Cellular origin of the chemokinetic inhibitor of polymorphononuclear leucocytes found in sera from patients with chronic lymphocytic leukaemia.

In a previous study, we demonstrated the existence in serum from patients with chronic lymphocytic leukaemia (CLL) of a cell-directed, heat-labile chemokinetic inhibitor of polymorphonuclear leucocytes (PMN). The aim of this investigation was to study the cellular origin of this inhibitor. Supernatants from short term cultured lymphocytes from 3 healthy persons and 5 patients with CLL, and from 16 different established human non-haematopoietic and haematopoietic cell lines were analyzed. Only the leukaemic B-lymphocytes from the CLL patients produced the inhibitor. The presence of the inhibitor was also demonstrated in supernatants from the fresh CLL cells from one CLL patient and a leukaemic cell line established from these cells using Epstein-Barr virus as the immortalizing agent. A lymphoblastoid cell line derived from the normal B-cells of the same CLL patient did not produce the chemokinetic inhibitor. We therefore conclude that the cellular origin of the heat-labile, cell-directed chemokinetic inhibitor of PMN migration is the CLL cell.