ic-X Imaging by #{246}-Curvefor the Detection of a Monoclonal B-Cell Population in the Peripheral Blood

Recently. ic-X analysis with the “D” value was developed by Ault to detect a minor population of malignant B cells in peripheral blood. This analysis is based on the KolmogorovSmirnov test, and the D value is calculated by a flowcytometer and a computer. We have recently devised a more sensitive parameter for the sc-X analysis than the D value called the �.-curve (c the #{244}c applies the same principle as that of the D value. Mixing experiments with k-type and A-type chronic lymphocytic leukemia cells revealed that the k could not only detect a minor population of malignant sc-B cells, but also that of malignant X-B cells using more sensitivity than the D value. A total of 49 blood N ON-HODGKIN’S LYMPHOMA (N H L) usually spreads to distant systemic lymphoid tissues even in the aleukemic phase; in contrast, Hodgkin’s disease contiguously invades other lymph nodes. NHL is generally considered to be a monoclonal tumor, except for special cases like Epstein- Barr virus-induced lymphomas after transplantation.’ Therefore, the continuous blood involvement with a minor population of NHL cells, which is thought to be undetectable by conventional smear cytology, since it might resemble the normal lymphocyte population with small or intermediate size, must be presumed in order to understand the mechanism of the multicentric development of NHL. Recently, Hu et a12 revealed monoclonal rearrangements of immunoglobulin genes of peripheral blood lymphocytes in 22 of 29 patients (76%) with B-cell lymphoma (BCL) and also in 16 of 23 patients (70%) with aleukemic BCL. This was performed by Southern blot hybridization with DNA probe specific for the joining region of the heavy-chain immunoglobulin gene (JK gene). This report proves that a minor population of lymphoma cells continuously spreads in the peripheral blood of patients with NHL. However, DNA analysis does not seem to be suitable for routine clinical use, since a large amount of blood sample is necessary for obtaining the sufficient cell number for analysis. In addition, radioactive agents must be used, and it is time consuming. In 1979, Ault3 had developed K-A analysis to quantitatively detect a minor population of BCL cells in the peripheral blood, using a flowcytometer (FCM) and a computer. Using the same principle we devised a more sensitive parameter for the K-A analysis, and we report the results of the basic investigation.