ABC is a quite used abbreviation so I doubt there are any TM issues by definition.
However I doubt there is a big market for for .do domains especially not among resellers and with a regfee of $100 this is not really the kind of domains you hold on to
It does not have any TM issues unless if there is a big firm in Dominican republic as ABC. Even through if there is a firm names ABC in Dominican Republic i don't feel much fear about it because of the popularity of the acronym.
Because of its .do you hardly find international end users for the domain. But you can go for local and find. Or you can develop. If you develop the domain, extension will not be a big problem