High DNA-B-AB result for an adult

I had a DNA-B-AB test done recently and it came back at 424, clearly above the reference score. I am 72 years old and no doctor is able to tell me what it means.  I know from research that it is used in children to determine strep/rheumatic fever but what does it mean for someone my age? ( I had rheumatic fever when I was five.)  They did a strep test and that was negative.    marshab1940

[Paderla Anitha, DNB]

Hello and hope you are doing well.

The high titers indicate a Streptococcal group A infection. Besides rheumatic fever and acute glomerulonephritis, it can cause pyoderma. Other tests like Antistreptolysin O titer and a bacterial culture will help in correlating this result.

Hope this helped and do keep us posted.