Sima Canaan-Kühl

Patients with Fabry Disease after Enzyme Replacement Therapy Dose Reduction Versus Treatment Switch

Because of the shortage of agalsidase-beta in 2009, many patients with Fabry disease were treated with lower doses or were switched to agalsidase-alfa. This observational study assessed end-organ damage and clinical symptoms during dose reduction or switch to agalsidase-alfa. A total of 105 adult patients with Fabry disease who had received agalsidase-beta (1.0 mg/kg body weight) for ≥1 year were nonrandomly assigned to continue this treatment regimen (regular-dose group, n=38), receive a reduced dose of 0.3-0.5 mg/kg (dose-reduction group, n=29), or switch to 0.2 mg/kg agalsidase-alfa (switch group) and were followed prospectively for 1 year. We assessed clinical events (death, myocardial infarction, severe arrhythmia, stroke, progression to ESRD); changes in cardiac, renal, and neurologic function; and Fabry-related symptoms (neuropathic pain, hypohidrosis, diarrhea, and disease severity scores). Organ function and Fabry-related symptoms remained stable in the regular-dose group. In contrast, estimated GFR decreased by about 3 ml/min per 1.73 m(2) (P=0.01) in the dose-reduction group, and the median albumin-to-creatinine ratio increased from 114 (0-606) mg/g to 216 (0-2062) mg/g (P=0.03) in the switch group. Furthermore, mean Mainz Severity Score Index scores and frequencies of pain attacks, chronic pain, gastrointestinal pain, and diarrhea increased significantly in the dose-reduction and switch groups. In conclusion, patients receiving regular agalsidase-beta dose had a stable disease course, but dose reduction led to worsening of renal function and symptoms. Switching to agalsidase-alfa is safe, but microalbuminuria may progress and Fabry-related symptoms may deteriorate.

“Periodic fever” without fever: two cases of non-febrile TRAPS with mutations in the TNFRSF1A gene presenting with episodes of inflammation or monosymptomatic amyloidosis

Background: Tumour necrosis factor (TNF) receptor associated periodic syndrome (TRAPS) is caused by dominant mutations in the TNFRSF1A gene. In typical cases TRAPS begins early in childhood and is characterised by high and remittent fever over a period of 1–4 weeks or longer, accompanied by systemic and local inflammation. Case reports: Patient 1 presented with recurrent episodes of weakness, migrating myalgias, arthralgias, exanthema, and chest pain lasting for 1–4 weeks, but without any fever over an initial period of 4 years at least. Diagnosis of TRAPS was confirmed by the heterozygous mutation Y20H in TNFRSF1A. Patient 2, a 23 year old woman never had any symptoms indicative of TRAPS. Genetic evaluation of all members of her family with a TRAPS index patient disclosed the T50M mutation in TNFRSF1A. A medical check up showed proteinuria, and renal biopsy disclosed AA amyloidosis. Conclusions: TRAPS associated mutations can induce considerable inflammation that is not necessarily accompanied by fever. Even monosymptomatic severe amyloidosis can occur in these patients. Genetic counselling and appropriate management to prevent or mitigate amyloidosis may be necessary.

Patients with Fabry Disease after Enzyme Replacement Therapy Dose Reduction and Switch–2-Year Follow-Up

Because of the shortage of agalsidase-β supply between 2009 and 2012, patients with Fabry disease either were treated with reduced doses or were switched to agalsidase-α. In this observational study, we assessed end organ damage and clinical symptoms with special focus on renal outcome after 2 years of dose-reduction and/or switch to agalsidase-α. A total of 89 adult patients with Fabry disease who had received agalsidase-β (1.0 mg/kg body wt) for >1 year were nonrandomly assigned to continue this treatment regimen (regular-dose group, n=24), to receive a reduced dose of 0.3-0.5 mg/kg and a subsequent switch to 0.2 mg/kg agalsidase-α (dose-reduction-switch group, n=28), or to directly switch to 0.2 mg/kg agalsidase-α (switch group, n=37) and were followed-up for 2 years. We assessed clinical events (death, myocardial infarction, severe arrhythmia, stroke, progression to ESRD), changes in cardiac and renal function, Fabry-related symptoms (pain, hypohidrosis, diarrhea), and disease severity scores. Determination of renal function by creatinine and cystatin C-based eGFR revealed decreasing eGFRs in the dose-reduction-switch group and the switch group. The Mainz Severity Score Index increased significantly in these two groups (P=0.02 and P<0.001, respectively), and higher frequencies of gastrointestinal pain occurred during follow-up. In conclusion, after 2 years of observation, all groups showed a stable clinical disease course with respect to serious clinical events. However, patients under agalsidase-β dose-reduction and switch or a direct switch to agalsidase-α showed a decline of renal function independent of the eGFR formula used.

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

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.

[Pain therapy for Fabry's disease].

Fabrys disease is an X-chromosome linked lysosomal storage disorder with α-galactosidase A deficiency and subsequent multiple organ involvement. An early and common symptom also in later stages of the disease is pain. This pain depends on various precipitating factors and can severely compromise the quality of life. So-called Fabry crises can lead to the necessity for intensive care treatment. The pain can be classified as predominantly neuropathic and is difficult to treat. In addition, medication has to be adjusted to concomitant cardiac and renal involvement in Fabrys disease. This review gives guidance for pain therapy in Fabrys disease based on the available evidence and on experience.

Endomyocardial biopsy in Anderson–Fabry disease: The key in uncertain cases

a Dept. of Cardiology, Charite, Campus Virchow Klinikum (CVK), Berlin, Germany b Dept. of Cardiology, Hospital Universitario Puerta de Hierro, Madrid, Spain c Dept. of Cardiology, Deutsches Herzzentrum Berlin (DHZB), Berlin, Germany d Dept. of Nephrology, Charite, Campus Virchow Klinikum (CVK), Berlin, Germany e Berliner Zentrum fur Regenerative Therapien (BCRT), Campus Virchow Klinikum (CVK), Berlin, Germany f Deutsches Zentrum fur Herz Kreislaufforschung (DZHK) — Standort Berlin/Charite, Germany

Schmerztherapie bei Morbus Fabry

Fabrys disease is an X-chromosome linked lysosomal storage disorder with α-galactosidase A deficiency and subsequent multiple organ involvement. An early and common symptom also in later stages of the disease is pain. This pain depends on various precipitating factors and can severely compromise the quality of life. So-called Fabry crises can lead to the necessity for intensive care treatment. The pain can be classified as predominantly neuropathic and is difficult to treat. In addition, medication has to be adjusted to concomitant cardiac and renal involvement in Fabrys disease. This review gives guidance for pain therapy in Fabrys disease based on the available evidence and on experience.

Fabry disease under enzyme replacement therapy—new insights in efficacy of different dosages

Background Fabry patients on reduced dose of agalsidase-beta or after switch to agalsidase-alfa show a decline in estimated glomerular filtration rate (eGFR) and an increase of the Mainz Severity Score Index. Methods In this prospective observational study, we assessed end-organ damage and clinical symptoms in 112 patients who had received agalsidase-beta (1.0 mg/kg) for >1 year, who were (i) non-randomly assigned to continue this treatment regime (regular-dose group, n = 37); (ii) received a reduced dose of agalsidase-beta and subsequent switch to agalsidase-alfa (0.2 mg/kg) or a direct switch to 0.2 mg/kg agalsidase-alfa (switch group, n = 38); or (iii) were re-switched to agalsidase-beta after receiving agalsidase-alfa for at least 12 months (re-switch group, n = 37) with a median follow-up of 53 (38-57) months. Results eGFR of patients in the regular-dose group remained stable. Patients in the switch group showed an annual eGFR loss of - 4.6  ±  9.1 mL/min/1.73 m2 (P < 0.05). Patients in the re-switch group also had an eGFR loss of - 2.2  ±  4.4 mL/min/1.73 m2 after re-switch to agalsidase-beta, but to a lower degree compared with the switch group (P < 0.05). Patients in the re-switch group suffered less frequently from diarrhoea (relative risk 0.42; 95% confidence interval 0.19-0.93; P = 0.02). Lyso-Gb3 remained stable in the switch (P = 0.97) and the regular-dose (P = 0.48) groups, but decreased in the re-switch group after change of the therapy regimen (P < 0.05). Conclusions After switch to agalsidase-alfa, Fabry patients experienced a continuous decline in eGFR, while this decline was attenuated in patients who were re-switched to agalsidase-beta. Decreasing lyso-Gb3 levels may indicate a better treatment response in the latter group.

Late-onset Bartter syndrome type II

Abstract Mutations in the ROMK1 potassium channel gene (KCNJ1) cause antenatal/neonatal Bartter syndrome type II (aBS II), a renal disorder that begins in utero, accounting for the polyhydramnios and premature delivery that is typical in affected infants, who develop massive renal salt wasting, hypokalaemic metabolic alkalosis, secondary hyperreninaemic hyperaldosteronism, hypercalciuria and nephrocalcinosis. This BS type is believed to represent a disorder of the infancy, but not in adulthood. We herein describe a female patient with a remarkably late-onset and mild clinical manifestation of BS II with compound heterozygous KCNJ1 missense mutations, consisting of a novel c.197T > A (p.I66N) and a previously reported c.875G > A (p.R292Q) KCNJ1 mutation. We implemented and evaluated the performance of two different bioinformatics-based approaches of targeted massively parallel sequencing [next generation sequencing (NGS)] in defining the molecular diagnosis. Our results demonstrate that aBS II may be suspected in patients with a late-onset phenotype. Our experimental approach of NGS-based mutation screening combined with Sanger sequencing proved to be a reliable molecular approach for defining the clinical diagnosis in our patient, and results in important differential diagnostic and therapeutic implications for patients with BS. Our results could have a significant impact on the diagnosis and methodological approaches of genetic testing in other patients with clinical unclassified phenotypes of nephrocalcinosis and congenital renal electrolyte abnormalities.

Schmerztherapie bei Morbus Fabry@@@Pain therapy for Fabry’s disease

Fabrys disease is an X-chromosome linked lysosomal storage disorder with α-galactosidase A deficiency and subsequent multiple organ involvement. An early and common symptom also in later stages of the disease is pain. This pain depends on various precipitating factors and can severely compromise the quality of life. So-called Fabry crises can lead to the necessity for intensive care treatment. The pain can be classified as predominantly neuropathic and is difficult to treat. In addition, medication has to be adjusted to concomitant cardiac and renal involvement in Fabrys disease. This review gives guidance for pain therapy in Fabrys disease based on the available evidence and on experience.