Asymmetric dimethylarginine in hematological malignancies: a preliminary study.

Asymmetric dimethylarginine (ADMA) is a product of protein hydrolysis and an endogenous competitive inhibitor of nitric oxide synthase. It is considered a new independent risk factor for endothelial dysfunction and cardiovascular diseases. Increased protein turnover, oxidative stress and impaired dimethylarginine dimethylaminohydrolase activity occurring in hematological malignancies may lead to increased dimethylarginines production. We have measured ADMA, symmetric dimethylarginine (SDMA) and L-arginine plasma levels in 43 patients with different types of hematological malignancies and in control group of 43 healthy volunteers. Mean ADMA and L-arginine plasma levels were higher in hematological group than in control group (1.59 vs 0.64; p<0.001 and 34.84 vs 28.35; p=0.044 respectively). Mean plasma levels of SDMA were not significantly different between the groups. Elevated ADMA plasma levels in patients with hematological malignancies interfere with nitric oxide metabolism and may influence their prognosis. Further prognostic studies are postulated to assess this phenomenon.