Detection of t(14;18) carrying cells in bone marrow and peripheral blood from patients affected by non-lymphoid diseases

Aims/Background-To assess the presence of bcl-2/J(H) rearrangements in bone marrow and peripheral blood lymphocytes from patients affected by diseases other than malignant lymphomas. The t(14;18) (q32;q21) translocation, whic h juxtaposes the bcl-2 oncogene on chromosome 18 and the J(H) segment of th e immunoglobulin heavy chain (IgH) genes on chromosome 14, is found frequen tly in follicular lymphomas. Methods-A sensitive semi-nested polymerase chain reaction (PCR) was used to detect t(14;18) translocation in bone marrow aspirates and peripheral bloo d lymphocytes from 48 patients. In 137 additional individuals peripheral bl ood lymphocytes only were tested. Results-Cells carrying bcl-2/J(H) rearrangements were detected in about a q uarter of the bone marrow samples and half of the peripheral blood lymphocy te samples. In seven patients, t(14;18) positive cells were found in both t he bone marrow and peripheral blood lymphocyte samples. The size of the PCR products and bcl-2/J(H) DNA sequence analysis showed that the same t(14;18 ) carrying clone was present in the bone marrow and the corresponding perip heral blood lymphocyte samples in three of these seven patients. Some patie nts had more than one bcl-2/J(H) rearrangement. There was no significant co rrelation between age and the translocation incidence. Cells carrying the t (14;18) translocation were present in peripheral blood lymphocyte samples w ith a similar incidence-between 47% and 52% in all age groups from 20 to 79 years. Patients older than 80 years had a lower (37%) but not significantl y different incidence. Conclusions-These findings suggest that patients affected by non-lymphoid d iseases may have several t(14;18) carrying cells and some of them undergo a clonal expansion. Whether individuals with t(14;18) positive cells are at a higher risk of lymphoid malignancies remains unanswered and further epide miological studies are required.