hemolytic anemia part 2 Flashcards
Where is bartonella bacilliformis (bacteria) endemic in the world?
Peru Ecuador,and Colombia
What is the main symptoms?
fever, hemolytic anemia, and splenomegaly
carrion’s disease (aka oroya fever)
acute phase: severe anemia
chronic phase: cutanous rash (peruvian warts)
what do you look for on a blood smear if you suspect bartonella bacilliformis?
long curved, dark rods inside red blood cells
where in the body is Clostridium perfingens a component of the normal flora?
the skin
what does Clostridium perfingens’ alpha toxin cause in the body?
gas gangrene
what clinical findings do you see in an infection of c. perfingens?
Trauma
septic abortions
Rare complication of Cholecystitis, or of various cancers;
very severe hemolysis
what does clostridium perfingens on a blood smear look like under the microscope?
gram-positive rods
you will also see hemolyzed rbc’s that are super faint under the stain
3 fates of red blood cells in warm autoimmune hemolytic anemia?
- full clearance via extravascular hemolysis (phagocytosis via RES system)
- partial clearance–>formation of microspherocytes (RES systems take a “bite” out of the cells, leaving as much hemoglobin as possible, which produces small, spherical, osmotically fragile cells)
- intravascular hemolysis, via complement system (which is initiated by anti-RBC antibody bound to RBC
main difference between warm and cold autoimmune hemolytic anemia under a microscope?
in cold temperatures, both cause blood cell clumping, but cold autoimmune hemolytic anemia has a wider ranger (all the way up to room temp which is 20*C) that causes clumping
main difference between warm and cold autoimmune hemolytic anemia using direct coombs tests?
both will have complement components attached to RBC, BUT
cold autoimmune hemolytic anemia will not have autoimmune antibodies bound to red blood cells at body temperature
also note, cold autoimmune hemolytic anemia involves Ig M antibody not Ig G
microscopic and lab clues to warm autoimmune hemolytic anema?
- serum testing indicating hemolysis
(LDH, unconj. bilirubin, haptoglobin) - Polychromasia (and reticulocytes to make up for hemolysis)
- Basophilic stippling
- Microspherocytes
- Nucleated red cells (erythroid precursor cells also making up for hemolysis)
- NO BLASTS OF MYELOCYTES–how you distinguish between this and malignancies
what does a microscopic smear termed leukoerythroblastic or “myelophthisic” look like?
you have nascent red blood cell precursors AND blasts and myelocytes
It can be thought of as a condition in which masses of abnormal cells in the bone marrow “kick out” normal components into the bloodstream.
If you are pretty sure it is warm autoimmune hemolytic anemia, but the direct coombs test was false, does that mean that there are no autoimmune antibodies bound to the blood?
not necessarily…it could mean that those antibody-tagged red blood cells have already been recycled/removed/lysed
to confirm this finding, do an indirect coomb’s test
What do you do in an indirect coomb’s test?
you mix a sample of red cells (NOT THE PATIENT’S RBCS) with the patient’s plasma (which should have the anti-RBC antibodies), then you add anti-antibody (anti-IgG) antibodies and see if there is agglutination
What test do blood banks use to test for minor antigens in blood samples?
indirect coomb’s test
true or false, the direct coomb’s test is very specific
false, The DAT is a nonspecific result. 8% of hospital patients have a positive DAT result, but not all of them have autoimmune hemolysis. A diagnosis of warm autoimmune hemolytic anemia requires concomitant clinical findings and lab findings consistent with such a diagnosis.
What is a non-lethal clinical disease associated with cold autoimmune hemolytic anemia?
Raynaud’s phenomenon, a painful vaso-occlusion of peripheral vessels in fingers and toes, in cold weather
clinical indications pointing to cold autoimmune hemolytic anemia?
1 Raynaud’s phenomenon *** 2 Hemolysis by serum testing (LDH, unconj. bilirubin, haptoglobin) 3 Red Cell agglutination *** 4 Polychromasia 5 Basophilic stippling 6. Nucleated red cells 7. No blasts or myelocytes
What sorts of conditions go along with warm autoimmune hemolytic anemia?
.Warm autoimmune hemolytic anemia is often seen in association with malignancies, although it is far from specific for that.
It also carries a poor overall prognosis.
What sort of conditions go along with cold autoimmune hemolytic anemia?
Cold agglutinins are occasionally seen in association with malignancies, but are more commonly a complication of infectious diseases or of a broader systemic autoimmune condition like SLE.
prognosis is chronic and is impacted by season
What are two clinical symptoms that you see in a transfusion rejection from minor antigens?
jaundice and weakness
Pathogenesis of TTP (Thrombotic thrombocytopenic purpura)
autoimmune antibodies to AdamTS13–the enzyme that cleaves von wildebrand factor (Cable-like protein that helps initiate hemostasis) to the proper length
you have hypercoagulation and excess clotting because VWF is too long, but then you use up all your platelets, so you have hypocoagulation and excess bleeding too
clinical findings of TTP
triad: fever, renal failure, fluctuating CNS symptoms
OH and you’ll have an absence of sepsis!
treatment for TTP
Plasmapheresis
