Phosphocysteamine in the Treatment of Cystinosis

Abstract

Cystinosis is a relatively rare recessive autosomal inherited metabolic disease. In this metabolic anomaly free cystin is accumulated in the cell lysozymes of the different body tissues. The nephritic form of the disease begins in infancy and leads to Fanconi syndrome with polyuria, polydisia, metabolic acidosis, phosphaturia and Vitamin D-resistent rickets. If not treated, it can end in chronic kidney insufficiency. In the beginning of the disease phosphocysteamine can prevent the accumulation of cystin in the lysozymes and can hinder the progress of the disease.
In our study we treated 15 cystinosis patients (7 girls, 8 boys) with phosphocystamine. The mean age at beginning of the symptoms was 8.4 months. Unfortunately, the disease was diagnosed and treatment started at a mean age of 3.58 years. Therefore, all patients had their kidney complications at the time the treatment with phosphocysteamind began. Anyhow, creatinine clearance increased after treatment in 12 patients. There was a significant relation between the time of beginning of the treatment and patients condition after treatment, i.e. the earlier the treatment began, the better was the function of the kidneys after treatment with phosphocysteamin.