Use of Cysteamine in the Treatment of Cystinosis

Study Overview
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Brief Summary
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Cystinosis is an inherited disease resulting in poor growth and kidney failure. There is no known cure for cystinosis, although kidney transplantation may help the renal failure and prolong survival. Both the kidney damage and growth failure are thought to be due to the accumulation of the amino acid cystine within the cells of the body. The cystine storage later damages other organs besides the kidneys, including the thyroid gland, pancreas, eyes, and muscle. The drug cysteamine (Cystagon) is an oral medication given to patients with cystinosis prior to kidney transplantation. The drug works by reducing the level of cystine in the white blood cells and muscle tissue. The drug may also decrease levels of cystine in the kidneys and other tissues. This study has several goals: Long-term surveillance of cysteamine (Cystagon) treated patients. Detection of new non-kidney complications of cystinosis. Maintenance of a patient population for genetic testing (mutational analysis) of the cystinosis gene.<TAB>

Detailed Description
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Patients with nephropathic cystinosis have been treated with the cystine-depleting agent cysteamine since 1978. This therapy prevents or delays renal deterioration, improves growth, and depletes parenchymal tissues of cystine. Based largely upon data produced through this protocol, the Food and Drug Administration approved cysteamine bitartrate for use in cystinosis patients on August 15, 1994. Cysteamine is available as CystagonR through Mylan Pharmaceuticals in 50 mg and 150 mg capsules and as ProcysbiR in 75 mg capsules. By virtue of the current protocol, patients are admitted to the NIH Clinical Center for investigations every two years, except for cases of great interest or urgency. On each 1-3 day admission, a battery of tests is performed and the adequacy of cystine depletion by cysteamine is monitored. This protocol demonstrates the course of cystinosis patients treated with cysteamine, describes new complications of the disorder in poorly treated adults, and maintains NHGRI expertise in the field. Its monitoring and followup of patients over the course of 3 decades represents an invaluable contribution to our understanding of the natural history of this rare disease.

Official Title
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Use of Cysteamine in the Treatment of Cystinosis

Conditions
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Cystinosis

Intervention / Treatment
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* Drug: Cysteamine


Participation Criteria
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Eligibility Criteria
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INCLUSION CRITERIA: Diagnosis of cystinosis, whether classical or one of the variants with later onset or no renal complications. Patients will be diagnosed as having cystinosis based upon a leucocyte cystine content greater than 1 nmol half-cystine/mg protein (normal, less than 0.2) and a typical clinical course. EXCLUSION CRITERIA: Inability to travel to the NIH. Age less than one week. Nonviable neonates and neonates of uncertain viability will be excluded.

Ages Eligible for Study
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Minimum Age: 1 Week
Maximum Age: 115 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Cystinosis<br>Patients with a diagnosis of cystinosis | Drug: Cysteamine<br>* Cystine-depleting agent<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Serve as a source of knowledge and advice for individual cystinosis patients and for the community at large | Serve as a source of knowledge and advice for individual cystinosis patients and for the community at large | Follow-up can occur every two years | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Cystinosis, Cystine, Lysomal Storage Disease, Mutation Analysis, Metabolic Disease, Natural History