Fluorescence image analysis of plasma cells in monoclonal gammopathies.

The DNA content of plasma cells was estimated by fluorescence image analysis in monoclonal gammopathies. Image analysis provides the possibility of measuring the bone marrow plasma cell population separately from the other myeloid cells. Plasma cells were labeled, identified and then relocated for propidium iodide intensity measurements. Patients with DNA malignancy grade > 0.20 or with DNA index > 1.15 had a poorer survival rate than did patients with a low DNA malignancy grade or DNA index. DNA malignancy grade is based on the variance of DNA values around the normal diploid peak, as proposed by Böcking. Of all the biologic and clinical parameters investigated, the serum beta 2 microglobulin level was the most important prognostic factor for survival in the multivariate regression analysis, and the DNA entropy index provided the most significant additional information.