Pathophysiology of Aplastic Anaemia
1975; Wiley; Volume: 31; Issue: s1 Linguagem: Inglês
10.1111/j.1365-2141.1975.tb00899.x
ISSN1365-2141
Autores Tópico(s)Neonatal Respiratory Health Research
ResumoS ummary . Aplastic anaemia is the clinical expression of reduced influx into the compartments of morphologically identifiable proliferating and maturing haemo‐poietic cells from the stem cell compartment. The bulk of evidence, especially the results of bone marrow transplantation, favours a primary alteration of the proliferation and/or differentiation of pluripotent haemopoietic stem cells. Experimental and clinical data suggest that a stem cell compartment which is reduced in size may compensate its output by adaptation of kinetics for a limited period of time; this could explain the well‐known time lag between exposure to potentially harmful drugs or viruses and manifestation of aplastic anaemia. Humoral regulating factors, as far as have been examined, show normal reactivity. A primary alteration of bone marrow stroma is less likely. However, the basic mechanism of aplastic anaemia may be heterogenous and some cases may be due to alteration in the micro‐environment of haemopoietic cells. In many, and maybe in all cases, haemopoietic insufficiency is induced by external factors on the basis of individual hypersensitivity. Chemical, physical and viral factors are known. Direct toxicity of these factors on stem cells is more likely than mediation through immune mechanisms.
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