| labs | Don't lyse me.... | Macro & Micro ... nutrients [Fe, B12, and etc] | In my genes [thalassemias, g6pd, etc] | Biochemical basis of RBCs |
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Nutritional B12 deficiency or Folate deficiency
Name the anemias corresponding to the following lab:
↓Hct ↑MCV ↔MCHC ↑RDW (anisocytosis) ↓reticulocytes +++progenitors size +++neutrophil size, +++segmentation ↑erythropoeitin ↓ blood cells (pancytopenia) ↑homocysteine (HCy) |
What is paroxysmal nocturnal hemoglobinuria?
B: an X-chromosome somatic mutation of PIGA (phosphatidylinositol glycan group A) gene in hematopoietic stem cell lineage ---> defective RBCs and platelets that are susceptible to intravascular hemolysis and thromboses which encodes a GPI that attaches surface proteins (DAF CD 55 and MIRL CD 59) to the RBC membrane. Test with flow cytometry vs daf and mirl to confirm.
This anemia happens intermittently and patients will often complain of having pink-tinged urine when they wake up.
Bonus: What is the etiology and what would you test for to confirm? |
What are: folate, thiamine, and cobalamin? aka Vitamin B9, Vitamin B1, and Vitamin B12.
Neurologic sx are caused by a deficiency in vitamin B12 (and B1-thiamine! ...we didn't learn yet). Lead can cause neurologic symptoms in case of lead poisoning but this was not in the question. B: The buildup of methylmalonic acid leads to reduced/abnormal fatty acid synthesis which is an important component of myelin ---> neurologic symptoms and demyelination
A 45 y/o alcoholic presents to the ED with AMS (altered mental status), fatigue, exertional dyspnea, and headaches. Name three major vitamins this person could be deficient in and which one (or two) are likely causing the neurologic symptoms in this patient.
Bonus: What is the mechanism for the neurologic symptoms. |
What is HbSC disease?
From L to R: ladder/control, HbSC, HbAS (sickle cell trait), HbS (sickle cell), cord blood, normal adult Hb
Identify the disorder caused by this electrophoresis finding [HbS + HbA2,O,C,E bands present] and explain why it only causes mild/moderate sickling.
Bonus: Name the others on the gel. |
What is Heme synthesis? What is ALA-synthase (aminolevulinic acid)?
B: (end product) heme
Succinyl-CoA is an important starting point for this pathway. Name it and its rate-limiting step.
Bonus: What is it inhibited by? |
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Anemia of Chronic Disease or Inflammation
Name the anemia corresponding to the following lab:
↔ or ↓ MCV ↔ or ↓ MCHC ↓ or ↔ Fe2+ (serum) = bound ↑Fe2+ (marrow) ↑ or ↔ ferritin = Fe2+ stores ↓TIBC ↓ %transferrin saturation ↑ hepcidin |
What is G6PD deficiency?
B: Heinz bodies and Bite cells
X-linked enzyme deficiency common in the Mediterranean and among 10% of African Americans, confers protection vs Malaria, and particularly targets older RBCs ?
Bonus: name some clinical descriptions of RBCs that you may find in this disorder. |
Who are Pregnant women and nursing infants?
B: Stay the same. It would increase if they were B12 deficient. Macrocytic anemia w/o central pallor, pancytopenia, hypersegmented neutrophils in peripheral blood, big "Megs" in the bone marrow. Can be normochromic
Patients who require folate include these special populations.
Bonus: Methylmalonic acid would (increase, decrease, remain unchanged) in the labs of someone who is folate deficient? What type of anemia is present and what are the blood cell characterisitcs? |
What is hereditary spherocytosis?
B: Parvovirus infection --> aplastic crises or Mononucleosis ---> hemolytic crises
This hemolytic anemia is characterized by autosomal dominant mutations in the RBC plasma membrane proteins and presents with bone marrow hyperplasia, gallstones/jaundice, and splenomegaly. It can reduce the lifespan of a red blood cell by 110 days!
Bonus: What can trigger aplastic and hemolytic crises in this patient? |
What are folate, B12, and cystathionine synthase, methionine synthase?
Ways homocysteine can become elevated include deficiencies in the following nutrients as well as defects in the following enzymes.
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Acute Blood Loss [throwaway question]
Name the cause of anemia corresponding to the following lab:
↓Hct ↑erythropoeitin 7 d: reticulocytosis +/- ↓ Fe2+ Patient presents immediately. |
What is Immunohemolytic anemia (AIHA) cold hemolysin type aka Paroxysmal Cold Hemoglobinuria?
B: DAT would be + against complement but not IgG unless the IgG was done at 0-4 deg C
A severe, often fatal hemolytic anemia that is seen (rarely) in children after a viral infection, and occurs as a result of IgG autoabys binding the P antigen blood group in the extremities (fingers, toes, ears) leading to a complement-mediated cell-lysis when the regions are warmed back up.
Bonus: Can you still use the DAT on this patient? |
Pernicious anemia (autoAby to IF), atrophic gastritis (metaplasia of gastric cells ---> reduced IF secretion), GI tract resection/surgery, hypocalcemia or abnormal pH (Zollinger Ellison syndrome), decreased pancreatic enzymes/pancreatitis, parasite/tapeworm, or drug-interactions (alcohol, colchicine, PPIs)
B: elderly, mainly because of increased prevalence of atrophic gastritis, (some also have increased use of PPIs)
Reduced absorption/malabsorption of B12 vitamin can be caused by the following conditions (name 3).
Bonus: What age group is susceptible to B12 deficiency and why? |
Hereditary causes:
• deficiency in methemoglobin reductase • HbM disease - an Hb variant with mutation that makes Hb resistant to being reduced by methemoglobin reductase Acquired causes: • drugs: topical anesthetics, NO • well water contax. w/ nitrates (NO3-)
Although rare, these are two underlying causes of inherited methemoglobinemia.
Bonus [scenario]: I live on a farm in a remote area, we get no running water or electricity. A young lady stayed with us once and left behind her benzocaine which I decided to use on my achy teeth. Soon after I became blue in the face and my tongue turned blue. These two things contributed to my condition. |
MTHFR - methylenetetrahydrofolate reductase: enzyme that turns Me=THF to N5Me-THF which is a more stable form of folate, B12 and methionine synthase helps turn that into THF which is used for DNA synthesis reactions
The function of MTHFR (methyl-THF-reductase) and what is special about its product.
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Intravascular hemolytic anemia: various types /causes
Name the anemia corresponding to the following lab:
↓haptoglobin ↑free Hb, methemoglobin (urine) ↑Epo ↑erythroid progenitors (BM) ↑reticulocytes ↑hemosiderin ↓Fe ↑bilirubin (indirect) |
Vaso-occlusive crises (hypoxia) ---> sequestration (in children w. intact spleens = rapid splenic enlargement, hypovolemia, and shock), and acute chest syndrome
B: Hand-foot syndrome (dactylitis)- painful bone crises in the extremities
The most common (and often fatal) clinical manifestations in a patient with Sickle cell anemia.
Bonus: Condition presenting early in life ( before 2 y/o) resembles osteomyelitis. |
What is Warm Aby type Immunohemolytic anemia?
B: Coomb's test + DAT, + IAT
This microcytic anemia is caused by IgG antibodies against a particular antigen on the RBC, and about half of the cases are idiopathic. The other half of cases might be due to autoimmune hypersensitivity or induced by antigenic drugs.
Bonus: What test would you use to confirm this and what result would you get? |
What are Frontal bossing, Maxillary overgrowth, "Crewcut" appearance, and prominent cheekbones/bony areas?
B: Ineffective hematopoiesis ---> accumulation, cortical erosion. Expanded areas of active hematopoiesis: skull ---> new bone formation---> frontal bossing, maxillary overgrowth, "crewcut" appearance. Hematopoiesis occurs wherever it can (extramedullary hematopoiesis d/t the severe anemia). Major (increased iron Hemachromatosis 2' to treatment w/ transfusion) & Minor: decreased iron, treatment usually just counseling
Clinical features on xray of Beta-thalassemia major include these classic signs (4). Bonus: explain why. What lab value is different between beta thalassemia major and beta thalassemia minor?
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Intrinsic factor ---> Parietal ----> haptocorrin (R-binder)
B: R-binder/factor/protein or TC-1 (transcobalamin-1)
This factor gets secreted by ________ cells of the stomach but cannot do its job until B12 dissociates from ________.
Bonus: What is another name for haptocorrin. |
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beta thalassemia
Name the anemia corresponding to the following lab:
↓MCV ↓MCHC ↓HbA ↑HbF (some cases) ↑HbA2 (some) ↑RDW (anisocytosis) ↑reticulocytes |
What is microangiopathic hemolytic anemia?/Intravascular hemolytic anemia?
B: schistocytes, helmet cells, burr cells, triangle cells No splenomegaly.
[Daily Double] This type of hemolytic anemia is related to trauma from cardiac prostheses (mechanical valves), parasitic infection, or a platelet disorder.
Bonus: Name the types of RBCs you would see on peripheral smear stain of this disorder. Would these patients present with splenomegaly? |
What is iron?
Cowmilk can inhibit iron absorption by 50% in infants < 1 year old.
Deficiency of this nutrient causes microcytic anemias.
Bonus: What is a dietary recommendation for newborns concerning getting adequate levels of this nutrient? |
What is HbBarts = gammax4
B: intrauterine blood transfusion
Form of hemoglobin that polymerizes in the total absence of alpha globin (hydrops fetalis).
Bonus: What treatment can be given to save the fetus? |
ferrochelatase,
B: they are photosensitive; Pb poisioning b.c it inhibits ferrochelatase.
Erythropoietic protoporphyria (EPP) is a chronic disease caused by a deficiency in _________________ and causes protoporphyrin accumulation in erythrocytes, bone marrow, and plasma.
Bonus: Why are these patients likened to vampires ? (not actually) What can exacerbate an acute form of this disease? |
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