Minocycline and autoimmunity.

Minocycline is the most widely prescribed systemic antibiotic for the management of acne. In the past several years, increasing attention has been paid to the drug, both for its potential use as a disease-modifying antirheumatic agent and for its propensity to engender untoward autoimmune reactions, including serum sickness-like disease, drug-induced lupus, and autoimmune hepatitis. This paper reviews the evidence for minocycline as an anti-inflammatory and immunomodulatory agent, its utility in the treatment of rheumatoid arthritis, and the spectrum of adverse reactions that have been ascribed to the drug in the past 5 years.     

Osteoarticular brucellosis and signs of autoimmunity]

We report two cases of osteoarticular brucellosis in childhood, which illustrate the diagnostic difficulties in non-endemic areas. CASE REPORT: A 12-year-old boy was admitted for a unilateral sacroiliitis for which the brucellosis origin was established by serological and blood cultures (without fever). Autoimmunity was detected and disappeared following the treatment of the affection. A six-year-old girl was admitted for a monoarthritis of the left ankle (with fever) for which the brucellosis origin was also established by serology and blood cultures. COMMENTS: The above cases underline the importance of knowing the atypical varieties of brucellosis. The brucellosis serologies need to take part in the etiological workup of an infectious osteoarthritis when a classic infectious cause cannot be proved. Blood cultures on a specific medium are essential to carry out, even in the case of apyrexia. Finally, the possibility of autoimmunity signs for the brucellosis has to be known to avoid orientating the diagnosis towards an autoimmune systemic disease.     

Insulin receptor autoimmunity and insulin resistance

The frequency of insulin receptor autoantibodies (IR-ab) was determined among adolescents and young adults with documented insulin resistance syndrome (IRS) with and without concomitant autoimmunity. The study population was comprised of 61 patients with obesity, acanthosis nigricans and insulin resistance (simple IRS); 12 with IRS and other autoimmune problems (lupus erythematosus, rheumatoid arthritis, dermatomyositis) (type B insulin resistance); six with autoimmune polyglandular syndrome type 2; and 40 healthy controls. Using our newly developed radiobinding assay system, we found no control positive while 25% of the patients with type B IRS (3/12) were positive, as expected. However, we found that 9.8% of the patients with simple IRS (6/61) were also reproducibly positive. All the latter patients with positive IR-ab were female with ovarian hyperandrogenism. The phenotype of those affected was otherwise unremarkably different from those without IR-ab. Our findings suggest that autoimmunity to insulin receptors may be causal in IRS especially for females with ovarian hyperandrogenism, and that IR-ab may be found in IRS besides those previously defined by the type B phenotype. Determining the level of IR-ab in childhood onset IRS may provide mechanistic insights into the genesis of insulin resistance and lead to novel treatment approaches.     

Genetic susceptibility in thyroid autoimmunity

The autoimmune thyroid diseases (AITD) include Graves' disease (GD) which manifests in hyperthyroidism and Hashimoto's thyroiditis (HT), manifesting as hypothyroidism. Genetic susceptibility in combination with external factors (e.g. dietary iodine) are believed to initiate the autoimmune response to thyroid antigens in AITD. Indeed, there is solid epidemiological data to support a strong genetic influence on the etiology of AITD including family and twin studies. Recently, there has been significant progress toward the identification of the AITD susceptibility genes. Several loci (genetic regions) that are linked with AITD have been mapped and in some of these loci putative AITD susceptibility genes have been identified. Some of these loci predispose to a single phenotype (GD or HT), while other loci are common to both diseases, indicating that there is a shared genetic susceptibility to GD and HT. The putative GD and HT susceptibility genes include both immune modifying genes (e.g. HLA, CTLA-4) and thyroid specific genes (e.g. TSHR, Tg) and it is likely that the final disease phenotype is a result of an interaction between these loci, as well as environmental influences.     

Endocrine autoimmunity in Turner syndrome

Background

Turner syndrome is caused by numeric and structural abnormalities of the X chromosome. An increased frequency of autoimmunity as well as an elevated incidence of autoantibodies was observed in Turner patients. The aim of this study was to conduct a retrospective analysis of the incidence of autoimmunity in 66 Italian patients affected by Turner syndrome.

Methods

Sixty-six unselected and consecutive Italian Turner patients were recruited. The association between age, karyotype and the presence of clinical/pre-clinical autoimmune disorders and of autoantibodies was examined.

Results

Out of the 66 Turner patients, 26 had thyroid autoimmune disorders (39.4%), 14 patients had Hashimoto’s thyroiditis with clinical or subclinical hypothyroidism (21.2%) and 12 patients had circulating anti-thyroid antibodies, echographic pattern of diffuse hypoechogenicity and normal thyroid hormone levels (18.2%). None were affected by Graves’ disease. We analyzed the overall incidence of thyroid autoimmunity within the 3 different age groups 0–9.9, 10–19.9 and 20–29.9 years. No statistically significant difference was observed in the incidence of thyroid autoimmunity within the age-groups (χ²-test p?>?0.05).Out of the 66 patients, 31 patients had the 45,X karyotype; within this first group 14 out of 31 patients were affected by autoimmune thyroid disease. A second group of 29 patients included 19 patients with mosaicism, 5 patients with deletions and 5 patients with ring chromosome; out of these 29 patients 7 were affected by autoimmune thyroid disease. A third group included 6 patients with X isochromosome; 5 out of 6 were affected by autoimmune thyroid disease. A statistically significant difference in the frequency of thyroid autoimmunity within the different karyotype groups was observed (χ²-test p?=?0.0173).When comparing the X isochromosome group with the pooled group of other karyotypes, of note, the frequency of thyroid autoimmunity was statistically higher in the X isochromosome group (Fisher exact test p?=?0.0315).

Conclusions

Our data confirm a high frequency of thyroid autoimmunity in Italian Turner patients. Patients with X isochromosome are more prone to develop thyroid autoimmunity. Further, an early assay of autoantibodies and monitoring thyroid hormones is fundamental for detecting hypothyroidism earlier and start adequate replacement therapy.

     

多发性抽动症与自身免疫相关性的研究

多发性抽动症是一种儿童时期起病的慢性神经精神性疾病,免疫学异常可能是部分易患儿童发病的潜在机制.研究发现,病原微生物感染后产生与中枢神经系统某些神经元发生交叉免疫反应的抗体,抗原抗体复合物沉积于中枢神经系统从而引发相应的临床症状.     

多发性抽动症与自身免疫相关性的研究

多发性抽动症是一种儿童时期起病的慢性神经精神性疾病,免疫学异常可能是部分易患儿童发病的潜在机制.研究发现,病原微生物感染后产生与中枢神经系统某些神经元发生交叉免疫反应的抗体,抗原抗体复合物沉积于中枢神经系统从而引发相应的临床症状.     

Mechanisms for induction of autoimmunity in humans

The triggering or immunogenic stimulus for human autoimmune diseases is unknown. It is not even known whether the stimulus is endogenous, i.e. truly "self" or exogenous, "non-self". Many autoimmune diseases are human lymphocyte antigen (HLA)-associated and demonstrate linkage to the HLA chromosome in family investigations. For most of these diseases, evidence is strong that the association is directly dependent on specific HLA class I or II molecules rather than on other genes located in the HLA region. Since HLA polymorphic HLA molecules have so far only been shown to have two distinct functions, both of which are immunological, a HLA association supports the notion that a particular disease is autoimmune. Furthermore, an association to a specific HLA allele implies that the immunogenic stimulus for autoimmunity would be one specific HLA-binding peptide and that, at least initially, autoimmunity is dependent on the reactivity of one or a limited number of potentially autoaggressive T cell clones. These findings are encouraging and form the basis for future preventive measures. One current theory is that autoimmune disease is precipitated by an environmental agent, such as a viral infection. Several different mechanisms to explain how a viral infection could induce autoimmune disease in humans are described and one specific example is presented for a virus-induced autoimmune disease in humans. The question of whether ITP could also be dependent on such a mechanism is briefly discussed.     

Maternal diet during pregnancy and islet autoimmunity in offspring

Background:  Recent studies on the etiology of type 1 diabetes mellitus (T1DM) suggest that the components of the infant diet are associated with islet autoimmunity (IA), a precursor of T1DM. The role of prenatal nutritional exposures has not been thoroughly investigated.
Methods:  The Diabetes Autoimmunity Study in the Young has enrolled newborns from 1993 to 2004 at increased risk for T1DM based on human leukocyte antigen (HLA) genotype and family history of T1DM. The child is tested for islet autoantibodies at 9 and 15 months, 2 yr, and annually thereafter. We conducted a cohort study of 642 subjects for whom a Willett food frequency questionnaire for the mother's third trimester diet was completed. A case is defined as a subject who tests positive for islet autoantibodies at two consecutive blood draws and is still positive (or diabetic) at last follow-up (n = 27).
Maternal consumption frequencies of potatoes, other root vegetables, gluten-containing foods, non-gluten cereal grains, cow's milk and cow's milk products, fruits, vegetables, meat and poultry, and fish were analyzed in a survival analysis.
Results:  Adjusting for breast-feeding duration, age at first cereal introduction, ethnicity, HLA genotype, family history of T1DM, and total caloric intake, higher maternal intake of potatoes (hazard ratio for one standard deviation difference: 0.49, 95% confidence interval: 0.28–0.86) was associated with a delayed time to IA onset. No other food groups ingested during pregnancy were associated with IA in the child.
Conclusions:  The composition of the maternal diet during pregnancy may play a role in the offspring's risk of development of IA and potentially T1DM.     

Seasonality of month of birth differs between type 1 diabetes patients with pronounced beta-cell autoimmunity and individuals with lesser or no beta-cell autoimmunity

OBJECTIVE: To establish whether children with type 1 diabetes mellitus (T1D) with signs of pronounced beta-cell-specific autoimmunity as reflected by high autoantibody titers or positivity for several beta-cell-specific autoantibodies show a different pattern of month of birth (MOB) compared with children with T1D and low beta-cell autoimmunity and that of the general population. RESEARCH DESIGN AND METHODS: Cosinor analysis was used to analyze MOB rhythmicity in Swedish children with new onset T1D (n = 572), in whom the glutamate decarboxylase autoantibody (GAD65Ab) titer was determined and compared with that in 833 healthy children, and in 505 children with T1D in Berlin, in whom the titers of autoantibodies to insulin, GAD65, and islet antigen-2 were compared with the MOB pattern in the general population (n = 446 571). RESULTS: In both cohorts of children with T1D, we found that children with either a high GAD65Ab titer (above the 80th percentile) or positivity for three beta-cell-specific autoantibodies differed in their pattern of MOB from the healthy population. CONCLUSIONS: Our past and present observations support the hypothesis that the autoimmune process leading to childhood T1D is in part triggered in the perinatal period by viral infections in genetically susceptible individuals. The present study suggests that the process is linked to titer levels of autoantibodies.