Are These Garbage Antibodies?

In my Middle Eastern experience, I have found antibody panels from a certain manufacturer show a lot of weak, nonspecific reactivity which disappears with another manufacturer’s panels, particularly when gamma-heavy-chain-specific reagents are used:

  • In the following example, 4/15 cells show weak or 1+ reactivity at AHG phase only using the manufacturer’s whole molecule IgG antiglobulin reagent—no reactions at enzyme phase.  This reagent detects both heavy and light chains.
  • When the panel from another manufacturer is used with a gamma-heavy-chain-specific reagent, there is no reactivity at either AHG or enzyme phases.

Normally, in my protocols, the first encounter in this situation, I would do extended RBC phenotyping beyond Rh and Kell systems as well.

In my experience, the nonspecific reactions detected are not clinically significant and they may be ignored if the conditions of the following algorithm is used:

  1. If nonspecific, enzyme-labile reactions found in the first manufacturer’s panels and AHG, then repeat with the second manufacturer’s panels using gamma-heavy-chain-specific reagents.
  2. If the second manufacturer’s panels are negative, use the latter for full AHG crossmatch and release crossmatch-compatible components if the panel is negative.

What do you do when you encounter this is in your laboratory?  Please share your thoughts.

Manufacturer 1’s Panel:

Manufacturer 2’s Panel: