Beta2-microglobulinuria as an early sign of cytomegalovirus infection following renal transplantation.

Abstract

The frequency of cytomegalovirus infection was studied in a prospective study of 106 kidney recipients. The detection of cytomegalovirus-immediate-early-antigen and cytomegalovirus-immunoglobulin (IgM) antibodies in serum was used as the reference method and showed that 23.6% (25/106) of all patients were infected. In addition, four urinary proteins (IgG and transferrin as glomerular markers and alpha1-microglobulin and beta2-microglobulin as tubular markers) were quantitatively measured in 24-h urine samples from all of the patients using an immunoluminometric assay (ILMA). In all cytomegalovirus infection cases a pronounced but isolated increase of urinary beta2-microglobulin excretion was observed. In 20 of 25 infected patients, the beta2-microglobulinuria occurred 1-21 days (median 5.0) earlier than the appearance of the cytomegalovirus-immediate-early-antigen in blood. Thus, it can be seen that the quantitative measurement of beta2-microglobulin in urine is useful for the early detection of cytomegalovirus infection following renal transplantation.