Background: Recent evidence suggest that group A ß-hemolytic streptococcal (GABHS) infection may increase the risk of pediatric autoimmune neuropsychiatric disorders (PANDAS) composed of the clinical signs of obsessive-compulsive and attention deficit hyperactivity disorders. The objective of this study was to compare the titer of antibodies against GABHS between children with PANDS and the controls.
Methods : This cross-sectional, case-control study was done in Hazrat Rasoul Hospital, in Tehran, Iran during 2008-2010. We compared serum antibodies streptolysin O, deoxyribonuclease B, and streptokinase against GABHS quantitatively in 79 cases with PANDAS and 39 age-matched controls. The area under ROC curve, sensitivity, specificity and positive predictive value (PPV) of tests were calculated.
Results : Most cases were studied in summer (57%) and spring (23%). The three aforesaid antibodies were higher in the cases (P=0.001). Antisterptolysin O (cut-off point 195) had a 90% sensitivity, 82% specificity and a 92% PPV, (CI=95%, 0.99-0.91). Anti streptokinase (cut-off point 223) had an 82% sensitivity, 82% specificity and a 95% PPV, (CI=95%, 0.934-0.735). Anti-DNase (cut-off point 140) had an 82% sensitivity, 82% specificity and a 95% PPV, (CI=95%, 0.99-0.91).
Conclusion: The study demonstrated a possible role for streptococcal infection in PANDAS. We found a significantly higher antibody titer against GABHS in OCD and ADHD cases in comparison with healthy children. Treatment of streptococcal infection is achievable by the use of long-acting penicillin. Use of aggressive treatment schedules like plasmaphresis, IVIG, etc needs further RCT studies.