AutoAntibody Tests Abstracts 1

© 2012

Stiff-person syndrome (SPS) and anti-GAD-related CNS degenerations: protean additions to the autoimmune central neuropathies

            (Ali, Rowley et al. 2011) Download

Stiff Person Syndrome (SPS) is a rare autoimmune neurological disease attributable to autoantibodies to glutamic acid decarboxylase (anti-GAD) more usually associated with the islet beta cell destruction of autoimmune type 1 diabetes (T1D). SPS is characterized by interference in neurons with the synthesis/activity of the inhibitory neurotransmitter gamma amino butyric acid (GABA) resulting in the prototypic progressive spasmodic muscular rigidity of SPS, or diverse neurological syndromes, cerebellar ataxia, intractable epilepsy, myoclonus and several others. Remarkably, a single autoantibody, anti-GAD, can be common to widely different disease expressions, i.e. T1D and SPS. One explanation for these data is the differences in epitope engagement between the anti-GAD reactivity in SPS and T1D: in both diseases, anti-GAD antibody reactivity is predominantly to a conformational epitope region in the PLP- and C-terminal domains of the 65 kDa isoform but, additionally in SPS, there is reactivity to conformational epitope(s) on GAD67, and short linear epitopes in the C-terminal region and at the N-terminus of GAD65. Another explanation for disease expressions in SPS includes ready access of anti-GAD to antigen sites due to immune responsiveness within the CNS itself according to intrathecal anti-GAD-specific B cells and autoantibody. Closer study of the mysterious stiff-person syndrome should enhance the understanding of this disease itself, and autoimmunity in general.


Auto-immune cerebellar ataxia with anti-GAD antibodies accompanied by de novo late-onset type 1 diabetes mellitus

            (Bayreuther, Hieronimus et al. 2008) Download

Autoantibodies to glutamic acid decarboxylase (GAD-Ab) have been described in stiff-man syndrome, type 1 diabetes mellitus and in patients with auto-immune polyglandular failure. In addition, a few patients with progressive cerebellar ataxia show high titres of GAD-Ab, suggesting an auto-immune origin. AIM: This is a report of a patient presenting with cerebellar ataxia associated to late-onset type 1 diabetes and polyendocrine auto-immunity. CASE REPORT: A 47-year-old woman with a past medical history of vitiligo and Graves' disease presented with late-onset type 1 diabetes. For two years, she had complained of progressive gait instability and oscillopsia. Neurological examination revealed multidirectional, horizontal rotatory fixation and gaze nystagmus, gait ataxia and mild limb ataxia in the left upper arm. METHODS: Imaging studies, electrophysiological studies, routine biological and detailed immunological screening as well as a study of cerebrospinal fluid (CSF) were performed. RESULTS: Brain magnetic resonance imaging showed cerebellar atrophy. Routine biological screening was normal. Immunological screening showed positivity for numerous antibodies (Ab), including GAD-Ab, thyroid peroxidase-Ab, thyroglobulin-Ab, 21-hydroxylase (adrenal)-Ab, gastric parietal cell-Ab and GM1 ganglioside IgG-Ab. CSF was normal, with no oligoclonal bands detected. GAD-Ab were positive in CSF, suggesting an auto-immune origin of the cerebellar ataxia. Treatment with intravenous immunoglobulin led to a slight improvement in nystagmus and gait instability. CONCLUSION: Auto-immune cerebellar ataxia related to GAD-Ab is a rare condition that typically affects women with late-onset type 1 diabetes or other auto-immune disorders, including auto-immune polyendocrinopathy. Immunomodulatory treatment may be effective.

Clinical applications of diabetes antibody testing

         (Bingley 2010) Download

CONTEXT: Autoantibodies to glutamate decarboxylase, islet antigen-2, insulin, and zinc transporter-8 are characteristic of type 1 diabetes. They are detectable before clinical onset and define the subgroup of patients with latent autoimmune diabetes in adults. Autoantibody assays are increasingly available to clinicians. This article reviews the prognostic significance of autoantibodies and considers the utility of diabetes antibody testing in routine clinical practice. EVIDENCE ACQUISITION: The medical literature to May 2009 was reviewed for key articles and consensus statements covering use of islet autoantibody testing for prediction and classification of diabetes and implications for therapy. EVIDENCE SYNTHESIS: Sensitive and specific glutamate decarboxylase and islet antigen-2 antibody assays are widely available, although to insulin autoantibody assays remain variable. Islet autoantibodies appear early in life, and testing for multiple antibodies identifies unaffected individuals at very high risk of type 1 diabetes with high sensitivity. This is important for research, but currently no intervention prevents or delays diabetes, and evidence of benefit from awareness of risk is weak. In non-insulin-treated diabetes, patients with autoantibodies progress to insulin requirement more rapidly, but evidence that testing benefits the individual patient is limited. Antibody testing is useful in classifying diabetes of other types. CONCLUSIONS: Islet autoantibody testing allows prediction of type 1 diabetes and definition of the latent autoimmune diabetes in adults subgroup of non-insulin-treated patients. Although useful for research, until therapies modulating the disease process become available, the benefit to individual patients is generally questionable. With a few exceptions, diabetes antibody testing does not yet have a role in routine clinical care.

Autoantibodies as predictors of disease: the clinical and experimental evidence

            (Bizzaro 2007) Download

Several studies have shown that autoimmune diseases are preceded by a long pre-clinical phase, and that many autoantibodies can be detected in the serum of asymptomatic subjects years before the clinical manifestations become evident. Tests for these autoantibodies could therefore be used in principle in screening studies on unselected populations to identify individuals predisposed to the development of the disease at an early stage, and start treatment or adopt preventive measures where possible. This aspect has aroused particular interest, as multiplex investigation techniques are already available, and microarray methods are under development, which will probably allow tens or hundreds of autoantibodies to be measured simultaneously. However, as no antibody assay offers 100% specificity, and the results are strongly dependent on the assay method used to measure the autoantibodies, it is essential to use assay methods with high diagnostic specificity, to minimize false positives and obtain a high positive predictive value. This review examines the various autoantibodies for which a role in predicting the development of an autoimmune disease has been demonstrated in long-term prospective studies.


Autoantibodies to human tryptophan hydroxylase and aromatic L-amino acid decarboxylase

            (Dal Pra, Chen et al. 2004) Download

OBJECTIVE: To assess the prevalence of autoantibodies (Abs) to tryptophan hydroxylase (TPH) and aromatic l-amino acid decarboxylase (AADC) in patients with different autoimmune diseases and to analyse their respective epitopes. DESIGN: TPH and AADC Abs were measured in an immunoprecipitation assay using (35)S-labelled full-length and fragments of TPH and AADC. METHODS: Patients with different autoimmune adrenal diseases (n=84), non-adrenal autoimmune diseases (n=37), idiopathic vitiligo (n=8) and 56 healthy blood donors were studied. RESULTS: Fourteen of twenty-three (61%) of patients with autoimmune polyglandular syndrome (APS) type I and 1/34 (3%) of patients with isolated Addison's disease (AD) were positive for TPH Abs. None of the patients with APS type II (n=27), coeliac disease (n=10), autoimmune thyroid disease (AITD) (n=11), type 1 diabetes mellitus (DM) (n=16) or idiopathic vitiligo (n=8) was positive for TPH Abs. AADC Abs were detected in 12/23 (52%) patients with APS type I, in 1/29 (3%) patients with APS type II and 1/34 (3%) patients with isolated AD. None of the patients with coeliac disease, type 1 DM, AITD or idiopathic vitiligo was positive for AADC Abs. TPH Abs were found to interact with the C-terminal amino acids (aa) 308-423, central aa 164-205 and N-terminal aa 1-105 of the TPH molecule. AADC Ab binding epitopes were within the C-terminal aa 382-483, the central aa 243-381 and the N-terminal aa 1-167. CONCLUSIONS: Our study suggests that TPH Abs and AADC Abs react with several different epitopes and that different epitopes are recognized by different sera. The prevalence of TPH Abs and AADC Abs in patients with APS type I in our study is in agreement with previous reports. TPH Abs and AADC Abs were found very rarely in patients with other forms of autoimmune adrenal disease and were not detected in patients with non-adrenal autoimmune diseases.

Identification of tryptophan hydroxylase as an intestinal autoantigen

         (Ekwall, Hedstrand et al. 1998) Download

BACKGROUND: Autoimmune polyendocrine syndrome type 1 (APS1) is an autosomal recessive disorder with both endocrine and non-endocrine features. Periodic gastrointestinal dysfunction occurs in 25-30% of APS1 patients. We aimed to identify an intestinal autoantigen. METHODS: A human duodenal cDNA library was immunoscreened with serum samples from APS1 patients. A positive clone was identified and used for in-vitro transcription and translation, followed by immunoprecipitation with serum samples from 80 APS1 patients from Norway, Finland, and Sweden. Sections of normal and APS1-affected small intestine were immunostained with serum from APS1 patients and specific antibodies. An enzyme-inhibition assay was used to characterise the autoantibodies. FINDINGS: We isolated a cDNA clone coding for tryptophan hydroxylase. 48% (38/80) of APS1 patients had antibodies to tryptophan hydroxylase, whereas no reactivity to this antigen was detected in patients with other autoimmune diseases (n=372) or healthy blood donors (n=70). 89% (17/19) of APS1 patients with gastrointestinal dysfunction were positive for antibodies to tryptophan hydroxylase, compared with 34% (21/61) of patients with no gastrointestinal dysfunction (p<0.0001). Serum from antibody-positive APS1 patients specifically immunostained tryptophan-hydroxylase-containing enterochromaffin cells in normal duodenal mucosa. No serotonin-containing cells were seen in duodenal biopsy samples from APS1 patients. Serum from antibody-positive APS1 patients almost completely inhibited activity of tryptophan hydroxylase. INTERPRETATION: Tryptophan hydroxylase is an endogenous intestinal autoantigen in APS1, and there is an association between antibodies to the antigen and gastrointestinal dysfunction. Analysis of antibodies to tryptophan hydroxylase may be a valuable diagnostic tool to predict and monitor gastrointestinal dysfunction in APS1.

Tryptophan hydroxylase autoantibodies and intestinal disease in autoimmune polyendocrine syndrome type 1

            (Ekwall, Sjoberg et al. 1999) Download

Tryptophan hydroxylase antibodies, associated with gastrointestinal disease in autoimmune polyendocrine syndrome type 1, are specific for this disease and not present in patients with other bowel disorders or healthy controls.

Challenges to the use of autoantibodies as predictors of disease onset, diagnosis and outcomes

         (Fritzler 2008) Download

Autoantibodies (AA) are a serological hallmark of most autoimmune diseases. In contrast to genetic markers that show a predisposition for disease development, certain AA serve as diagnostic biomarkers and classification criteria for a number of these conditions. The role of AA is still not clearly understood: some are pathogenic, some disease specific and others serve as predictors of disease outcome, but little is known about those that protect against disease or serve as signatures of the inciting agent of autoimmunity. Because of growing evidence that some AA antedate clinical diagnosis, significant effort is being spent on gathering evidence regarding their value as predictors of disease onset and outcome. Although many studies have shown that specific AA are detected in the pre-clinical phase and are biomarkers of increased risk of developing an autoimmune disease, they are currently not widely used to determine risk or as a pre-clinical screen. Additional prospective and retrospective studies are urgently needed to determine the precise risk of developing autoimmune disease in the presence of various AA. Such studies must be attended by the development of strategies for earlier diagnosis and novel therapeutic interventions of early disease.

Diagnosis of Parkinson's disease based on disease-specific autoantibody profiles in human sera

            (Han, Nagele et al. 2012) Download

Parkinson's disease (PD), hallmarked by a variety of motor disorders and neurological decline, is the second most common neurodegenerative disease worldwide. Currently, no diagnostic test exists to identify sufferers, and physicians must rely on a combination of subjective physical and neurological assessments to make a diagnosis. The discovery of definitive blood-borne biomarkers would be a major step towards early and reliable diagnosis. Despite attention devoted to this search, such biomarkers have remained elusive. In the present study, we used human protein microarrays to reveal serum autoantibodies that are differentially expressed among PD and control subjects. The diagnostic significance of each of these autoantibodies was evaluated, resulting in the selection of 10 autoantibody biomarkers that can effectively differentiate PD sera from control sera with a sensitivity of 93.1% and specificity of 100%. PD sera were also distinguishable from sera obtained from Alzheimer's disease, breast cancer, and multiple sclerosis patients with accuracies of 86.0%, 96.6%, and 100%, respectively. Results demonstrate that serum autoantibodies can be used as highly specific and accurate biomarkers for PD diagnosis throughout the course of the disease.

Stiff-person syndrome associated with cerebellar ataxia and high glutamic acid decarboxylase antibody titer

            (Kono, Miyajima et al. 2001) Download

Glutamic acid decarboxylase (GAD) is the main target of humoral autoimmunity in patients with insulin-dependent diabetes mellitus (IDDM) and stiff-person syndrome. We reviewed the case of a 46-year-old woman who had cerebellar ataxia before getting stiff-person syndrome and IDDM with high anti-GAD autoantibody titers. This was a rare case in which there were both the clinical symptoms of stiff-person syndrome and cerebellar ataxia. In western blot analysis her serum reacted with 65-kDa proteins from rat cerebellum, cerebral cortex, and spinal cord. Autoantibodies to GAD may cause functional impairment of gamma-aminobutyric acid (GABA) neurons in the spinal cord as well as in the cerebellum.


Autoantibodies and the risk of cardiovascular events

         (Liang, Kremers et al. 2009) Download

OBJECTIVE: Inflammation and autoimmunity are associated with increased cardiovascular (CV) risk in patients with rheumatoid arthritis. This association may also be present in those without rheumatic diseases. Our purpose was to determine whether rheumatoid factor (RF), antinuclear antibody (ANA), and cyclic citrullinated peptide antibody (CCP) positivity are associated with increased risk of CV events and overall mortality in those with and without rheumatic diseases. METHODS: We performed a population-based cohort study of all subjects who had a RF and/or ANA test performed between January 1, 1990, and January 1, 2000, and/or CCP test performed between September 1, 2003, and January 1, 2005, with followup until April 1, 2007. Outcomes were ascertained using diagnostic indices from complete medical records, including CV events [myocardial infarction (MI), heart failure (HF), and peripheral vascular disease (PVD)] and mortality. Cox models were used to analyze the data. RESULTS: There were 6783 subjects with RF, 7852 with ANA, and 299 with CCP testing. Of these, 10.4%, 23.9%, and 14.7% were positive for RF, ANA, and CCP, respectively. Adjusting for age, sex, calendar year, comorbidity, and rheumatic disease, RF and ANA positivity were significant predictors of CV events [hazard ratio (HR) 1.24 and 1.26] and death (HR 1.43 and 1.18). Adjusting for age, CCP positivity was associated with CV events, but this association was not statistically significant (HR 3.1; 95% CI 0.8, 12.3). CONCLUSION: RF and ANA positivity are significant predictors of CV events and mortality in both those with and those without rheumatic diseases. These results support the role of immune dysregulation in the etiology of CV disease.

Diagnosis of Alzheimer's disease based on disease-specific autoantibody profiles in human sera

            (Nagele, Han et al. 2011) Download

After decades of Alzheimer's disease (AD) research, the development of a definitive diagnostic test for this disease has remained elusive. The discovery of blood-borne biomarkers yielding an accurate and relatively non-invasive test has been a primary goal. Using human protein microarrays to characterize the differential expression of serum autoantibodies in AD and non-demented control (NDC) groups, we identified potential diagnostic biomarkers for AD. The differential significance of each biomarker was evaluated, resulting in the selection of only 10 autoantibody biomarkers that can effectively differentiate AD sera from NDC sera with a sensitivity of 96.0% and specificity of 92.5%. AD sera were also distinguishable from sera obtained from patients with Parkinson's disease and breast cancer with accuracies of 86% and 92%, respectively. Results demonstrate that serum autoantibodies can be used effectively as highly-specific and accurate biomarkers to diagnose AD throughout the course of the disease.

Aromatic-L-amino-acid decarboxylase, a pyridoxal phosphate-dependent enzyme, is a beta-cell autoantigen

            (Rorsman, Husebye et al. 1995) Download

Different autoantigens are thought to be involved in the pathogenesis of insulin-dependent diabetes mellitus, and they may account for the variation in the clinical presentation of the disease. Sera from patients with autoimmune polyendocrine syndrome type I contain autoantibodies against the beta-cell proteins glutamate decarboxylase and an unrelated 51-kDa antigen. By screening of an expression library derived from rat insulinoma cells, we have identified the 51-kDa protein as aromatic-L-amino-acid decarboxylase (EC 4.1.1.28). In addition to the previously published full-length cDNA, forms coding for a truncated and an alternatively spliced version were identified. Aromatic L-amino acid decarboxylase catalyzes the decarboxylation of L-5-hydroxytryptophan to serotonin and that of L-3,4-dihydroxyphenylalanine to dopamine. Interestingly, pyridoxal phosphate is the cofactor of both aromatic L-amino acid decarboxylase and glutamate decarboxylase. The biological significance of the neurotransmitters produced by the two enzymes in the beta cells remains largely unknown.

Predictors of autoimmune disease: autoantibodies and beyond

            (Rose 2008) Download

Increased emphasis has been placed in recent years on predictive biomarkers to foretell the onset or future course of disease. In autoimmune diseases, autoantibodies have proven to be valuable biomarkers because of their technical sensitivity, specificity, and stability during storage. Their predictive value is limited, however, by their prevalence. At present, predictive studies have utilized long-time evaluation of stable populations, families with one index case or retrospective investigations where large serum repositories are available. Our increasing knowledge of the steps leading from benign autoimmunity to frank autoimmune disease has suggested ways by which subtle genetic differences combined with assessment of the pattern of critical mediators can trace the progression of disease. The new tools of multiplex testing and information handling open opportunities to identify early signposts of disease.


Organ specific-autoantibodies: their role as markers and predictors of disease

            (Sarzi-Puttini and Doria 2008) Download

Autoantibody testing for autoimmune disease

         (Self 2010) Download

The proper use and interpretation of serologic testing for diagnosing autoimmune diseases presents a challenge to clinicians for several reasons. Most laboratory tests for autoimmune disease are significantly less than 100% sensitive or specific. In addition, different techniques for the same antibody test may give different results, such as indirect immunofluorescence and multiplex bead assay for antinuclear antibody. Autoantibody testing should only be performed in the context of the clinical workup of patients who have a reasonable likelihood of having the disease for which the testing is relevant. Otherwise, the predictive value of a positive test is too low. Particularly with antinuclear antibody and antineutrophil cytoplasmic antibody testing, clinicians must know the methodology through which the tests are being performed, and should develop a relationship with the laboratory pathologist so that inconsistent or surprising results can be investigated.

The PEVKEK region of the pyridoxal phosphate binding domain of GAD65 expresses a dominant B cell epitope for type 1 diabetes sera

            (Tong, Myers et al. 2002) Download

Molecular mimicry between the 65-kDa isoform of glutamic acid decarboxylase (GAD65) and the protein 2C (P2C) of Coxsackie B4 virus (CBV) may initiate human type 1 diabetes. GAD65 contains a motif that has a 6-amino acid identity with CBV-P2C (PEVKEK), whereas the weakly autoantigenic isoform, GAD67, contains PEVKTK. A human-derived monoclonal antibody (mAb) MICA3 reacts with a surface loop of GAD65 that includes PEVKEK, and mutagenic deletion of this loop was shown to reduce reactivity of GAD with the mAb by 70%. To establish that the PEVKEK motif on GAD65 contains a major epitope for diabetes sera and to identify the amino acids involved, mutants of nucleotides of GAD65 and GAD67 at sites in the PEVKEK motif were created and the expressed proteins used for radioimmunoprecipitation (RIP) tests with sera from patients with type 1 diabetes. A potent mouse mAb (GAD6) to GAD65, and a rabbit polyclonal antibody (AB108) to GAD67, were used to standardize the reactivity of the diabetes sera with the mutant molecules. Of 45 type 1 diabetes sera tested, 30 (67%) had an 80% or greater reduction of reactivity to GAD65(delta258-270) vs. intact GAD65. Various single-surface amino acids in the PEVKEK epitope region of GAD65 were mutated, but most molecules carrying these mutations reacted similarly to the parent molecule. However after point mutation of the equivalent motif of GAD67 (PEVKTK to PEVKEK), there was an increase in the reactivity of 12 of 49 (24%) type 1 diabetes sera tested; 7 of 8 sera reactive with GAD67 showed increased reactivity with GAD67(T273E), and 5 previously negative sera gained reactivity with GAD67(T273E). Thus, the PEVKEK motif on GAD65 contributes to serologic reactivity of type 1 diabetes sera. This favors the hypothesis that CBV infection causes type 1 diabetes by the process of viral mimicry with cross-reactivity to a critical epitope of GAD65.

Antibodies as predictors of complex autoimmune diseases and cancer

         (Vojdani 2008) Download

The pathologic role of autoantibodies in many autoimmune diseases is widely accepted. An enzyme immunoassay was used for measurement of antibodies against disease-specific antigens and etiologic agents for cross-reactive antigens associated with them. This antibody assay was applied to a panel of antigens for the detection of different neuroautoimmune diseases that included multiple sclerosis, motor peripheral neuropathies, multifocal motor neuropathy, amyotrophic lateral sclerosis, pediatric autoimmune neuropsychiatric disorder associated with streptococcal infection. We studied women with pregnancies complicated by neural tube defect, neuroborreliosis, autism and patients with possible somatic hypermutation. Antibodies were also measured against antigens and etiologic agents associated with primary biliary cirrhosis and chronic obstructive pulmonary disease. And, finally, antibodies were measured against several tumor antigens or peptides which are expressed in prostatic, breast and colon tissues. This panel of different autoantibodies was applied to 290 patients with neuroautoimmune disorders, cancer, and possible somatic hypermutation. The levels of these antibodies against different tissue-specific antigens and etiologic agents associated with them were significantly elevated in patients versus controls. We hope that this novel 96 antigen-specific ELISA will be used in additional studies that will prove its clinical efficacy, not only for the early diagnosis of many neuroautoimmune, liver and lung autoimmune disorders, but also for prognosis and the implementation of preventive steps for many complex diseases.


Antibodies as predictors of complex autoimmune diseases

            (Vojdani 2008) Download

Emerging evidence has suggested environmental factors such as infections and xenobiotics and some dietary proteins and peptides in the pathogenesis of many autoimmune diseases. Considering the fact that autoantibodies can often be detected prior to the onset of a disease, in this study an enzyme immunoassay was used for measurement of antibodies against different highly purified antigens or synthetic peptides originating not only from human tissue, but also from cross-reactive epitopes of infectious agents, dietary proteins and xenobiotics. The measurement of antibodies against a panel of antigens allows for identification of patterns or antibody signatures, rather than just one or two markers of autoimmunity, thus establishing the premise for increased sensitivity and specificity of prediction, as well as positive predictive values. This panel of different autoantibodies was applied to 420 patients with different autoimmune diseases, including pernicious anemia, celiac disease, thyroiditis, lupus, rheumatoid arthritis, osteoarthritis, Addison's disease, type 1 diabetes, cardiovascular disease and autoimmunity, which are presented in this article. In all cases, the levels of these antibodies were significantly elevated in patients versus controls. Antibody patterns related to neuroautoimmune disorders, cancer, and patients with somatic hypermutation will be shown in a subsequent article. We believe that this novel 96 antigen-specific autoantibody or predictive antibody screen should be studied for its incorporation into routine medical examinations. Clinicians should be aware that the detection of antibodies should not automatically mean that a patient will definitely become ill, but would rather give a percentage of risk for autoimmune disease over subsequent months or years.


References

Ali, F., M. Rowley, et al. (2011). "Stiff-person syndrome (SPS) and anti-GAD-related CNS degenerations: protean additions to the autoimmune central neuropathies." J Autoimmun 37(2): 79-87.

Bayreuther, C., S. Hieronimus, et al. (2008). "Auto-immune cerebellar ataxia with anti-GAD antibodies accompanied by de novo late-onset type 1 diabetes mellitus." Diabetes Metab 34(4 Pt 1): 386-8.

Bingley, P. J. (2010). "Clinical applications of diabetes antibody testing." J Clin Endocrinol Metab 95(1): 25-33.

Bizzaro, N. (2007). "Autoantibodies as predictors of disease: the clinical and experimental evidence." Autoimmun Rev 6(6): 325-33.

Dal Pra, C., S. Chen, et al. (2004). "Autoantibodies to human tryptophan hydroxylase and aromatic L-amino acid decarboxylase." Eur J Endocrinol 150(3): 313-21.

Ekwall, O., H. Hedstrand, et al. (1998). "Identification of tryptophan hydroxylase as an intestinal autoantigen." Lancet 352(9124): 279-83.

Ekwall, O., K. Sjoberg, et al. (1999). "Tryptophan hydroxylase autoantibodies and intestinal disease in autoimmune polyendocrine syndrome type 1." Lancet 354(9178): 568.

Fritzler, M. J. (2008). "Challenges to the use of autoantibodies as predictors of disease onset, diagnosis and outcomes." Autoimmun Rev 7(8): 616-20.

Han, M., E. Nagele, et al. (2012). "Diagnosis of Parkinson's disease based on disease-specific autoantibody profiles in human sera." PLoS One 7(2): e32383.

Kono, S., H. Miyajima, et al. (2001). "Stiff-person syndrome associated with cerebellar ataxia and high glutamic acid decarboxylase antibody titer." Intern Med 40(9): 968-71.

Liang, K. P., H. M. Kremers, et al. (2009). "Autoantibodies and the risk of cardiovascular events." J Rheumatol 36(11): 2462-9.

Nagele, E., M. Han, et al. (2011). "Diagnosis of Alzheimer's disease based on disease-specific autoantibody profiles in human sera." PLoS One 6(8): e23112.

Rorsman, F., E. S. Husebye, et al. (1995). "Aromatic-L-amino-acid decarboxylase, a pyridoxal phosphate-dependent enzyme, is a beta-cell autoantigen." Proc Natl Acad Sci U S A 92(19): 8626-9.

Rose, N. R. (2008). "Predictors of autoimmune disease: autoantibodies and beyond." Autoimmunity 41(6): 419-28.

Sarzi-Puttini, P. and A. Doria (2008). "Organ specific-autoantibodies: their role as markers and predictors of disease." Autoimmunity 41(1): 1-10.

Self, S. E. (2010). "Autoantibody testing for autoimmune disease." Clin Chest Med 31(3): 415-22.

Tong, J. C., M. A. Myers, et al. (2002). "The PEVKEK region of the pyridoxal phosphate binding domain of GAD65 expresses a dominant B cell epitope for type 1 diabetes sera." Ann N Y Acad Sci 958: 182-9.

Vojdani, A. (2008). "Antibodies as predictors of complex autoimmune diseases." Int J Immunopathol Pharmacol 21(2): 267-78.

Vojdani, A. (2008). "Antibodies as predictors of complex autoimmune diseases and cancer." Int J Immunopathol Pharmacol 21(3): 553-66.