269b Acquired hemolytic anemias

Question 1

spherocytes - more or less membrane than normal?

Answer 1

less - makes it a sphere

more = target cell

Question 2

reticulocytes - stain?

Answer 2

methylene blue –> stains ribosomal RNA

Question 3

LDH?

Answer 3

lactate dehydrogenase is released from RBCs when they are destroyed

Question 4

autoimmune hemolysis - detection tests?

Answer 4

Autoimmune hemolytic anemias are usually Coombs+

Direct Coombs test—anti-Ig/compliment 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. Used in blood bank.

Question 5

Warm antibody hemolytic anemia - what is it? what causes it?

Answer 5

Warm agglutinin: IgG –> Mo in spleen eat part of RBC and leaves smaller RBC (extravascular)

chronic anemia seen in SLE, CLL, or with certain drugs (e.g., a-methyldopa, penicillin) that bind RBCs (Ab think its foreign) OR induce autoimmune inducing

(“warm weather is GGGreat”).

Question 6

Warm antibody hemolytic anemia - lab findings?

Answer 6

microspherocytes
anemia
reticulocytosis
nRBCs
other signs of hemolytic anemia

Question 7

Warm antibody hemolytic anemia - Rx?

Answer 7

stop drugs
folate
steroids (1st line) –I ab production
splenectomy - refractory cases

Question 8

Cold antibody hemolytic anemia - what is it? causes?

Answer 8

Cold agglutinin: IgM –> polysaccharides on RBC surface –> activates complement –> acute anemia triggered by cold, usually not clinically significant; old people on hands/feet

seen in CLL, Mycoplasma pneumonia infections, or infectious mononucleosis

(“cold ice cream—yuMMM”).

Question 9

Cold antibody hemolytic anemia - what is it? causes?

Answer 9

Cold agglutinin: IgM –> activates complement; acute anemia triggered by cold, usually not clinically significant

seen in CLL, Mycoplasma pneumonia infections, or infectious mononucleosis

(“cold ice cream—yuMMM”).

Question 10

alloimmune (not own) hemolytic disease of the newborn - which antibody from mom attacks fetal RBCs? other newborn hemolysis?

Answer 10

IgG

ABO hemolytic disease - from differences between mom and fetus ABO; IgG crosses from mom

Question 11

Macroangiopathic anemia - cause? RBC appearance?

Answer 11

Prosthetic heart valves and aortic stenosis may also cause hemolytic anemia 2° to mechanical destruction.

schistocytes/ helmet cells

Question 12

Paroxysmal nocturnal hemoglobinuria

Answer 12

^ 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 and strange thrombotic events.

Question 13

Acanthocyte (spur cell, spiny RBCs) - causes?

Answer 13

Liver disease

abetalipoproteinemia (states of cholesterol dysregulation).