Recent publications highlighted the importance of tracking total kidney volume (TKV) as a biomarker for disease progression in children and young adults with autosomal dominant polycystic kidney disease (ADPKD). Researchers also assert its usefulness in determining efficacy for current and emerging pharmacological treatments.
TKV can be measured using magnetic resonance imaging (MRI), computed tomography (CT), or ultrasound. And while the management of ADPKD – the most common genetic cause of kidney failure – mainly focuses on managing multisystem morbidity, as well as mortality, the past decade has seen advances in earlier detection, prognosis and treatment.
Among these advances is the understanding that serum creatinine and glomerular filtration rate (GFR), as biomarkers, can fall short as a primary screening tool because they may miss subclinical disease and early stage disease, or may reflect only advanced disease.
By contrast, TKV can help determine a patient’s risk for progressing to kidney failure, and can do so earlier on in the decades-long progression of the disease. Additionally, TKV can play an important role in clinical trials where patients can be selected for study endpoints designed to measure “benefit” for drug intervention trials.
Now that a selective V2 vasopressin receptor antagonist (tolvaptan) is available in Canada, with the possibility of new agents on the horizon, there is optimism. Or as authors Grantham and Torres state in their paper published in Nature Reviews Nephrology (2016): TKV can be used to monitor treatment efficacy in patients with normal levels of renal function, before the pathologic processes of ADPKD cause extensive fibrosis and irreversible loss of functioning renal tissue.
Written by: MaryAnne Pankhurst
Grantham JJ, Torres VE, The importance of total kidney volume in evaluating progression of polycystic kidney disease, Nat Rev Nephrol 2016; 12(11): 667-77