T₈-Lymphocytes in Cyclical Neutropenia

J. Graham Smith, M. Ann Smith, Bath Clinical Area Pathology Service, Area Central Laboratory, Royal United Hospital (North), Combe Park, Bath BA1 3NG (UK) Following the recent publication by Ucci et al. in Ada Haematologica [77: 177–179, 1987], we would like to correct any misunderstanding concerning our paper [J.G. Smith et al.: Br. J. Haematol. 60: 481–489] as cited by the above authors. The peripheral blood T8-lymphocytes which were found in our patient with cyclical neutropenia were not suppressor, neither phenotypically (fcγ-) nor functionally, as claimed by Ucci et al. These cycled in phase with marrow granu-lopoietic activity, but out of phase with peripheral blood neutrophil counts. Functionally, they produced large quantities of GM-CSF spontaneously. In our patient, we were able to demonstrate deficient production of GM-CSF by monocytes [which are derived from the same stem cell (CFU-GM), which is thought to be defective in cyclical neutropenia] and therefore concluded that the circulating T8 Fcγlymphocytes were compensating for the humoral defect in the monocytic lineage. More recently, using cell sorter experiments, we have found that marrow T8 cells (taken from trephine biopsies devoid of peripheral blood contamination) are predominantly Fcγand produce GM-CSF spontaneously [J.G. Smith et al.: Br. J. Haematol 60: 370 (abstr.); J.G. Smith et al.: submitted for publication]. Lastly, the title of our paper is misquoted by Ucci et al. and should read ‘Cyclical Neutropenia and T8 Lymphocyte-Mediated Stimulation of Granulopoie-sis’.