Detection of elevated amounts of urinary pseudouridine in cancer patients by use of a monoclonal antibody.

Preparation of anti-pseudouridine monoclonal antibodies (MoAbs) and their applications for the quantitation of urinary pseudouridine in cancer patients are described. Seven MoAbs were selected. Five MoAbs were specific for pseudouridine and two MoAbs were cross-reactive with uridine. The most specific antibody, APU-6, was used in an enzyme-linked immunosorbent assay (ELISA) to determine urinary pseudouridine. Sensitivity was in the picomole range and the accuracy was nearly equal to that of the high performance liquid chromatography (HPLC) assay. The amount of pseudouridine in the urine of 28 healthy donors was 31.17 +/- 9.94 nmol/mumol creatinine. In 55% (35/63) of patients with cancer, urinary pseudouridine was elevated above the normal mean + 2 SD (51.04 nmol/mumol creatinine). Particularly, all of the patients (15/15) with leukemia and lymphoma had elevated levels of pseudouridine. These results suggest that urinary pseudouridine might be useful as a marker for leukemia and lymphoma.