The role of asymmetric and symmetric dimethylarginine in acute deep vein thrombosis

New biomarkers and imaging approaches for the diagnosis of deep venous thrombosis

PURPOSE OF REVIEW

Symptoms suggestive of deep vein thrombosis (DVT) are extremely common in clinical practice, but unfortunately nonspecific. In both ambulatory and inpatient settings, clinicians are often tasked with evaluating these concerns. Here, we review the most recent advances in biomarkers and imaging to diagnose lower extremity DVT.

RECENT FINDINGS

The modified Wells score remains the most supported clinical decision rule for risk stratifying patients. In uncomplicated patients, the D-dimer can be utilized with risk stratification to reasonably exclude lower extremity DVT in some patients. Although numerous biomarkers have been explored, soluble P-selectin has the most promise as a novel marker for DVT. Imaging will be required for many patients and ultrasound is the primary modality. Nuclear medicine techniques are under development, and computed tomography (CT) and magnetic resonance venography are reasonable alternatives in select patients.

SUMMARY

D-dimer is the only clinically applied biomarker for DVT diagnosis, with soluble P-selectin a promising novel biomarker. Recent studies have identified several other potential biomarkers. Ultrasound remains the imaging modality of choice, but CT, MRI, or nuclear medicine tests can be considered in select scenarios.

Toxic Dimethylarginines: Asymmetric Dimethylarginine (ADMA) and Symmetric Dimethylarginine (SDMA)

Asymmetric and symmetric dimethylarginine (ADMA and SDMA, respectively) are toxic, non-proteinogenic amino acids formed by post-translational modification and are uremic toxins that inhibit nitric oxide (NO) production and play multifunctional roles in many human diseases. Both ADMA and SDMA have emerged as strong predictors of cardiovascular events and death in a range of illnesses. Major progress has been made in research on ADMA-lowering therapies in animal studies; however, further studies are required to fill the translational gap between animal models and clinical trials in order to treat human diseases related to elevated ADMA/SDMA levels. Here, we review the reported impacts of ADMA and SDMA on human health and disease, focusing on the synthesis and metabolism of ADMA and SDMA; the pathophysiological roles of these dimethylarginines; clinical conditions and animal models associated with elevated ADMA and SDMA levels; and potential therapies against ADMA and SDMA. There is currently no specific pharmacological therapy for lowering the levels and counteracting the deleterious effects of ADMA and SDMA. A better understanding of the mechanisms underlying the impact of ADMA and SDMA on a wide range of human diseases is essential to the development of specific therapies against diseases related to ADMA and SDMA.