Hematologic Disorders – Classified by Cell/Component Affected

Platelets

• Thrombocytopenia:

  • Definition: Decreased platelet count
  • Clinical Manifestations: Bleeding, petechiae (small, red or purple spots on the body)

• Idiopathic Thrombocytopenic Purpura (ITP):

  • Description: Autoimmune disorder resulting in destruction of platelets by the immune system.

Red Blood Cells

• Sickle Cell Anemia:

  • Pathophysiology: Abnormal hemoglobin leads to sickling of red blood cells (RBCs).

• Polycythemia:

  • Definition: Increased RBC mass
  • Clinical Implications: Results in hyperviscosity, leading to complications like thrombosis.

White Blood Cells

• Neutropenia:

  • Definition: Low neutrophil count
  • Clinical Implications: Significantly increases the risk of infections.

• Acute Lymphoblastic Leukemia (ALL):

  • Description: A condition characterized by malignant lymphoid precursors affecting blood and bone marrow.

• Acute Myelogenous Leukemia (AML):

  • Description: A type of cancer where there are malignant myeloid precursors in the bone marrow.

Plasma Cells

• Multiple Myeloma:
  • Description: A malignancy of plasma cells which produce monoclonal immunoglobulin leading to various health complications.

Coagulation Factors

• Hemophilia A:

  • Definition: A bleeding disorder caused by a deficiency in Factor VIII.

• Vitamin K Deficiency Bleeding:

  • Pathophysiology: Results in decreased levels of clotting factors II, VII, IX, and X, leading to bleeding disorders.

Diseases Classified by Cause

Genetic

• Hirschsprung’s Disease:

  • Description: Absence of enteric ganglion cells leading to megacolon.

• Inguinal Hernia:

  • Classification: Congenital or acquired weakness of the abdominal wall.

Infectious

• Pseudomembranous Colitis:

  • Cause: Toxin produced by Clostridioides difficile.

• Acute Appendicitis:

  • Cause: Bacterial obstruction of the appendix.

Inflammatory / Autoimmune

• Ulcerative Colitis:
  • Definition: Chronic mucosal inflammation of the colon.

Structural / Mechanical

• Diverticulosis:

  • Description: Herniation of the mucosa through the muscular layer of the colon.

• Peptic Ulcer Disease:

  • Causes: Infection by Helicobacter pylori or nonsteroidal anti-inflammatory drugs (NSAIDs).

Major Hematologic Disorders

Aplastic Anemia

• Symptoms: Fatigue, increased susceptibility to infections, and bleeding tendencies.
• Cells Affected: Pancytopenia (deficiency of all three blood cell types).
• Cause: Failure of the bone marrow to produce blood cells.
• Prognosis: Typically fatal without medical intervention.
• Onset: Can occur at any age.

Leukemias (Summary)

Genetic Defects

• Sickle Cell Anemia:

  • Description: A point mutation in the hemoglobin gene resulting in valine replacing glutamic acid in the β-globin chain.

• Thalassemia:

  • Definition: Decreased production of either α or β globin chains leading to anemia.

Hemoglobin Types

• Hemoglobin A:

  • Structure: Comprised of two alpha and two beta chains (α₂β₂).

• Hemoglobin A₂:

  • Structure: Comprised of two alpha and two delta chains (α₂δ₂).

• Hemoglobin F:

  • Structure: Comprised of two alpha and two gamma chains (α₂γ₂); exhibits higher oxygen affinity compared to adult hemoglobin.

Genetic Translocations

• t(9;22):

  • Associated with Chronic Myelogenous Leukemia (CML); referred to as the Philadelphia chromosome.

• t(15;17):

  • Associated with Acute Promyelocytic Leukemia (APL).

Coagulation Factors (Common Names)

• I: Fibrinogen
• II: Prothrombin
• VII: Proconvertin
• VIII: Antihemophilic factor
• IX: Christmas factor
• X: Stuart-Prower factor

Multiple Myeloma

• Manifestations: Bone pain, increased risk of fractures, anemia, renal failure.
• Diagnosis: Characterized by M-protein spike in serum, presence of Bence Jones proteins in urine, and observable bone lesions.

Classification of Anemias

• Microcytic Anemia:

  • Most commonly due to iron deficiency.

• Normocytic Anemia:

  • Characteristic of aplastic anemia.

• Macrocytic Anemia:

  • Often due to Vitamin B12 deficiency.

Dental Caries Formation

• Mechanism: Plaque bacteria metabolize sugars to produce acid, leading to demineralization of enamel.

Definitions & Causes

• Stomatitis: Inflammation of the oral cavity.
• Sialadenitis: Infection of the salivary glands.
• Dysphagia: Difficulty in swallowing.
• Achalasia: Failure of the lower esophageal sphincter to relax properly.
• Gastritis: Inflammation of the stomach lining.
• Esophagitis: Inflammation of the esophagus.

Features of Inflammatory Bowel Diseases

• Hepatocellular Carcinoma:
  • Risk Factors: Cirrhosis, infections with hepatitis B and C viruses.
  • Biomarker: Alpha-fetoprotein (AFP) elevated in serum.

Hereditary Liver Diseases

• Hemochromatosis:

  • Genetic condition (Autosomal Recessive) resulting in iron overload in the body.

• Wilson Disease:

  • Genetic condition (Autosomal Recessive) leading to copper accumulation in tissues.

• α1-Antitrypsin Deficiency:

  • Condition that can lead to respiratory and liver complications.

Hepatitis Virus Genome Transmission

Common Tumors

• Salivary Gland:
  • Pleomorphic adenoma.
• Esophagus:
  • Squamous cell carcinoma.
• Liver:
  • Hepatocellular carcinoma.

Cirrhosis Causes

• Etiology:
  • Chronic alcohol consumption, chronic hepatitis B/C infections, fatty liver disease.

Jaundice

• Cause: Elevated bilirubin levels as a result of liver disease, hemolysis, or bile duct obstruction.

Types of Hyperbilirubinemia

• Unconjugated: Typically associated with hemolysis or conditions that reduce hepatic uptake.
• Conjugated: Often results from bile duct obstruction.

Pancreatic Secretions

Digestive Enzymes

• Amylase: Breaks down carbohydrates.
• Lipase: Breaks down fats.
• Trypsin: Breaks down proteins.
• Chymotrypsin: Breaks down proteins into smaller peptides.

Hormones

• Insulin: Lowers blood glucose levels.
• Glucagon: Raises blood glucose levels.
• Somatostatin: Inhibits insulin and glucagon release.

GI Tract Products

Exocrine Products

• Enzymes necessary for digestion.

Endocrine Products

• Hormones such as gastrin, secretin, and cholecystokinin (CCK).

Definitions of Renal Terms

• Oliguria: Significantly reduced urine output.
• Anuria: Absence of urine output.
• Polyuria: Excessive urine production.
• Proteinuria: Presence of protein in the urine, often indicating kidney disease.
• Autodigestion: Damage caused by a digestive enzyme acting on the tissue itself.
• Insulinoma: Tumor that secretes insulin inappropriately.
• Polydipsia: Excessive thirst often associated with diabetes.
• Polyphagia: Excessive hunger, commonly linked to metabolic disorders.

Diabetes Mellitus

Features of Types

Pancreatic Cancer

• Location: Predominantly found in the head of the pancreas.
• Incidence: Rarer than other cancers, but has a high mortality rate.

Diabetes Complications

• Long-term Complications:
  • Neuropathy (nerve damage), nephropathy (kidney damage), retinopathy (eye damage), and increased cardiovascular disease risk.