When is a strep. titer considered to be abnormal, or "elevated"?

Depends Upon the Lab: The standard numbers depend upon each testing lab. They base it on numbers studied in research trials of noninfected and infected (proven) patients.

Varies: The results vary from laboratory to laboratory, and the results usually indicate the "normal" levels for that lab. The aso test does not predict if complications will occur following a streptococcal infection, nor do they predict the type or severity of the disease. If symptoms of rheumatic fever or glomerulonephritis are present, an elevated aso level may be used to help confirm the diagnosis.