Rapid S-phase determination of non-Hodgkin's lymphomas with the use of an immunofluorescence bromodeoxyuridine labeling index procedure

Cell kinetic measurements are currently being investigated to determine if they are useful in the clinical management of patients with non-Hodgkin's lymphomas (NHLs). Although the tritiated thymidine labeling index (TLI) is the standard method of S-phase measurement, it is difficult to perform. The authors describe a slide-based immunofluorescence labeling index (LI) method that uses 5-bromo-2-deoxyuridine (BrdUrd) as the pulsing medium and a monoclonal antibody (BU-1) to BrdUrd. The BrdUrd LI was performed on 217 NHLs and compared with routine histologic results. The authors found a median BrdUrd LI of 0.9% for low-grade NHLs; 7.5% for intermediate-grade; 10.4% for high-grade; and 2.2% for T-cell NHLs. This method provides a rapid, reliable S-phase measurement that can be easily performed in the clinical laboratory. It should replace the TLI and allow wide application of S-phase measurements in the NHL.