Download MMSC 433 Exam 1 Study Guide Complete Solutions and more Study Guides, Projects, Research Microbiology in PDF only on Docsity!
1 / 14
MMSC 433 Exam 1 Study Guide Complete Solutions
1. iron absorption: -ferric iron is taken in from diet
-ferric iron is reduced by duodenal cytochrome B to become ferrous iron -ferrous iron is absorbed into enterocytes by DMT 1 -absorbed iron is stored as ferritin, or sent into portal hepatic circulation and carried by transferrin to developing RBCs
2. transferrin: plasma carrier protein for ferrous iron
3. high iron level regulation: -hepcidin is released from hepatocytes
-ferroportin is inactivated, leading to decreased iron being transported into circulation
4. low iron level regulation: -hepcidin is down regulated by hepatocytes
-ferroportin becomes activated and transports iron out of the enterocytes and into circulation
5. dietary iron sources: red meat, legumes, dark leafy vegetables, whole grains
6. ferrous iron: the form of iron that is able to be utilized in the body for developing red cells
7. prussian blue stain: stain that is used to identify iron in tissues and bone marrow
8. thomas plot: a chart that is used to compare soluble transferrin receptors/ log ferritin to hemoglobin concentration of reticulocytes to identify the iron
status of the patient -iron status is used to correlate to certain diseases/ anemias
9. stage 1 iron deficiency (progressive loss of storage iron): - asymptomatic
-RBCs develop normally
2 / 14 -serum ferritin low
10. stage 2 iron deficiency (exhaustion of iron storage pool): -subclinical symptoms
-hemoglobin in retics is decreased, hemogram appears normal still -iron deficiency erythropoiesis is occurring -hepcidin decreased -serum iron and ferritin decreased -RDW, TIBC and sTRs increased -prussian blue stain of BM is negative for iron
11. stage 3 iron deficiency (frank anemia): -patient exhibits fatigue, weakness, pallor, glossitis, koilonychia and pica
-H/H decreased -hypochromic/ microcytic anemia -FEP, TIBC and sTR increased -ferritin, hepcidin and serum iron decreased
12. sideroblastic anemia: -iron deposits in the mitochondria of erythroblast cells in the bone marrow interfere with biosynthesis of heme
-caused by genetic inheritance of drugs/ bone marrow toxins (lead, antibiotics, chemotherapeutics) -ringed sideroblasts are highly indicative of the disease -basophillic stippling is common in lead poisoning -normocytic normochromic cells
13. iron deficiency anemia (IDA): -caused by inadequate intake, increased need or malabsorption of iron, poor diet or chronic blood loss
-symptoms: fatigue, weakness, pallor, spooning of the nails (koilonychia) and pica -H/H decreased
4 / 14 -symptoms: fever, glossitis, loss of appetite, neurologic abnormalities (pins and needles, numbness, hallucinations and paranoia/ megaloblastic madness)
- pancytopenia -decreased H/H
- macrocytosis -increased MCV, high RDW -hypersegmented neutrophils -nuclear cytoplasmic asynchrony _M:E ratio 1:1 to 1: -teardrop cells, schistocytes and microspherocytes in PB -Howell jolly bodies (DNA remnants) and cabot rings (figure 8) -increased bilirubin and LDH
18. G6PD deficiency: -decrease in G6PD enzyme causes underproduction of NADPH, leading to inability to reduce glutathione for detox of
H2O
-H2O2 oxidizes hemoglobin in the RBCs, leading to formation of heinz bodies -can be induced by oxidative drugs -symptoms: jaundice, anemia, hyperbilirubinemia -N/N anemia -anisocytosis, poikilocytosis -spherocytes and schistocytes in PB -heinz bodies seen with crystal violet -G6PD activity decreased -fluorescent spot test negative
5 / 14
19. hereditary spherocytosis (HS): -proteins in the RBC membrane disrupt vertical interactions and destabilize the lipid bilayer, causing loss
of membrane material that leads to formation of spherocytes -mutations in genes for ankyrin, alpha and beta spectrin or protein 4.2 lead to increased membrane permeability to Na+ and K+, leading to cellular dehydration -splenic conditioning: abnormal RBCs are targeted by macrophages and lead to anemia -HS triad: N/N anemia, jaundice and splenomegaly -spherocytes and polychromasia in PB -increased MCHC and RDW -increased osmotic fragility -EMA binding test: low fluorescence -autohemolysis test: 10-50%, decreased in presence of glucose
20. hereditary spherocytosis (HS) treatment: -splenectomy: prevents targeting of RBCs by splenic macrophages and keeps cells in
circulation longer
21. babesia: -tick transmitted disease
-can be transmitted by transfusion of infected blood unit -symptoms: can be asymptomatic, fever, chills, headache, sweats, nausea, fatigue, jaundice, splenomegaly, he- patomegaly -H/H decreased
- reticulocytosis -decreased serum haptoglobin
- bilirubinemia -leukopenia, thrombocytopenia -hemoglobinuria, proteinuria
22. 50-160 (ug/dL): serum iron reference range
7 / 14
35. ringed sideroblasts: iron congregates in the mitochondria of developing erythroblasts
-*hallmark of sideroblastic anemia)
36. basophilic stippling: ribosomal RNA in reticulocytes breaks down
-hallmark of lead poisoning
37. erythropoietic protoporphyrias (EPP): -mutated FECH gene leads to lack of ferrocheletase en- zyme which impairs production of
porphyrins -symptoms: photosensitivity, anemia -propoporphyrin increased in RBCs and in feces -ferrochelatase enzyme decreased or missing -genetic testing reveals mutated FECH gene
38. porphyria: impaired production of porphyrin component of heme due to missing or deficient enzymes
-leads to buildup of products from pathway in the tissues -cell death causes products to leak into urine and feces -severe burns when exposed to sunlight due to fluorescent products
39. schillings test: test that was once used to diagnose pernicious anemia
-part 1: oral intake of radiolabeled B12 and IM dose of nonlabeled B12, 24 hour urine sample is assesed for absorption of vitamins (>5%= normal, <5%=impaired absorption) -part 2: if part 1 is impaired, test is repeated with addition of intrinsic factor to oral dose (>5%= pernicious anemia due to lack of IF, <5%= malabsorptive disorder)
40. disorders of ineffective erythropoiesis: -megaloblsatic anemia
-aplastic anemia
41. pernicious anemia (PA): -autoimmune destruction of parietal cells by CD4+ T cells leads to lack of intrinsic factor, which inhibits B
absorption
8 / 14 -B12 deficiency inhibits DNA synthesis, leading to anemia and megaloblastic RBCs -symptoms: usually appear in 6th decade of life, fever, glossitis, lack of appetite, neurologic abnormalities (pins and needles, numbness, hallucinations, paranoia/ megaloblastic maddness) -serum B12 decreased -achlorhydria: lack of H+ in stomach -increased gastrin -decreased H/H -*blocking antibodies to IF and parietal cells
- macrocytosis
- pancytopenia -hypersegmented neutrophils
42. pernicious anemia treatment: -intramuscular injection of B12 (bypasses need for IF to absorb)
43. vitamin B12 (cobalamin):
44. folate: many different forms
45. diphyllobothrium latum (fish tapeworm): -parasite that is capable of splitting cobalamin from IF and makes the cobalamin unable to
absorb -leads to deficiency
46. folate absorption: -folate polyglutamate is taken in from the diet, and converted to folate monoglutamate
-folate monoglutamate is taken up into enterocytes and converted into 5-methyl THF
- 5-methyl HF is released into circulation and is taken up by cells to catalyze reactions needed for DNA synthesis
47. vitamin B12 (cobalamin) absorption: -pepsin and HCL remove B12 from food products, B12 binds to haptochorrin
10 / 14 -increased adipocytes in bone marrow, severe hypocellularity of RBC precurors
52. fanconi's anemia (FA) etiology: -congenital form of aplastic anemia due to inherited bone marrow failure
-inheritance of FANCA or FANCB gene leads to chromosome instability and increased breakage when exposed to DNA cross linking agents
53. fanconi's anemia (FA) symptoms: -physical malformations present at birth in 2/3 of attected individuals
-radial hypoplasia, microencephaly, hip dislocation, hyper/ hypopigmentation, short stature, low birth weight, tripha- langeal thumb -bone marrow failure by age 40 -increased risk of cancers/ tumors
54. fanconi's anemia (FA) lab findings: -chromosome instability testing: increased breakage when exposed to DNA cross-linked agents
(diepoxybutane or mitomycin C) -lymphocytes have increased chromosomal fragility
- pancytopenia
- reticulocytopenia -hypocellular BM -macrocytic RBCs (increased MCV)
55. Fanconi's anemia (FA) treatment: hematopoietic stem cell transplant in BM
56. pancytopenia: a decreased in all cell lines (WBC, RBC and PLT)
-can be caused by deficiency of folate/ B
57. G6PD class I: <1% activity of G6PD
58. G6PD class II: <10% activity of G6PD
-can be induced by fava beans
59. G6PD class III: 10-60% activity of G6PD
11 / 14
60. G6PD class IV: 60-150% activity of G6PD
-no clinical symptoms
61. G6PD class V: >150% G6PD activity
-no clinical symptoms
62. G6PD deficiency lab findings: -N/N anemia
-decreased H/H -anisocytosis/ poikilocytosis -spherocytes, schistocytes and heinz bodies present in PB -increased retics, polychromasia -serum haptoglobin, LDH and indirect bili increased (hemolysis) -fluorescent spot test negative
63. PK deficiency lab findings: - reticulocytosis
-anisocytosis, poikilocytosis -increased bili and LDH -decreased haptoglobin -normal osmotic fragility -autohemolysis test does not correct itself in presence of glucose -fluorescent spot test increased
64. autohemolysis test (HS vs. PK deficiency): -hereditary spherocytosis: 10-50% hemolysis, cor- rected by adding glucose
-PK deficiency: adding glucose to system does NOT decrease hemolysis
65. PNH pathophysiology: -acquired stem cell mutation that results in lack of GPI anchor proteins, so CD55 and CD59 are unable to stay on the surface
13 / 14 -merezoites cause formation of brown hemozoin pigment
73. plasmodium ovale: infects reticulocytes
-infected cells appear oval shaped with fringed edges -Schuttner's slipping present in trophozoite stage
74. plasmodium malariae: infects older RBCs
-band form causes a thin, dark band to form across the RBC
75. hereditary xerocytosis (HX): -inherited mutation of the PIEZ01 gene leads to defects in membrane permeability that allows K+ to leak out
of the cell, leading to dehydrated RBCs symptoms: mild to moderate anemia, hydrops fetalis, jaundice and splenomegaly
- reticulocytosis -increased MCHC -decreased osmotic fragility -stomatocytes, target cells, burr cells -puddled hemoglobin (shown in picture)
76. hereditary xerocytosis (HX) treatment: -usually not necessary
-supportive transfusions
77. hereditary pyropoikilocytosis (HPP): -a variant of HE that causes extreme poikilocytosis with a large number of schistocytes
-EMA binding test: low fluorescence -increased thermal sensitivity (fragmentation at 41-45 C) -low MCV
78. hereditary pyropoikilocytosis (HPP) treatment: -splenectomy and supportive transfusions
14 / 14
79. hereditary elliptocytosis (HE): -inherited hemolytic anemia caused by defective alpha / beta spectrin, or protein 4.1 that disrupts
horizontal interactions in the RBC cytoskeleton -mutations in SPTA1, SPTB and EP41 genes disrupt interactions of the spectrin dimer and destabilize the cytoskeleton, forming elliptocytes -symptoms: usually asymptomatic, mild compensated anemia -cigar shaped elliptocytes -increased osmotic fragility
80. hereditary elliptocytosis (HE) treatment: - splenectomy
-RBC transfusions to treat anemia
81. south asian ovalocytosis (SAO): -a variant of HE caused by inherited mutation to SLC4A1 gene, producing a mutated Band 3
protein -cells have increased rigidity due to mutated band 3 protein -provides resistance to P. malaria parasite (increased incidence of mutation in malaria endemic parts of the world) -ovalocytes with 1-2 transverse ridges seen in PB -no treatment needed
82. stomatocytes: RBC morphology associated with Rh null syndrome
