Background: Streptokinase, which is injected intravenously with a standard dose of 1.5 MIU, is the most widely used thrombolytic agent around the world. What is so important about this bioproduct is the level of antistreptokinase (anti-sk) antibody in the population, which is directly correlated to the incidence of streptococcal infections in that population.
Objective: Since Iran is an endemic area for streptococcal infections, this study was conducted to assess the anti-sk level in an Iranian population. Materials and
Methods: 97 males and 47 females referred to Modarress Hospital of Tehran for coronary angiography and cardiac catheterization were included. 10 ml of venous blood was taken before angiographies from each patient. According to the angiography reports, the patients were divided into three groups: Coronary Artery Diseases (CAD, n=95), Rheumatic Heart Disease (RHD, n=19) and normal coronaries (n=30). The anti-sk antibody level was assessed in the serum samples of all patients using Enzyme Linked Immunosorbant Assay.
Results: In 23.2% of patients with CAD, 40% of normal coronaries and 73.7% of patients with RHD, the serum samples contained more than 2 arbitrary units (AU) of anti-SK antibody which regarded as high levels. There was no significant difference between the anti-sk level of patients with CAD and normal coronaries (2.03 ± 3.02 AUs vs. 2.52 ± 2.23 AU), but the level of antibody in RHD group (8.16 ± 10.1 AU) was significantly higher than other groups (p<0.05). No significant correlation was observed between antibody levels and the age or gender of patients.
Conclusion: We concluded that the level of anti-sk antibody is high in Iranian population as compared to other endemic areas for streptococcal infections. Also we found no relation between the level of antibody and sex and age of patients. This study accentuated the necessity of assessment of drug efficacy in endemic areas for streptococcal infections especially in those patients with valvular heart disease.