URINARY-EXCRETION OF ADENOSINE-DEAMINASE BINDING-PROTEIN IN NEONATES TREATED WITH TOBRAMYCIN

The potential tubulotoxicity of tobramycin and cefotaxim were assessed in neonates by measuring the urinary level of adenosine deaminase bin ding protein (ABP) and urinary alpha(1)-microglobulin and beta(2)-micr oglobulin. In a prospective study, 33 neonates who received tobramycin and cefotaxim for suspected neonatal sepsis were compared with 48 unt reated newborns during the first 10 days of life. The urinary concentr ations of ABP and its excretion rates, corrected for body weight and b ody surface area, were significantly increased from the Ist day of tre atment. Urinary alpha(1)-microglobulin and beta(2)-microglobulin were not elevated under tobramycin and cefotaxim during the first 2 days of treatment. We conclude that ABP may be a sensitive marker for the det ection of proximal renal tubular injury during tobramycin and cefotaxi m treatments of neonates, The increase in urinary ABP which occurs bef ore an elevation of urinary alpha(1)-microglobulin and beta(2)-microgl obulin may reflect earlier structural than functional alterations, How ever, since none of the treated infants had signs of electrolyte disor ders or glomerular dysfunction, the clinical relevance of ABP measurem ent should be re-evaluated.