The activities of delta-aminolaevulinic acid synthase and haem synthase in experimental sideroblastic anaemia. Effect of mitochondrial iron excess on the enzyme activity in peripheral red blood cells

The use of molecular profiling for diagnosis and research in non-Hodgkin's lymphoma

Molecular profiling facilitates the understanding of the genetic processes underlying the development of cancer, and makes it possible to use specific signatures to prognosticate clinical outcome and to predict response to specific treatments. There has been a great increase in the availability of tools for exploring genetic abnormalities in cancer cells, which have allowed a more comprehensive characterization of the mutations, translocations, and copy-number variations that may affect the development of cancer or therapy response. An improved understanding of the molecular basis of cancer is helping also in the identification of new molecular targets for therapy.

Severe isoniazid related sideroblastic anemia

Isoniazid induced sideroblastic anemia is a rare event. We report case of a 45 year old Caucasian women with development of severe anaemia 4 month after introduction of Isoniazid as part of Tuberculosis treatment. While haemoglobin fell to 47 g/L and erythrocyte count to 1.5 G/L, reticulocytes were very low (reticulocyte production index of 0.48), but bone marrow aspirate showed an accelerated erythropoiesis with ringsideroblasts. Anaemia rapidly resolved after cessation of Isoniazid. We postulate an Isoniazid induced inhibition of the δ-Amino-levulinat-synthase resulting in marked depletion of heam synthesis.

Haem biosynthesis in refractory sideroblastic anaemia associated with the preleukaemic syndrome

The activities of 5 enzymes of the haem biosynthetic pathway and the protoporphyrin concentrations have been measured in peripheral red blood cells of 23 patients having a preleukaemic syndrome with refractory sideroblastic anaemia. A decreased delta-aminolaevulinic acid synthase (ALA-S) activity, an increased uroporphyrinogen I synthase activity and an increased red cell protoporphyrin concentration were consistent findings. Patients with abnormal leucocyte and/or platelet counts in the peripheral blood as well as patients with an excess of blast cells in the bone marrow had the lowest ALA-S activities. A further decrease in ALA-S activity was observed in 3 patients after leukaemic change in the disease. Patients having cytogenetic abnormalities showed no unique enzyme abnormalities. These results indicate that enzymatic disturbances of haem synthesis cannot be used as prognostic indicator of leukaemic transformation in refractory sideroblastic anaemia, but a very low ALA-S activity appears to accompany the development of a leukaemia in such patients.