(A) Disease knowledge
Our bone marrow is like a factory for manufacturing blood cells, and mature blood cells are like parts that have been processed and tested to be qualified to leave the factory, while hematopoietic stem cells are like the blanks of parts that have to go through a series of processing procedures in the bone marrow before they can become qualified parts and leave the factory. If there are problems with the blanks themselves, the parts processed from them will definitely be substandard products and will be detected by the inspectors before leaving the factory and destroyed in the factory to ensure the quality and not allowed to leave the factory. The essence of myelodysplastic syndrome (MDS) is that the bone marrow hematopoietic stem cells (blanks) are abnormal, and the blood cells (substandard products) developed by their differentiation are destroyed in the bone marrow (destroyed in the factory), resulting in a reduction of peripheral (factory) blood cells, often red blood cells, white blood cells and platelets, which eventually cause a series of clinical manifestations including anemia, infection and bleeding. Therefore, although MDS patients have active bone marrow hematopoiesis, they show abnormal hematopoietic cell development (called pathologic hematopoiesis) and reduced peripheral blood cells (called ineffective hematopoiesis), and the pathologically developed hematopoietic cells in the bone marrow often come from the same ancestor (called clonal). Acute myeloid leukemia.
MDS can occur in any age group, mainly in the elderly. The risk of MDS increases with long-term exposure to toxins and radiation, which can cause damage to hematopoietic stem cells and the hematopoietic microenvironment. MDS with a clear cause is called secondary MDS and is mainly associated with the application of chemotherapeutic agents, especially alkylating agents.
(ii) Clinical manifestations.
Patients with MDS may show symptoms of anemia due to decreased red blood cells and decreased hemoglobin, similar to the above-mentioned anemia caused by other etiologies, i.e., pallor, weakness, shortness of breath, palpitations, and in severe cases, heart failure and coma; various infections may also occur due to decreased leukocytes, with whistling tract infections being the most common; MDS patients with decreased platelets may show bleeding, with skin and mucous membrane bleeding being the most common, and in severe cases, Intracranial hemorrhage and death can occur in severe cases.
(iii) Diagnosis and treatment.
Based on the patient’s history and clinical manifestations of anemia, infection and bleeding, the doctor will first ask the patient to check the blood routine. If the blood routine shows a decrease in hemoglobin along with a large red blood cell volume, with or without a decrease in white blood cell or platelet count, it will prompt the doctor to think of the possibility of MDS, and further examination will be conducted. The doctor may order serum folate and vitamin B12 tests to rule out megaloblastic anemia, and may order bone marrow aspiration, bone marrow biopsy, and chromosomal tests to confirm the diagnosis and rule out other hematologic disorders with similar presentations. If the patient’s serum folate and vitamin B12 levels are not low and the bone marrow shows “pathological hematopoiesis”, especially with chromosomal abnormalities (commonly -5, 5q-, -7, 7q-, -Y, trisomy 8 and 20q -The diagnosis of MDS is made when other blood disorders are excluded, and the patient is then staged according to WHO criteria (RA, RCMD, RAEB-I, RAEB-II, 5q- syndrome, etc.) and scored according to the MDS Prognostic Score System (IPSS) to determine whether the patient is at low, intermediate or This is used to predict the prognosis of the patient and to guide the selection of treatment measures.
The treatment of MDS includes the following three aspects
1. Supportive therapy.
In severe anemia and thrombocytopenia, red blood cell and platelet suspension can be transfused; when serum ferritin >1000μg/L, iron expulsion therapy should be given; active control of infection; EPO, G-CSF, GM-CSF and other hematopoietic cytokines can be tried according to specific conditions.
2.Improve the hematopoietic efficiency of pathological hematopoietic clones
(1) Immunosuppressants: glucocorticoids, cyclosporine A (CSA), etc.
(2) Immunomodulators: thalidomide, thalidomide (Revlimid), etc.
(3) Other.
(1) Androgens
(2) Arsenic, all-trans retinoic acid, a-D3, etc.
(3) Cell membrane protectors: amifostine
④Hexketone cocaine to improve microcirculation
⑤ For those with cyclic iron granulocytosis, high dose vitamin B6 (200mg/day) can be applied.
3. Eradicate pathological hematopoietic clones and restore normal hematopoiesis
(1) The person with more primitive cells can choose chemotherapy: low-dose Marfan or pre-excitation program, etc.
(2) Demethylation drugs: 5-heterocytidine or decitabine
(3) Allogeneic hematopoietic stem cell transplantation: the only method to cure MDS.
Although allogeneic bone marrow transplantation is the only method that can cure MDS, patients need to bear about 30% of the risk of transplant-related death; while the other methods mentioned above cannot cure MDS and their efficiency is not satisfactory, they are an option to prolong life and maintain their quality of life for older, low-risk patients. Therefore, doctors should fully weigh the pros and cons according to many factors such as patient staging, prognosis score, age, and physical condition in order to provide the most suitable treatment options for patients.
(iv) Prevention.
Excessive exposure to toxins and radiation should be avoided. With the continuous improvement of people’s living standard, the pollution of home decoration materials; low amount of radiation from computers and cell phones; frequent CT and other X-ray examinations, etc. may be risk factors for the occurrence of hematologic neoplastic diseases such as MDS, and excessive exposure should be avoided as much as possible. Patients who have received chemotherapy or radiotherapy for other neoplastic diseases should have regular blood tests to detect the signs of MDS early. Patients who have been diagnosed with MDS should try to maintain a calm state of mind and cooperate actively with their doctors. Patients with thrombocytopenia should keep their blood pressure stable, avoid strenuous exercise and mood swings, monitor themselves for bleeding manifestations (subcutaneous bleeding spots, petechiae, oral blisters, etc.), and seek medical attention if they feel unwell or find abnormalities.