PROSPECTIVE-STUDY OF URINARY PROTEINS IN EARLY INFANCY

ABSTRACT. Karlsson, F. A., Hardell, L.‐I., and Hellsing, K. (Departments of Clinical Research, Internal Medicine, Paediatrics and Clinical Chemistry, University Hospital, Uppsala, Sweden). A prospective study of urinary proteins in early infancy. Acta Paediatr Scand, 68: 663, 1979.—Urinary concentrations of protein, albumin, β2‐microglobulin, α‐amino nitrogen, and creatinine were determined in forty‐one full‐term infants on seven occasions up to six months of age. Except for β2‐microglobulin the concentrations were highest on the first day, followed by a rapid decrease to a constant level within two weeks. Protein diminished approximately seven‐fold, albumin twenty‐fold, α‐amino nitrogen three‐fold and creatinine five‐fold. By contrast, β2‐microglobulin, a low molecular weight protein, first increased three‐fold between day 1 and day 5, thereafter decreasing slowly 17‐fold during the first three months of age. The data indicate that different kidney functions mature asynchronously. Copyright © 1979, Wiley Blackwell. All rights reserved