bubble_chart Overview

Myelodysplastic syndrome (MDS) is a group of clonal hematopoietic system diseases with an unclear etiology. It predominantly affects elderly individuals but is also not uncommon in children. Patients with a prolonged disease course often progress to leukemia, hence it was previously referred to as "preleukemia."

bubble_chart Clinical Manifestations

The presentation is atypical, primarily manifesting as anemia, possibly accompanied by fever or bleeding symptoms, with some cases showing hepatosplenomegaly.

bubble_chart Auxiliary Examination

1. Blood picture: Approximately half of the cases exhibit pancytopenia, while others may show reductions in only one or two cell lines. The anemia is normocytic or macrocytic, with anisocytosis, presence of macrocytes, poikilocytes, basophilic stippling, Howell-Jolly bodies, and nucleated red blood cells. Leukocytes and ring-shaped nuclei leukocytes are often observed, with reduced or absent specific granules in the cytoplasm. Platelets are grade I reduced, occasionally elevated, and giant platelets may be seen. (These changes in blood cells are collectively referred to as dyshematopoiesis).
2. Bone marrow findings: Hypercellularity. Dyshematopoiesis is observed in three, two, or any single lineage of blood cells. The erythroid series shows prominent megaloblastic changes: nuclear lobulation or multinucleation, karyorrhexis, pyknosis, with odd-numbered nuclei being particularly characteristic. Some cases may exhibit ringed sideroblasts. The granulocytic series demonstrates maturation arrest, nuclear-cytoplasmic asynchrony, excessive, reduced, or absent cytoplasmic granules, and binucleated granulocytes may be seen. Bone marrow biopsy may reveal immature granulocytes and abnormal localization of immature precursors (ALIP). Monocytosis is present. The megakaryocytic series may show lymphoid micro-megakaryocytes (a characteristic finding), megakaryocytes with round nuclei, etc. Megakaryocyte counts may be reduced.
3. Other abnormalities: Approximately half of the cases exhibit chromosomal abnormalities, such as 5q-, -7, +8, etc. Progenitor cell cultures in vitro show poor growth, with reduced or absent colony formation of CFU-GM, CFU-MK, and CFU-E, and an increased cluster-to-colony ratio.

Exclusion of other diseases associated with dyshematopoiesis and pancytopenia: Conditions with dyshematopoiesis, such as chronic myeloid leukemia, erythroleukemia, megaloblastic anemia, myelofibrosis, primary thrombocythemia, acute megakaryoblastic leukemia, congenital dyserythropoietic anemia, and malignancies, should be ruled out. Diseases with pancytopenia, such as aplastic anemia and paroxysmal nocturnal hemoglobinuria (PNH), should also be excluded.

bubble_chart Treatment Measures

There is no mature treatment experience yet, and currently, the principle of treatment based on disease stage (type) is advocated. For example, RA and RAS can primarily use hematopoietic-regulating drugs, including androgens, adrenocortical hormones, vitamin B6, etc. For RAEB, RAEBT, and CMML, the following methods can be selected.

(I) Induction differentiation

Options include:

1. Cis or all-trans retinoic acid 2–4 mg/(kg·d), [20–100 mg/(m²·d)] orally, course of 6–12 weeks or longer.
2. α-interferon 3 million U/(m²·d), 5 days per week, course of 5–7 weeks or longer.
3. Indirubin 50–100 mg/(m²·d), divided into 3 oral doses, course of 3 months or longer.
4. Fortune plumyew twig and leaf ester alkaloid 0.3–0.5 mg/(m²·d), intravenous drip, once daily or every other day, 10–15 times as one course.
5. Combination therapy (1) Retinoic acid 100 mg/(m²·d) + 6μG 12.5–25 mg/(m²·d), used together for 2–8 weeks. (2) Retinoic acid + vincristine 1–2 mg/(m²·d) each time, used for 2–8 weeks. (3) Fortune plumyew twig and leaf ester alkaloid 1.5 mg/(m²·d) + levamisole 100 mg/d, divided into 3 oral doses + α-interferon 2.5 million U/(m²·d) + vitamin D₃ 300,000 U/2 weeks + prednisone 20 mg/(m²·d), 14 days as one course, rest for 14 days, then start the second course.

(II) Stimulating hematopoiesis

The following drugs can be selected:

1. Stanozolol 0.05 mg/kg, three times daily. Course of 3–12 months.
2. High-dose methylprednisolone 30 mg/(m²·d) (total dose ≤1000 mg/d), used for 3 days.
3. Colony-stimulating factor GM-CSF 120 μg/m²·d, used for 2 weeks, with a 2-week interval, up to 3 courses; or G-CSF 2 μg/(kg·d), used for 7 days, rest for 3 days, then another course.
4. Recombinant interleukin-3 (rhIL-3) 250–500 μg/(kg·d), used for 15 days.

(III) Chemotherapy

Options include:

1. Low-dose Ara-C 10–20 mg/(m²·d), one course over 3 weeks.
2. Anthracyclines (1) Aclarubicin 3–14 mg/(m²·d), used continuously for 7–10 days as one course, total of 2 courses; (2) Idarubicin 25–50 mg/(m²·d), divided into 4 oral doses, taken on day 1, day 14, or day 21, 2–3 weeks as one course, total of 2–4 courses.
3. Etoposide (VP16) 100 mg/(m²·d) for 5 days, then reduced to 50 mg/(m²·d), twice weekly, can be used for CMML treatment.
4. Small dose fortune plumyew twig and leaf ester alkaloid 0.3～0.6mg/(m²‧d), once daily or every other day, 10～15 times per course, rest for 10～15 days, then proceed to the next course.
5. Combination chemotherapy Using DA, DAT, HA, HOAP, DOAP, DHA, or MA regimens to treat MDS (excluding RA and RAS) and secondary leukemia has been reported to achieve remission in 49% of cases.

(4) Bone marrow transplantation

Allogeneic bone marrow transplantation is the most effective treatment for MDS, especially suitable for pediatric RAEB. Therefore, this method should be chosen when conditions permit. Autologous bone marrow transplantation is also worth trying.