Esterase cytochemistry in primary myelodysplastic syndromes and megaloblastic anaemias: demonstration of abnormal staining patterns associated with dysmyelopoiesis

Abstract

Summary. Acid alpha naphthyl acetate esterase (ANAE) and combined ANAE‐chloroacetate esterase cytochemistry was performed on 121 bone marrow aspirates from primary myelodysplastic syndromes (MDS) and a secondary dysplasia—megaloblastic anaemia (MA). The investigation demonstrated the presence of abnormal ANAE positive granulocyte populations in a significant proportion of cases. These cells, in which the staining patterns were characterized by atypical granular ANAE positivity and double ANAE‐chloroacetate reactions, were shown immunologically to lack the receptor and antigenic characteristics of monocytes and morphologically to be granulocytes. Isoelectric focusing, however, indicated that the atypical esterase cytochemistry of these granulocytes was due to the presence of markedly increased concentrations of ANAE isoenzymes usually found in monocytes. Atypical ANAE‐staining granulocytes were particularly evident in MDS marrows showing sideroblastic erythroid changes, whilst in MA they were mainly seen in cases of intermediate severity. It is suggested that these cells are associated with dysmyelopoietic changes in both malignant and non‐malignant conditions.

Cytochemical, immunological and ANAE‐isoenzyme studies in acute myelomonocytic leukaemia: A study of 39 cases

“…In contrast to the findings of Tavassoli et a1 (17), blasts were not seen to simultaneously express significant ANAE and CAE enzyme activities. These 'double-esterase' positive cells were, however, occasionally seen in more mature coexisting granulocyte populations, the existence of which we consider to reflect secondary dys-myelopoiesis (18)(19) and to be independent of leukaernic category.…”

“…The proportions of blasts expressing thevarious mo- nocyte-associated membrane determinants was, in 26/35 cases, reasonably consistent. In these, Mcabdefined monocytic components were found to comprise 10-30% blasts in 18 cases, 30-60% in 6 and 60% positive in 2. As with ANAE cytochemistry, however, the remaining 9 cases showed considerable phenotypic heterogeneity.…”

Transfusion-Dependent Thalassemia in Northern Sarawak: A Molecular Study to Identify Different Genotypes in the Multi-Ethnic Groups and the Importance of Genomic Sequencing in Unstudied Populations

“…The co-inheritance of α-thalassemia with transfusion-dependent β-thalassemia is an important factor in producing milder forms of thalassemia major [18]. Studies showed that patients who co-inherited the 2 α-globin gene deletion showed less severe clinical outcomes [19].…”