Blood Disorders and Diagnostic Tests Quiz

Blood Disorders and Diagnostic Tests

• Blood disorders encompass conditions affecting white and red blood cells, leading to various diseases.
• White blood cell disorders include leukemia and lymphoma.
• Red blood cell disorders primarily comprise anemia (a red blood cell abnormality).

Hematopoiesis

• Each type of blood cell originates from a specific parent cell.
• The hematopoietic stem cell initiates this process.
• Some cells remain stem cells after division, following specific chemical signals.
• Different cell types arise from myeloid and lymphoid stem cells.

White Blood Cells

• Neutrophils, eosinophils, basophils, monocytes, and lymphocytes are types of white blood cells.
• Leukemia (affecting myeloid and lymphoid cells) and lymphoma (affecting lymphoid tissues) are abnormal conditions involving these cells.

Leukemias

• Malignant diseases affecting bone marrow and blood.
• Abnormal, nonfunctional white blood cells circulate.
• Two types: acute (undifferentiated white blood cells) and chronic (immature white blood cells).
• Compromised immune function often leads to infections.

Acute Leukemias

• Acute lymphocytic leukemia (ALL) is the most common type of leukemia in children and adolescents. Lymphoid precursors proliferate, displacing normal cells.
• Often associated with disseminated intravascular coagulation (DIC), causing bleeding.
• Laboratory indicators include neutropenia, anemia, thrombocytopenia, elevated lactate dehydrogenase (LDH) and uric acid levels. Diagnosis relies on bone marrow biopsy, specifically assessing blast cells percentage.
• Acute myeloid leukemia (AML) involves no mature myelocytes, red blood cells, and platelets. Undifferentiated cells accumulate in bone marrow, blood, spleen and liver. Genetic factors like chromosomal translocations are common.
• Laboratory considerations include neutropenia, anemia, thrombocytopenia, elevated LDH, and uric acid levels. Diagnosis hinges on bone marrow biopsy which must include at least 20% blasts.

Chronic Leukemias

• Chronic lymphocytic leukemia (CLL) is the most common form of leukemia in adults in Western countries.
• CLL may be asymptomatic for years, characterized by small, non-functional lymphocytes. Diagnosis often necessitates bone marrow biopsy and flow cytometry. Abnormal B lymphocytes are common in these cases.
• Chronic myeloid leukemia (CML), also known as chronic myelogenous leukemia, accounts for about 20% of adult leukemias.
• CML features increased granulocyte numbers in the bone marrow.
• Laboratory indicators include elevated uric acid levels and the diagnostic Philadelphia chromosome translocation (t(9;22)).

Lymphomas

• A malignancy stemming from lymphatic system cells (B cells or T cells). The cause is unknown, perhaps from viral infection or DNA mutations.
• Hodgkin lymphoma involves abnormal B cells and five classifications.
• It frequently starts with a single painless lymph node in the cervical region. Reed-Sternberg cells are indicators.
• Non-Hodgkin lymphoma (more than 30 types) originates from abnormal B or T cells, eight times more frequent than Hodgkin. Peripheral lymph nodes often enlarge. Peripheral blood tests are not typically helpful in diagnosis.
• Early-stage lymphomas may exhibit normal hematology and clinical biochemistry results but diagnosis ultimately rests on imaging and biopsies.

Red Blood Cells

• Anemia arises from a deficiency in red blood cells or hemoglobin.
• Anemia symptoms include weakness, dizziness, pale mucous membranes, lightheadedness, and tachycardia.
• Anemia types categorize based on red blood cell size and hemoglobin count: microcytic, normocytic, and macrocytic, and hypochromic, normochromic, and hyperchromic.

Hemoglobin

• Hemoglobin is a vital protein facilitating oxygen and carbon dioxide transport. It comprises four globin chains surrounding heme.
• Iron is an essential component of heme, found in tissues and enzymes. Iron absorption is regulated by feedback mechanisms and involves transferrin for transport.
• Heme comprises porphyrin and iron, essential for oxygen binding. Heme production is often associated with RBC maturation in bone marrow.

Iron Deficiency Anemia

• Iron deficiency anemia develops due to insufficient iron.
• Diagnosing iron deficiency anemia often requires testing levels such as iron, total iron-binding capacity (TIBC), ferritin in conjunction with CBC and hematology results.
• Anemia may manifest in low hemoglobin, hematocrit and mean corpuscular volume (MCV), MCH, MCHC.

Pernicious Anemia

• Pernicious anemia stems from vitamin B12 deficiency, often manifested as a macrocytic anemia with low or normal iron levels, normal total iron-binding capacity (TIBC). The presence of gastric atrophy is often characteristic
• Hemolytic conditions associated with pernicious anemia show an elevated indirect bilirubin with elevated LDH.

Hemoglobin Breakdown

• Hemoglobin breakdown produces bilirubin.
• Unconjugated bilirubin is transported to the liver by albumin and converted to conjugated bilirubin, then excreted in the bile.
• Bilirubin is converted further by bacteria in the intestines.

Sickle Cell Anemia

• Sickle cell anemia is caused by abnormal hemoglobin S (HbS). Results from homozygous hemoglobin S (HbS), a genetic mutation.
• Cells assume a sickle shape, get destroyed in the spleen, and cause chronic anemia.
• Laboratory testing including sickling tests and electrophoresis are used in diagnosing this condition.

Thalassemia

• Thalassemia are inherited blood disorders affecting alpha or beta-globin chains. Mutations in these genes cause varying severity, with more severe cases impacting more genes.
• Anemia is a symptom manifested via lower hemoglobin levels. Lower red cell count and mean corpuscular volume (MCV) are often seen.

Anemia of Chronic Diseases

• Anemia associated with chronic disorders (like rheumatoid arthritis, diabetes, or heart disease) is categorized as normocytic and normochromic.
• Characterized by decreased overall red blood cell count, reduced iron levels, and decreased erythropoietin production. Red blood cell lifespan can be shortened.

Clinical Importance of WBC Count

• Complete blood count (CBC) WBC differential, can help detect leukemia, lymphoma, or other complications through classifying subtypes or indicating treatment response.

This quiz explores various blood disorders, including the types of white and red blood cells, hematopoiesis, and specific conditions such as leukemia and lymphoma. Test your knowledge of how these disorders affect the body and the underlying mechanisms involved in blood cell formation.