Mr Wilson's comments came in an email to a constituent who had asked if he would wear a red ribbon supporting World AIDS day.
Ms Bradley was speaking on BBC's The View on Thursday.
"I know Sammy, I know him well.  I know he's forthright," she said.
"I know he says what he thinks and what he feels. If I'm honest, I would say I was slightly disappointed by that reaction. I believe it wouldn't have been that difficult to wear a red ribbon in support.
"I don't believe that would have been difficult for anyone to do", she added.
Her comments came after the East Antrim MP said there are areas of medicine and diseases which "have not received the same attention as AIDS and which affect far more people".
These diseases were "not always as a result of lifestyle choices", he said, adding they "deserve higher priorities then they have been given at present".
The DUP MP told his constituent that considerable resources had been put into dealing with AIDS "sometimes at the expense of other illnesses which affect people, such as dementia and cancer, and which are not always as a result of their own behaviour".
Mr Wilson said he appreciated his constituent's concerns about AIDS but added: "You will appreciate that there are people who suffer from mental health problems, dementia and cancer which also have a huge impact on their lives and which are equally deserving of resources".
The DUP MLA Paula Bradley has said she is disappointed by comments made by her party colleague Sammy Wilson questioning the emphasis placed on HIV & AIDS over other diseases.