Genealogy / Families from Poland - finding out their names prior to immigration? [6]

My great Grandfather was born in Istebna in the 1880's and my wife's great grand parents were both born in Warsaw in the 1880's. All name's were changed when they immigrated to (mine) was the US, my wife's immigrated to Canada and later the US. My question is, is there a way to find their names prior to immigration? And possibly family history.