Representative patterns of residual disease found in patients in LTR post-SCT/DLI. Panels A and B show 2 individual patients who, despite not meeting criteria for molecular relapse, were persistently positive for BCR-ABL transcripts at a low level. On the x-axis are months post-SCT/DLI. The results of the quantitation of BCR-ABL transcripts (■) are expressed as the ratio of BCR-ABL to ABL mRNA (y-axis, in a logarithmic scale). The results of the RQ-PCR for gBCR-ABL are represented as diamonds: ♦, gBCR-ABL–positive; ◆, gBCR-ABL–negative. (A) All 4 samples tested, 2 of which were transcript-positive, were gBCR-ABL–negative. (B) Of 5 transcript-positive samples tested, 1 was gBCR-ABL–positive, at the very limit of sensitivity of the assay. Of 24 samples tested from 9 patients in long-term remission (LTR) post-SCT/DLI, this was the single instance of gBCR-ABL positivity, despite 14 of 24 samples being transcript-positive.