Selective Theca Cell Dysfunction in Autoimmune Oophoritis Results in Multifollicular Development, Decreased Estradiol, and Elevated Inhibin B Levels

We describe the clinical course of three women with presumptive autoimmune oophoritis who developed multiple follicles but very low to undetectable estradiol levels. Multiple follicles developed spontaneously in all subjects and during pulsatile GnRH treatment for ovulation induction in subject 1. The development of multiple dominant follicles was accompanied by LH levels in the postmenopausal range and FSH levels at the upper limit for premenopausal women. Serum inhibin B levels were elevated appropriately in the setting of multifollicular development, but estradiol levels remained low. Measurement of estradiol precursors demonstrated androstenedione and estrone levels below the 95th percentile in normal women. Adrenal cortical antibodies, and antibodies to 21-hydroxylase and P450 side chain cleavage enzymes were identified in all subjects. All subjects met the criteria for premature ovarian failure during follow-up. Subject 1 later developed adrenal failure, whereas subject 3 had adrenal failure at the time of the study. These subjects elucidate the hormonal pattern in autoimmune oophoritis, before the full criteria for premature ovarian failure are met. The elevated inhibin A and B levels, which accompany the development of multiple small and dominant follicles in these women, suppress FSH relative to LH levels, virtually independent of estradiol. These data provide further evidence for an important role of inhibin B and inhibin A in the negative feedback control of FSH. In addition, the normal inhibin A and inhibin B production in the absence of estradiol precursors and estradiol provide insight into the selective dysfunction of the theca cells in autoimmune oophoritis

Measuring adrenal autoantibody response: Interlaboratory concordance in the first international serum exchange for the determination of 21-hydroxylase autoantibodies

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Inflammatory Adipokines, High Molecular Weight Adiponectin, and Insulin Resistance: A Population-Based Survey in Prepubertal Schoolchildren

BackgroundThe aim of this study was to investigate sex differences and associations of high molecular weight (HMW) adiponectin, leptin and proinflammatory adipokines, individually or in combinations, with adiposity and insulin resistance (IR) measures in prepubertal childhood.MethodologyWe studied 305 prepubertal children (boys/girls: 144/161; Tanner stage 1; age: 5-13 yr), included in a cohort of 44,231 adolescents who participated in an extensive Italian school-based survey. According to Cole's criteria, 105 individuals were lean (L; boys/girls: 59/46), 60 overweight (OW; boys/girls: 32/28) and 140 obese (OB; boys/girls: 70/70). Measurements comprised total and HMW adiponectin, leptin, as well as a panel of proinflammatory adipokines/chemokines associated with diabetes risk.Principal findingsLeptin-, and the leptin-to-HMW adiponectin ratio (L/HMW)-, increased progressively (pConclusionsIn prepubertal children, leptin emerges as a sex-independent discrimination marker of adiposity degree and as a useful, sex-associated predictor of the systemic insulin resistance

Prevention and treatment of autoimmune diseases with plant virus nanoparticles

Plant viruses are natural, self-assembling nanostructures with versatile and genetically programmable shells, making them useful in diverse applications ranging from the development of new materials to diagnostics and therapeutics. Here, we describe the design and synthesis of plant virus nanoparticles displaying peptides associated with two different autoimmune diseases. Using animal models, we show that the recombinant nanoparticles can prevent autoimmune diabetes and ameliorate rheumatoid arthritis. In both cases, this effect is based on a strictly peptide-related mechanism in which the virus nanoparticle acts both as a peptide scaffold and as an adjuvant, showing an overlapping mechanism of action. This successful preclinical testing could pave the way for the development of plant viruses for the clinical treatment of human autoimmune diseases

Humoral immunity to recombinant human autoantigens in organ-specific autoimmune disease

HUMORAL IMMUNITY TO RECOMBINANT HUMAN AUTOANTIGENS IN ORGAN-SPECIFIC AUTOIMMUNE DISEASESAlberto Falorni, from Endocrine & Diabetes Unit, Department of Molecular Medicine, KarolinskaInstitute, Stockholm, Sweden Insulin-dependent diabetes mellitus (IDDM) and idiopathic Addison's disease are organ-specificautoimmune diseases characterized by the presence of circulating autoantibodies. The role ofautoantibodies in the pathogenesis of these diseases is not fully understood, but their presence can beused as a marker for diagnosis and prediction. The development of novel autoantibody assays is acritical step in improving both the accuracy of IDDM prediction and our understanding of themechanims of autoantibody formation. Several islet proteins are target of circulating autoantibodies inIDDM, and the enzyme glutamic acid decarboxylase (GAD) is a major autoantigen in this disease. In our project we developed sensitive and specific radiobinding assays for GAD65Ab andGAD67Ab, which used in vitro translated recombinant human GAD65 or rat GAD67. Subsequentlywe improved the critical steps of our GAD65Ab assay, and we developed a novel, semi-automatedassay which allows a single operator to analyse up to 400 serum samples per week. Our GAD65Abassay was validated in international workshops, and found to have highest diagnostic sensitivity andspecificity for IDDM. Using our GADAb immunoassays, we have demonstrated the high occurrence ofGAD65Ab in Japanese patients with short-duration IDDM. GAD65Ab were also found in 10/20 (50%)slowly progressive IDDM patients, that demonstrates an underlying autoimmunity in these patients. InCaucasians, GAD65Ab were found in 75-76% (and GAD67Ab in 15-20%) of IDDM patients and only1-1.5% of healthy subjects. Occurrence of GAD65Ab was both age- and gender-dependent, andprevalence of GAD65Ab resulted higher in female and in adult patients. In IDDM patients with clinicalonset between age 20 and 40 years, presence of GAD65Ab had the highest diagnostic sensitivity for thedisease, as compared to ICA or IAA. GAD65Ab, ICA and IAA were found in 11.5%, 8.1%-and10.8%, respectively, of offspring of IDDM father and in only 2.1%, 1.4% and 2.8%, respectively, ofoffspring of IDDM mothers. These data were interpreted to demonstrate that IDDM mothers transmitislet autoimmunity less frequently to their offspring than IDDM fathers. As the risk for IDDM isapproximately 5-fold lower in offspring of IDDM mothers than offspring of IDDM fathers, the resultsof our study demonstrate that prevalence of autoantibodies in offspring of IDDM parents correlates withthe disease risk. In two studies, GAD65Ab and GAD67Ab were found in Graves' or APS I patients,also in absence of clinical signs of IDDM. We used hybrid molecules generated by substitution ofregions of GAD65 with homologous regions of GAD67 to localise the major, IDDM-relatedGAD65Ab epitopes in the central and carboxy-terminal domains of GAD65. In the same study, titres ofcarboxy-terminal GAD65 epitope-specific antibodies were significantly higher in IDDM patients than inhealthy controls and may, hypothetically, be used to distinguish IDDM from healthy children. The enzyme steroid-21-hydroxylase (P450c21) is a major autoantigen in autoimmune Addison'sdisease. To determine the diagnostic sensitivity and specificity of P450c21Ab for autoimmuneAddison's disease we developed a novel radiobinding assay using in vitro translated P450c21.P450c21Ab were found in 16/16 (100%) idiopathic Addison patients with less than 20 years diseaseduration, and in 8/12 (67%) patients with more than 20 years disease duration. Levels of P450c21Abinversely correlated with disease duration. The diagnostic sensitivity of P450c21Ab, as detected in ourradiobinding assay, was compared to that of a classical indirect immunofluorescence assay for adrenalcortex autoantibodies, and found to be higher. In two separate studies, P450c21Ab were not found in 5patients with adrenoleukodystrophy and in 7 patients with either post-tuberculosis or post-adrenalectomy Addison's disease. In patients with other endocrine autoimmune diseases, P450c21Abwere shown to be highly specific for Addison's disease. We have also shown that single, naturally-occuring amino acid substitutions of the COOH-terminal domain of P450c21 inhibit antibody binding,by modifying one or more conformation-dependent autoantibody epitope(s). In conclusion, we have demonstrated that presence of GAD65Ab or P450c21Ab is stronglyassociated with IDDM or Addison's disease, respectively. Our GAD65Ab and P450c21Ab assaysshould prove useful to identify subjects at high risk for these organ-specific autoimmune diseases.Key words: IDDM, Addison's disease, autoantibodies, recombinant autoantigens, radioimmunoassay, disease prediction, glutamic-acid decarboxylase, steroid-21-hydroxylaseISBN-91-628-2121-