Nonspecific Reactions due to Reagents Near Expiration Date

This is an updated version of a previous post.

Whenever I had a “nonspecific” antibody, I had to first rule out issues with the reagents themselves. The following example shows weak to 2+ reactions in the panel cells and autocontrol.

The variability in the reactions made me initially uncomfortable about called this WAIHA. I then checked the panel details: the testing was done only six days before the panel outdate.

I told my staff to repeat the workup with the new panel expiring five weeks later. The difference is astounding!!

Remember:  if you work in the Middle East, the environmental conditions can be extreme in summer (>50C).  Do you know how your reagents were handling during transport?

My advice: if you are concerned there is a clinically significant antibody but cannot confirm it, consider repeating the workup using fresh reagents and a fresh specimen. Repeating the workup after a few days may make the detection clearer.

Original Panel with Near Expiry Reagents:

Test performed 7/2/06, reagents expire 13/2/06:

Same Patient with New Reagents and New Sample:

Test Performed 14/2/06, reagents expire 20/306: