We have been performing an IEL check on duodenal biopsie since about 2000, often as a formal (or "by eyeballing") CD30-amplified villous tip score (VTS).

About gluten sensitive & protein sensitive enteropathies HERE.

References:

1. Histopathology 54(7):783-795 (photos clearly showing advantage of counting with CD3), June 2009.
2. Biagi F, et. al., "Intraepithelial lymphocytes in the villous tip: do they indicate potential coeliac disease?", J Clin Pathol, 57:835-839, 2004. (the use & advantage of CD3 amplification)

(began to post 9/14/2009)