[FSGS collapsing variant during anabolic steroid abuse: Case Report].

Anabolic Androgenic Steroids (AAS) is an hormone family whose use has considerably increased among body-builders during the last decades. The AAS abuse, especially associated with other drugs or nutritional supplements and protein loads, may cause a variety of pathologies to several organs with a mechanism related to dosage, timing and substance. The kidney is the main metabolizer of these drugs and it can be acutely or chronically damaged with ESKD. The literature reports some cases of Focal Segmental Glomerulosclerosis (FSGS) in body-builders who abused of AAS. However, the link is not well understood and limited to some case-studies. In this paper, we report the case of a young body-builder who developed a FSGS collapsing variant with ESKD after prolonged abuse of AAS and a strongly hyperproteic diet and other dietary supplements. The patient underwent a genetic test because of the rapid and irreversibile onset of ESKD. The test showed a gene mutation of ACTN4, predisposing and causal of some genetic forms of FSGS. It was a very complex case, caused by several factors. The mutant protein of ACTN4 gene makes most vulnerable the cytoskeleton of the podocytes to external disturbances. That would explain why in those patients where the mutation has occurred, only those patients subject to "unfavorable environmental conditions", like the abuse of AAS, can develop a disease.