Article concerning on that issue (5)
I believe the answer is:
there
'on that issue' is the definition.
(eg 'you're wrong there')
'article concerning' is the wordplay.
'article' becomes 'the' (the definite article in English).
'concerning' becomes 're' (both can mean on a particular topic).
'the'+'re'='THERE'
(Other definitions for there that I've seen before include "on that issue" , "please feel reassured!" , "in that case" , "Place: as indicated" , "that's the point" .)