Full Idea
Explanation of a fact is some other fact or set of facts. And so Inference to the Best Explanation is inference to facts; someone who employs it cannot but take a realist attitude to a theory which is preferred on these grounds.
Gist of Idea
Inference to the Best Explanation is done with facts, so it has to be realist
Source
Alexander Bird (Philosophy of Science [1998], Ch.4)
Book Reference
Bird,Alexander: 'Philosophy of Science' [UCL Press 2000], p.146
A Reaction
So my personal commitment to abduction is entailed by my realism, and my realism is entailed by my belief in the possibility of abduction. We can't explain the properties of a table just by referring to our experiences of tables.