What Causes Antistreptolysin O Titre?

Hello. My question is why would I have an elevated ASO titer for over 6 months. It s only slightly elevated 232 - 220 - 238. But I have had penicillin shot, rocephin, amoxicillin, and Augmentin. It all began because I had significant bilateral joint pain, blood in my urine, unexplained weight loss, continuous mouth sores. All of it occurred after having my first child. Before that I had no medical issues. Was thought to have RA at first because my brother has Felty Syndrome. Went to rheumatologist. Thought I could have lupus bc my monocytes were high and my WBC were low. But all labs for lupus were negative. Now told I have viral arthritis. Still have bilateral joint pain but feel much better. I did have elevated CRP of 14. RA factor was 8.4. Now both are lowered but my aso was 238 and the highest it has been after all those antibiotics. Also I am 37 and had a baby 13 months ago. I had to do invitro related unexplained infertility but later revealed I had high FSH. Still had a successful implantation and pregnancy.