Decreased Antibody-Dependent Cellular Cytotoxicity in Preleukemic Syndromes

Abstract

In a previous report we showed decreased antibody-dependent cellular cytotoxicity (ADCC) activity of both leukemic and non-leukemic cells in human acute leukemia. In our present study, ADCC against tumor target cells was evaluated in 13 patients with preleukemic syndromes. ADCC was found to be significantly decreased in aplastic anemia, sideroblastic anemia, paroxysmal nocturnal hemoglobinuria and pure red cell aplasia, suggesting that impairment of immune defence capacity may precede the development of leukemia in man.

Altered Self-reactive Antibody Repertoires are a General Feature of Patients with Myelodysplastic Syndrome

“…However, self-reactive antibody repertoires in patients with warm autoimmune haemolytic anaemia were altered, as compared to those of healthy individuals, before starting a transfusion therapy, and remained altered, as compared to those of healthy individuals, irrespective of the regular application of red blood cell concentrates (Stahl et al, unpublished data). In addition, broadly distorted immune functions including altered B cell functions have been reported in MDS irrespective of RBC transfusions [23][24][25][26][27], and support our conclusion that altered patterns of self-reactivity are a feature of MDS rather than being an epiphenomenon due to the transfusion of red blood cell concentrates.…”

“…Thus, decreased T cell counts [23] and shifts in the normal T4/T8 ratio [24] as well as impaired B cell counts [25], altered B cell functions [26], and the occurrence of autoreactive antibodies [5,6,27] have been reported in patients with MDS. Autoreactivity has long been considered as a pathological phenomenon [28].…”

Deficiency of Lymphocyte Lectin-Dependent Cytotoxicity in Myelodysplastic Syndromes

“…The normal ADCC is in agree ment with Kerndrup et al [12], but in conflict with Janowska-Wieczorek et al [14]. However, the latter em ployed unfractionated leukocytes as effector cells, and these results may not therefore be comparable.…”

“…Thus, T lym phocytes from patients with MDS show a defective mitogenic response, an altered distribution of peri pheral blood (PB) subpopulations, and patients fre quently have either a polyclonal or monoclonal serum Ig component [2][3][4][5][6][7], Less data exist on lymphocyte-mediated cytotoxic activities which are one functional expression of the cell regulation involved in hemopoiesis, in the sur veillance mechanism against early neoplasias and in the defence against infectious disease [8,9]. Some au thors have explored NK activity and antibody-dependent cellular cytotoxicity (ADCC) by the standard 51Cr release assay [7,10,[11][12][13][14], but no data exist, to our knowledge, on mitogen-induced cellular cytotox icity (MICC) in MDS. In this study we examined pe ripheral blood mononuclear cell (PBMNC) surface markers, NK activity, [both in the 5lCr release assay and in a single cell cytotoxicity assay (SCCA)], ADCC and MICC in patients with MDS.…”