Klepacki et al. (Clin Chim Acta. 2013 Jun 5;421:91-7. doi: 10.1016/j.cca.2013.03.003) developed reliable methodology to measure adenosylmethionine (SAM) and S-adenosylhomocysteine (SAH) levels via LC-MS/MS. The found SAH concentrations to be elevated in kidney transplant patients associated with acute rejection and nephrotoxicity events compared to healthy controls and transplant patients without transplant dysfunction.
This brings up interesting questions about the role of metabolism of sulfur containing amino acids and methyl donors in kidney failure. Additionally, since SAH is converted into homocysteine, it seems logical for homocysteine to be regularly measured in kidney transplant patients, and to consider MTHFR genotyping and folate supplementation in abnormal genotypes to avoid further overloading this pathway.
Hilary Vernon, MD PhD