Hematological Diseases Overview

Hematological Disease

• Hematopoiesis begins with hematopoietic stem cells in the adult bone marrow
• Three key factors for red blood cell (RBC) formation: iron, erythropoietin, and vitamin B12
• RBC lifespan: 120 days
• Platelet lifespan: 5-10 days
• Neutrophil lifespan: 6-8 hours
• Lymphocyte lifespan: many years
• Senescent cells are removed by the spleen, liver, and bone marrow through phagocytosis
• Mean corpuscular volume (MCV): measures the average RBC volume
• Mean corpuscular hemoglobin (MCH): measures the average weight of hemoglobin
• Mean corpuscular hemoglobin concentration (MCHC): measures the average concentration of hemoglobin per unit volume
• Hematocrit (HCT): percentage of whole blood occupied by intact red blood cells

Aplastic Anemia (Bone Marrow Aplasia)

• A rare, potentially fatal blood disorder characterized by pancytopenia and hypocellular bone marrow
• Etiology can be idiopathic, inherited (Fanconi Anemia), or acquired (due to toxins, viruses, radiation, or drugs, like sulfonamides and anti-rheumatic drugs)
• Clinical features include anemia, leukopenia (increased infection susceptibility), thrombocytopenia (bleeding), and oral manifestations (pallor, gingival bleeding, etc.)
• Diagnosis requires hypocellular bone marrow and depression of at least one blood cell lineage
• Lab findings: normal MCV and MCHC

Red Blood Cell Disorders

• Erythrocytosis is an increase in circulating red blood cells (characterized by raised hematocrit)
• Conditions are categorized as relative or absolute and based on primary causes or secondary causes.
• Relative Erythrocytosis: The red blood cell count is normal, but plasma volume is low
• Absolute Erythrocytosis:The red blood cell count exceeds 125 % of the predicted value, often indicative of Polycythemia Vera (PV), associated with increased blood viscosity
• Polycythemia Vera (PV): A rare disease with an elevated red blood cell count and increased blood viscosity, where etiology may include genetic mutations
• PV oral manifestations: erythema (red-purple color) of mucosa, glossitis, gingival bleeding tendency, varicosities in the ventral tongue
• Oral health considerations about erythrocytosis must be assessed before initiating any treatment and therapy

Iron Deficiency Anemia (IDA)

• IDA is a microcytic hypochromic anemia
• Causes include chronic blood loss, impaired iron absorption, and increased iron requirements
• Clinical features include general manifestations such as pallor, fatigue, dyspnea, palpitation, tachycardia, bone pain, and oral manifestations such as pale oral mucosa, angular cheilitis, glossitis, and recurrent aphthous stomatitis
• Diagnosis involves clinical presentation and laboratory findings

Plummer-Vinson Syndrome

• A syndrome of glossitis, cheilosis, dysphagia, and esophageal webs, sometimes associated with iron deficiency anemia
• Oral symptoms include burning sensation of lips and tongue, beefy-red tongue, dysphagia (solids)
• Treatment is focused on iron supplementation

Vitamin B12 & Folate Deficiency Anemia (Megaloblastic Anemia)

• Vitamin B12 and folate deficiency are common causes of megaloblastic anemia (normochromic/macrocytic anemia)
• These deficiencies impair DNA synthesis
• Vitamin B12 is essential for neurological development
• Causes of deficiency include malabsorption (e.g. atrophic gastritis, Crohn's disease), certain medications (e.g. proton pump inhibitors), and surgical resections

Folate Deficiency Anemia

• Inadequate intake or increased physiologic requirement (pregnancy, lactation) may cause folate deficiency anemia
• Laboratory testing for diagnosis can include blood tests

Pernicious Anemia

• An autoimmune disease that targets intrinsic factor, essential for vitamin B12 absorption
• Results in vitamin B12 deficiency
• Clinical characteristics include neurological symptoms along with other symptoms of anemia, often characterized by severe vitamin B12 deficiency

Hemolytic Anemia

• A group of diseases in which red blood cells are destroyed at a faster rate than they are produced.
• When bone marrow is unable to keep up, hemolytic anemia develops.
• Hemolytic anemia can be inherited or acquired, and symptoms, and diagnosis are variable depending on the cause.

Hemoglobinopathies (Including Sickle Cell Disease)

• Inherited disorders or abnormalities of hemoglobin synthesis.
• Sickle Cell Disease: A hereditary disease where a point mutation in the hemoglobin beta globin gene results in abnormal hemoglobin (HbS) that polymerizes under low oxygen conditions, leading to the formation of sickle-shaped red blood cells
• Consequences: shortened lifespan of red blood cells, vaso-occlusive events, and hemolytic anemia, requiring treatment to manage symptoms.
• Symptoms can include increased periodontitis, mucosal pallor, delayed eruption, discolored or depapillated tongues, and osteomyelitis.

Thalassemia

• A group of inherited autosomal recessive disorders characterized by a disturbance of either alpha (a) or beta (β) Hb chain production
• Oral manifestations : Pallor, weakness, jaundice, and abnormal facial bones with deformed craniofacial changes