I. What is myelodysplastic syndrome about? Myelodysplastic syndrome (MDS) is a group of malignant clonal disorders of hematopoietic stem cell origin. MDS is an age-related disease, with the majority of patients older than 60 years of age. The annual incidence can reach 12/100,000 in people aged 80 years or older. Both men and women can develop the disease. The incidence of the disease is on the rise as people’s living standards and lifestyles change, and as the country becomes more industrialized. The cause of MDS is not well established, but when the medical history is followed, there is a history of repeated hair dyeing, years of driving, exposure to organic solvents or inks, or a history of occupancy within a short period of time after renovation of a new house. It is thought to be closely related to exposure to organic benzene compounds. A few studies have suggested an association with viral infections and poor eating habits. In contrast, secondary MDS generally refers to the above-mentioned lesions occurring distantly after the tumor has been treated with radiation and castration. As a result of genetic damage to hematopoietic cells due to the above-mentioned pathogenic factors, clonal hematopoiesis develops in the bone marrow and forms a state of stasis with residual normal hematopoiesis. The body produces excessive T-lymphocyte immunity against both residual normal and clonal cells, resulting in excessive apoptosis of hematopoietic cells, ineffective hematopoiesis in the bone marrow, and a decrease in peripheral blood lineage one to three. At the same time, malignant clones are inhibited from immediately transforming to leukemia. Once this balance is disturbed, MDS transforms into AML. How do I know I have MDS? MDS is characterized by anemia, bleeding, and fever of unknown origin. Physical examination may show varying degrees of anemia, subcutaneous petechiae, and bleeding gums. Some patients may have yellow sclera or hepatosplenomegaly. Most patients show a decrease in whole blood cells (erythrocytes, leukocytes and platelets) or both lines, while a few have simple anemia, thrombocytopenia or leukopenia. Most bone marrow smears show active hyperplasia, some normal hyperplasia, and a few hypoplasia. Bone marrow shows pathological hematopoiesis (that is, odd, abnormal cell morphology). Pathological cells should account for 10% or more of the cells in the lineage to be diagnostic. The cell morphology of each lineage can be clearly identified in plastic-embedded bone marrow sections. If there are clinical signs of anemia, infection or hemorrhage, peripheral blood showing reduced lineage one to three, active or normal myeloproliferation, a few hypoproliferation, but combined with pathological hematopoiesis of at least one lineage, the pathological cells must be >10% of the cells of that lineage. No improvement in blood picture after 1 month of treatment with vitamin B12, folic acid, iron, vitamin B6, etc. The diagnosis of MDS can be made if other diseases with similar manifestations can be ruled out, but it is necessary to go to a specialized hospital for a full set of MDS tests to confirm the diagnosis by a specialist. How to treat MDS? When MDS is diagnosed, the patient should be subtyped and risk assessed according to the World Health Organization (WHO) classification criteria and the International Prognostic Score System (IPSS) in order to provide targeted treatment. This requires a comprehensive complementary work-up to be performed. Single-collection platelets should be used as much as possible, and specially matched (HLA-consistent) platelets should be applied when necessary to reduce the production of homologous antibodies in the recipient. Blood products should be transfused after low-dose cobalt 60 irradiation whenever possible, as MDS cases are often immunodeficient (especially those receiving chemotherapy), and coupled with HLA incompatibility, there is a risk of transfusion-associated graft-versus-host disease (GVGD). Common treatments for low-/intermediate-risk patients include the use of cytoprotective agents. Anti-apoptotic drugs, anti-vascular proliferative drugs, immunomodulatory drugs, etc. The main goal is to maintain the patient’s blood cells in as normal a range as possible, to ensure that the patient can live a normal life and to delay further disease progression. For patients who have already transformed to leukemia or have a tendency to transform to leukemia, chemotherapy or demethylation drugs should be used in time to control the disease or achieve complete remission. Patients who are young and in good general condition should undergo hematopoietic stem cell transplantation as soon as possible. It is possible for the patient to achieve long-term survival.