Quinidine: this is the ‘innocent bystander’ b/c immune complexes are formed. Quinidine
acts as the hapten, and the IgM Ab attaches; so, the drug and IgM are attached together,
circulating in the bloodstream. This is a different HPY – type III, and will die a different way,
b/c this is IgM. When IgM sees the immune complex, it will sit it, and activate the classical
pathway 1-9, leading to intravascular hemolysis, and haptoglobin will be decreased, and in
the urine, Hb will be present.
Microangiopathic hemolytic anemia
RBC’s all fragmented – schistocytes (schisto – means split). MCC chronic intravascular hemolysis =
aortic stenosis, in this dz, the cells hit something; therefore have intravascular hemolysis, Hb in the
urine and haptoglobin is down. This is a chronic intravascular hemolysis, and you will be losing a lot
of Hb in the urine; what does Hb have attached to it? Fe; so what is another potential anemia you
can get from these pts? Fe def anemia. Example: will describe aortic stenosis (systolic ejection
murmur, 2nd ICS, radiates to the carotids, S4, increased on expiration, prominent PMI), and they
have the following CBC findings: low MCV, and ‘fragmented’ RBC’s (schistocytes) – this is a
microangiopathic hemolytic anemia related to aortic stenosis.
Other causes of schistocytes: DIC (lil fibrin strands split RBCs right apart b/c RBC is very fragile);
thrombotic thrombocytopenic purpura, HUS – see schistocytes. When you have platelet plugs
everywhere in the body, the RBCs are banging into these things causing schistocytes and
microangiopathic hemolytic anemia. Example: runner’s anemia, esp. long distance you smash RBC’s
as you hit the pavement; very commonly, you go pee and see Hb in it; to prevent, use bathroom b4.
Another cause of hemolytic anemia: malaria – falciparum b/c you have multiple ring forms (gametocyte
(comma shaped and ringed form). It produces a hemolytic anemia, which correlates with the fever. The
fever occurs when the cells rupture (the hemolytic anemia).
Intrinsic vs. Extrinsic Hemolytic anemia:
1. Intrinsic – something wrong with RBC, causing it to hemolyze: such as no spectrin, or not
decay accelerating factor to neutralize complement, no G6PD enzyme in pentose phosphate
shunt, or abnormal Hb (ie HbS). Therefore, something wrong inside the Hb molecule, causing it
2. Extrinsic – nothing wrong with the RBC, just at the wrong place at the wrong time; ie it just
happened to smash into the calcified valve (nothing was wrong with it, until it hit the valve).
Then it will be dreading going to the cords of bilroth with destroy it b/c it has been marked with
IgG and C3b for phagocytosis.
Something intrinsically wrong with the RBC causing it to hemolyze but there’s nothing wrong with
the BM (but something intrinsically wrong with the RBC), and the corrective ret ct is greater than
MAD – MC intrinsic probs
Membrane defect (spherocytosis, paroxysmal nocturnal hemoglobinuria), Abnormal Hb (SC
Deficiency of enzyme (G6PD def).