Myelodysplastic syndrome (MDS) is a group of heterogeneous blood disorders that occurs due to clonal hematopoietic disorders in the bone marrow. This hematopoietic disorder leads to one or more cytopenias (involving red blood cells, white blood cells, platelets) affecting the myeloid cell lineage. It is also considered a premalignant condition and may even transform into acute myeloid leukemia. Although, myelodysplastic syndrome can occur at any age, it is primarily considered a disease of the elderly affecting individuals in their 70s. The disease incidence is greater in men as compared to women. The incidence of myelodysplastic syndrome has been increasing. This could be attributed to sophistication in diagnosis and also to the increasing elderly population.
What Are Early Signs Of Myelodysplastic Syndrome?
The clinical manifestations of myelodysplastic syndrome are caused due to immature or defective blood cells of myeloid lineage produced by the bone marrow. The lack of healthy cells in the peripheral blood stream leads to various signs and symptoms of the disease. Even before the development of myelodysplastic syndrome, patients may be found to have idiopathic nonmegaloblastic macrocytic anemia along with neutropenia or mild thrombocytopenia. The clinical presentation of myelodysplastic syndrome varies from patient to patient as in some patients, the disease progression is invariably slow while in others it takes an aggressive course presenting with severe life threatening complications. (1)
The signs of myelodysplastic syndrome include anemia, neutropenia and/or thrombocytopenia.
Anemia: It is the most common sign in patients with myelodysplastic syndrome due to decreased red blood cells in the peripheral blood. Red blood cells are associated with carrying and supplying oxygen to different tissues in the body. Therefore, the symptoms associated with reduced blood cells are due to decreased supply of oxygen in different cells and tissues. This leads to fatigue, malaise, weakness; pallor of skin and mucus membranes, increased somnolence, headaches, irritability, dizziness, palpitations, and tachycardia and in severe cases may lead to congestive heart failure in patients with an underlying cardiac condition.
Leukopenia: The most common form of leukopenia (reduced white blood cells) associated with myelodysplastic syndrome is neutropenia. Since, myeloid cell lineage is affected in myelodysplastic syndrome and neutrophils make up to 40-80% of all white blood cells, it is the most common form of leukopenia in MDS. White blood cells help in fighting infections (bacterial, fungal, viral) in the body and help maintain innate immunity. Therefore, reduced neutrophils in peripheral blood will lead to increased chances of infection and presence of fever due to infection. There are increased chances of bacterial infection (pneumonia, urinary tract infection) and fungal infection.
Thrombocytopenia: It occurs due to reduced platelets in the peripheral blood. Platelets play an important role in blood clotting; therefore, reduced platelet count will lead to increased chances of bleeding. There will be manifestations of easy bruising, ecchymoses or petechiae. Severe thrombocytopenia is associated with bleeding from nose (epistaxis) and bleeding from gums. There may also be signs of hematuria (blood in urine), hemoptysis (blood in vomit) and melena (blood in stools). Sometimes, in menstruating women, there might be increased menstrual blood loss.
Some patients with myelodysplastic syndrome may even have signs of splenomegaly. Splenomegaly is usually seen in patients with chronic mylomonocytic leukemia (CMML). CMML is a subtype of myelodysplastic syndrome and often overlaps with it. Splenomegaly may lead to complications of spontaneous rupture and intra abdominal blood loss. This blood loss may even lead to death. (1)
The exact cause of myelodysplastic syndrome is still unknown. It can be divided into two classes, primary (idiopathic or de novo) and secondary type. Genetics and environmental factors have been known to play an important role in the etiology of the disease. The secondary type of myelodysplastic syndrome occurs subsequent to prior exposure to chemotherapeutic agents (mostly alkylating agents, topoisomerase II inhibitors), radiations, chemicals (benzene, insecticides, fungicides, and weed killers), viral infections and cigarette smoking. In a few cases, familial myelodysplastic syndrome has also been noted. (2)
- What is Myelodysplastic Syndrome: Causes, Types, Signs, Symptoms
- Myelodysplastic Syndromes: Staging, Risk Factors, Complications, Diagnosis
- Myelodysplastic Syndromes Treatments: Chemotherapy, Immunotherapy, Bone Marrow Transplant
- Myelodysplastic Syndromes or MDS: Treatment for Side Effects, Children with MDS
- Myelodysplastic Syndromes: Survival Rates, Prognosis, Recurrence, Remission, Lifestyle Changes, Prevention
- Coping with Myelodysplastic Syndromes & its Follow-Up Care