True statement about Antistreptolysin &;O&; titre is

In Rheumatic fever and glomerulonephritis, a retrospective diagnosis of streptococcal infection may be established by demonstrating high levels of antibody to streptococcal toxins. The standard test in antistreptolysin O titration. High levels are usually found in acute rheumatic fever but in glomerulonephritis, titers are often low. Reference: Textbook of Microbiology; Anathanarayan and paniker's; 10th edition; Page no: 218