Japan to go abroad to see a doctor | myelodysplastic syndrome causes, symptoms, diagnosis, classification introduction

2022-05-01 0 By

MDS (myelodysplastic syndromes) is a disorder in which hematopoietic stem cells (HEMATopoietic stem cells), the main source of three types of blood cells (red blood cells, platelets, and white blood cells), are abnormal.In myelodysplastic syndrome, a variety of symptoms occur due to a reduction in blood cells and their inability to function properly, but abnormalities such as cytopenia are often found on blood tests during physical examinations when there are no symptoms.About Myelodysplastic syndrome 1. What is myelodysplastic syndrome?Blood contains blood cells such as white blood cells, lymphocytes, red blood cells that carry oxygen, and platelets that stop bleeding.These cells are formed from hematopoietic stem cells, which form blood cells in the bone marrow inside the bone and proliferate as they differentiate (immature cells become mature cells) (Figure 1).Hematopoietic stem cells are divided into bone marrow stem cells and lymphoid stem cells. The former give rise to red blood cells, platelets, various neutrophils and monocytes, while the latter give rise to B lymphocytes, T lymphocytes and NK cells.MDS: Myelodysplastic syndromes is a disease in which hematopoietic stem cells are abnormal, which are the main sources of three kinds of blood cells (red blood cells, platelets, and white blood cells).Not only can the three systems of maturation of red blood cells, platelets, and white blood cells be abnormal at the same time, but also the three systems can be developed gradually.Syndromes are called syndromes because they are not one disorder but a collection of similar disorders.Blood cells made from abnormal hematopoietic stem cells exhibit abnormal function and microscopic shape (dysplasia).Because of this abnormality, the cells remain immature during their differentiation, producing ineffective hematopoiesis (cell damage) even when they appear to be mature, and fewer blood cells flow through the blood.Thus, in myelodysplastic syndrome, blood tests first indicate abnormalities in the number of blood cells such as anemia (a decrease in red blood cells), thrombocytopenia, and abnormal white blood cell counts (decrease or increase).In addition, acute myeloid leukemia may progress as myelodysplastic syndrome progresses.2. Symptoms In myelodysplastic syndrome, symptoms occur due to a reduction in blood cells and their inability to work properly, but abnormalities such as cytopenia can often be found on a blood test during a physical examination when there are no symptoms.The onset of symptoms varies from patient to patient.Specifically, symptoms such as poor color, general fatigue, palpitations and shortness of breath caused by decreased red blood cells, as well as skin and mucous punctures bleeding and nose bleeding caused by thrombocytopenia.More susceptible to infection due to neutropenia and reduced function of one of the white blood cells, possibly accompanied by fever, etc.In most cases, the cause is unknown.If the chromosomes of bone marrow cells are examined, about 50 percent of them will have chromosomal abnormalities, but these are not congenital, cannot be passed on to people, and cannot be infected.However, some myelodysplastic syndromes are known as “treatment-associated myelodysplastic syndromes” (MDS), which develop as a side effect of treatment several years after treatment with cytotoxic anticancer drugs or radiation for other cancers in the past.In this case, a genetic abnormality occurs in the cells that make blood for some reason, which is thought to be related to the disease.Diagnosis The diagnosis of myelodysplastic syndrome is confirmed by the presence of cytopenia and morphologic abnormalities in the peripheral blood on blood tests and the presence of dysplasia of blood cells (morphologic abnormalities) on bone marrow tests (Table 1).It is important to distinguish it from other cytopenia disorders such as aplastic anemia, which can be distinguished by bone marrow examination.In addition, acute leukemia is diagnosed when the percentage of primitive cells in the blood or bone marrow exceeds 20 percent.Table 1 The diagnostic criteria for myelodysplastic syndrome are partly adapted from Regulations for the Management of Hematopoietic Tumors, March 2010 (1st edition), edited by Society of Hematology of Japan and Society of Lymphatic Reticular Systems of Japan (Golden Won Press) 5.Classification of disease types (according to the classification of cancer characteristics) After diagnosis, according to the proportion of mother cells, chromosomal abnormalities, hematopoietic cell dysplasia (morphological abnormalities) degree and other characteristics of classification, determine the type of disease.The higher the proportion of mother cells, the higher the risk of developing acute leukemia.The classification of disease types has been based on the FAB classification proposed in 1982, but the WHO classification modified in 2008 is now widely used (Table 2).Table 2 Classification of myelodysplastic syndromes (WHO Classification 4, 2008) 3 Cytopenia is occasionally seen in both systems.Pancytopenia (reduction of blood cells in 3 systems) is classified as MDS-U.4 RaEB-1 is classified if there are less than 5% blasts in bone marrow and 2~4% blasts in peripheral blood.RCUD and RCMD with a peripheral blood blast content of 1% were classified as MDS-U.European corpuscles: the fusion and deformation of various particles in normal myeloid leukocytes are in the shape of longitudinal rods, which are characteristic during the formation of myeloblasts.Raeb-2 is classified as raEB-2 if there are less than 5% euclidian bodies in peripheral blood and less than 10% euclidian bodies in bone marrow.Brunning R et al., WHO Classification of Hematopoietic and Lymphoid Neoplasms, 2008;88-93,IARC. 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