auto immune hemolytic anemia pt 1 - cold reacting auto abs

Immune hemolytic anemia: shortened RBC survival
mediated through the immune response, specifically
by _____ antibody

humoral

what are the 3 broad categories of immune hemolytic anemias

• alloimmune

• autoimmune hemolytic anemia (AHA)

• drug induced immune hemovtic anemia

what is autoimmune hemolytic anemia

shortening of time RBCd survive in circulation (less than 90 to 120 days)

pathophysiology of immune hemolysis: ______: destruction on RBCs within the blood
vessels. This type of hemolysis is rare.

intra vascular

what is a classic example of an intravascular immune hemolysis

serious ABO incompatibility ( anti a or -b are destorying rbcs in the blood vessels)

pathophysiology of immune hemolysis: ______: destruction of RBCs that occurs after
sensitized cells are removed from circulation by the spleen via the reticuloendothelial system

Extra-vascular

which type of in vivo hemolysis is more common

extravascular

which causative agent(s) is/are most frequently associated w extravascular hemolysis

IgG

which causative agent(s) is/are associated w both intra or extra vascular hemolysis

Complement

which pathophysiology of immune hemolysis is less frequent

intravascular hemolysis

in what conditions is intravascular hemolysis most seen

• ABO mismatch

• paroxysmal hemoglobin hematuria (PNH)

what are lab indicators for intravascular hemolysis 5

• hemoglobinemia (plasma pink or red)

• hemoglobinuria (pee pink, red, brown, or almost black)

• decreased serum haptoglobin (theres lots of free hb therefore all the haptoglobin is bound to it)

• elevated LDH (enzyme present in rbcs have spilled out)

• RBC are schistocytes (fragments)

what are the lab indicators for extravascular hemolysis 5

• increase serum bilirubin (rbcs being destroyed)

• spherocytes (due to spleen sequestering out cells w IgG)

• agglutination

• increased reticulocytes (bone marrow trying to compensate therefore is pushing out red cells prematurely)

• dec hb and hct

how do u diagnose hemolytic anemia

t/f a pos DAT proves autoimmune hemolytic anemia (AIHA)

F( THO IT IS a v good guide, it isnt definitive)

if autocontrol is pos, it may detect ___ sensitization

in vitro sensitization

t/f when auto control is pos, dat is pos

f ( dat may be neg if ac is pos)

t/f DAT detects in vitro sensitization while AC detect s in vivo sensitization

f; DAT detects in vivo sensitization (a/c can detect both)

t/f majority of individuals with hemolytic anemia are DAT pos

t (83%)

majority of DAT, when eluate is run are reactive t/f

f (79% of positive
DAT are nonreactive eluate)

what are the 3 major types of autoimmune hemolytic anemia (AIHA)

• COLD autoimmune hemolytic anemia

• WARM (WAIHA)

• drug in duced

which autoimmune HA: The antibodies
react optimally at 4C. May also react at room temperature.

cold

what type of AIHA: The
antibodies react optimally at 37C.

WAIHA

what type of AIHA: Patient produces antibody to
a particular drug or drug complex which causes damage to
patient’s RBCs

drug induced

list from lowest incidence to highest the autoimmune hemolytic anemias

• drug induced

• cold

• waiha

what antibodies are cold autoimmune hemolytic anemias associated w

cold auto abs

t/f someone w a cold hemolytic anemia, their anemia gets worse in the winter

t

what i the most common benighn cold auto antibody

anti-I

T/F benign cold auto abs are present in the serum of most healthy individuals

t

what are the rare benign cold auto antibodies

anti IH and anti-i

t/f benign cold abs are non red cell immune

t

whaat type of abs are benign cold abs

IgM

are benign cold abs clinically significnt

typically no

if you perform a serial dilution on a sample w benign cold autoabs, what wuld their titer be

low (Patient produces antibody to
a particular drug or drug complex which causes damage to
patient’s RBCsless than 64)

if you think you have a benign cold ab, what do u do to make it react stronger

enzyme treat it

benign cold autoabs react w ____ cells but not w ____ cells

adult cells; cord cells

why are cold benign autoantibodies a problem

• if reacting at RT can mask significant abs

whats an easy way to stop cold auto abs for interfering

pre warm sample

DAT done on ___ samples to avoid false pos

EDTA

during ABO typing, how can cold autoantibodies interfere

Cells heavily coated with cold agglutinin cause spontaneous
agglutination (evth pos even Rh ctrll)

Cells heavily coated with cold agglutinin cause spontaneous
agglutination. whats the sltn

-wash cells 2x with warm saline
-incubate at 37C for at least 1 hour , then wash with warm
saline
-thiol reagent e.g. dithiothreitol can be used (DTT)
-auto adsorption technique

THIS IS THE SAME SAMPLE, WHAT DOES THIS MEAN

there was a cold auto antibody present. it was warmed/ washed w warm saline and spat out the reult on the bottom

if everyth is pos during abo/ rh testing, what direction does it point you in

sampe has a cold auto ab

t/f cold antibodies can cause false pos in wk d if clotted sample and polyspecific rgt is used

t

cold antibodies can cause false pos in wk d if clotted sample and ______ rgt is used

polyspecific

how do you stop cold auto ab from causing false rxns during Rh typing

• use monoclonal rgts

• - warm saline wash w thiol rgts

Cold agglutinins found in the sera of group A1
and A1B individuals (and occasionally group B)
may have anti-____specificity.

anti-H

which ABO groups have the largest amt of H antigen nd will therefore react the best with anti H and anti-IH

group O and A2

which ABO groups have the least amt of H antigen nd will therefore react the weakest with anti H and anti-IH

Group A1 and A1B

Less commonly encountered cold autoagglutinins
have been described, such as

• anti-Pr

• -Gd

• -Sdx

• -Rx

Anti-IH and anti-H give weaker
reactions with group ___ and ___,
stronger with group ___

A, B, O (much more H ag on O cells)

pathologic cold autoagglutinins may cause mild to life threatening _____

acute intravascular lysis

what causes pathologic cold autoagglutinins

idiopathic (primary)

• not associated w any demonstratable underlying disease

acute, transient (secondatry)

• associated w a primary disease state

  • mycoplasmo pneumoniae

    • anit-I

    • hemolysis rare but rapid onset may occur usually 2-3rd week of illness

  • infectious mono

    • anti-I

    • wide thermal range

what is the diagnosis that has auto anti-I

• Mycoplasma pneumoniae

what is the diagnosis that has auto anti-i

infectious mononucleosis

in which population is cold hemagglutinin disease most common (CHD)

ppl over 50 yo

what is typically the cold auto ab present in cold hemagglutinin disease (CHD)

anti-I

when is cold hemagglutinin disease usually displayed

winter (triggered when body temp goes below 28 deg c)

CHD: antibody agglutinates the red cells, fixing complement causing auto-
agglutination and signs of ____ also known as ______
phenomenon.

acrocyanosis ; Raynaud

if CHD id rlly bad what are the characteristic signs that are displayed (chronic anemia)

• weakness

• pallor

• weight loss

why is DAT pos in CHD

DUE TO COMPLEMENT****

what are the lab findings of CHD 4

• reticulocytosis (bone marrow trying to compensate for anemia)

• pos DAT

• peripheral slide: agglutination, polychromasia

• autoagglutination of sample (automated CBC difficult)

what does a peripheral slide have if pt has CHD

• agglutination

• polychromasia

why is CHD a problem during surgeries

some surgeries u need to cool the body down therefore must do special testing

treatment for CHD 4

• keep pt warm

• pt move to warmer climate

• plasmapheresis

• must transfuse w washed red cells

paroxysmal cold hemoglobinuria (PCH) affects mostly who?

• children and young adults w viral illnesses such as

  • measles

  • mumps

  • chicken pox

  • infectious mono

what is the main characteristic of paroxysmal cold hemoglobinuria

intermittent, recurring episodes of hemoglobinuria after being exposed to cold

what are the symptoms of PCH 6

• hemoglobinuria after exposed to cold

• sudden onset of fever

• shaking cills

• malaise

• tummy cramp

• back pain

Red cell destruction in PCH is caused by a cold autoantibody called a

biphasic autohemolysin

what does a biphasic autohemolysin do

• Binds to patient’s red cells at low temperatures and fixes complement
• Hemolysis occurs when body temperature rises to 37 ̊C

what is the classic biphasic autohemolysin antibody produced during PCH*****

donath landsteiner ab

donath landsteiner antibody has ____ specificity and is ____

autoanti-P specificity; IgG

Lab findings of PCH 5

• severe and rapid anemia (as low as 40 g/L)

• polychromasia

• nrbcs

• poikilocytosis

• donath landsteiner positive test for confirmation

what is the treatment for chronic and acute PCH

chronic: must protect from cold

acute: most infection end once underlying infection is treated

what are the rgts for the donath landsteineer test

• freshly collected pooled normal plasma

• 50% group O P1 positive washed cells

when is the donath lanndsteiner test considered pos

when pt serum w or w/o complement causes hemolysis in the tubes that were incubated first in melting ice then at 37 C and there was NO hemolysis in any tubes kept j at 37 or melting ice only.

donath-landsteiner test: A3, B3 , C3 tubes serve as a ____ of the normal sera complement source and should manifest no hemolysis

control

wht is the diff between benign and pathological auto antibodies

benign reacts only w adult cells but not cord cells. pathological react w both adult and cord cells