Hormones, autoimmune diseases

Latex agglutination immunoassays are easily formatted into simple kits which can provide yes/no and semiquantitative estimates of antigen (or antibody) in a sample. The first such assay was developed in 1957 for rheumatoid factor (15) and assays are on the market for the deterrnination of many species of bacteria, fungi. Mycoplasma, parasites, ckettsia, and vimses, as well as for the deterrnination of autoimmune disease, hormones (qv), dmgs (see Pharmaceuticals), and blood proteins (16). Latex agglutination is also the basis of many home pregnancy tests. 

Types of autoimmune diseases vary widely, from organ-specific diseases such as thyroiditis where there may be stimulation (thyrotoxicosis) by antibody against the receptor for pituitary thyroid-stimulating hormone (TSH) or inhibition (myxoedema) by cell destruction probably mediated by NK cells and autoantibody, through to non-... 

In the adult population, the prevalence of overt hypothyroidism is 19 per 1000 women and 1 per 1000 men with annual incidence of overt hypothyroidism is 4 per 1000 women and 0.6 per 1000 men. Subclinical hypothyroidism is also more common in women, the incidence increases with age, with up to 10% of women older than 60 years having an increased thyroid-stimulating hormone concentration. Subclinical hypothyroidism is more common in people who have been treated for hyperthyroidism with radioactive iodine or surgery, and in those with organ-specific autoimmune diseases, such as pernicious anaemia, type 1 diabetes mellitus, or Addison s disease. 

Worldwide, the most common thyroid disorder is hypothyroidism resulting from dietary iodine deficiency. In iodine-replete areas of the world, most thyroid disorders are the result of autoimmune disease. The symptoms manifested in hypothyroid and hyperthyroid states are largely independent of any underlying disorder of the thyroid gland itself they are a function of the degree of hormone deficiency or excess. 

Hypothyroidism, a condition in which the circulating concentrations of thyroid hormones are too low, is the most prevalent thyroid disease. Primary hypothyroidism, the commonest form, is an autoimmune disease (Hashimoto s thyroiditis) often associated with goitre. Like other autoimmune diseases, it is more prevalent in women (4 per 1000) than in men (1 per 1000). Other causes include thyroidectomy, radioac tive ablation and, in some countries, iodine deficiency. Hypothyroidism can also be caused by several drugs, including lithium, interleukin-2 and interferon. Secondary hypothyroidism is a disease caused by decreased secretion of TSH by the pituitary. 

Understanding the molecular basis of immune responses has allowed the definition of mechanisms by which cellular function is altered by local hormones or autacoids in infections, cancer, autoimmune diseases, and organ transplant rejection. These processes present targets for therapeutic intervention. 

Endocrine factors. Most autoimmune diseases occur with unequal frequency in males and females. For example. Graves and Hashimoto s are 4-5 times, and SLE 10 times, more common in females, while ankylosing spondylitis is 3-4 times more frequent in males. These differences are believed to be the result of hormonal influences. A second well-documented hormonal effect is the marked reduction in disease severity seen in many autoimmune conditions during pregnancy. Rheumatoid arthritis is perhaps the classic example of this effect. In some cases there is also a rapid exacerbation (rebound) after birth. 

Treatments for autoimmune disease have traditionally been immunosuppressive, antiinflammatory or palliative. Non-immunological therapies, such as hormone replacement in Hashimoto s thyroiditis, treat the outcomes of the autoaggressive response. Dietary manipulation limits the severity of coeliac disease. Steroidal or NSAID treatment limits the inflammatory symptoms of many diseases. 

There is indirect evidence of sex differences in immunology. Women have a higher incidence of autoimmune diseases such as multiple sclerosis, rheumatoid arthritis, and systemic lupus erythematosus. The influence of sex hormones on the immune system may provide insight into these immunological disorders. For example, estrogen stimulates both humoral and cell-mediated immunity, whereas testosterone has the opposite effect (126). Therefore, it is not surprising that there is sex-dependent variability in response to immunosuppressive agents. 

Autoimmune disease of the thyroid can cause over- or underproduction of thyroid hormone. 

An example of the gender dilemma is illustrated in systemic lupus erythematosus (SLE) an autoimmune disease that occurs more frequently in women than men. The gender difference is attributed to differences in the metabolism of sex hormones or regulation by gonadotropin releasing hormone (GnRH). When it occurs in men, SLE tends to be more severe (Yacoub Wasef, 2004). Recent studies also indicate that SLE may be more common in nonwhite women of child bearing... 

Rheumatoid arthritis is a chronic, inflammatory, autoimmune disease of unknown etiology that if left untreated results in progressive joint destruction, deformity, disability, and premature death. Theories of possible etiologies include genetic, hormonal, viral, autoimmune, and environmental factors. The disease peaks between the fourth through sixth decades of life and is two to three times more common in women than in men. Differences in prevalence rates between ethnic groups are small. 

Recent reviews Hst more than 400 biotechnology-based pharmaceutical formulations either registered in clinical trials or undergoing review by the regulatory agencies for the treatment of nearly 150 diseases including cancer, infectious diseases, autoimmune diseases, and AIDS/HIV (1,2). Biotechnology-based pharmaceuticals already on the markets include recombinant blood factors, recombinant hormones, cytokines, vaccines, monoclonal antibody-based products, and therapeutic enzymes. 

The etiology of abnormal autoantibody production and development of SLE is still unknown. Genetic, environmental, and hormonal factors all may play arole in loss of self tolerance and expression of disease. A popular theory is that autoimmune disease such as SLE develops in genetically susceptible individuals after exposure to a triggering agent, possibly something in the environment. ... 

Graves disease An autoimmune disease in which the B lymphocytes synthesize an immunoglobulin (thyroid-stimulating immunoglobulin, TSIg) that binds to and activates the TSH receptor in such a way that the thyroid hormones do not feedback inhibit the receptor-effector interaction, leading to a hyperthyroid condition. 

Hypothyroidism (thyroid hormone deficiency) may result from autoimmune disease (Hashimoto s disease) or from deficient synthesis of TSH or TRH (thyroid-stimulating hormone-releasing factor). Because adequate ingestion of iodine is a prerequisite for thyroid hormone synthesis, iodine deficiency also causes hypothyroidism. In children, thyroid hormone deficiency (called cretinism) causes depressed growth and mental retardation. Severe hypothyroidism in adults (myxedema) results in symptoms such as edema (abnormal fluid accumulation) and goiter. Hypothyroidism is usually treated with hormone replacement therapy. 

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