ABSTRACT: In 1991, the FAB group published a proposal to designate acute leukemias with minimal signs of myeloid differentiation as AML-M0. This proposal was meant to offer a provisional basis for the study of immature myeloid forms, with the understanding that it was susceptible to changes and improvements with new information derived from the laboratory. Since then there have been a number of reports detailing the biological and clinical features of patients with AML-M0. In this article we review the laboratory data acquired from various sources and suggest a partial modification of diagnostic criteria.     © 1999 Academic Press

Keywords: AML-M0, diagnosis, FAB, classification, myeloperoxidase.

Reprint requests to: Roberto Stasi, M.D., Department of Medical Sciences, Regina Apostolorum Hospital, Via S. Francesco, 50, 00041 Albano Laziale, ITALY, phone: +39 6 9324661 (switchboard), fax: +39 6 9321138, e-mail: roberto.stasi@schering-plough.it.

ABSTRACT: The major elements of bone pathology in Gaucher disease are a failure of osteoclast and osteoblast function, resulting in osteopenia and also osteonecrosis. T lymphocytes have recently been found to be involved in the regulation of osteoblast/osteoclast activity in vitro. In the present report the peripheral blood T major lymphocyte subsets were investigated in a group of genotyped type 1 Gaucher disease patients. A total of 31 patients were studied: 21 non-splenectomized (5 N370S homozygotes) and 10 splenectomized (of whom 1 was a N370S homozygote). The results show that non-splenectomized patients present a decrease in absolute numbers of peripheral blood T lymphocytes, specially the CD4+ T subset. However, when patients were analyzed with respect to the presence of bone disease, the number of CD8+ T lymphocytes was found to be statistically significantly lower in patients presenting bone involvement. Furthermore, lower numbers of CD8+ T lymphocytes were significantly correlated with higher levels of plasma tartrate resistant acid phosphatase (TRAP) activity, a putative marker of osteoclast cell activity. These in vivo findings are in agreement with the results reached in vitro by others. They provide an additional marker of disease severity in Gaucher disease. In the group of genotyped Gaucher disease patients, the majority of the N370S homozygous patients presented a clinically milder phenotype, including the absence of bone involvement, confirming earlier reports predicting that a number of these patients may remain undiagnosed. Collectively the homozygosity for the N370S mutation and normal T cell numbers may provide additional markers for the clinical heterogeneity of Gaucher disease.     © 1999 Academic Press

Keywords: Gaucher's disease, chitotriosidase, tartrate resistant acid phosphatase, CD8 positive T lymphocytes, bone pathology.

Reprint requests to: Prof. Maria de Sousa, Departamento de Patologia e Imunologia Molecular, Instituto de Biologia Molecular e Celular da Universidade do Porto, Rua do Campo Alegre, 823, 4150 Porto, PORTUGAL, phone: 351 2 6074900 (ext: 367), fax: 351 2 6099157, e-mail: mdesousa@ibmc.up.pt.