Temporal Association of Certain Neuropsychiatric Disorders Following Vaccination of Children and Adolescents: A Pilot Case-Control Study.

BACKGROUND: Although the association of the measles, mumps, and rubella vaccine with autism spectrum disorder has been convincingly disproven, the onset of certain brain-related autoimmune and inflammatory disorders has been found to be temporally associated with the antecedent administration of various vaccines. This study examines whether antecedent vaccinations are associated with increased incidence of obsessive-compulsive disorder (OCD), anorexia nervosa (AN), anxiety disorder, chronic tic disorder, attention deficit hyperactivity disorder, major depressive disorder, and bipolar disorder in a national sample of privately insured children. METHODS: Using claims data, we compared the prior year's occurrence of vaccinations in children and adolescents aged 6-15 years with the above neuropsychiatric disorders that were newly diagnosed between January 2002 and December 2007, as well as two control conditions, broken bones and open wounds. Subjects were matched with controls according to age, gender, geographical area, and seasonality. Conditional logistic regression models were used to determine the association of prior vaccinations with each condition. RESULTS: Subjects with newly diagnosed AN were more likely than controls to have had any vaccination in the previous 3 months [hazard ratio (HR) 1.80, 95% confidence interval 1.21-2.68]. Influenza vaccinations during the prior 3, 6, and 12 months were also associated with incident diagnoses of AN, OCD, and an anxiety disorder. Several other associations were also significant with HRs greater than 1.40 (hepatitis A with OCD and AN; hepatitis B with AN; and meningitis with AN and chronic tic disorder). CONCLUSION: This pilot epidemiologic analysis implies that the onset of some neuropsychiatric disorders may be temporally related to prior vaccinations in a subset of individuals. These findings warrant further investigation, but do not prove a causal role of antecedent infections or vaccinations in the pathoetiology of these conditions. Given the modest magnitude of these findings in contrast to the clear public health benefits of the timely administration of vaccines in preventing mortality and morbidity in childhood infectious diseases, we encourage families to maintain vaccination schedules according to CDC guidelines.

Hypothesis: conjugate vaccines may predispose children to autism spectrum disorders.

The first conjugate vaccine was approved for use in the US in 1988 to protect infants and young children against the capsular bacteria Haemophilus influenzae type b (Hib). Since its introduction in the US, this vaccine has been approved in most developed countries, including Denmark and Israel where the vaccine was added to their national vaccine programs in 1993 and 1994, respectively. There have been marked increases in the reported prevalence of autism spectrum disorders (ASDs) among children in the US beginning with birth cohorts in the late 1980s and in Denmark and Israel starting approximately 4-5 years later. Although these increases may partly reflect ascertainment biases, an exogenous trigger could explain a significant portion of the reported increases in ASDs. It is hypothesized here that the introduction of the Hib conjugate vaccine in the US in 1988 and its subsequent introduction in Denmark and Israel could explain a substantial portion of the initial increases in ASDs in those countries. The continuation of the trend toward increased rates of ASDs could be further explained by increased usage of the vaccine, a change in 1990 in the recommended age of vaccination in the US from 15 to 2 months, increased immunogenicity of the vaccine through changes in its carrier protein, and the subsequent introduction of the conjugate vaccine for Streptococcus pneumoniae. Although conjugate vaccines have been highly effective in protecting infants and young children from the significant morbidity and mortality caused by Hib and S. pneumoniae, the potential effects of conjugate vaccines on neural development merit close examination. Conjugate vaccines fundamentally change the manner in which the immune systems of infants and young children function by deviating their immune responses to the targeted carbohydrate antigens from a state of hypo-responsiveness to a robust B2 B cell mediated response. This period of hypo-responsiveness to carbohydrate antigens coincides with the intense myelination process in infants and young children, and conjugate vaccines may have disrupted evolutionary forces that favored early brain development over the need to protect infants and young children from capsular bacteria.

Children with Tourette's syndrome may suffer immunoglobulin A dysgammaglobulinemia: preliminary report.

BACKGROUND: Postinfectious autoimmunity has been implicated in Tourette's syndrome and obsessive-compulsive disorder (TS/OCD), whereas increased frequency of upper respiratory tract infections (URTI) in TS/OCD patients suggests immune deficiency. We hypothesized that antineuronal antibodies may be elevated in patients (reflecting autoimmune processes), and levels of total immunoglobulins (Igs) may be decreased (reflecting immune deficiency). METHODS: We analyzed plasma of TS/OCD patients (n = 24) and healthy age- and sex-matched control subjects (n = 22) by enzyme-linked immunosorbent assay (ELISA) for the levels of total and specific IgG, IgM, and IgA against antigens previously identified in multiple sclerosis (myelin basic protein and myelin-associated glycoprotein) and Sydenham's chorea (ganglioside-GM1, lysoganglioside, and tubulin). RESULTS: Total IgA was decreased in TS/OCD patients (median 115 mg/100 mL) compared with control subjects (141 mg/100 mL; p = .02). Specific IgA against all antigens, except tubulin were also decreased in the patients (MPB 0 vs. 13 [ELISA units [EU]; myelin-associated glycoprotein 29 vs. 44 EU, p = .04; ganglioside GM1 21 vs. 35 EU, p = .01; lysoganglioside 44 vs. 56 EU, p = .03; tubulin 44 vs. 44 EU, p = .8). The levels of total IgA and anti-myelin basic protein (MBP) IgA were significantly lower in the subgroup of pediatric autoimmune neuropsychiatric disorder associated with Streptococcus (PANDAS) cases (n = 10) than in non-PANDAS cases (n = 9; total IgA 98 mg/100 mL vs. 133 mg/mL, p = .03; anti-MBP IgA 1 vs. 6 EU, p = .03) or healthy control subjects (total IgA 141 mg/100 mL, p = .02; anti-MBP IgA 13 EU, p = .005). CONCLUSIONS: At least some TS/OCD patients may suffer IgA dysgammaglobulinemia, possibly rendering the children more prone to URTI.