CLS 3311 Advanced Clinical Immunohematology

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CLS 3311Advanced Clinical Immunohematology

• Autoimmune Hemolytic Anemia

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Auto-immune Hemolytic Anemia

• Drop in hemoglobin and hematocrit due to
  shortened red cell survival.
• Antibody directed against self antigens on the
  patients red blood cells
• Most react with high incidence antigens such as
  anti-e or anti-I.

• Hemolytic Anemia
• Auto Immune
• Antibody Specificity

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Auto-immune Hemolytic Anemia

• Mixing patient serum with most donor, reagent and
  self red blood cells will cause
• Agglutination or
• Coating with antibody and/or Complement or
• Cell lysis (or a combination of all three!!)
• Auto antibodies can hide or mask the presence
  of clinically significant allo antibodies
• Categories
• Warm autoimmune hemolytic anemia (70)
• Cold autoimmune hemolytic anemia (18)
• Drug induced hemolytic anemia (2)

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Auto-immune Hemolytic Anemia

• First step
• Rule out Other Causes Of Hemolysis such as
• Hereditary spherocytosis
• Hemoglobinopathy
• Sickle cell crisis
• Infusion of hemolyzed RBCs
• Infusion of toxic substances
• Need to ASSESS current patient status

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ASSESSMENT of Patient Status

• Patient History
• Transfusion and pregnancy history
• Patient Medication History
• Laboratory Tests
• DAT using both polyspecific (anti-IgG, -C3d) and
  monospecific antisera (anti-IgG)
• Antibody Identification on both serum and eluate.
  Compare results of each.
• Tests to search for additional clinically
  significant, unexpected antibodies such as an
  auto adsorption.

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Cold Autoimmune Hemolytic Anemia

• Table 21-1, page 439 Harmening compares Benign to
  Pathological cold auto antibodies. Be comfortable
  with this table.
• Benign cold auto-antibody
• Tend to have a low titer (lt4)
• Tendency to react at 25oC or optimally at 4oC
• Specificity usually anti-I
• May be detected only using enzyme treated cells
• Typically good Complement activators (IgM)
• Only seen when using Polyspecific AHG reagent.

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Cold Hemagglutinin DiseasePathological Cold Auto
Antibodies

• Tend to have a high titer (gt1000 at 4oC)
• Broad thermal range of reactivity up to 32oC
• Specificity anti-I, anti-P, etc.
• May be detected only using enzyme treated cells
• Typically good Complement activators (IgM)

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Cold Hemagglutinin Disease Pathologic Cold Auto
Antibody

• Chronic
• Idiopathic No known cause
• Acute/transient secondary to infectious disease
  or condition
• Mycoplasma pneumoniae or Infectious Mono
• Paroxysmal Cold Hemoglobinuria
• Table 21-6, page 443 Harmening

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Cold Hemagglutinin Disease Pathologic Cold Auto
Antibody

• Chronic
• Often seen in elderly patients
• Tends to be associated with Lymphoma, CLL,
  Waldenstroms macroglobulinemia
• Increased Erythrocyte Sedimentation Rate (ESR)
• Raynauds syndrome and hemoglobinuria seen during
  cold weather

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Cold Hemagglutinin Disease Pathologic Cold Auto
Antibody

• Acute/Transient
• Often secondary to lymphoproliferative disease
  (lymphoma) or Mycoplasma pneumonia infections
  (anti-I specificity)
• Also seen in patients with Infectious
  Mononucleosis with anti-i specificity.
• Transient When infectious process is complete
  auto antibodies fade.

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Cold Hemagglutinin Disease Pathologic Cold Auto
Antibody

• Paroxysmal Cold Hemoglobinuria
• Auto-Antibody with anti-P specificity
• Antibody is a Biphasic IgG class antibody that
  binds complement at cold temperatures and lyses
  red cells at warm temperatures
• Donath-Landstiener test is confirmatory for PCH
  (Refer to P Blood Group Lecture)

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Effects of Cold Auto Antibodies on Laboratory
Testing

• Forward ABO Grouping
• If cells are heavily coated with auto-antibody,
  they may spontaneously agglutinate on forward
  grouping.
• How is this corrected?
• Pre-warming all reagents and patient samples.
• In extreme cases may need to chloroquin treat
  patient red cells to remove auto-antibody from
  cell surface.

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Effects of Cold Auto Antibodies on Laboratory
Testing

• ABO Reverse Grouping
• Cold auto antibody can agglutinate Reagent red
  cells due to testing at room temperature
• How is this corrected?
• Pre-warming serum and reagent RBCs
• High titer antibody? May need to auto absorb
  patient serum.
• Rh Typing
• If Weak D testing is required may get False
  Positive using polyspecific AHG correct using
  Monospecific AHG.

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Effects of Cold Auto Antibodies on Laboratory
Testing

• Antibody Identification
• Auto-anti-I will agglutinate
• Patients own cells and all adult panel cells
• Fails to agglutinate or only weakly agglutinates
  cord blood cells
• Confirm that it is indeed anti-I
• Look for clinically significant allo antibody
  that can be masked by the cold auto antibody.
• Pre-warm serum
• Start testing at 37oC
• Use monospecific anti-IgG

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Effects of Cold Auto Antibodies on Laboratory
Testing

• Compatibility Testing
• Look for incompatibility due to clinically
  significant allo Antibody that may be masked by
  the cold auto antibody.
• Pre-warm serum
• Start testing at 37oC
• Use monospecific anti-IgG
• Loss of reactivity at 37oC then donor cells are
  suitable for transfusion. In other words, if
  after 37oC incubation there is no more
  agglutination then you can safely transfuse those
  donor cells.

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Effects of Cold Auto Antibodies on Laboratory
Testing

• Direct Antiglobulin Test (DAT)
• Positive with cold auto antibodies
• Only Complement (C3 components) is present
  because these are IgM antibodies
• Use Monospecific Is it IgG or C coating the
  RBC? Test with both anti-C3d and anti-IgG AHG to
  differentiate DAT specificity.
• Eluate Not usually performed because it is only
  Complement coating the red blood cell.

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Warm Autoimmune Hemolytic Anemia

• CLINICAL CHARACTERISTICS
• Most common AIHA
• Moderate to severe hemolytic anemia
• More likely to have an anemia that requires txn.
• Frequently hemolysis has an acute onset with
  increased reticulocytes and spherocytes
  (indicating extra-vascular hemolysis)
• 80 of cases involve IgG class auto-Antibody

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Clinical Characteristics of WARM Auto Antibodies

• May activate complement some do, some dont.
• Usually have enhanced reactivity with enzyme
  treated cells (Ficin, Papain)
• Antibody Specificity is usually against a high
  incident antigen, frequently involving the Rh
  system such as anti-e.
• Here is a great article on Compatibility Testing
  in WAIHAs by George Garratty from the University
  of Southern California. http//www.cbbsweb.org/cbg
  arrattyaiha.html

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Effects of WARM Auto Antibodies on Laboratory
Testing

• ABO Grouping - usually not a problem
• Rh Typing - can be a problem with IgG coated red
  blood cells.
• Use monoclonal anti-D or Chemically Modified
  anti-D
• Can Chloroquin treat red blood cells to remove
  antibody and perform Weak D. Must be careful
  because chloroquin can denature some Rh antigens.

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Effects of WARM Auto Antibodies on Laboratory
Testing

• Direct Antiglobulin Test
• Positive in the following combinations
• Approx. 67 have both IgG and C coating
• Approx. 20 have IgG only coating
• Approx. 3 have C only coating

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Effects of WARM Auto Antibodies on Laboratory
Testing

• Antibody Identification
• Patient History Very important
• Pregnancy and transfusion history may indicate
  possible presence of an allo antibody in addition
  to the auto antibody.
• Transfusion May also indicate presence of donor
  red blood cells if transfused within last 120
  days. Patient phenotype is very important and
  hard to perform with donor cells present.
• Medications Some medications have been
  implicated in Warm AHIA.

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Effects of WARM Auto Antibodies on Laboratory
Testing

• Antibody Identification
• Is it Necessary to identify the Warm Auto
  Antibody?
• Its helpful to know the specificity of the
  auto-antibody, BUT this may not be possible or
  practical.
• MUST KNOW if there is an underlying unexpected
  clinically significant allo antibody.
• Warm auto-antibodies tend to be more difficult to
  adsorb out of patient serum than the cold
  auto-antibodies. May want to treat patient cells
  with ZZAP prior to Auto Adsorption with patient
  serum.

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Effects of WARM Auto Antibodies on Laboratory
Testing

• Antibody Identification
• May take multiple adsorptions to remove
  sufficient antibody to enable detection of allo
  antibody.
• CANNOT do AUTO absorption if the patient has been
  transfused in the last 120 days. Why?
• Can do an adsorption with allogeneic red cells.
  May need to do multiple adsorptions with various
  Rh phenotypes (R1R1, rr, R2R2). Must also vary
  clinically significant blood groups phenotypes,
  too, such as Kell, Kidd and Duffy.

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Warm Autoimmune Hemolytic Anemia

• Selection Of Blood For Transfusion
• Transfusion of patients with WAIHA is usually NOT
  recommended. Why?
• Transfused cells are usually destroyed as rapidly
  as the patients own cells.
• When transfusion is unavoidable, usually must
  transfuse with Least Incompatible Blood.
• Patient is generally transfused with small
  volumes, to maintain O2 carrying capacity, until
  hemolysis diminishes or other therapy can effect
  a more lasting benefit.

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Drug-Induced Immune Hemolytic Anemia's

• Most drugs are probably capable of binding
  loosely, or firmly, to circulating cells, which
  can lead to an immune response.
• Antibodies can be formed to the drug itself or to
  the drug plus membrane components.
• When an antibody is formed against the
  combination of the drug and membrane it may
  recognize primarily the drug or primarily the
  membrane.
• Figure on next slide illustrates these options.

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AABB Technical Manual, 14th Edition, Page 440
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Drug-Induced Immune Hemolytic Anemia's

• Four Mechanisms
• Drug-Dependent Antibodies reactive with
  Drug-Coated Red Cells
• Other Drug-Dependent Antibodies Immune Complex
  Mechanism
• Drug-Independent Antibodies Autoantibody
  Production
• Nonimmunologic Protein Adsorption

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Drug Induced Immune Hemolytic Anemia's

• Drug-Dependent Antibodies Reactive with
  Drug-Coated Red Cells
• Drug binds firmly to the RBC membrane and
  antibody is mainly directed against the drug
  itself. Drug Adsorption mechanism.
• DAT Strongly positive with IgG. May have some
  C.
• IAT Non reactive. Unless using drug coated RBCs.
• Eluate Is reactive with drug coated red cells,
  only.
• Medications Penicillin and Cephalosporins.

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Figure 20-2. The drug adsorption mechanism. The
drug binds tightly to the red cell membrane
proteins. If a patient develops a potent
anti-drug antibody, it will react with the
cell-bound drug. Such RBCs will yield a positive
result in the DAT using anti-IgG reagents.
Complement is usually not activated and lysis is
primarily extravascular in nature. Penicillin-G
is the prototype drug.
AABB Technical Manual, 14th Edition, Page 442
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Drug-Dependent Antibodies Reactive with
Drug-Coated Red Cells

• Penicillin
• Approx. 3 of patients receiving high dose
  penicillin (millions of unit per day)
  intravenously develop a positive DAT.
• Occasionally they develop hemolytic anemia
• Hemolysis develops gradually and can become life
  threatening if etiology is unrecognized.
• Discontinuation of drug stops process. May take
  weeks for hemolysis to stop completely.

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Drug-Dependent Antibodies Reactive with
Drug-Coated Red Cells

• Cephalosporins
• Approx 4 receiving 1st or 2nd generation
  cephalosporins develop a positive DAT.
• Prevalence and severity of cephalosporin induced
  immune hemolysis appears to be increasing.
• Discontinue drug and process stops. May take
  weeks for hemolysis to stop completely.

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Drug Induced Immune Hemolytic Anemia's

• Other Drug-Dependent Antibodies Immune
  Complex Mechanism
• Drugs that do NOT bind well to the red cell
  membrane.
• Previous theory implied drug/anti-drug immune
  complex formation Never Proven! But we still use
  the immune complex designation to describe this
  mechanism.
• May cause acute intravascular hemolysis and be
  difficult to demonstrate serologically.
• Antibody can be either IgG or IgM

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Other Drug-Dependent Antibodies Immune Complex
Mechanism

• DAT C may be only globulin easily detected on
  the red cells
• IAT (and Eluate) Non reactive. Unless using drug
  coated RBCs.
• Acute intravascular hemolysis with hemoglobinemia
  and hemoglobinuria. Renal failure is common.
• Severe hemolytic episodes may recur after initial
  exposure, even with very small doses of the drug.

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Drug Induced Immune Hemolytic Anemia's

• Drug-Independent Antibodies Autoantibody
  Production
• The drug initially induces an immune response
  that results in the formation of an auto antibody
  directed against the red cell. The antibody has
  NO reactivity with the drug.
• Some appear indistinguishable from WAIHA
• DAT Strongly positive with IgG
• IAT and Eluate react strongly with all cells
  tested (without drug coating)
• Medication ?-methyldopa, L-dopa, etc.

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Nonimmunologic Protein Adsorption

• Cephalosporins (primarily cephalothin)
• Cephalothin (Keflin) alters the red cell membrane
  so that it adsorbs proteins (albumin, IgA, IgG,
  IgM, and C components) in a non specific and non
  immunologic manner. The red cell membrane becomes
  sticky.
• DAT and IAT Positive with most AHG reagents.
• Panel and Eluate No pattern, reacts with
  everything at AHG phase.

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