Subject(s)
Brain Abscess/etiology , Meningitis, Listeria/diagnosis , Amoxicillin/administration & dosage , Amoxicillin/therapeutic use , Antibodies, Bacterial/analysis , Brain Abscess/diagnostic imaging , Brain Abscess/drug therapy , Follow-Up Studies , Humans , Listeria monocytogenes/immunology , Male , Meningitis, Listeria/drug therapy , Meningitis, Listeria/immunology , Middle Aged , Penicillins/administration & dosage , Penicillins/therapeutic use , Time Factors , Tomography, X-Ray ComputedABSTRACT
Increased apoptosis of myeloid precursors appears to contribute to the pathophysiology of cytopenias in myelodysplastic syndromes (MDS). Fas /APO-1(CD95) is a cell surface protein inducing an apoptotic signal after its binding to Fas ligand or to a functional anti-Fas antibody. Here we studied Fas expression by immunocytochemistry on marrow slides from 30 cases of MDS. Increased Fas expression in erythroblasts and/or immature granulocytes, compared to controls, was seen in 12 (40%) of the cases. In addition, in 16 of the 18 cases with > or = 5% marrow blasts, a variable proportion of blasts expressed Fas. Increased apoptosis was found by morphological analysis and/or TUNEL technique in marrow cells from 8 of the 26 cases analyzed (31%) The ability of Fas antigen to trigger apoptosis was studied after addition of a functional anti Fas antibody in 5 of the patients with Fas overexpression. Addition of this antibody, however, only lead to mild increase of apoptosis in immature granulocytes (but not other myeloid cells) in 2 of the 5 cases. Thus, increased Fas expression is seen in myeloid and/or blast cells in the majority of MDS cases. However, the relationship between this finding and increased apoptosis in MDS still remains to be established.
