PERIPHERAL-BLOOD MONOCLONAL PLASMA-CELLS AS A PREDICTOR OF SURVIVAL IN PATIENTS WITH MULTIPLE-MYELOMA

The purpose of this study was to quantitate the number and labeling in dex of monoclonal plasma cells in the blood of patients with newly dia gnosed multiple myeloma (MM) to learn if these values were independent prognostic factors for survival. Patients were candidates for this st udy if they had untreated myeloma requiring therapy, were evaluated at our institution between 1984 and 1993, and had a sample of blood anal yzed with a sensitive immunofluorescence technique for monoclonal plas ma cells and the blood B-cell labeling index (BLI). The % blood monocl onal plasma cells (%BPC) and the BLI were analyzed along with stage, m arrow plasma cell LI, % marrow plasma cells, calcium, creatinine, albu min, beta-2-microglobulin, and C-reactive protein as univariate and mu ltivariate factors for survival. Eighty percent of the 254 patients ac crued to this study had monoclonal BPC detected. The median % BPC was 6% and 57% (144 of 254) of patients had a high number (greater than or equal to 4%). Patients with greater than or equal to 4% BPC had a med ian survival of 2.4 years vs 4.4 years for those with <4% BPC (P < .00 1). The BLI was also prognostic (P = .008). In a multivariate analysis , the %BPC, age, albumin, stage, marrow plasma cell LI, and the BLI we re independent factors for survival. The %BPC and the marrow plasma ce ll LI best separated the group into low, intermediate, and high risk m yeloma with median survivals of 52, 35, and 26 months, respectively. P atients with high %BPC were less likely to have lytic bone disease fro m their MM (P = .002). The % BPC and the BLI are independent prognosti c factors for survival and are useful in identifying patients as low, intermediate, and high risk. Clonal cells in the blood should be quant ified in future clinical trials for myeloma. (C) 1996 by The American Society of Hematology.