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