Introduction: Group A Beta-Hemolytic Streptococcus (GABHS) can induce PANDAS
(pediatric autoimmune neuropsychiatric disorders associated with streptococcal infection).
GABHS is the most important and common bacterial cause of acute pharyngitis in Iranian
children. We studied the role of GABHS (anti-streptococcal antibodies) in suspected cases of
PANDAS in a cross sectional studies.
Methods: Across sectional study was done in 2 pediatric psychiatric /and neurologic clinics
in Tehran (Rasul Akram and Aliasghar Hospital) during 2008-2010. We studied serum antistreptococcal
antibodies (anti streptolysin O, anti Deoxyribonuclease B, and anti-streptokinase
(ABcam-ELISA, USA) in 76 cases with psychiatric manifestation (OCD, ADHD) in compare
with 39 healthy controls. These antibodies were studied in 53 cases with movement disorders
(Tic/ Tourette syndrome ) in compare with 76 healthy controls. Sensitivity, specificity and
positive predictive value of tests were calculated.
Results: In movement disorders ASOT, Anti-DNase and Anti streptokinase was significantly
higher than controls (p<0.0001, p=0.000, p<0.00001)
ASOT (cut off level> 200IU/ml) had 75% sensitivity 84% specificity and 80% PPV Antistreptokinase
(cut off level> 332 IU/ml) had 34% sensitivity 85% specificity, and 72% PPV
Anti-DNase (cut off level> 140IU/ml) had 70% sensitivity 99% specificity and PPV 90% for
differentiating the group. ASOT, Anti-DNase and Anti streptokinase titer was significantly higher
than controls (p<0.0001, p=0.000, p<0.0001). ASOT had 90% sensitivity 82% specificity,
PPV 92% Anti streptokinase: 82% sensitivity 82% specificity, PPV 95% Anti DNase: 92%
sensitivity 82% specificity, PPV 92% for differentiation the cases from normal controls.
Discussion: These findings support that a post infectious immune mechanism to GABHS
may play a role in the pathogenesis of PANDAS in our children. A combination of throat
culture, rapid antigen detection test, and serologic testing for GABHS is required to achieve
maximum sensitivity and specificity for diagnosis. We prefer to use antibiotic prophylaxis in
PANDAS cases for preventing recurrent streptococcal infections. Ongoing research is needed
for identifying optimum diagnostic, prevention and therapeutic approach especially, aggressive
treatment (intravenous immunoglobulin, plasmaphresis).
Type of Study:
Original |
Subject:
Clinical Neuroscience Received: 2014/03/17 | Accepted: 2014/09/11 | Published: 2015/01/1