Spot Urine Protein/Creatinine Ratio as an Alternative to 24-Hour Urine Collection for Measuring Proteinuria in Patients With Multiple Myeloma: A Prospective Study.

Measurement of 24- hour urine protein electrophoresis (PEP) and immunofixation (IFE) are part of standard diagnostic evaluation and monitoring of patients with suspected and diagnosed monoclonal plasma cell disorder for baseline evaluation of renal dysfunction or nephrotic syndrome. Measurement of 24-hour urine protein can however be time consuming and cumbersome and many centers have moved towards random urine protein measurements. The evidence for correlation between spot urine protein creatinine ratio (SUPC) and 24-hour urine protein measurements its scarce. Therefore, we have carried out a prospective study with a sample size of 40 multiple myeloma (MM) patients to demonstrate this correlation. Our results suggest a good correlation between SUPC and 24-hour urine protein measurements, suggesting SUPC testing is a reliable and easier alternative to 24-hour urine collection. These findings should now be confirmed in larger patient populations including early stage plasma cell disorders, light chain amyloidosis and symptomatic MM.