Proteinuria caused by tubule-interstitial renal disease is confirmed by excretion of -: (A) Albumin, (B) Light chain, (C) Immunoglobulin A, (D) Tamm-Horsfall protein
Answer is B. Tubular proteinuria is a result of tubulointersitial disease affecting the proximal renal tubules and interstitium. This results in decreased proximal reabsorption of proteins--in paicular, low molecular weight proteins (generally below 25,000 Daltons) such as beta-2 microglobulin (light chain) are excreted Ref Harrison20th edition pg 295