non-aromatic ring, while for the seven other compounds the chromophore system including the pyridone ring consists of two or three aromatic rings. One of the two compounds with low 1O(2) yields was distinctly less phototoxic and did not induce photogenotoxic effects. The other, structurally an indolo derivative and not the common thieno derivative, was, however, similarly phototoxic as the seven compounds with high 1O(2) quantum yield and was also clearly photogenotoxic indicating that different action pathways, not involving singlet oxygen, have to be considered at least for this compound.

Head-impulse testing in Fabry disease--vestibular function in male and female patients.

AIM: To study the prevalence of peripheral vestibular deficit in male and female patients with Fabry disease and to assess the effect of enzyme replacement therapy (ERT) on peripheral vestibular function using quantitative head-impulse testing. METHODS: Using dual search-coils the vestibulo-ocular reflex during rapid rotational head thrusts to both sides was recorded in 21 patients (13 male, 8 female) with Fabry disease prior to ERT initiation. ERT consisted of infusions of gene-activated human alpha-galactosidase A (agalsidase alfa; Replagal) every 2 weeks at doses of 0.2 mg/kg. Eight patients were tested again approximately 6 and 12 months after the initiation of ERT. RESULTS: At baseline examination, 15 of the patients with Fabry disease (71%; 11 males, 4 females) showed reduced peripheral vestibular function. The deficit was unilateral in nine patients (3 females) and bilateral in six patients (1 female). The severity of the vestibular deficit was not significantly different between male and female patients. After 12 months of ERT, the average vestibular deficit on the weaker side tended to improve; however, the change was not significant (p = 0.10). CONCLUSION: Fabry disease affects peripheral vestibular function in both male and female patients. Females seem to be affected less frequently than males, but, on average, vestibular deficits are not different between the two groups. To confirm or reject the tendency for vestibular improvement during ERT, more patients need to be tested and longer follow-up periods are required.

Effects of enzyme replacement therapy with agalsidase alfa on glomerular filtration rate in patients with Fabry disease: preliminary data.

UNLABELLED: Progressive deposition of globotriaosylceramide results in severe complications involving the kidney, heart and brain in both hemizygous male and heterozygous female patients with Fabry disease. Analysis of renal data from FOS--the Fabry Outcome Survey--suggests that enzyme replacement therapy with agalsidase alfa can significantly improve renal function in patients with Fabry disease, at least in those with a mild decrease in glomerular filtration rate, and may also be able to slow down the natural decline in renal function in patients with a moderate reduction in glomerular filtration rate. CONCLUSION: Initial results from the large cohort of patients within FOS indicate that treatment with agalsidase alfa has beneficial effects on kidney function in patients with Fabry disease.