CD34⁺ and CD34⁻ B cells in the blood of myeloma patients have IgH rearrangements identical to those of autologous BM plasma cells. (A) through (G) represent analysis of sorted lymphocyte subsets from 7 different patients. In each panel the top half shows CDR3 rearrangements amplified by nested PCR from 10³ sorted cells of the indicated PBMC subsets, using consensus primers to FR2a and JH1 followed by a second-stage PCR amplification using consensus primers to FR2b and JH2.7 The bottom half of each panel shows the hybridization of amplified products with end-labeled patient-specific ASO probes. Patient A was post chemotherapy with stable disease. Patients B through D were in relapse. Patient E was analyzed at relapse (no. 11), during his second round of chemotherapy (no. 15) where a partial response occurred, and in the progressive stage of disease (nos. 17 and 18). Patient F was at diagnosis and untreated. Patient G had received the first two cycles of chemotherapy after diagnosis.