Urinary excretion of beta2-microglobulin in renal stone patients under normal conditions and during acidosis and alkalosis.

The urinary excretion of beta2-microglobulin was studied under normal conditions and during acidosis and alkalosis in 65 patients with renal stones. Eleven patients were studied under two of these conditions. Four out of 51 patients examined under normal conditions had an increased excretion of beta2-microglobulin in their urine. Four out of five patients with distal acidification defects were found to have an increased excretion of beta2-microglobulin during induced acidosis. During alkalosis, four out of eight patients with acidification defects increased their excretion of the protein. The tubular proteinuria that could be provoked during acute acidosis and alkalosis was considered to be secondary to changes in the acid-base status and may indicate a renal tubular defect.