[Support system for diagnosing hematologic malignancies].

Abstract

We established a Southern blot hybridization using a DIG-labeled probe to detect monoclonal integration of HTLV-1 proviral genome. DIG was labeled by the PCR method and this probe was as sensitive as the 32P-labeled probe and able to detect only 1.6% of ATL cells. The clinical diagnoses of 44 patients with monoclonal band(s) were all ATL. In contrast, the clinical diagnoses of 39 patients without monoclonal band(s) were diseases other than ATL. We also performed a long PCR of HTLV-1 to characterize the integrated provirus. The method allowed us to find a defective provirus, which was frequently observed in aggressive forms of ATL; 14 of the 18 patients with acute type(78%), 6 of the 9 patients with lymphoma type(67%), and 2 of the 12 patients with chronic type(17%) had the defective provirus. We established a simultaneous PCR for each region of HTLV-1 for further examination of the defective provirus. To detect the monoclonality of IgH gene rearrangement of B-cells, we performed PCR according to the method described. None of 13 patients with T-lymphoproliferative disorders showed a monoclonal band. In contrast, 12 of 13 patients with CLL(92%), 22 of 25 patients with common ALL(88%), 18 of 24 patients with B-lymphoma(75%), and 3 of 3 patients with hairy cell leukemia(100%) showed a monoclonal band. We are now expanding this kind support system for the clinical diagnosis at a molecular biology level in the central laboratory.