Proteinuria and Albuminuria at Point of Care

Proteinuria is a key diagnostic and pathophysiological aspect of kidney dysfunction, influencing the progression of kidney and systemic diseases. Both general practitioners and specialists should be able to discriminate the relevance of proteinuria, starting from a urine sample, and eventually referring selected patients to a nephrologist for further diagnostic workup and treatment, because most kidney diseases are not symptomatic until renal function is lost or severely compromised. As the interpretation of proteinuria is dependent on the method used to detect it, the aim of this article was to review laboratory and point-of-care diagnostic methods for proteinuria in different settings, such as the prevention and follow-up of common chronic diseases (i.e., hypertension, diabetes, chronic kidney disease). Urine dipsticks remain the most widely used method for detecting proteinuria, although different types of proteinuria, extreme pH values and urine concentration may affect their results. Albumin to creatinine ratio and protein to creatinine ratio performed on a spot urine sample are reliable tests that can effectively replace 24-hour urine collection analysis in clinical practice