Standardising clinical outcomes measures for adult clinical trials in Fabry disease: A global Delphi consensus

BACKGROUND

Recent years have witnessed a considerable increase in clinical trials of new investigational agents for Fabry disease (FD). Several trials investigating different agents are currently in progress; however, lack of standardisation results in challenges to interpretation and comparison. To facilitate the standardisation of investigational programs, we have developed a common framework for future clinical trials in FD.

METHODS AND FINDINGS

A broad consensus regarding clinical outcomes and ways to measure them was obtained via the Delphi methodology. 35 FD clinical experts from 4 continents, representing 3389 FD patients, participated in 3 rounds of Delphi procedure. The aim was to reach a consensus regarding clinical trial design, best treatment comparator, clinical outcomes, measurement of those clinical outcomes and inclusion and exclusion criteria. Consensus results of this initiative included: the selection of the adaptative clinical trial as the ideal study design and agalsidase beta as ideal comparator treatment due to its longstanding use in FD. Renal and cardiac outcomes, such as glomerular filtration rate, proteinuria and left ventricular mass index, were prioritised, whereas neurological outcomes including cerebrovascular and white matter lesions were dismissed as a primary or secondary outcome measure. Besides, there was a consensus regarding the importance of patient-related outcomes such as general quality of life, pain, and gastrointestinal symptoms. Also, unity about lysoGb3 and Gb3 tissue deposits as useful surrogate markers of the disease was obtained. The group recognised that cardiac T1 mapping still has potential but requires further development before its widespread introduction in clinical trials. Finally, patients with end-stage renal disease or renal transplant should be excluded unless a particular group for them is created inside the clinical trial.

CONCLUSION

This consensus will help to shape the future of clinical trials in FD. We note that the FDA has, coincidentally, recently published draft guidelines on clinical trials in FD and welcome this contribution.

Probiotics for intestinal decolonization of ESBL-producing Enterobacteriaceae: a randomized, placebo-controlled clinical trial

OBJECTIVES

Infections with extended spectrum β-lactamase (ESBL)-producing Enterobacteriaceae (EPE) are a major healthcare concern. Our goal was to investigate whether a probiotic mixture could be used for eradication therapy in patients with prolonged intestinal EPE carriage.

METHODS

We performed a randomized, placebo-controlled, single-blinded clinical superiority trial in the south of Sweden between February 2017 and April 2019. Probiotic Vivomixx®, a mixture of 8 different living bacterial strains or placebo was given to adult outpatients intestinally colonized for at least 3 months with EPE. Patients with suspected active infections at the time of evaluation were excluded, and also those with immunosuppression, severe psychiatric disorder, drug abuse or dementia. Each patient in the probiotic arm was administered 2 sachets (9.0 × 10¹¹ live bacteria) twice daily for 2 months. The primary outcome was intestinal EPE eradication at the end of the 1-year follow-up, as shown by 3 consecutive negative EPE rectal swabs during the follow-up year. The per protocol follow-up for all patients was 1, 3, 6 and 12 months after the initiation of the intervention. ClinicalTrials.gov Identifier: NCT03860415.

RESULTS

In total, the target size of 80 patients were included. The median age was 68 years in both groups. The number of females in the probiotics group was 23 (58%) and in the placebo group 28 (70%). At the end of the trial, 12.5% (5 out of 40) of the patients in the probiotic group had achieved successful eradication of EPE, as defined by the primary outcome, in the intention to treat analysis. In the placebo group, 5% (2 out of 40) of the patients had achieved successful eradication of EPE (odds ratio 2.71; 95% confidence interval (CI), 0.49-14.9; p 0.24).

CONCLUSIONS

Successful EPE eradication was observed in very few individuals. This trial did not support Vivomixx® as being superior to placebo for intestinal decolonization in adult patients with chronic colonization of EPE, but was limited in power.

Impact of immunosuppressive therapy on therapy-neutralizing antibodies in transplanted patients with Fabry disease

BACKGROUND

Inhibitory antibodies towards enzyme replacement therapy (ERT) are associated with disease progression and poor outcome in affected male patients with lysosomal disorders such as Fabry disease (FD). However, little is known about the impact of immunosuppressive therapy on ERT inhibition in these patients with FD.

METHODS

In this retrospective study, we investigated the effect of long-term immunosuppression on ERT inhibition in male patients with FD (n = 26) receiving immunosuppressive therapy due to kidney (n = 24) or heart (n = 2) transplantation.

RESULTS

No ERT-naïve transplanted patient (n = 8) developed antibodies within follow-up (80 ±72 months) after ERT initiation. Seven (26.9%) patients were tested ERT inhibition positive prior to transplantation. No de novo ERT inhibition was observed after transplantation (n = 18). In patients treated with high dosages of immunosuppressive medication such as prednisolone, tacrolimus and mycophenolate-mofetil/mycophenolate acid, ERT inhibition decreased after transplantation (n = 12; P = 0.0160). Tapering of immunosuppression (especially prednisolone) seemed to re-increase ERT inhibition (n = 4, median [range]: 16.6 [6.9; 36.9] %; P = 0.0972) over time. One ERT inhibition-positive patient required interventions with steroid therapy and increased doses of tacrolimus, which also lowered ERT inhibition.

CONCLUSION

We conclude that the immunosuppressive maintenance therapy after transplantations seems to be sufficient to prevent de novo ERT inhibition in ERT-naïve patients. Intensified high dosages of immunosuppressive drugs are associated with decreased antibody titres and decreased ERT inhibition in affected patients, but did not result in long-term protection. Future studies are needed to establish ERT inhibition-specific immunosuppressive protocols with long-term modulating properties to warrant an improved disease course in ERT inhibition-positive males.

Composition of human faecal microbiota in resistance to Campylobacter infection

In mice, specific species composition of gut microbiota enhances susceptibility to Campylobacter jejuni but little is known about the specific composition of the human gut microbiota in providing protection from infections caused by enteropathogens. Healthy adult individuals, who travelled in groups from Sweden to destinations with an estimated high risk for acquisition of Campylobacter infection, were enrolled. Faecal samples, collected before travelling and after returning home, were cultured for bacterial enteropathogens, and analysed for Campylobacter by PCR and for the species composition of the microbiota by 16S amplicon massive parallel sequencing. The microbiota compositions were compared between persons who became infected during their travel and those who did not. A total of 63 participants completed the study; 14 became infected with Campylobacter, two with Salmonella and 47 remained negative for the enteropathogens tested. After exclusion of samples taken after antimicrobial treatment, 49 individuals were included in the final analyses. Intra-individual stability of the microbiota was demonstrated for samples taken before travelling. The original diversity of the faecal microbiota was significantly lower among individuals who later became infected compared with those who remained uninfected. The relative abundances of bacteria belonging to the family Lachnospiraceae, and more specifically its two genera Dorea and Coprococcus, were significantly higher among those who remained uninfected. The travel-related infection did not significantly modify the faecal microbiota composition. Species composition of human gut microbiota is important for colonization resistance to Campylobacter infection. Especially individuals with a lower diversity are more susceptible to Campylobacter infection.

Enzyme replacement therapy for mucopolysaccharidosis VI: long-term cardiac effects of galsulfase (Naglazyme®) therapy

Characteristic cardiac valve abnormalities and left ventricular hypertrophy are present in untreated patients with mucopolysaccharidosis type VI (MPS VI). Cardiac ultrasound was performed to investigate these findings in subjects during long-term enzyme replacement therapy (ERT) with recombinant human arylsulfatase B (rhASB, rhN-acetylgalactosamine 4-sulfatase, galsulfase, Naglazyme®). Studies were conducted in 54 subjects before ERT was begun and at specific intervals for up to 96 weeks of weekly infusions of rhASB at 1 mg/kg during phase 1/2, phase 2, and phase 3 trials of rhASB. At baseline, mitral and aortic valve obstruction was present and was significantly greater in those ≥12 years of age. Mild mitral and trace aortic regurgitation were present, the former being significantly greater in those <12 years. Left ventricular hypertrophy, with averaged z-scores ranging from 1.6-1.9 SD greater than normal, was present for ages both <12 and ≥12 years. After 96 weeks of ERT, ventricular septal hypertrophy regressed in those <12 years. For those ≥12 years, septal hypertrophy was unchanged, and aortic regurgitation increased statistically but not physiologically. Obstructive gradients across mitral and aortic valves remained unchanged. The results suggest that long-term ERT is effective in reducing intraventricular septal hypertrophy and preventing progression of cardiac valve abnormalities when administered to those <12 years of age.

Acute Cerebrovascular Disease in the Young

Background and Purpose—

Strokes have especially devastating implications if they occur early in life; however, only limited information exists on the characteristics of acute cerebrovascular disease in young adults. Although risk factors and manifestation of atherosclerosis are commonly associated with stroke in the elderly, recent data suggests different causes for stroke in the young. We initiated the prospective, multinational European study Stroke in Young Fabry Patients (sifap) to characterize a cohort of young stroke patients.

Methods—

Overall, 5023 patients aged 18 to 55 years with the diagnosis of ischemic stroke (3396), hemorrhagic stroke (271), transient ischemic attack (1071) were enrolled in 15 European countries and 47 centers between April 2007 and January 2010 undergoing a detailed, standardized, clinical, laboratory, and radiological protocol.

Results—

Median age in the overall cohort was 46 years. Definite Fabry disease was diagnosed in 0.5% (95% confidence interval, 0.4%–0.8%; n=27) of all patients; and probable Fabry disease in additional 18 patients. Males dominated the study population (2962/59%) whereas females outnumbered men (65.3%) among the youngest patients (18–24 years). About 80.5% of the patients had a first stroke. Silent infarcts on magnetic resonance imaging were seen in 20% of patients with a first-ever stroke, and in 11.4% of patients with transient ischemic attack and no history of a previous cerebrovascular event. The most common causes of ischemic stroke were large artery atherosclerosis (18.6%) and dissection (9.9%).

Conclusions—

Definite Fabry disease occurs in 0.5% and probable Fabry disease in further 0.4% of young stroke patients. Silent infarcts, white matter intensities, and classical risk factors were highly prevalent, emphasizing the need for new early preventive strategies.

Clinical Trial Registration Information—

URL: http://www.clinicaltrials.gov .Unique identifier: NCT00414583

Comparison of femoral and carotid blood pressure during laparoscopy in piglets

PURPOSE

The impact of a capnoperitoneum on the known blood pressure (BP) difference of the upper and lower limb was studied in piglets.

METHODS

Eleven German Landrace piglets (body weight, 4.3-7.4 kg; mean body weight, 6.2 kg) were studied. Arterial lines were placed in the right carotid and right femoral artery for pressure monitoring. Intraabdominal pressure levels were increased in steps of 6 mm Hg up to 24 mm Hg.

RESULTS

We found that elevated intraabdominal pressures up to 24 mm Hg did not change the preexisting systolic BP difference between the carotid and femoral arteries. Systolic femoral artery pressure constantly remained 5% higher than its carotid counterpart. In addition, mean and diastolic values were not affected.

CONCLUSIONS

Arterial BP measurements recorded at the legs of piglets when abdominal pressure is increased by up to 24 mm Hg can be used for intraoperative assessment of systemic arterial BP.

Safety of agalsidase alfa in patients with Fabry disease under 7 years

AIM

To evaluate the safety and explore the efficacy of enzyme replacement therapy (ERT) for Fabry disease with agalsidase alfa in young children enrolled in the Fabry Outcome Survey (FOS).

METHODS

This retrospective chart review identified eight children (mean age= 5.0±1.6 [mean ±SD]) in FOS who began treatment with agalsidase alfa (0.2 mg/kg, i.v., every other week) when <7 years old. Vital signs and adverse events were monitored throughout the study period. Glomerular filtration rate (GFR) was estimated, and left ventricular mass indexed to height(2.7) (LVMi) was assessed with echocardiography. Patients received 1.2-6.7 years of treatment (mean=4.2 years).

RESULTS

Infusion reactions occurred in three patients and were of mild or moderate severity. IgG antibodies to agalsidase alfa were found in one patient who experienced two mild and one moderate infusion reactions. Mean GFR was within the normal range at baseline and remained normal. LVMi was above the 75th percentile of age-matched children in 5 of 6 patients evaluated at baseline. Only two patients exceeded this threshold at their last assessment.

CONCLUSION

Long-term observation will be needed to determine whether early initiation of ERT will prevent major organ dysfunction in these patients.

Multidisciplinary management of Hunter syndrome

Hunter syndrome is a rare, X-linked disorder caused by a deficiency of the lysosomal enzyme iduronate-2-sulfatase. In the absence of sufficient enzyme activity, glycosaminoglycans accumulate in the lysosomes of many tissues and organs and contribute to the multisystem, progressive pathologies seen in Hunter syndrome. The nervous, cardiovascular, respiratory, and musculoskeletal systems can be involved in individuals with Hunter syndrome. Although the management of some clinical problems associated with the disease may seem routine, the management is typically complex and requires the physician to be aware of the special issues surrounding the patient with Hunter syndrome, and a multidisciplinary approach should be taken. Subspecialties such as otorhinolaryngology, neurosurgery, orthopedics, cardiology, anesthesiology, pulmonology, and neurodevelopment will all have a role in management, as will specialty areas such as physiotherapy, audiology, and others. The important management topics are discussed in this review, and the use of enzyme-replacement therapy with recombinant human iduronate-2-sulfatase as a specific treatment for Hunter syndrome is presented.

Association between polymorphisms of endothelial nitric oxide synthase gene (NOS3) and left posterior wall thickness (LPWT) of the heart in Fabry disease

Fabry disease is an X-chromosomal storage disorder due to loss-of-function mutations of the GLA gene encoding the lysosomal enzyme α-galactosidase A. Accumulating glycosphingolipid deposits disturb the function of various cells, in particular that of myocytes, arterial smooth-muscle cells, and vascular endothelium. Hypertrophic cardiomyopathy, for example measured by left posterior wall thickness (LPWT) of the heart, represents a major component of Fabry disease morbidity in adult patients. Endothelium-derived nitric oxide (eNO), produced by eNO synthase (eNOS), is a key regulator of vessel wall function and cardiovascular homeostasis. We analysed the effect of the polymorphisms c.894G > T (p.Glu298Asp) in exon 7 and the 27 bp tandem repeat (VNTR; allele a: 4 and allele b: 5 repeats) in intron 4 of the NOS3 gene, encoding eNOS, on LPWT of 102 patients with Fabry disease. For the association analysis, the distance of each patient's LPWT value from the cohort-specific, age-dependent regression line point (expected values) was used. In the cohort of 46 male patients, LPWT mean value of the group with GG genotype at position c.894 was smaller by 1 mm than that of (GT + TT) (p = 0.058). LPWT of patients with bb was thicker by 1.4 mm than that of (ab + aa) (p = 0.022). In patients with haplotype Ga, a thinner LPWT was seen than in those with Tb (p = 0.006). While no correlation was found between the GLA genotype and LPWT, the difference of 2.44 mm between the relative LPWT mean values of the two extreme NOS3 groups corresponds to the absolute LPWT increase that an average male patient with Fabry disease experiences during about 12 years. These are the first data showing a significant association of non-GLA-derived sequence variants with the cardiac phenotype in Fabry disease that may in part explain the great phenotypic variability of the disease.

Identification of a novel compound heterozygote SCO2 mutation in cytochrome c oxidase deficient fatal infantile cardioencephalomyopathy

Fatal infantile cardioencephalomyopathy (OMIM No. 604377) is a disorder of the mitochondrial respiratory chain and is characterised by neonatal progressive muscular hypotonia and cardiomyopathy because of severe Cytochrome c oxidase deficiency. Here we report a novel mutation in the Cytochrome c oxidase assembly gene SCO2 in an infant with fatal infantile cardioencephalomyopathy despite normal initial metabolic screening.

CONCLUSION

In newborns with unexplained muscular hypotonia and cardiomyopathy genetic testing of mitochondrial respiratory chain disorders might be helpful to establish a final diagnosis and guide treatment decisions.

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 alpha-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.

The right ventricle in Fabry disease

AIM

Left ventricular (LV) hypertrophy is a common feature in Fabry disease-related progressive infiltrative hypertrophic cardiomyopathy and affects both men and women, but at different ages. To date, however, little is known about the role of right ventricular (RV) function in Fabry disease. Therefore, this study aimed to investigate the extent of RV involvement in patients with Fabry disease.

METHODS

Echocardiographic examination of the right and left ventricle was carried out in 129 patients (80 women and 49 men) with Fabry disease.

RESULTS

RV hypertrophy was present in 46 patients (35.7%). Of these patients, 13 showed signs of severely depressed right systolic function (tricuspid annulus movement < 10 mm and a prolonged RV pre-ejection period/pulmonary ejection time ratio) and six patients showed additional severe depression of parameters of diastolic function (pseudo-normal or restrictive RV filling pattems). Those patients with RV hypertrophy and severely compromised systolic and diastolic function had the highest LV masses (92 +/- 11.7 g/m(2.7)).

CONCLUSION

RV involvement is common in Fabry disease and ultimately progresses to severe systolic and diastolic RV dysfunction. These findings might explain why patients with preserved LV function can develop clinical features such as reduced exercise capacity, organomegaly and lymphoedema.

[Duration of induced seizures during selective pharyngeal brain cooling]

Whole body hypothermia can be used to treat the injured brain (e.g. after hypoxic events). Side effects include hemodynamic instability, coagulopathy and infection. Because of these side effects it appears reasonable to cool the brain selectively (selective brain cooling, SBC) without changing the core temperature. A new animal model was used to demonstrate SBC from the pharynx and to examine effects of SBC on the duration of pharmacologically induced seizure activity. Sprague-Dawley rats (n=18, 12 successful experiments) were sedated and mechanically ventilated. Invasive blood pressure monitoring was instituted and blood gases were drawn to evaluate the arterial blood gas status. Electrical brain activity was recorded using a microneedle in the extracellular compartment of the rat brain cortex. Cooled water was circulated through a small tubing into and out of the pharynx of the animals. The cortical as well as the rectal temperature were recorded. After the injection of a single dose of bicuculline (1 mg/kg i.v.) per animal the duration of the induced seizure activity was measured and compared with the temperature prior to the induction of seizure activity. The cortical blood flow (CBF) was detected using intra tissue Doppler signals in the rat cortex in the same location as the EP-study. The influence of a brain temperature reduction between 36.5 degrees to 31.5 degrees C on the seizure duration was examined. There was a positive correlation between the seizure duration and the cortical temperature (r=0.64). Also the CBF was increased during seizure activity (p=0.02) and the increase correlated weakly with cortical temperature (r=0.18). The core temperature remained in the normothermic range (36.9+/-0.7 degrees C) Conclusion: The duration of induced seizures correlates with local brain temperature. In the future further studies should examine the efficiency of induced (selective) brain cooling to treat prolonged seizure activity.

Cumulative incidence rates of the mucopolysaccharidoses in Germany

In order to estimate the cumulative incidence rates of the mucopolysaccharidoses (MPS) in Germany, a retrospective epidemiological survey covering the period between 1980 and 1995 was implemented. Multiple ascertainment sources were used to identify affected patients. A prevalence of approximately 0.69 cases per 100,000 births was obtained for MPS I (Hurler phenotype). Within the study period, 4 patients with Hurler/Scheie phenotype and 7 cases with Scheie disease were detected. The cumulative incidence for MPS II (Hunter syndrome) was estimated as 0.64 cases per 100,000 births (1.3 cases per 100,000 male live births); that for MPS III (Sanfilippo syndrome types A, B and C) as 1.57 cases in 100,000 births; that for MPS IV A (Morquio syndrome) as 0.38 cases in 100,000; and that for MPS VI (Maroteaux-Lamy syndrome) as 0.23 cases per 100,000 births. Two cases of MPS IVB (beta-galactosidase deficiency) have been identified, but no patients with MPS VII or MPS IX. A relatively high number of patients with MPS IIIB, MPS IVA and MPS VI were of Turkish origin. The crude rate for all types of mucopolysaccharidoses is approximately 3.53 cases in 100,000 live births. The cumulative incidence pattern of MPS in Germany was compared with the corresponding rates among other industrial nations obtained from recent literature: the crude cumulative rates for all types of mucopolysaccharidoses (3.4-4.5 in 100,000 live births) were similar among all published populations; however, different frequencies of the various forms of MPS were observed.

Successful pregnancy outcome in a patient with Fabry disease receiving enzyme replacement therapy with agalsidase alfa

Fabry disease is an inherited lysosomal storage disease caused by deficiency of alpha-galactosidase A. Enzyme replacement therapy for this multisystem progressive disease has been available only since 2001. We here report the first known successful pregnancy of a female patient receiving such therapy.

Fabry disease: overall effects of agalsidase alfa treatment

BACKGROUND

Fabry disease is a rare X-linked disorder caused by deficient activity of the lysosomal enzyme alpha-galactosidase A. Progressive accumulation of the substrate globotriaosylceramide in cells throughout the body leads to major organ failure and premature death. The Fabry Outcome Survey (FOS) is a European outcomes database which was established to collect data on the natural history of this little-known disease and to monitor the long-term efficacy and safety of enzyme replacement therapy (ERT) with agalsidase alfa. This paper presents the first analysis of the FOS database on the effects of ERT on renal function, heart size, pain and quality of life.

DESIGN

The effects of 1 and 2 years of ERT with agalsidase alfa on renal function (assessed by estimated glomerular filtration rate), heart size (assessed by echocardiography), pain (assessed by the Brief Pain Inventory) and quality of life (assessed by the European Quality of Life Questionnaire EQ-5D) were analyzed in a cohort of 545 patients, 314 of whom were receiving treatment (188 for at least 12 months and 92 for at least 24 months; mean duration of treatment, 17 months; maximum duration, 56 months).

RESULTS

Treatment with agalsidase alfa stabilized renal function in patients with a mild or moderate deterioration in renal function at baseline, reduced left ventricular size in patients who had an enlarged heart at baseline, and improved pain scores and quality of life. These improvements were similar in hemizygous men and heterozygous women with Fabry disease.

CONCLUSIONS

Enzyme replacement therapy with agalsidase alfa leads to significant clinical benefits in patients with Fabry disease, and treatment is likely to alter the natural history of this disorder.

Fabry disease defined: baseline clinical manifestations of 366 patients in the Fabry Outcome Survey

BACKGROUND

Fabry disease is a rare X-linked disorder caused by deficient activity of the lysosomal enzyme alpha-galactosidase A. Progressive accumulation of the substrate globotriaosylceramide in cells throughout the body leads to major organ failure and premature death. In response to the recent introduction of enzyme replacement therapy, the Fabry Outcome Survey (FOS) was established to pool data from European clinics on the natural history of this little-known disease and to monitor the long-term efficacy and safety of treatment. This paper presents the first analysis of the FOS database and provides essential baseline data against which the effects of enzyme replacement can be measured.

DESIGN

Baseline data from a cohort of 366 patients from 11 European countries were analysed in terms of demography and clinical manifestations of Fabry disease.

RESULTS

Misdiagnosis of Fabry disease is common, and the mean delay from onset of symptoms to correct diagnosis was 13.7 and 16.3 years in males and females, respectively. Although previously thought to have serious manifestations only in hemizygous men, the FOS database has confirmed that females heterozygous for Fabry disease are similarly affected. Furthermore, signs and symptoms of Fabry disease may be present from early childhood.

CONCLUSIONS

With the advent of enzyme replacement therapy, it is important that general practitioners and physicians in a range of specialties recognize the signs and symptoms of Fabry disease so that effective treatment can be given. Baseline data from FOS demonstrate that enzyme replacement therapy should not be restricted to hemizygous men, but should be considered for both heterozygous females and children.

The Mainz Severity Score Index: a new instrument for quantifying the Anderson-Fabry disease phenotype, and the response of patients to enzyme replacement therapy

Anderson-Fabry disease (AFD) is an X-linked disorder caused by deficient activity of the lysosomal enzyme alpha-galactosidase A. The availability of enzyme replacement therapy (ERT) for this debilitating condition has led to the need for a convenient and sensitive instrument to monitor clinical effects in an individual patient. This study aimed to develop a scoring system--the Mainz Severity Score Index (MSSI)--to measure the severity of AFD and to monitor the clinical course of the disease in response to ERT. Thirty-nine patients (24 males and 15 females) with AFD were assessed using the MSSI immediately before and 1 year after commencing agalsidase alfa ERT. Control data were obtained from 23 patients in whom AFD was excluded. The MSSI of patients with AFD was significantly higher than that of patients with other severe debilitating diseases. The MSSI indicated that, although more men than women had symptoms classified as severe, overall, the median total severity scores were not significantly different between male and female patients. One year of ERT with agalsidase alfa led, in all patients, to a significant (p < 0.001) reduction in MSSI score (by a median of nine points). This study has shown that the MSSI score may be a useful, specific measure for objectively assessing the severity of AFD and for monitoring ERT-related treatment effects.

Electrocardiographic signs of hypertrophy in fabry disease-associated hypertrophic cardiomyopathy

AIMS

Fabry disease results from deficient activity of the lysosomal enzyme alpha-galactosidase A. Progressive accumulation of the major substrates leads, in both men and women, to progressive hypertrophic cardiomyopathy. We aimed to evaluate the utility of different electrocardiographic (ECG) parameters for assessing the degree and severity of hypertrophic cardiomyopathy in patients with Fabry disease.

METHODS

A total of 166 ECGs of 94 hemi- and heterozygous patients with Fabry disease were analysed and compared with echocardiographic-estimated left ventricular mass (LVM).

RESULTS

There was a significant (p < 0.0001) correlation between QRS duration (R2 = 0.59), 12-lead amplitude/duration product (R2 = 0.61), Sokolow-Lyon voltage/duration product (R2 = 0.52) and LVM. Analysis of receiver operating characteristics revealed that the 12-lead amplitude/duration product had the highest sensitivity-specificity relationship (p < 0.01 compared with the Cornell index).

CONCLUSION

In general, ECG signs of left ventricular hypertrophy correlated well with LVM as revealed by echocardiography. Of the parameters studied, the 12-lead amplitude/duration product was the most successful at describing the severity of cardiac involvement in Fabry disease. These data suggest that ECG parameters have potential for use as a simple and cost-effective means of screening for hypertrophic cardiomyopathy in patients with Fabry disease.

The Fontan-operation: from intra- to extracardiac procedure

PURPOSE

For treatment of univentricular heart, the Fontan operation has been established as the definitive palliation. The current controversy is mainly based on the high incidence of arrhythmias after an intra-atrial lateral tunnel Fontan operation.

METHODS

From January 1995 until April 2002, 46 children underwent a Fontan-type operation with or without a small fenestration. In 33 patients (group I) an intracardiac tunnel and in 13 patients (group II) an extracardiac conduit procedure was performed.

PRINCIPAL FINDINGS

There was no perioperative mortality. All patients showed postoperative a significant increase of arterial oxygen saturation, from 76 to 86% after surgery with fenestration, or to 90.5% without fenestration respectively. In patients with fenestration procedure, the saturation rose to 90% after closure of fenestrations 9 to 12 months after operation.

CONCLUSIONS

Modified Fontan operations can be performed in normothermia on the beating heart with acceptable mortality. The extracardiac conduit Fontan procedure has the benefits of less surgical injury and a higher intraoperative flexibility.