del 11(q23) as a prognostic factor of iron overload in refractory anemia with ringed sideroblasts

Abstract

MEBíêAi OURN deI 11(q23) as a prognostic factor ofiron overload in refractory anemia with ringed sideroblasts Disciplina de Hematologia e Hemoterapia, Escola Paulista de Medicina-UNIFESP -São Paulo, BrazilWe present the case of a patient with MOS RARS subtype with loss of part of the long arm of chromosome 11 dei 11(q23). This a cytogenetic abnormality that occurs in 7°1o to 20°10 of RARS cases not related to poor prognosis. It seems that this deletion is a marker of iron overload in MOS.UNITERMS: Myelodysplasia. Iron overload. Refractory anemia with ringed sideroblasts. Karyotype. INTRODUCTION.M yelodysplastic syndrome (MDS) is acIonaI pluripotent stem cell proliferation. The term gathers together a group of disorders that show hematological cell displasia with different leveIs óf peripheral cytopenia, gene~ally with hypercellular bone marrow. Defective maturation is associated with the precursor cell proliferation.Usually, patients are older than 50 years, MDS being rare in childhood and adolescence, and symptoms relate directly to cytopenia. The etiology is almost always unkn9wn (primary MDS) but can be secondary to myelotoxic drugs like the antineoplastic ones (secondary MDS). FAB classification has established 5 subtypes I: refractory anemia(RA), refractory anemia with ringed sideroblasts (RARS), refractory anemia with excess of blasts(RAEB), refractory anemia~ith excess of blasts in transformation (RAEBt) and chronic myelomonocytic leukemia (CMML), though some clinicaI presentations do not fit into any of them, like MD~with marrow fibrosis or hypocellularity. Address for correspondence: Maria de Lurdes Lopes Ferrari ChauffailleAround 80% of the patients present karyotype abnormalities in marrow cells, the most frequent being: trissomy 8, loss of part of the long .arms of chromosomes 5,7,9,20 or 21, and monossomy 7.or 9. 2 These abnormalities are of independent prognostic value. Vorhoef et al.(1991) studied karyotype prognostic importance in MDS patients and observed differ~nt survival times among patients with complex karyotype (7 months of survival) versus single abnormalities (21 months) versus normal karyotype (30 months).Evolution follows the subtype. So, benign subtypes like RA and RARS rarely evolve into acute leukemia, and the patient r~mains with chronic anemia refractory to 1514 therapy. The subtypes RAEB, RAEBt and CMML are more aggressive in that 30 to 50% of the patients evolve into acute leukemia with mean survival of 5 to 10 months for the first two, and 20 months for CMML. Acquired RARS is a chronic macrocytic anemia related to a disorder in heme biosynthesis, ineffective erythropoiesis without reticulocytosis and mitocondrial iron overload that leads to the presentation of more than 15 ringed sideroblasts per 100 erythroblasts. Only 10% evolve into acute myeloid leukemia (AML). Serum iron, ferritin and transferin saturation leveIs are high, as well as in bone marrow, as shown by cytochemical staining.Here, the case of a patient with RARS and chromosomal abnormality deI 11(q23) with iron...