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First Aid > Hematology and Oncology - Pathology (1) > Flashcards

Hematology and Oncology - Pathology (1) Flashcards

1
Q

Associated pathologies of these pathologic RBC forms

  • Acanthocyte
  • Basophilic stippling
  • Bite cell
  • Elliptocyte
  • Macro-ovalocyte
  • Ringed sideroblast
A
  • Acanthocyte (spur cell) [A]
    • Liver disease, abetalipoproteinemia (states of cholesterol dysregulation).
    • Acantho = spiny.
  • Basophilic stippling [B]
    • Anemia of Chronic Disease, alcohol abuse, Lead poisoning, Thalassemias.
    • Basically, ACi_D_ alcohol is LeThal.
  • Bite cell [C}
    • G6PD deficiency.
  • Elliptocyte [D]
    • Hereditary elliptocytosis.
  • Macro-ovalocyte [E]
    • Megaloblastic anemia (also hypersegmented PMNs), marrow failure.
  • Ringed sideroblast [F]
    • Sideroblastic anemia.
    • Excess iron in mitochondria = pathologic.
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2
Q

Associated pathologies of these pathologic RBC forms

  • Schistocyte
  • Sickle cell
  • Spherocyte
  • Teardrop cell
  • Target cell
A
  • Schistocyte (helmet cell) [G]
    • DIC, TTP/HUS, traumatic hemolysis (i.e., mechanical heart valve prosthesis).
  • Sickle cell [H]
    • Sickle cell anemia.
  • Spherocyte [I]
    • Hereditary spherocytosis, autoimmune hemolysis.
  • Teardrop cell [J]
    • Bone marrow infiltration (e.g., myelofibrosis).
    • RBC “sheds a tear” because it’s been forced out of its home in the bone marrow.
  • Target cell [K]
    • HbC disease, Asplenia, Liver disease, Thalassemia.
    • “HALT,” said the hunter to his target.
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3
Q

Heinz bodies

  • Process
  • Associated pathology
A
  • Process
    • Oxidation of hemoglobin sulfhydryl groups –>Ž denatured hemoglobin precipitation and phagocytic damage to RBC membrane –>Ž bite cells.
    • Visualized with special stains such as crystal violet.
  • Associated pathology
    • RBC pathology
    • Seen in G6PD deficiency
    • Heinz body–like inclusions seen in α-thalassemia.
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4
Q

Howell-Jolly bodies

  • Process
  • Associated pathology
A
  • Process
    • Basophilic nuclear remnants found in RBCs.
    • Howell-Jolly bodies are normally removed from RBCs by splenic macrophages.
  • Associated pathology
    • RBC pathology
    • Seen in patients with functional hyposplenia or asplenia.
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5
Q

Anemias

  • Normocytic
A
  • Normocytic (MCV = 80-100 fL)
    • Nonhemolytic (reticulocyte count normal or decreased)
      • ACD
        • May first present as a normocytic anemia and then progress to a microcytic anemia.
      • Aplastic anemia
      • Iron deficiency (early)
      • Chronic kidney disease
    • Hemolytic (reticulocyte count increased)
      • Intrinsic
        • Sickle cell anemia
        • HbC defect
        • RBC membrane defect: hereditary spherocytosis
        • RBC enzyme deficiency: G6PD, pyruvate kinase
        • Paroxysmal nocturnal hemoglobinuria
      • Extrinsic
        • Autoimmune
        • Infections
        • Microangiopathic
        • Macroangiopathic
    • Normally, you AAIC with SHa_RRP_ AIMM
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6
Q

Anemias

  • Microcytic
  • Macrocytic
A
  • Microcytic (MCV < 80 fL)
    • Thalassemias
    • ACD
      • May first present as a normocytic anemia and then progress to a microcytic anemia.
    • Iron deficiency (late)
      • May first present as a normocytic anemia and then progress to a microcytic anemia.
    • Lead poisoning
    • Sideroblastic anemia
      • Copper deficiency can cause a microcytic sideroblastic anemia.
    • Small TAILS
  • Macrocytic (MCV > 100 fL)
    • Megalobalstic
      • Folate deficiency
      • Orotic aciduria
      • B12 deficiency
    • Non-megaloblastic
      • Liver disease
      • Alcoholism
      • Reticulocytosis
    • Big FOB LAR
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7
Q

Iron deficiency

  • Type of condition
  • Description
  • Findings
A
  • Type of condition
    • Microcytic, hypochromic (MCV < 80 fL) anemia
  • Description
    • Decreased iron due to chronic bleeding (GI loss, menorrhagia), malnutrition/absorption disorders or increased demand (e.g., pregnancy) –>Ž decreased final step in heme synthesis.
  • Findings
    • Decreased iron, increased TIBC, decreased ferritin.
    • Fatigue, conjunctival pallor [A].
    • Microcytosis and hypochromia [B].
      • May manifest as Plummer-Vinson syndrome (triad of iron deficiency anemia, esophageal webs, and atrophic glossitis).
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8
Q

α-thalassemia

  • Type of condition
  • Description
    • Defect
    • cis
    • trans
  • Findings
    • 4 allele deletion
    • 3 allele deletion
    • 1-2 allele deletion
A
  • Type of condition
    • Microcytic, hypochromic (MCV < 80 fL) anemia
  • Description
    • Defect: α-globin gene deletions –>Ž decreased α-globin synthesis.
    • cis deletion prevalent in Asian populations
    • trans deletion prevalent in African populations.
  • Findings
    • 4 allele deletion:
      • No α-globin.
      • Excess γ-globin forms γ4 (Hb Barts).
      • Incompatible with life (causes hydrops fetalis).
    • 3 allele deletion:
      • HbH disease.
      • Very little α-globin.
      • Excess β-globin forms β4 (HbH).
    • 1–2 allele deletion:
      • No clinically significant anemia.
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9
Q

β-thalassemia

  • Type of condition
  • Description
  • Findings
    • β-thalassemia minor
    • β-thalassemia major
    • HbS/β-thalassemia heterozygote
A
  • Type of condition
    • Microcytic, hypochromic (MCV < 80 fL) anemia
  • Description
    • Point mutations in splice sites and promoter sequences –>Ž decreased β-globin synthesis.
    • Prevalent in Mediterranean populations.
  • Findings
    • β-thalassemia minor (heterozygote):
      • β chain is underproduced.
      • Usually asymptomatic.
      • ƒƒDiagnosis confirmed by increased HbA2 (> 3.5%) on electrophoresis.
    • β-thalassemia major (homozygote):
      • β chain is absent –>Ž severe anemia [C] requiring blood transfusion (2° hemochromatosis).
      • ƒƒMarrow expansion (“crew cut” on skull x-ray) –>Ž skeletal deformities.
        • “Chipmunk” facies.
      • Extramedullary hematopoiesis (leads to hepatosplenomegaly).
        • Increased risk of parvovirus B19-induced aplastic crisis.
      • Major –>Ž increased HbF (α2γ2).
        • HbF is protective in the infant and disease only becomes symptomatic after 6 months.
    • HbS/β-thalassemia heterozygote
      • Mild to moderate sickle cell disease depending on amount of β-globin production.
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10
Q

Lead poisoning

  • Type of condition
  • Description
  • Findings
A
  • Type of condition
    • Microcytic, hypochromic (MCV < 80 fL) anemia
  • Description
    • Lead inhibits ferrochelatase and ALA dehydratase –>Ž decreased heme synthesis and increased RBC protoporphyrin.
    • Also inhibits rRNA degradation, causing RBCs to retain aggregates of rRNA (basophilic stippling).
    • High risk in old houses with chipped paint.
  • Findings
    • LEAD:
      • Lead Lines on gingivae (Burton lines) and on metaphyses of long bones [D] on x-ray.
      • Encephalopathy and Erythrocyte basophilic stippling.
      • Abdominal colic and sideroblastic Anemia.
      • Drops—wrist and foot drop.
        • Dimercaprol and EDTA are 1st line of treatment.
    • Succimer used for chelation for kids
      • It “sucks” to be a kid who eats lead.
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11
Q

Sideroblastic anemia

  • Type of condition
  • Description
    • Defect
    • Causes
  • Findings
  • Treatment
A
  • Type of condition
    • Microcytic, hypochromic (MCV < 80 fL) anemia
  • Description
    • Defect in heme synthesis.
      • Hereditary: X-linked defect in δ-ALA synthase gene.
    • Causes: genetic, acquired (myelodysplastic syndromes), and reversible (alcohol is most common, lead, vitamin B6 deficiency, copper deficiency, and isoniazid).
  • Findings
    • Ringed sideroblasts ([E] with iron-laden mitochondria) seen in bone marrow.
    • Increased iron, normal TIBC, increased ferritin.
  • Treatment
    • Pyridoxine (B6, cofactor for δ-ALA synthase).
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12
Q

Megaloblastic anemia

  • Type of condition
  • Description
  • Findings
A
  • Type of condition
    • Macrocytic (MCV > 100 fL) anemia
  • Description
    • Impaired DNA synthesis –>Ž maturation of nucleus of precursor cells in bone marrow delayed relative to maturation of cytoplasm.
  • Findings
    • Abnormal cell division –>Ž pancytopenia.
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13
Q

Folate deficiency

  • Type of condition
  • Causes
  • Findings
A
  • Type of condition
    • Megaloblastic macrocytic (MCV > 100 fL) anemia
  • Causes
    • Malnutrition (e.g., alcoholics), malabsorption, antifolates (e.g., methotrexate, trimethoprim, phenytoin), increased requirement (e.g., hemolytic anemia, pregnancy).
  • Findings
    • Hypersegmented neutrophils, glossitis, decreased folate, increased homocysteine but normal methylmalonic acid.
    • No neurologic symptoms (distinguishes from B12 deficiency).
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14
Q

B12 deficiency (cobalamin)

  • Type of condition
  • Causes
  • Findings
A
  • Type of condition
    • Megaloblastic macrocytic (MCV > 100 fL) anemia
  • Causes
    • Insufficient intake (e.g., strict vegans), malabsorption (e.g., Crohn disease), pernicious anemia, Diphyllobothrium latum (fish tapeworm), proton pump inhibitors.
  • Findings
    • Hypersegmented neutrophils [A], glossitis, decreased B12, increased homocysteine, increased methylmalonic acid.
    • Neurologic symptoms
      • Subacute combined degeneration (due to involvement of B12 in fatty acid pathways and myelin synthesis)
      • Peripheral neuropathy with sensorimotor dysfunction
      • ƒƒDorsal columns (vibration/proprioception)
      • Lateral corticospinal (spasticity)
      • ƒƒDementia
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15
Q

Orotic aciduria

  • Type of condition
  • Description
  • Findings
A
  • Type of condition
    • Megaloblastic macrocytic (MCV > 100 fL) anemia
  • Description
    • Inability to convert orotic acid to UMP (de novo pyrimidine synthesis pathway) because of defect in UMP synthase.
    • Autosomal recessive.
    • Presents in children as megaloblastic anemia that cannot be cured by folate or B12 with failure to thrive.
    • No hyperammonemia (vs. ornithine transcarbamylase deficiency— orotic acid with hyperammonemia).
  • Findings
    • Hypersegmented neutrophils, glossitis, orotic acid in urine.
    • Treatment: uridine monophosphate to bypass mutated enzyme.
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16
Q

Nonmegaloblastic anemias

  • Type of condition
  • Description
  • Findings
A
  • Type of condition
    • Macrocytic (MCV > 100 fL) anemia
  • Description
    • Macrocytic anemia in which DNA synthesis is unimpaired.
    • Causes:
      • Liver disease
      • Alcoholism
      • Reticulocytosis –>Ž increased MCV
      • Drugs (5-FU, zidovudine, hydroxyurea).
  • Findings
    • Macrocytosis and bone marrow suppression can occur in the absence of folate/B12 deficiency.
17
Q

Normocytic, normochromic anemia

  • Definition
  • Intravascular hemolysis
  • Extravascular hemolysis
A
  • Definition
    • Normocytic, normochromic anemias are classified as nonhemolytic or hemolytic.
    • The hemolytic anemias are further classified according to the cause of the hemolysis (intrinsic vs. extrinsic to the RBC) and by the location of the hemolysis (intravascular vs. extravascular).
  • Intravascular hemolysis
    • Decreased haptoglobin, increased LDH, schistocytes and increased reticulocytes on peripheral blood smear
    • Urobilinogen in urine (e.g., paroxysmal nocturnal hemoglobinuria, mechanical destruction [aortic stenosis, prosthetic valve], microangiopathic hemolytic anemias).
  • Extravascular hemolysis
    • Macrophage in spleen clears RBC.
    • Spherocytes in peripheral smear, increased LDH plus increased unconjugated bilirubin, which causes jaundice (e.g., hereditary spherocytosis).
18
Q

Anemia of chronic disease

  • Type of condition
  • Description
  • Findings
A
  • Type of condition
    • Nonhemolytic, normocytic anemia
  • Description
    • Inflammation Ž–> increased hepcidin (released by liver, binds ferroportin on intestinal mucosal cells and macrophages, thus inhibiting iron transport) –> decreased release of iron from macrophages.
  • Findings
    • Decreased iron, decreased TIBC, increased ferritin.
    • Can become microcytic, hypochromic
19
Q

Aplastic anemia

  • Type of condition
  • Caused by…
  • Findings
  • Symptoms
  • Treatment
A
  • Type of condition
    • Nonhemolytic, normocytic anemia
  • Caused by failure or destruction of myeloid stem cells due to:
    • Radiation and drugs (benzene, chloramphenicol, alkylating agents, antimetabolites)
    • Viral agents (parvovirus B19, EBV, HIV, HCV)
    • Fanconi anemia (DNA repair defect)
    • Idiopathic (immune mediated, 1° stem cell defect); may follow acute hepatitis
  • Findings
    • Pancytopenia characterized by severe anemia, leukopenia, and thrombocytopenia.
    • Normal cell morphology, but hypocellular bone marrow with fatty infiltration [A] (dry bone marrow tap).
  • Symptoms
    • Fatigue, malaise, pallor, purpura, mucosal bleeding, petechiae, infection.
  • Treatment
    • Withdrawal of offending agent, immunosuppressive regimens (antithymocyte globulin, cyclosporine), allogeneic bone marrow transplantation, RBC and platelet transfusion, G-CSF, or GM-CSF.
20
Q

Chronic kidney disease

  • Type of condition
  • Findings
A
  • Type of condition
    • Nonhemolytic, normocytic anemia
  • Findings
    • Decreased EPO –>Ž decreased hematopoiesis.
21
Q

Hereditary spherocytosis

  • Type of condition
  • Description
  • Findings
  • Labs
  • Treatment
A
  • Type of condition
    • Extravascular intrinsic hemolytic normocytic anemia
  • Description
    • Defect in proteins interacting with RBC membrane skeleton and plasma membrane (e.g., ankyrin, band 3, protein 4.2, spectrin).
    • Less membrane causes small and round RBCs with no central pallor (increased MCHC, increased red cell distribution width) –>Ž premature removal of RBCs by spleen.
  • Findings
    • Splenomegaly, aplastic crisis (parvovirus B19 infection).
  • Labs
    • Osmotic fragility test (+).
    • Eosin-5-maleimide binding test useful for screening.
    • Normal to decreased MCV with abundance of cells
      • Masks microcytia.
  • Treatment
    • Splenectomy.
22
Q

G6PD deficiency

  • Type of condition
  • Description
  • Findings
  • Labs
A
  • Type of condition
    • Intravascular/extravascular intrinsic hemolytic normocytic anemia
  • Description
    • Most common enzymatic disorder of RBCs.
    • X-linked recessive.
    • Defect in G6PD Ž–> decreased glutathione –>Ž increased RBC susceptibility to oxidant stress.
    • Hemolytic anemia following oxidant stress (classic causes: sulfa drugs, antimalarials, infections, fava beans).
  • Findings
    • Back pain, hemoglobinuria a few days after oxidant stress.
  • Labs
    • Blood smear shows RBCs with Heinz bodies and bite cells.
  • “Stress makes me eat bites of fava beans with Heinz ketchup.”
23
Q

Pyruvate kinase deficiency

  • Type of condition
  • Description
  • Findings
A
  • Type of condition
    • Extravascular intrinsic hemolytic normocytic anemia
  • Description
    • Autosomal recessive.
    • Defect in pyruvate kinase –>Ž decreased ATP –>Ž rigid RBCs.
  • Findings
    • Hemolytic anemia in a newborn.
24
Q

HbC defect

  • Type of condition
  • Description
  • Findings
A
  • Type of condition
    • Extravascular intrinsic hemolytic normocytic anemia
  • Description
    • Glutamic acid-to-lysine mutation at residue 6 in β-globin.
  • Findings
    • Patients with HbSC (1 of each mutant gene) have milder disease than have HbSS patients.
25
Q

Paroxysmal nocturnal hemoglobinuria

  • Type of condition
  • Description
  • Findings
  • Labs
  • Treatment
A
  • Type of condition
    • Intravascular intrinsic hemolytic normocytic anemia
  • Description
    • Increased complement-mediated RBC lysis (impaired synthesis of GPI anchor for decay-accelerating factor that protects RBC membrane from
      complement) .
    • Acquired mutation in a hematopoietic stem cell.
    • Increased incidence of acute leukemias.
  • Findings
    • Triad: Coombs (-) hemolytic anemia, pancytopenia, and venous thrombosis.
  • Labs
    • CD55/59 (-) RBCs on flow cytometry.
  • Treatment
    • Eculizumab.
26
Q

Sickle cell anemia

  • Type of condition
  • Description
  • Pathogenesis
  • Findings
  • Complications in sickle cell disease (SS)
  • Diagnosis
  • Treatment
A
  • Type of condition
    • Extravascular intrinsic hemolytic normocytic anemia
  • Description
    • HbS point mutation causes a single amino acid replacement in β chain (substitution of glutamic acid with valine) at position 6.
    • Newborns are initially asymptomatic because of increased HbF and decreased HbS.
    • Heterozygotes (sickle cell trait) have resistance to malaria.
    • 8% of African Americans carry the HbS trait.
  • Pathogenesis
    • Low O2, dehydration, or acidosis precipitates sickling (deoxygenated HbS polymerizes), which results in anemia and vaso-occlusive disease.
  • Findings
    • Sickled cells are crescent-shaped RBCs [A].
    • “Crew cut” on skull x-ray due to marrow expansion from increased erythropoiesis (also in thalassemias).
  • Complications in sickle cell disease (SS)
    • Aplastic crisis (due to parvovirus B19).
    • Autosplenectomy (Howell-Jolly bodies)Ž –> increased risk of infection with encapsulated organisms
      • Early splenic dysfunction occurs in childhood.
    • Splenic sequestration crisis.
    • Salmonella osteomyelitis.
    • Painful crisis (vaso-occlusive): dactylitis. (painful hand swelling), acute chest syndrome (most common cause of death in adults), avascular necrosis, stroke.
    • Renal papillary necrosis (due to low O2 in papilla; also seen in heterozygotes) and microhematuria (medullary infarcts).
  • Diagnosis
    • Hemoglobin electrophoresis.
  • Treatment
    • Hydroxyurea (increased HbF) and bone marrow transplantation.
27
Q

Autoimmune hemolytic anemia

  • Type of condition
  • Description
    • Warm
    • Cold
  • Findings
A
  • Type of condition
    • Extrinsic hemolytic normocytic anemia
  • Description
    • Warm agglutinin (IgG)
      • Chronic anemia seen in SLE, CLL, or with certain drugs (e.g., α-methyldopa)
      • “Warm weather is GGGreat”
    • Cold agglutinin (IgM)
      • Acute anemia triggered by cold
      • Seen in CLL, Mycoplasma pneumonia infections, or infectious mononucleosis
      • “Cold ice cream—yuMMM”
    • Many warm and cold AIHA are idiopathic in etiology.
  • Findings
    • Autoimmune hemolytic anemias are usually Coombs (+).
    • Direct Coombs test
      • Anti-Ig antibody (Coombs reagent) added to patient’s blood.
      • RBCs agglutinate if RBCs are coated with Ig.
    • Indirect Coombs test
      • Normal RBCs added to patient’s serum.
      • If serum has anti-RBC surface Ig, RBCs agglutinate when anti-Ig antibodies (Coombs reagent) added.
28
Q

Microangiopathic anemia

  • Type of condition
  • Description
  • Pathogenesis
  • Findings
A
  • Type of condition
    • Extrinsic hemolytic normocytic anemia
  • Description
    • Seen in DIC, TTP-HUS, SLE, and malignant hypertension.
  • Pathogenesis
    • RBCs are damaged when passing through obstructed or narrowed vessel lumina.
  • Findings
    • Schistocytes (helmet cells) are seen on blood smear due to mechanical destruction of RBCs.
29
Q

Macroangiopathic anemia

  • Type of condition
  • Description
  • Findings
A
  • Type of condition
    • Extrinsic hemolytic normocytic anemia
  • Description
    • Prosthetic heart valves and aortic stenosis may also cause hemolytic anemia 2° to mechanical destruction.
  • Findings
    • Schistocytes on peripheral blood smear.
30
Q

Infections (anemia)

  • Type of condition
  • Description
A
  • Type of condition
    • Extrinsic hemolytic normocytic anemia
  • Description
    • Increased destruction of RBCs (e.g., malaria, Babesia).
31
Q

Lab values in anemia

  • Transferrin
  • Ferritin
  • For each (increased/decreased)
    • Serum iron
    • Transferrin or TIBC (indirectly measures transferrin)
    • Ferritin
    • % transferrin saturation (serum iron/TIBC)
  • Iron deficiency
  • Chronic disease
  • Hemochromatosis
  • Pregnancy / OCP use
A
  • Transferrin
    • Transports iron in blood
  • Ferritin
    • 1° iron storage protein of body
  • Iron deficiency
    • Serum iron: Decreased (1°)
    • Transferrin or TIBC: Increased
    • Ferritin: Decreased
    • % transferrin saturation: Really decreased
  • Chronic disease
    • Serum iron: Decreased
    • Transferrin or TIBC: Decreased
      • Evolutionary reasoning—pathogens use circulating iron to thrive.
      • The body has adapted a system in which iron is stored within the cells of the body and prevents pathogens from acquiring circulating iron.
    • Ferritin: Increased (1°)
    • % transferrin saturation: No effect
  • Hemochromatosis
    • Serum iron: Increased (1°)
    • Transferrin or TIBC: Decreased
    • Ferritin: Increased
    • % transferrin saturation: Really increased
  • Pregnancy / OCP use
    • Serum iron: No effect
    • Transferrin or TIBC: Increased (1°)
      • Transferrin production is increased in pregnancy and by OCPs.
    • Ferritin: No effect
    • % transferrin saturation: Decreased
32
Q

Leukopenias

  • For each
    • Cell count
    • Causes
  • Neutropenia
  • Lymphopenia
  • Eosinopenia
A
  • Neutropenia
    • Cell count: Absolute neutrophil count < 1500 cells/mm3
    • Causes: Sepsis/postinfection, drugs (including chemotherapy), aplastic anemia, SLE, radiation
  • Lymphopenia
    • Cell count: Absolute lymphocyte count < 1500 cells/mm3
      (< 3000 cells/mm³ in children)
    • Causes: HIV, DiGeorge syndrome, SCID, SLE, corticosteroids,a radiation, sepsis, postoperative
  • Eosinopenia
    • Cell count: N/A
    • Causes: Cushing syndrome, corticosteroids
      • Corticosteroids don’t cause neutrophilia, but eosinopenia and lymphopenia.
      • Corticosteroids decrease activation of neutrophil adhesion molecules, impairing migration out of the vasculature to sites of inflammation.
      • In contrast, corticosteroids sequester eosinophils in lymph nodes and cause apoptosis of lymphocytes.
33
Q

Heme synthesis, porphyrias, and lead poisoning (388)

  • The porphyrias
  • Lead
A
  • The porphyrias
    • Hereditary or acquired conditions of defective heme synthesis
    • Lead to the accumulation of heme precursors.
  • Lead
    • Inhibits specific enzymes needed in heme synthesis, leading to a similar condition.
34
Q

Lead poisoning

  • Affected enzymes
  • Accumulated substrate
  • Presenting symptoms
A
  • Affected enzymes
    • Ferrochelatase
    • ALA dehydratase
  • Accumulated substrate
    • Protoporphyrin, δ-ALA (blood)
  • Presenting symptoms
    • Microcytic anemia, GI and kidney disease.
    • Children—exposure to lead paint–> Ž mental deterioration.
    • Adults—environmental exposure (battery/ammunition/radiator factory) –>Ž headache, memory loss, demyelination.
35
Q

Acute intermittent porphyria

  • Affected enzyme
  • Accumulated substrate
  • Presenting symptoms
  • Treatment
A
  • Affected enzyme
    • Porphobilinogen deaminase
  • Accumulated substrate
    • Porphobilinogen, δ-ALA, coporphobilinogen (urine)
  • Presenting symptoms (5 P’s)
    • Painful abdomen
    • Port wine–colored urine
    • Polyneuropathy
    • Psychological disturbances
    • Precipitated by drugs, alcohol, and starvation
  • Treatment
    • Glucose and heme, which inhibit ALA synthase.
36
Q

Porphyria cutanea tarda

  • Affected enzyme
  • Accumulated substrate
  • Presenting symptoms
A
  • Affected enzyme
    • Uroporphyrinogen decarboxylase
  • Accumulated substrate
    • Uroporphyrin (teacolored urine)
  • Presenting symptoms
    • Blistering cutaneous photosensitivity [A].
    • Most common porphyria.

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