Recently the Gluten Intolerance Group (GIG) ran a study comparing the reactions of individuals, based on Celiac Antibody results, following the consumption of gluten-reduced beers vs. gluten-free beers.
What led to this research being done is the concern that current testing methods being used by manufacturers of gluten-reduced beers are not sufficient for measuring the existence of proteins following the various processes that are being used in the manufacture of these gluten-reduced beers.
The testing results indicated the there are some reactions to gluten-reduced beers. These reactions are as varied as the individuals included in the study. What is not certain is what triggers the reactions and so further testing will be needed to confirm the findings.
At this point the final analysis of the study was to issue a statement that gluten-removed beers may be unsafe for people with CD.
You can read the statement from GIG at the above link.