Cystine-depleting therapy (CDT) breaks cystine into cysteine and cysteine-cysteamine mixed disulfide, which can exit the lysosome independently of the cystinosin transporter and cause up to 95% decrease of cystine in cells.1,2
Oral cysteamine reduces cystine levels in leukocytes and tissues 
Cysteamine eye drops dissolve corneal crystals CDT works to lower cystine levels and may help limit or delay damage to the body.3-7 Treatment cannot correct the underlying systemic metabolic defect of cystinosis.8 Oral CDT does not remove cystine from the cornea thus requiring the use of cysteamine eye drops.9,10 Learn about a CDT option to help manage cystinosis.
Management of cystinosis involves specific treatment with CDT and supportive therapies to address renal and extrarenal complications.2
Cystinosis causes damage throughout the body, but symptoms often present in the kidneys first.2,6 Most children develop end-stage renal disease (ESRD) and require a kidney transplant by 10 years of age when left untreated.11,12
A kidney transplant will address renal failure, but renal replacement therapy may be necessary until a new kidney is received.11,12
A kidney transplant may prolong survival but will not correct the underlying systemic metabolic defect of cystinosis.11,13 Cystine will continue to accumulate in other organs and may lead to hypothyroidism, pancreatic endocrine and exocrine dysfunction, various neurological abnormalities, and other comorbidities.13
1. Gahl WA, Balog JZ, Kleta R. Nephropathic cystinosis in adults: natural history and effects of oral cysteamine therapy. Ann Intern Med. 2007;147(4):242-250. 2. Gahl WA, Thoene JG, Schneider JA. Cystinosis. N Engl J Med. 2002;347(2):111-121. 3. Brodin-Sartorius A, Tête MJ, Niaudet P, et al. Cysteamine therapy delays the progression of nephropathic cystinosis in late adolescents and adults. Kidney Int. 2012;81(2):179-189. 4. Gahl WA. Early oral cysteamine therapy for nephropathic cystinosis. Eur J Pediatr. 2003;162(suppl 1):S38-S41. 5. Nesterova G, Gahl WA. Cystinosis: the evolution of a treatable disease. Pediatr Nephrol. 2013;28(1):51-59. 6. Elmonem MA, Veys KR, Soliman NA, van Dyck M, van den Heuvel LP, Levtchenko E. Cystinosis: a review. Orphanet J Rare Dis. 2016;11:47. Published April 22, 2016. 7. Langman CB, Barshop BA, Deschênes G, et al. Controversies and research agenda in nephropathic cystinosis: conclusions from a “Kidney disease: improving global outcomes” (KDIGO) controversies conference. Kidney Int. 2016;89(6):1192-1203. 8. Levtchenko EN, van Dael CM, de Graaf-Hess AC, et al. Strict cysteamine dose regimen is required to prevent nocturnal cystine accumulation in cystinosis. Pediatr Nephrol. 2006;21(1):110-113. 9. Kasimer RN, Langman CB. Adult complications of nephropathic cystinosis: a systematic review. Pediatr Nephrol. 2021;36(2):223-236. 10. Dureau P, Broyer M, Dufier JL. Evolution of ocular manifestations in nephropathic cystinosis: a long-term study of a population treated with cysteamine. J Pediatr Ophthalmol Strabismus. 2003;40(3):142-146. 11. Nesterova G, Gahl W. Nephropathic cystinosis: late complications of a multisystemic disease. Pediatr Nephrol. 2008;23(6):863-878. 12. Van Stralen KJ, Emma F, Jager KJ, et al. Improvement in the renal prognosis in nephropathic cystinosis. Clin J Am Soc Nephrol. 2011;6(10):2485-2491. 13. Almond PS, Matas AJ, Nakhleh RE, et al. Renal transplantation for infantile cystinosis: long-term follow-up. J Pediatr Surg. 1993;28(2):232-238.
