Recent advances in the treatment of cystinosis

Abstract

Cysteamine bitartrate capsules (Cystagon) have been approved by the US Food and Drug Administration for use in patients with nephropathic cystinosis. Plasma cysteamine concentrations were virtually identical at various times following ingestion of either cysteamine hydrochloride or Cystagon capsules in 24 normal control subjects. A transfer study was done with eight cystinosis patients who had been receiving either cysteamine hydrochloride or phosphocysteamine for many years. The plasma cysteamine concentration was significantly higher 2h after Cystagon and the leukocyte cystine content was significantly lower at all times after Cystagon compared to older forms of the drug. These differences are probably the result of greater patient compliance in taking the capsules compared to the older, liquid forms of the drug. A new method for following the course of renal glomerular deterioration in diseases such as cystinosis has been published recently. This method was used to re-analyse data on the efficacy of cysteamine treatment and to re-analyse new data on treating cystinosis patients with either of two doses of cysteamine (1.30 g/m2 per day and 1.95 g/m2 per day). This new method agrees well with other methods and shows that both doses of drug are equally effective in maintaining glomerular function.

The evaluation and treatment of gastrointestinal disease in children with cystinosis receiving cysteamine

“…However, this would seem unlikely because plasma cysteamine concentrations after oral cysteamine bitartrate peak at one to two hours, and gradually fall to immeasurable levels six hours later. 25 The mean symptom score fell during the study from 6.9 to 0.7, with the most dramatic improvement occurring within the first four weeks of omeprazole therapy. The most commonly reported symptoms of nausea, vomiting, anorexia, and pain responded best to acid suppression.…”

Lysosomal storage diseases: Diagnostic confirmation and management of presymptomatic individuals

“…Cysteamine is used successfully to preserve renal function in cystinosis. [13][14][15] Substrate reduction therapy (SRT) with N-butyldeoxynojirimycin (OGT-918, miglustat, Zavesca; Actelion, Basel, Switzerland) reduces production of glycosphingolipids by inhibiting glucosylceramide synthase, the first step of their biosynthesis. SRT is approved for use in GD, although side effects preclude its more widespread use, 16,17 and NiemannPick type C in Europe.…”

Long-term outcome of nephropathic cystinosis: a 20-year single-center experience

“…In recent decades, NC prognosis has considerably improved due to the introduction of treatment with 2-mercaptoethylamine, or cysteamine, which allows cystine clearance from the lysosomal compartment [2,[9][10][11]. Treatment with cysteamine has been further optimized by methods to monitor intraleucocyte cystine (ILC) levels that allow dose adaption of cysteamine to maintain target ILC levels of ILC [11][12][13][14].…”