False positives and autoimmune diseases

Question

Hi Dr. Franscino. Please answer this question. I will definitely be donating either way. I went for an HIV test today at Planned Parenthood. I did the two week ELISA blood test instead of a rapid oral test. I have an autoimmune disease - hashimoto's thyroiditis. What is the likelihood if I am HIV negative that it will come back false positive. I am scared that after waiting two weeks it will come back positive even if i'm not and then I will have to wait more weeks scared that I am HIV positive for the confirmation tests. Thank you.

Answer

Hi,

The chances that Hashimoto's thyroiditis would cause a false-positive HIV test are negligible at best. I see no reason for concern.

By the way, most testing sites (including Planned Parenthood's) generally will run the confirmatory test (Western Blot) automatically if the screening test (ELISA) is repeatedly reactive (positive). You shouldn't have any additional wait time.

Dr. Bob