Table 5.

Detection of Clone 8 (Identified in Brain Tissue of Case 2) in Peripheral Blood CD8⁺CD45RO⁺ T Cells by Clone-specific PCR

		Cell samples
Blood sample; no. of cells per PCR tube	PCR specific for V region of clone no.	Analyzed by clone-specific PCR	Positive for specific product
12 mo; 103	2	10	0/10
31 mo; 103	2	10	1/10
12 mo; 103	3	9	0/9
12 mo; 5 × 102	3	1	0/1
12 mo; 102	3	5	0/5
31 mo; 103	3	10	0/10
12 mo; 103	8	10	6/10
31 mo; 103	8	10	8/10
31 mo; 102	8	20	2/20

Each set of primers consisted of the Vβ-specific primer and a nested pair of CDR3-specific primers. The clonal V region sequences were inserted into plasmid vectors, and the resulting constructs were stably transfected into Jurkat cells. To positively control single target amplification of the clonal V region sequence, single Jurkat control cells carrying a single copy of the respective V region DNA were sorted into tubes containing, as indicated, 10³ or 10² irrelevant CD8⁺CD45RO⁺ T cells from a healthy donor. These samples were analyzed in parallel with the T cell samples from blood of case 2 under identical conditions (results of control amplifications are discussed in Materials and Methods).