Group A streptococcal infections and tic disorders in an Italian pediatric population

Increased antistreptococcal antibody titers and anti-basal ganglia antibodies in patients with Tourette syndrome: controlled cross-sectional study

The association between Tourette syndrome, attention-deficit hyperactivity disorder (ADHD), and obsessive-compulsive disorder following streptococcal infections has been documented, but with conflicting reports. We thus felt it was important to investigate this association in a group of Italian patients not previously documented. We took blood on 69 patients with Tourette syndrome and 72 age- and sex-matched tic-free controls. Laboratory staff were blind to the diagnostic status of the subjects. Evidence of recent streptococcal infection was defined using antistreptolysin titers. Anti-basal ganglia antibodies were determined using human basal ganglia sections. Statistical analysis was conducted using analysis of variance and chi-square tests. Raised antistreptolysin titers were found in 41 of 69 (59%) patients with Tourette syndrome and 14 of 72 (19%) controls (P = .000). Positive anti-basal ganglia antibodies were found in 22 of 69 (32%) subjects with Tourette syndrome compared with 7 of 72 (10%) controls, which was also significant (P = .002). Raised antistreptolysin titers were detected in 18 of 22 (82%) patients with Tourette syndrome with positive anti-basal ganglia antibodies and 22 of 47 (47%) patients with negative anti-basal ganglia antibodies (P = .01). These results support the reported association between streptococcal infection and anti-basal ganglia antibodies and some patients with Tourette syndrome.

Therapeutic failures of antibiotics used to treat macrolide-susceptible Streptococcus pyogenes infections may be due to biofilm formation

Streptococcus pyogenes infections often fail to respond to antibiotic therapy, leading to persistent throat carriage and recurrent infections. Such failures cannot always be explained by the occurrence of antibiotic resistance determinants, and it has been suggested that S. pyogenes may enter epithelial cells to escape antibiotic treatment. We investigated 289 S. pyogenes strains isolated from different clinical sources to evaluate their ability to form biofilm as an alternative method to escape antibiotic treatment and host defenses. Up to 90% of S. pyogenes isolates, from both invasive and noninvasive infections, were able to form biofilm. Specific emm types, such as emm6, appeared to be more likely to produce biofilm, although variations within strains belonging to the same type might suggest biofilm formation to be a trait of individual strains rather than a general attribute of a serotype. Interestingly, erythromycin-susceptible isolates formed a significantly thicker biofilm than resistant isolates (P < 0.05). Among resistant strains, those carrying the erm class determinants formed a less organized biofilm than the mef(A)-positive strains. Also, prtF1 appeared to be negatively associated with the ability to form biofilm (P < 0.01). Preliminary data on a selection of strains indicated that biofilm-forming isolates entered epithelial cells with significantly lower efficiency than biofilm-negative strains. We suggest that prtF1-negative macrolide-susceptible or mef(A)-carrying isolates, which are poorly equipped to enter cells, may use biofilm to escape antimicrobial treatments and survive within the host. In this view, biofilm formation by S. pyogenes could be responsible for unexplained treatment failures and recurrences due to susceptible microorganisms.

Immunology of obsessive-compulsive disorder

Childhood OCD often develops into a chronic illness that lasts decades. Proof that some type of immunotherapy (such as antibiotic prophylaxis) could significantly reduce recurrence or exacerbation of symptoms of OC or tics would suggest a supportive role for immune triggers in the onset or worsening of these conditions and provide additional tools for improving outcome. The validity of PANDAS will continue to be questioned, however,because demonstrating a clear causation will be difficult on a background ofa common childhood illness. Along with the previously mentioned immuno-therapy study, validation of the PANDAS phenotype (broadly interpreted)would be advanced from new and continued research in the following areas: (1) prospective studies to identify infectious triggers in the onset and exacerbations of OCD spectrum disorders, (2) biological measures for immune and genetic susceptibility, and (3) large scale epidemiological studies demonstrating the relationship between infection and OCD spectrum disorders. The assimilation of these study results should allow for elucidation of the immune system's role in the onset and maintenance of OCD.

Síndromes neuropsiquiátricas pós-estreptocócicas

Nesta revisão narrativa, o nosso objetivo foi descrever as síndromes neuropsiquiátricas pós-estreptocócicas e discuti-las à luz das evidências científicas atuais sobre os possíveis mecanismos patogenéticos envolvidos. Nos últimos anos, uma série de distúrbios do movimento, como tiques, distonia, parkinsonismo, e transtornos psiquiátricos, como o transtorno obsessivo-compulsivo (TOC) e o transtorno de hiperatividade com déficit de atenção (THDA), vem sendo considerada parte do espectro das manifestações pós-estreptocócicas. O termo PANDAS (acrônimo do inglês: pediatric autoimmune neuropsychiatric disorder associated with streptococcus) foi inclusive cunhado para descrever um subgrupo de pacientes com TOC e tiques que exibe flutuação clínica dos sintomas associada a infecção estreptocócica. Entretanto a análise crítica das evidências clinicolaboratoriais não apóia esse espectro ampliado das manifestações pós-estreptocócicas. Apenas na coréia de Sydenham há evidências consistentes de patogênese mediada por processo auto-imune pós-estreptocócico.

Association of group A streptococcal emm types with virulence traits and macrolide-resistance genes is independent of the source of isolation

Streptococcus pyogenes (group A streptococci; GAS) recovered from paediatric pharyngitis (101 isolates) and asymptomatic children (79 isolates) in the same geographical area and period, as well as isolates collected during an enhanced national surveillance programme for GAS invasive diseases (79 isolates), were screened for the incidence of the streptococcal pyrogenic exotoxin (spe) genes speA and speC, as well as the macrolide-resistance genes erm(B), erm(A) subclass erm(TR) and mef(A), and typed by emm sequencing. The speA gene was detected with comparable incidence among throat isolates (13.9 % of asymptomatic children and 16.8 % of pharyngitis isolates) and in 25 % of invasive cases; in contrast, speC incidence was, surprisingly, higher in paediatric populations (55.4 % in pharyngitis isolates and 65.8 % in asymptomatic children) than in invasive isolates (30 %; P < 0.0001). Macrolide resistance was detected in 26.6, 38.0 and 37.6 % of strains belonging to invasive, asymptomatic and pharyngitis populations, respectively. The different incidences of exotoxin and antibiotic-resistance genes among populations did not appear to have an intrinsic clinical significance, but may reflect the propensity of these traits to be associated with certain emm types independent of the source from which the strains were isolated. Further investigations with larger emm-type populations are warranted to confirm this.

Association between streptococcal infection and obsessive-compulsive disorder, Tourette's syndrome, and tic disorder

OBJECTIVE

Reports have suggested that streptococcal infection may be etiologically related to pediatric autoimmune neuropsychiatric disorders (PANDAS), but there are few good epidemiologic studies to support this theory. Using population-based data from a large West-Coast health maintenance organization, we assessed whether streptococcal infection was associated with increased risk for obsessive-compulsive disorder (OCD), Tourette's syndrome (TS), or tic disorder.

METHODS

This is a case-control study of children 4 to 13 years old receiving their first diagnosis of OCD, TS, or tic disorder between January 1992 and December 1999 at Group Health Cooperative outpatient facilities. Cases were matched to controls by birth date, gender, primary physician, and propensity to seek health care.

RESULTS

Patients with OCD, TS, or tic disorder were more likely than controls to have had prior streptococcal infection (OR: 2.22; 95% CI: 1.05, 4.69) in the 3 months before onset date. The risk was higher among children with multiple streptococcal infections within 12 months (OR: 3.10; 95% CI: 1.77, 8.96). Having multiple infections with group A beta-hemolytic streptococcus within a 12-month period was associated with an increased risk for TS (OR: 13.6; 95% CI: 1.93, 51.0). These associations did not change appreciably when limited to cases with a clear date of onset of symptoms or with tighter matching on health care behavior.

CONCLUSION

These findings lend epidemiologic evidence that PANDAS may arise as a result of a postinfectious autoimmune phenomenon induced by childhood streptococcal infection.

Association of common cold with exacerbations in pediatric but not adult patients with tic disorder: a prospective longitudinal study

Cross-sectional data and case studies suggest a temporal relationship between fluctuations in tic severity and preceding infections. In this study, we aimed to examine this possible relationship in a prospective longitudinal design. Two groups of tic disorder patients were included, a pediatric group between 7 and 15 years of age (n = 20), and an adult group over 15 years of age (n = 41). During a 24-week period, participants were asked to fill out weekly self questionnaires regarding the presence of tic exacerbations and the experience of the common cold. In addition, 6 throat swabs were taken at monthly intervals and cultured for streptococci; also, 3 serial serum assessments of streptococcal antibodies were performed at 8-week intervals. In the pediatric group, our results indicated a strong association between the self report of a common cold and a symptom exacerbation 4 weeks later (Odds ratio = 4.685; p = 0.001). In the adult group, we found no association between reports of common cold and tic exacerbations. Association with streptococcal infections could not be determined owing to the limited number of observed streptococcal infections. Thus, this study points to a hitherto unknown association of common viral infections with tic exacerbations in children, which may support the involvement of immune dysregulation in tic disorders.

Annotation: PANDAS: a model for human autoimmune disease

BACKGROUND

Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcus infections (PANDAS) is a recently recognized syndrome in which pre-adolescent children have abrupt onsets of tics and/or obsessive-compulsive symptoms, a recurring and remitting course of illness temporally related to streptococcal infections, and associated neurologic findings including adventitious movements, hyperactivity and emotional lability.

METHODS

Inspired by observations of similar symptoms in children with Sydenham's chorea, a search was undertaken for clinical and laboratory evidence in support of the new syndrome.

RESULTS

Consistent and predictable clinical findings have been described in a large case series. Magnetic resonance imaging has supported the postulated pathobiology of the syndrome with evidence of inflammatory changes in basal ganglia. Antibasal ganglia antibodies have been found in some acute cases, mimicking streptococcal antigen epitopes.

CONCLUSIONS

While PANDAS remains a controversial diagnostic concept, it has stimulated new research endeavors into the possible links between bacterial pathogens, autoimmune reactions, and neuropsychiatric symptoms.

PANDAS: current status and directions for research

The recognition of the five criteria for PANDAS (pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections) by Swedo et al established a homogenous subgroup of children with childhood onset obsessive-compulsive disorder (OCD) and/or tic disorders. The five clinical characteristics that define the PANDAS subgroup are the presence of OCD and/or tic disorder, prepubertal age of onset, abrupt onset and relapsing-remitting symptom course, association with neurological abnormalities during exacerbations (adventitious movements or motoric hyperactivity), and a temporal association between symptom exacerbations and a Group-A beta-hemolytic streptococcal (GAS) infection. These five criteria have been used for the purpose of systematic research on the phenomenology and unique therapies for the PANDAS subgroup as well as studies of the pathophysiology of post-streptococcal OCD and tic disorders. The etiology of OCD and tics in the PANDAS subgroup is unknown, but is theorized to occur as a result of post-streptococcal autoimmunity in a manner similar to that of Sydenham's chorea. The working hypothesis for the pathophysiology begins with a GAS infection in a susceptible host that incites the production of antibodies to GAS that crossreact with the cellular components of the basal ganglia, particularly in the caudate nucleus and putamen. The obsessions, compulsions, tics, and other neuropsychiatric symptoms seen in these children are postulated to arise from an interaction of these antibodies with neurons of the basal ganglia.

Prospective longitudinal study of children with tic disorders and/or obsessive-compulsive disorder: relationship of symptom exacerbations to newly acquired streptococcal infections

BACKGROUND

It has been proposed that infection by group A beta-hemolytic streptococci (GABHS) can trigger acute symptom exacerbations among patients with Tourette's syndrome (TS) or obsessive-compulsive disorder (OCD), via autoimmune mechanisms.

OBJECTIVE

To examine the temporal relationship between newly acquired GABHS infections (and other immunologic indices) and acute exacerbations of tics and obsessive-compulsive symptoms.

METHODS

Pediatric patients (7-17 years of age) with TS and/or OCD (N = 47) and healthy control subjects (N = 19) were prospectively monitored for newly acquired GABHS infections, nonspecific markers of acute inflammatory responses, and D8/17-reactive cells (a marker of rheumatic fever). Objective monthly ratings of tic and obsessive-compulsive symptom severity were used to determine the timing of symptom exacerbations.

RESULTS

The overall rate of acute exacerbations of neuropsychiatric symptoms was 0.56 exacerbations per patient per year. The average rate of new GABHS infections, using a stringent definition, was 0.42 infections per subject per year among patients, compared with 0.28 infections per subject per year for control subjects. The association between symptom exacerbations and new GABHS infections among patients was no greater than that expected on the basis of chance. At baseline, patients demonstrated significantly higher levels of D8/17-reactive cells and neopterin, compared with control subjects, but there was no consistent pattern of change when exacerbation time points were compared with baseline or follow-up time points.

CONCLUSIONS

The results suggest no clear relationship between new GABHS infections and symptom exacerbations in an unselected group of patients with TS and/or OCD.

Detecting pediatric autoimmune neuropsychiatric disorders associated with streptococcus in children with obsessive-compulsive disorder and tics

BACKGROUND

A subgroup of children with obsessive-compulsive and tic disorders are proposed to have an infectious trigger. The purpose of this study was to investigate the relationship between group A streptococcal titers and symptom fluctuations in children with a clinical course resembling that described for pediatric autoimmune neuropsychiatric disorders associated with streptococcus.

METHODS

Twenty-five children with obsessive-compulsive disorder and/or tic disorder were evaluated for neuropsychiatric severity and group A streptococcal antibody titers (streptolysin O, deoxyribonuclease B, and carbohydrate A) at 6-week intervals for > or = six consecutive evaluations (total visits=277).

RESULTS

Children with large symptom fluctuations (n=15) were compared with children without dramatic fluctuations (n=10). Co-movements of obsessive-compulsive/tic severity and group A streptococcal antibodies were assessed. In subjects with large symptom changes, positive correlations were found between streptococcal titers and obsessive-compulsive severity rating changes (p=.0130). These subjects were also more likely to have elevated group A streptococcal titers during the majority of observations (p=.001). Tic symptom exacerbations occurred more often in the fall/winter months than spring/summer months (p=.03).

CONCLUSIONS

Patients with marked obsessive-compulsive/tic symptom changes may be characterized by streptococcal titer elevations and exhibit evidence of seasonal tic exacerbations.

Childhood-onset obsessive-compulsive disorder and tic disorders: case report and literature review

A subgroup of childhood-onset obsessive-compulsive disorder (OCD) and tic disorders has been found to have a postinfectious autoimmune-mediated etiology. Clinical observations and systematic investigations have shown that a subgroup of children with OCD and/or tic disorders have the onset and subsequent exacerbations of their symptoms following infections with group A beta-hemolytic streptococci (GABHS). This subgroup has been designated by the acronym PANDAS: pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections. Five clinical characteristics define the PANDAS subgroup: presence of OCD and/or tic disorder, prepubertal symptom onset, sudden onset or abrupt exacerbations, association with neurological abnormalities during exacerbations (adventitious movements or motoric hyperactivity), and the temporal association between symptom exacerbations and GABHS infections. The proposed poststreptococcal inflammatory etiology provides a unique opportunity for treatment and prevention, including immunomodulatory therapies such as plasma exchange and intravenous immunoglobulin. A placebo-controlled trial revealed that both intravenous immunoglobulin and plasma exchange were effective in reducing neuropsychiatric symptom severity (40 and 55% reductions, respectively) for a group of severely ill children in the PANDAS subgroup. Further research is required to determine why the treatments are helpful and to ascertain whether or not antibiotic prophylaxis can help prevent poststreptococcal symptom exacerbations.

Diagnosing Tourette syndrome: is it a common disorder?

OBJECTIVES

The evaluate the prevalence of Tourette syndrome (TS).

METHODS

A review of the literature on TS was undertaken to examine the prevalence of TS in mainstream children as well as those in special education.

RESULTS

Recent studies have indicated that TS occurs in around 1% of youngsters in mainstream schools between the ages of 5 and 16 years. It is even more common in youngsters with special educational needs.

CONCLUSIONS

TS is more common than was previously documented.

An immunological marker (D8/17) associated with rheumatic fever as a predictor of childhood psychiatric disorders in a community sample

BACKGROUND

Previous studies have documented that various behavioral disturbances accompany Sydenham's chorea, a neurologic variant of rheumatic fever. Further, an immunological marker associated with rheumatic fever (monoclonal antibody D8/17) has been reported to be elevated in several neuropsychiatric disorders, most frequently tics and obsessive-compulsive disorder. We examined this association in a community sample of children previously identified as being D8/17 positive or negative. It was hypothesized that D8/17 positivity would predict increased rates of tics and obsessive-compulsive disorder, even in the absence of Sydenham's chorea. Possible associations with other disorders accompanying Sydenham's chorea--hyperactivity, anxiety, and depression, also were explored.

METHOD

From 1991 to 1995, 2631 children (mean age = 9.6 +/- 1.6 years) from a low socioeconomic area of Mexico City were screened for the D8/17 marker. In a 2- to 5-year follow-up of 240 of these children (108 positive and 132 negative), structured psychiatric interviews and rating scales were administered to the child and main caretaker. Assessments were conducted and scored blind to the child's D8/17 status.

RESULTS

No association was seen between D8/17 positivity and tics or OCD.

CONCLUSION

This study failed to provide support for the generalized use of D8/17 as a marker of susceptibility to tics and OCD in a community sample.

Tourette's syndrome: a cross sectional study to examine the PANDAS hypothesis

BACKGROUND

The classical neurological disorder after group A beta haemolytic streptococcal infection is Sydenham's chorea. Recently a tic disorder occurring after group A streptococcal infection has been described and termed PANDAS (paediatric autoimmune neuropsychiatric disorders associated with streptococcal infection). It is proposed that antibodies induced after group A streptococcal infection react with basal ganglia neurones in Sydenham's chorea and PANDAS. Anti-basal ganglia antibodies (ABGA) are present in most cases of acute Sydenham's chorea, but rarely in controls.

OBJECTIVE

To investigate the hypothesis that Tourette's syndrome may be associated with group A streptococcal infection and ABGA.

METHODS

100 patients with Tourette's syndrome (DSM-IV-TR) were enrolled in a cross sectional study. Children with neurological disease (n = 50) and recent uncomplicated streptococcal infection (n = 40), adults with neurological disease (n = 50), and healthy adults (n = 50) were studied as controls. Recent group A streptococcal infection was defined using antistreptolysin O titre (ASOT). ABGA were detected using western immunoblotting and indirect immunofluorescence.

RESULTS

ASOT was raised in 64% of children with Tourette's syndrome compared with 15% of paediatric neurological disease controls (p < 0.0001), and in 68% of adults with Tourette's syndrome compared with 12% of adult neurological controls and 8% of adult healthy controls (p < 0.05). Western immunoblotting showed positive binding in 20% of children and 27% of adults with Tourette's syndrome, compared with 2-4% of control groups (p < 0.05). The most common basal ganglia binding was to a 60 kDa antigen, similar to the proposed antigen in Sydenham's chorea. Indirect immunofluorescence revealed autoantibody binding to basal ganglia neurones. Serological evidence of recent group A streptococcal infection, assessed by a raised ASOT, was detected in 91% (21/23) of Tourette's syndrome patients with positive ABGA compared with 57% (44/77) with negative ABGA (p < 0.01).

CONCLUSIONS

The results support a role of group A streptococcal infection and basal ganglia autoimmunity in a subgroup of patients with Tourette's syndrome and suggest a pathogenic similarity between Sydenham's chorea and some patients with Tourette's syndrome.

Antistreptococcal, neuronal, and nuclear antibodies in Tourette syndrome

Previous studies have suggested associations between Tourette syndrome and attention-deficit-hyperactivity disorder and antistreptococcal antibodies and between Tourette syndrome and antinuclear antibodies. In this study, antistreptolysin O, antideoxyribonuclease B, antinuclear, and antineuronal antibodies were measured in 41 children with Tourette syndrome and 38 controls, selected without regard to history of streptococcal infection. Results revealed that mean antistreptococcal titers did not differ between diagnostic groups. In addition, multiple regression analysis was unable to predict antistreptococcal antibody titers according to age and diagnosis. The frequency of elevated antistreptolysin O titers, based on a cutoff of 1:240, was significantly higher (P = 0.04) in patients with attention-deficit-hyperactivity disorder (64%) than in the group without attention-deficit-hyperactivity disorder (34%) but not when dichotomized according to age-matched normal values. No analysis of antideoxyribonuclease B titers identified any differences between groups. Antinuclear antibody titers were at least 1:160 in three of 33 Tourette syndrome patients; only one subject manifested a homogeneous staining pattern. Multiple regression analyses were unable to predict antinuclear, antineuronal, or anti-HTB-10 antibody titers according to the combination of age, diagnosis, and antistreptococcal titer. We suggest that longitudinal rather than single-point-in-time laboratory measurements be evaluated before definitive conclusions are drawn on associations between the diagnosis of Tourette syndrome, attention-deficit-hyperactivity disorder, or obsessive-compulsive disorders and antistreptococcal or antinuclear antibody titers.

Is Tourette's syndrome an autoimmune disease?

We provide a review of recent research findings which support the involvement of autoimmunity in childhood-onset tic disorders, in particular the presence of antineuronal autoantibodies, D8/17 B lymphocyte overexpression, a marker of chorea associated with streptococcal infection, and possible beneficial effects of immunomodulatory intervention. One of the most controversial areas in this field is the validity of the proposed PANDAS concept. Some researchers have delineated a putatively unique subgroup of patients, from the spectrum of illness encompassing Tourette's syndrome and obsessive-compulsive disorder (OCD), whose tics and obsessive-compulsive symptoms are shown to arise in response to beta-hemolytic streptococcal infections. They designated it by the term pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections (PANDAS). Herein we additionally present pros and cons concerning the concept of PANDAS. Finally, recommendations for future research directions are given.

Tics and problem behaviors in schoolchildren: prevalence, characterization, and associations

OBJECTIVE

Tic disorders are the most common movement disorder diagnosed in children and have symptoms that fluctuate in frequency and intensity over time. We conducted an 8-month longitudinal observational study to determine the variations in frequency of motor tics and associated problem behaviors.

METHODS

A total of 553 children, kindergarten through sixth grade, were observed monthly from November 1999 to June 2000 by 3 raters. Motor tics were recorded by location and rated for severity as none (0), mild (1), moderate (2), or severe (3). Problem behaviors were rated as absent (0), subclinical (1), or clinical (2) in each of 6 categories: disruptive, hyperactive, impulsive, aggressive, anxious, and distracted.

RESULTS

The monthly point prevalence of motor tics ranged from 3.2% to 9.6%, with an overall frequency of 24.4%. The monthly point prevalence of problem behaviors ranged from 2.6% to 11.0%, with an overall frequency of 25.7%. The incidence of motor tics and problem behaviors was significantly higher during the winter months of November through February, compared with the spring months of March through June (motor tics: z = 4.97; problem behaviors: z = 3.79). Motor tics were observed in 2 distinct patterns (isolated and persistent), which varied by the number of months present, gender ratio of affected children, severity of tic symptoms, and association with problem behaviors.

CONCLUSIONS

Motor tics and problem behaviors are frequent occurrences among schoolchildren and seem to occur more frequently during the winter months. For most children, the tics were mild, observed on only 1 occasion, and were not accompanied by problem behaviors.