Lecture 139 Flashcards
(105 cards)
1
Q
What are the two types of macrocytic anemias?
A
Megaloblastic anemias and non-megaloblastic anemias
2
Q
What is the general mechanism in megaloblastic anemia?
A
Defective or impaired DNA synthesis leads to ineffective hematopoiesis
3
Q
What type of neutrophils are seen in megaloblastic anemias?
A
Hypersegmented neutrophils
4
Q
What vitamin circulates mostly as methyltetrahydrofolate (methyl THF)?
A
Folate (B9)
5
Q
WHat effect does B12 have on methyl-THF?
A
Removes the methyl group to create THF
6
Q
What vitamin is required to convert methylmalonyl-CoA to succinyl-CoA?
A
B12
For myelin synthesis
7
Q
Increased homocysteine and normal methylmalonic acid is seen in what vitamin deficiency?
A
Folate deficiency
8
Q
Increased homocystein and increased methylmalonic acid are seen in what vitamin deficiency?
A
B12 deficiency
9
Q
Where is folate absorbed in the body?
A
Jejunum
10
Q
What type of inflammation is common in folate & B12 deficiency?
A
Glossitis
11
Q
B12 is cleaved from dietary proteins in the somach by ____
A
Pepsin
12
Q
____ (AKA ____) binds B12 in the stomach
A
Salivary R-binder (AKA haptocorrin)
13
Q
What cells produce intrinsic factor (IF)?
A
Parietal cells
14
Q
Where to pancreatic proteases cleave B12 from R-binder?
A
In the duodenum
15
Q
After B12 is cleaved from R-binder, what does it bind to?
A
B12 binds to intrinsic factor
16
Q
Where is the B12-IF complex absorbed?
A
Terminal ileum
17
Q
Autoimmune destruction of parietal cells leading to decreased IF describes what type of anemia?
A
Pernicious (megaloblastic) anemia
18
Q
What can cause terminal ileum damage?
A
Chron’s disease, tapeworm
19
Q
Neurological changes are common in what type of anemia?
A
B12 deficient megaloblastic anemia
20
Q
Neurological degeneration in B12 deficiency is seen in what neural structures?
A
Dorsal columns and lateral corticospinal tracts
21
Q
A schilling test differentiates between:
A
B12 deficiency and pernicious anemia
22
Q
An inability to convert orotic acid to UMP due to a defect in UMP synthase describes what type of megaloblastic anemia?
A
Orotic aciduria
23
Q
What is the inheritance pattern of orotic aciduria?
A
Autosomal recessive
24
Q
Failure to thrive, developmental delay, and orotic acid in the urine are signs of:
A
Orotic aciduria
25
What is the treatment for orotic aciduria?
Uridine monophosphate
26
What characteristic of megaloblastic anemia is absent in nonmegaloblastic macrocytic anemia?
No hypersegmented neutrophils
27
What are common causes of non-megaloblastic macrocytic anemia?
Alcoholism, liver disease, certain drugs, Diamond-Blackfan anemia
28
Congenital pure red cell aplasia due to an intrinsic defect in erythroid progenitor cells describes what condition?
Diamond-Blackfan anemia
29
When is Diamon-blackfan anemia diagnosed?
First year of life
30
What physical anomalies are seen in Diamond-Blackfan anemia?
Short stature, craniofacial abnormalities, upper extremity abnormalities
31
Labs showing elevated HbF but decreased total hemoglobin indicate what cause of non-megaloblastic macrocytic anemia?
Diamond-Blackfan anemia
32
What two processes are involved in normocytic anemias?
Underproduction of RBCs or peripheral destruction (hemolysis)
33
If corrected retic <3%, what does it indicate?
Inadequate RBC production
34
If corrected retic >3%, what does it indicate?
RBC destruction or loss (hemolysis or hemorrhage)
35
How is corrected retic calculated?
Corrected retic = (retic % * (patient's hematocrit/45))
36
What type of hemolysis involves RBCs destroyed by macrophages in spleen/liver/lymph nodes?
Extravascular hemolysis
37
Splenomegaly, jaundice, elevated unconjugated bilirubin, and risk of bilirubin gallstones can indicate what location of hemolytic anemia?
Extravascular hemolysis
38
Increased LDH, increased bilirubin, and increased reticulocyte count indicates what type of anemia?
Hemolytic anemia
39
What RBC shape can be seen on peripheral smear in extravascular hemolysis?
Spherocytes
40
What type of hemolysis involves RBCs destroyed within blood vessels?
Intravascular hemolysis
41
Free hemoglobin in the blood and urine, hemosiderinuria, and decreased haptoglobin can indicate what type of hemolysis?
Intravascular hemolysis
42
What is the inheritance pattern of hereditary spherocytosis?
Autosomal dominant
43
Defects in RBC membrane skeletal proteins that cause RBC membrane blebs, leading to spherocytes and extravascular hemolysis describes what anemia?
Hereditary spherocytosis
44
A parovirus B19 infection in a patient with hereditary spherocytosis increases risk of:
Aplastic crisis
45
Increased RDW and MCHC, splenomegaly, jaundice, and unconjugated bilirubin gallstones are signs of what hemolytic anemia?
Hereditary spherocytosis
46
How is hereditary spherocytosis diagnosed?
Osmotic fragility test
47
How is hereditary spherocytosis treated?
Splenectomy to alleviate the anemia, spherecytes will remain
48
An acquired defect in myeloid stem cells that leads to a alck of GPI anchor, leading to RBCs susceptible to complement-mediated destruction describes what type of anemia?
Paroxysmal nocturnal hemoglobinuria (PNH)
49
What protective proteins that inhibit complement are affected by PNH?
CD55 and CD59
50
What aspect of sleep activates complement in PNH?
Mild respiratory acidosis during sleep
51
What location descriptor is given to PNH?
Intravascular hemolysis
52
Pancytopenia, thrombosis in hepatic, portal, or cerebral veins, and pink urine in the morning are signs of why type of hemolytic anemia?
Paroxysmal nocturnal hemoglobinuria (PNH)
53
How is PNH diagnosed?
Flow cytometry showing absent CD55 and CD59
54
What is the treatment for PNH?
Eculizumab
| Targets complement protein C5 to block formation of the MAC
55
What is the inheritance pattern of sickle cell disease?
Autosomal recessive
56
What gene is mutated in sickle cell disease?
Beta-globin
57
What causes RBC sickling in SCD?
HbS polymerizes in deoxygenated conditions
58
Erythroid hyperplasia in marrow in SCD can cause what signs?
Crewcut skull x-ray, chipmunk facies
59
Parovirus B19 increases risk of what in SCD?
Aplastic crisis
60
What are some of the possible vaso-occlusive crises associated with SCD?
Dactylitis, autosplenectomy, acute chest syndrome, pain crises, renal papillary necrosis
61
What are the typical peripheral smear findings in SCD?
Sickle cells and target cells
62
How is SCD treated?
Hydroxyurea to increase HbF
63
What is the inheritance pattern of hemoglobin C disease?
Autosomal recessive
64
What mutation is involved in hemoglobin C disease?
Beta-globin chain mutation
65
Characteristic hemoglobin crystals within RBCs and target cells indicate what type of hemolytic anemia?
Hemoglobin C disease
66
What is the inheritance pattern of G6PD deficiency?
X-linked recessive
67
What is the underlying mechanism of G6PD deficiency?
Reduced half-life of G6PD leads RBCs to be vulnerable to oxidative stress
68
What are some oxidative triggers in G6PD deficiency?
Infections, certain drugs, fava beans
69
Is the African or Mediterranean variant of G6PD deficiency more severe?
Mediterranean is more severe
70
Acute, episodic hemolysis triggered by oxidants in G6PD deficiency leads to what symptoms?
Hemoglobinuria, back pain, jaundice
71
What is seen on a peripheral smear in G6PD deficiency?
Heinz bodies and bite cells
72
When are G6PD levels best measured?
Weeks after episode
73
What is the inheritance pattern of pyruvate kinase deficiency?
Autosomal recessive
74
What is the mechanism behind pyruvate kinase deficiency?
Decreased ATP causes RBC rigidity, leading to extravascular hemolysis in the spleen
75
What moelcule is accumulated in pyruvate kinase deficiency? What is the result?
2,3-BPG, decreased RBC affinity for O2, leading to easier O2 release
76
What cells are seen on a peripheral smear for pyruvate kinase deficiency?
Burr cells (echinocytes)
77
When does pyruvate kinase deficiency present?
In newborns as hemolytic anemia
78
What antibody is involved in warm agglutinin AIHA?
IgG
79
What are the treatments for warm agglutinin AIHA?
Steroids, rituximab, splenectomy if refractory
80
What antibody is involved in cold agglutinin AIHA?
IgM
81
What is the mechanism behind cold agglutinin AIHA?
Low temepratures causes IgM binding to RBCs and C3b opsonizes for splenic destruction
82
What are the causes of cold agglutinin AIHA?
Mycoplasma pneumoniae, infectious mononucleosis, CLL
83
Painful fingers/toes turning blue/pale in cold environments is a sign of what type of hemolytic anemia?
Cold agglutinin AIHA
84
How is cold agglutinin AIHA treated?
Rituximab, cold avoidance
85
What test is used to diagnose auotimmune hemolytic anemia?
Coombs test
86
What type of RBCs are seen on peripheral smear in autoimmune hemolytic anemia?
Spherocytes
87
RBCs that are mechanically destroyed while traveling in alrge vessel or across abnomral surfaces is known as:
Macroangiopathic hemolytic anemia
88
What are some causes of macroangiopathic hemolytic anemia?
Prosthetic heart valves, aortic stenosis
89
What is seen on a peripheral smear in macroangiopathic hemolytic anemia?
Schistocytes
90
RBCs that are destroyed as they pass through obstructed small vessels is known as:
Microangiopathic hemolytic anemia
91
DIC, TTP/HUS, SLE, HELLP syndrome, HTN emergency can all cause what type of hemolytic anemia?
Microangiopathic hemolytic anemia
92
What is seen on a peripheral smear in microangiopathic hemolytic anemia?
Schistocytes
93
What causes Babesiosis?
Babesia parasite from tick bite
94
What are some possible causes of aplastic anemia?
Radiation, viruses, Fanconi anemia, indipathic, drugs
95
Failure/destruction of hematopoietic stem cells causes what type of anemia?
Aplastic anemia
96
What are common lab findings in aplastic anemia?
Pancytopenia, low retic count, elevated EPO
97
What conditions can cause echinocytes (Burr cells)?
Pyruvate kianse deficiency, sometimes uremia
98
What condition can cause dacrocytes (teardrop cells)?
Bone marrow infiltration (myelofibrosis)
99
What conditions can cause schistocytes (helmet cells)?
Angipathic heomlysis, RBC fragmentation in narrowed/obstructed vessels or artifical valves
100
What condition can cause Bite cells?
G6PD deficiency
101
What conditions can cause spherocytes?
Hereditary spherocytosis, autoimmune hemolysis
102
What conditions can cause target cells?
HbC disease, asplenia, liver disease, thalassemia (HALT)
103
What are Howell-Jolly bodies?
RBC inclusions of basophilic nuclear remnants typically removed by the spleen
104
What is basophilic stippling?
RBC ribosomal precipitates, seen in sideroblastic anemias, thalassemias, lead poisoning
105
What are Heinz bodies?
Denatured hemoglobin from oxidative stress
