In situ cell cycle kinetics in bone marrow biopsies following sequential infusions of IUdR/BrdU in patients with hematopoietic malignancies

Examination of the proliferative characteristics of myeloblasts was undertaken in situ in bone marrow (BM) biopsies of patients with acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS) following sequential infusions of iodo- (IUdR) and bromodeoxyuridine (BrdU). The ability to identify S-phase cells which have incorporated both or either one of the labels in vivo by using two monoclonal antibodies in vitro permitted the measurement of labeling index (LI) and durations of S-phase (Ts) and the total cell cycle (Tc) both from the BM aspirates and biopsies. While the LI is 2–3 times higher in biopsies, Ts and Tc are fairly comparable in the two samples in 8/10 cases ( p = 0.02 and 0.003 respectively). Advantages associated with the determination of cell cycle parameters in BM biopsies have been discussed at length.