[Beta 2-microglobulinuria in cytomegalovirus infections following kidney transplantation].

In a prospective study the occurrence of cytomegalovirus (CMV) infection was diagnosed by demonstrating CMV-immediate early antigen (IEA) in the blood in 13 out of 68 (19%) patients who had undergone renal transplantation (27 women, 41 men, mean age 46.3 [21-64] years). Twenty-four hour urine samples were collected at the same time for quantitative determination of selected marker proteins by immunoluminometric assays (IgG and transferrin as glomerular markers, alpha 1-microglobulin and beta 2-microglobulin as tubular markers). In all 13 confirmed cases of CMV infection there was an isolated rise in urinary beta 2-microglobulin excretion amounting to more than three times the normal. In 11 of the 13 cases the beta 2-microglobulinuria was noted before the CMV-IEA test became positive. This suggests that quantitative assay of beta 2-microglobulin in the urine may be of value in the early diagnosis of CMV infection--a matter of some prognostic importance--and may hence offer additional support for therapeutic decisions.