Urinary excretion of albumin and retinol-binding protein in lithium-treated patients.

Urinary excretion of albumin and retinol-binding protein was measured by means of sensitive and specific immunochemical methods in a transverse study of 20 lithium-treated patients and 24 apparently healthy individuals. Albumin creatinine clearance ratios were significantly higher in the lithium-treated patients, which may indicate glomerular lesions. Microalbuminuria correlated highly to duration of lithium therapy. No significant difference between the retinol-binding protein creatinine clearance ratios in the two groups could be shown. This suggests that the catabolism of low-molecular-mass proteins in the proximal tubules was normal.