Increased urinary beta 2-microglobulin after cancer chemotherapy

The serum and urinary concentrations of beta 2-microglobulin (beta 2-m) and creatinine and the urinary concentration of albumin and IgG were measured in 14 patients with hematologic malignancies before and during chemotherapy. There was a transient increase in urinary beta 2-m in nine of the 14 patients during chemotherapy. All of the nine patients but only one of the other five patients had had recent multiple chemotherapy. The urinary beta 2-m increased in 24 courses of chemotherapy given to these nine patients and was already abnormal before 13 of these courses. The increase in urinary beta 2-m was not associated with an increase in serum beta 2-m or a significant increase in urinary albumin or IgG excretion. These results suggest that chemotherapy causes a marked transient tubular proteinuria, particularly in patients who have had previous chemotherapy.