[Correlation between availability of GM progenitors and endogenous CSA production in neutropenia]

We studied some cases with granulopoiesis disorders, owing to different causes, all showing peripheral neutropenia. Can these cases benefit by the growth factors G-CSF administration? To answer this question we assayed the bone marrow CFU-GM growth of the neutropenic patients with standard source of CSA and employing as CSA source the autologous peripheral blood mononucleated cells (APBMN). We proposed ourselves to investigate the granulopoiesis regulation referring to the relation between number of GM-progenitor cells and levels of CSA. The bone marrow CFU-GM cultures were performed by Pike and Robinson's double layer agar technique. For the evaluation of growth we applied the criterion of the dishes topographic lecture according to Ghizzi and De Caro. We plotted the experimental data both as absolute count of observed aggregates (tPP) and as dynamic patterns of in vitro aggregate proliferation, by differentiating the early proliferative events (AC-A and AC-B) from the later ones (AC-C). We observed cases showing growths higher under CSA standard source than under autologous source (CAA) and vice versa. In other cases there are not noteworthy differences. To estimate these growth patterns and to interpret the experimental data we correlated the autologous stimulus capacity to the CFU-GM absolute counts. Most cases of neutropenia showed inverse correlation between the two indexes. We consider a reduced stimulus capacity may be fit when the CFU-GM growth is high. We retain this capacity of modulating the CSA production as index of kept regulation of the granulopoiesis and, then, these cases can spontaneously evolve towards the neutropenia resolution.