Localization of B and T cell
I think the reason you are having trouble discerning the statement is because it doesn't really make much sense, nor is it in my opinion sufficiently explained in the paper. The sentences preceding the it give a little explanation as to what the author may be getting at:


  So far, 1500 allergenic structures have been identified. Online allergen databases and allergy prediction tools are being used to find cross-reactivity between known allergens. Localization of B and T cells in the allergen may not coincide.


During an exaggerated immune response (allergy) the lymphocytes (B and T) will localize (travel or accumulate at) to the site of the antigen (allergen). 

If I could guess I would say the author is stating that data has shown that no immune response is taking place (data generated by assessing the accumulation of lymphocytes near the allergen), despite the fact that these online allergen predictors say that an immune response should be generated.

The statement in my opinion moves to discredit these online allergen predictors. 

I did look over some of the rest of the manuscript, and found two other ambiguities within. 

The author does cite another paper in your sentence that may shed more light on this:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2686541/?report=reader

An overview of it provided little clarity however.

I fear that only  a crystal ball or this question addressed to the senior author may answer your question with complete certainty:

Dr. Rajat Kumar De 
Professor 
Machine Intelligence Unit 
Indian Statistical Institute 
203 Barrackpore Trunk Road, Kolkata 700108, India.