INCIDENCE OF APOPTOSIS IN HIV-MYELOPATHY, MYELODYSPLASTIC SYNDROMES AND NONSPECIFIC INFLAMMATORY LESIONS OF THE BONE-MARROW

Myelodysplastic syndromes, AIDS-related myelopathy and non-specific in flammatory reactions (mostly rheumatoid myelitis) are characterized by normo to hypercellular bone marrow but frequently display cytopenias in the peripheral blood, In the current study we have addressed the qu estion whether this situation reflects an increased programmed cell de ath in haemopoiesis. For this purpose, the in situ end-labelling techn ique was applied to formalin-fixed and paraffin-embedded trephine biop sies derived from patients and a control group without any haematologi cal disorder, Results were evaluated by morphometry. Significantly mor e apoptotic cell death was observed in the haemopoietic marrow of pati ents with either disease, Using double-immunohistochemistry with the m onoclonal antibody PG-M1 (CD68), we were able to demonstrate that appr oximately one third of the apoptotic cells were ingested by macrophage s, Our findings are in keeping with previously published data that pos tulated increased frequencies of macrophages in these disorders as wel l as raised serum levels of TNF-alpha.