[Detection of minimal tumor cells in peripheral blood patients with non-Hodgkin's lymphoma by Southern blot analysis].

We studied peripheral blood mononuclear cells, bone marrow cells and lymph node cells from 30 patients with non-Hodgkin's lymphoma by DNA hybridization. Clonal JH or TCR beta gene rearrangements were detected in peripheral blood or bone marrow mononuclear cells from 15 of 30 (50.0%) patients studied, including 31.8% of those without evidence of tumor cells by morphological method. Four of 9 cases demonstrated identical clonal gene rearrangements at diagnosis and in remission phase in peripheral blood mononuclear cells. The presence of clonal gene rearrangements roughly correlated with the clinical stage of disease. And the proportion of clonal rearrangements was higher in the groups with small & medium sized cell types (64.3%) than in the group with large cell type (33.3%). So, we concluded that Southern blot analysis was more useful than morphological method to detect monoclonality of circulating lymphoma cells and minimal tumor cells.