VALIDITY OF RANDOM URINES TO QUANTITATE PROTEINURIA IN CHILDREN WITH HUMAN-IMMUNODEFICIENCY-VIRUS NEPHROPATHY

Accurate assessment of proteinuria in pediatric patients infected with the human immunodeficiency virus (HIV) is limited by constraints impo sed by timed urine collections and low creatinine excretion in very il l patients with low muscle mass, We therefore sought to validate the u se of random urine specimens to quantitate total protein and creatinin e excretion in a population of 236 HIV-positive children, A mathematic al derivation for estimating urine volume (V) was constructed. The acc uracy of the final calculation [V=832 (kL/Ucr)BSA] (where k=constant, L body length, UCr urine creatinine and BSA body surface area) was tes ted by regression analysis comparing the calculated and measured volum e of 31 urines from ambulatory HIV-negative patients. The correlation coefficient was highly significant (r=0.77, P less than or equal to 0. 0001). The relationship was also applied to 23 timed urine specimens f rom HIV-positive patients with similar significance (r=0.87, P < 0.000 1). A regression analysis of measured proteinuria against the urine pr otein: creatinine ratio (U-pr/U-Cr) in these same urines from the HIV- positive patients yielded a significant relationship both in the linea r (r=0.95, y=0.4x) and the logarithmic regression (r=0.97, y=x+0.4). T hese data support the use of random U-pr/U-cr ratios to estimate daily proteinuria in HIV-infected pediatric patients despite low creatinine excretion rates. The previously accepted values continue to apply, wi th U-pr/U-Cr less than or equal to 2.0 considered normal and >2.0 repr esentative of nephrotic proteinuria.