Table 1.

CD19 epitope distribution on circulating B cells in MM PBMC.

	% of PBMC expressing CD19 Epitopes
Source of PBMC (n)	B4	FMC63	Leu12
Healthy donors (5)	7 ± 4	7 ± 3	6 ± 4
MM patients (12)	30 ± 6	27 ± 5	2 ± 1
Patient PBMC tested at different stages of treatment (n)†
Diagnosis (6)			3.4 ± 3
Intermittent chemotherapy* (52)			4.1 ± 0.6
Off treatment (29)			6.7 ± 1.7
Terminal disease (10)			2.1 ± 1

Values represent the mean ± SE.

n = number of donors tested.

^*For those patients on intermittent chemotherapy, blood samples were taken at least 3 weeks after their last cycle.

^†Values for staining with B4 or FMC63 were comparable to those shown in the top section of this table and have been published previously (Bergsagel, Masellis, Szczepek, Mant, Belch, and Pilarski 1995); they did not differ among patients at differing stages of treatment.