Minimal change disease

Minimal change disease (MCD) is the most common form of idiopathic nephrotic syndrome (NS) in children (70% to 90% of cases) and is characterised by minimal histological changes in the kidney. In adults, MCD is the cause of NS in 10% to 15% of cases.

Children typically present with peripheral oedema, associated with heavy proteinuria, hypoalbuminaemia, and hyperlipidaemia, although some are asymptomatic. Adults have similar symptoms and signs but may also have hypertension, haematuria, and acute kidney injury at the point of diagnosis.

Corticosteroid therapy is the mainstay of treatment. Long-term corticosteroid therapy has significant adverse effects; therefore, if needed, corticosteroid-sparing therapies can be added. However, most children outgrow MCD and stop having relapses during their teenage years.

In children aged up to 12 years, treatment is typically empirical, with kidney biopsy usually reserved for those patients who do not respond to corticosteroid therapy or have frequent relapses, or for diagnosis in infants aged <1 year old. Kidney biopsy is required for diagnosis in adults.

MCD is the most common form of nephrotic syndrome (a clinical condition characterised by heavy proteinuria, oedema, hypoalbuminaemia, and hyperlipidaemia) affecting children.[1]Vivarelli M, Massella L, Ruggiero B, et al. Minimal change disease. Clin J Am Soc Nephrol. 2017 Feb 7;12(2):332-45. https://cjasn.asnjournals.org/content/12/2/332.long http://www.ncbi.nlm.nih.gov/pubmed/27940460?tool=bestpractice.com [2]Trautmann A, Boyer O, Hodson E, et al. IPNA clinical practice recommendations for the diagnosis and management of children with steroid-sensitive nephrotic syndrome. Pediatr Nephrol. 2023 Mar;38(3):877-919. https://link.springer.com/article/10.1007/s00467-022-05739-3 http://www.ncbi.nlm.nih.gov/pubmed/36269406?tool=bestpractice.com ​​​​​​ Early studies determined that up to 90% of children respond to corticosteroid therapy, such that kidney biopsy is not routinely performed at disease onset.[2]Trautmann A, Boyer O, Hodson E, et al. IPNA clinical practice recommendations for the diagnosis and management of children with steroid-sensitive nephrotic syndrome. Pediatr Nephrol. 2023 Mar;38(3):877-919. https://link.springer.com/article/10.1007/s00467-022-05739-3 http://www.ncbi.nlm.nih.gov/pubmed/36269406?tool=bestpractice.com ​ If biopsy is performed, the most frequent findings are minimal histological changes in the kidney, hence the name minimal change disease.​​[3]Kidney Disease: Improving Global Outcomes (KDIGO) Glomerular Diseases Work Group. KDIGO 2021 clinical practice guideline for the management of glomerular diseases. Kidney Int. 2021 Oct;100(4s):S1-276. https://www.kidney-international.org/article/S0085-2538(21)00562-7/fulltext ​ MCD is typically primary (idiopathic) but may also be secondary to another condition. Although MCD usually presents in childhood, it can occur in adults, when kidney biopsy is required for confirmation of the diagnosis.[3]Kidney Disease: Improving Global Outcomes (KDIGO) Glomerular Diseases Work Group. KDIGO 2021 clinical practice guideline for the management of glomerular diseases. Kidney Int. 2021 Oct;100(4s):S1-276. https://www.kidney-international.org/article/S0085-2538(21)00562-7/fulltext