Enzyme Panel Details

Principle:

Performing antibody panels using both enzyme (ficin, bromelin, and/or papain)-treated  and routine panel cells may be necessary to detect most clinically significant antibodies

Policy:

  1. Regular (LISS) panels are to be performed using AHG reagents whereas enzyme panels done by the gel technology must use the saline (NaCl)-enzyme card.
  2. Perform BOTH enzyme and routine panels in the following situations
    1. All patients with sickle cell anemia and thalassemia
    2. Antibody pattern of panreactivity with a negative autocontrol (see attached examples)
    3. Antibody workup that does not show a specific pattern with the regular panel alone
    4. Any case with a previous history of antibodies with a current negative antibody screen
    5. Any other case that you are directed to do so by the transfusion medicine consultant, supervisor, or senior technologist.
  3. Remember the reactivities of the following antibody specificities with enzyme-treated cells:
    1. Reactions may not be the same with papain vs ficin-treated cells!
    2. Enzyme-labile with both papain- and ficin-treated cells:  Fya, Fyb, M, N, Ge2, Yta, Rg, Ch, Pr, Tn, Mg, Mia, Cla, Jea, Nya, JMH, Inb
    3. Variable, enzyme-labile or weakened, some unchanged with both papain and ficin-treated cells:  S, s, U
    4. Variable reactions with papain (labile, weakened, unchanged, or increased) but usually increased or unchanged with ficin-treated cells:  Kell system (K, k, Kpa, Kpb)
    5. Reactions are increased or unchanged with both papain and ficin-treated cells:  Rh (D, C, c, E, e), Jka, Jkb, Lea, Leb, Lua, Lub, P1, H, most cold antibodies, autoantibodies, Tja (PP1Pk)

Example 1:

Antibody to High-Incidence/Prevalence or Public Antigen:

Reactions destroyed by enzyme (typical of anti-Ge2):

Example 2:

Antibody to high-incidence antigen, reactions unchanged or enhanced by enzyme—VERY DANGEROUS PATTERN:  Examples:  Anti-H, Anti-Tja (PP1Pk), anti-k (cellano), anti-U