PMN cells from chronic myeloid leukemia (CML) patients show defective chemotaxis in remission

The chemotactic index (C.I.) of granulocytes from chronic myeloid leukemia (CML) patients at diagnosis and in subsequent remission was measured using different concentrations of the synthetic chemotactic peptide, N-formyl-methionyl-leucyl-phenylalanine (FMLP), by time lapse cinematography and compared with that of normal granulocytes. The C.I. of CML polymorphonuclear leucocytes (PMNL) at diagnosis and in remission was significantly lower than the C.I. of PMNL from normal subjects (p less than 0.001 and 0.05 greater than p greater than 0.02, respectively). PMNL from CML patients at diagnosis showed increased speed after stimulation with FMLP. In most of the CML patients, the highest values of C.I., speed and the number of motile cells were obtained at FMLP concentrations of 10-100-fold higher than those required for normal PMNL. These results suggest an alteration in the interaction between FMLP and its receptors and that events occurring after FMLP binding are also altered. It was earlier shown that PMNL from CML patients in the active stages of the disease show defective chemotaxis. Present studies show persistence of such defective cells in the peripheral blood of CML patients in remission. These results also suggest that defects in PMNL from CML patients in remission. These results also suggest that defects in PMNL from CML patients may be constitutional.