ASO increased, blood tests in rheumatic fever
Rheumatic fever mainly affects the age group 5-15 years, and is due to beta hemolytic streptococcal infections, which is initially located in the pharynx, and due to a genetic susceptibility it strongly stimulates the immunity. This attacks our own body by antibodies against streptococcus (joints, heart, skin, small vessels) causing specific symptoms.
ASO means anti-streptolysin O antibodies titer produced by streptococcus.
What you should know about ASO
- Normal value is less than 200 UTodd.
- Increased ASO can be met from the second-third week after the onset of pharyngeal infection and it has maximum values in the 5th week and can stay up to 9 months.
It is a marker of recent streptococcal infection, but does not support the diagnosis of rheumatic fever.
Antibiotics cause increased ASO values, and corticosteroids (preparations as prednisone) cause a rapid decrease and normalize high ASO.
There can be high levels of ASO in monoclonal gammopathies (multiple myeloma, macroglobulinemia Waldenstrom) and hyperlipidemia (high cholesterol, its fractions and / or triglycerides) of various causes. These results are called false positives.
Other analyzes necessary in rheumatic fever are:
1. pharyngeal exudate which confirms the presence of streptococci in the pharynx.
2. inflammatory evidence:
- ESR is expanded to 50-70 mm / h (drops to normal after passing the rheumatic spurt);
- Alpha 2 globulin has elevated values, fibrinogen shows high values (during inflammation is released by connective tissue);
- Increased C-reactive protein (0.1-1.5 mg% is normal).