AUTOIMMUNE DISEASES

Addison’s disease

It is the most common form of adrenal insufficiency

caused by autoimmune destruction of the steroid producing cells in the adrenal glands. (i.e. primary adrenocortical insufficiency whereas secondary forms may occur as a result of pituitary hypothalamic disease.

Addison disease

Primary Addison disease is relatively rare, with a prevalence of 5-15 per 100,000 in Europe and the United states.

usually slowly progressive patients generally present with such

manifestations as malaise, anorexia, hyperpigmentation, hypotension and salt wasting.

Addison disease

Laboratory diagnosis: primarily rest on the lack of a cortisol response

to adrenocorticotropic hormone stimulation. diagnosis may be supported by:

> radiological procedures> revealing small, non-calcified adrenal glands>detection of autoantibodies to adrenal cortical cells. (These autoantibodies are directed to enzymes involved is steroid synthesis, such as 21-hydroxylase. Anti body deposition and complement fixation to adrenal cortical cells is apparent upon microscopic examination).

Addison disease The involvement of T-cells is postulated

due to a major association with HLA-B8 and HLA-DR3.

Nevertheless, the exact role of antibodies and/or T-cells in the pathogenesis of Addison disease remains elusive.

It can present as an isolated entity or in combination with other autoimmune diseases.

Goodpasture’s disease also referred as anti-Glomerular

Basement Membrane (anti-GBM) disease characterized by rapidly progressive

glomerulonephritis and/or pulmonary haemorrhage.

Anti-BGM is very rare, with an incidence of approximately 1 case per 100,000 per year.

It affects primarily white males.

Goodpasture’s disease Laboratory diagnosis: Patients present with respiratory insufficiency, or

both. Kidney biopsy may reveal necrotizing crescentic glomerulonephritis with a typical linear deposition of anti-GBM antibodies.

Early diagnosis is mandatory in order to prevent end-stage renal disease or death.

Detection of circulating anti-GBM antibodies and/or in situ presence of anti-BGM antibodies in kidney biopsies are diagnostic for anti-GBM disease.

Anti-GBM antibodies are directed to the non-collagenous domain of the Alpha 3 chain of type IV collagen.

Goodpasture’s disease

Pathogenicity of autoantibodies is well established:

they cause damage to the basement membrane in the lung and kidneys via a type II hypersensitivity reaction.

A genetic association has been made between anti-GBM disease and HLA-DR15. This HLA type appears to have the unique capacity to bind many peptide sequences within the non collagenous domain of type IV collagen.

Myasthenia gravis a disorder of transmission at a

neuromuscular junction characterized by muscle weakness.

estimated prevalence of disease varies between 5-15 cases per 100 000.

There are two peak disease incidence with different male/female ratios: before age 40, women are three times more commonly affected whereas in the older age group, males predominate.

Myasthenia gravis

Prominent feature of MG: painless fatigable weakness of selected

muscle groups. frequently presents with ptosis and

diplonia. Limb and neck flexor weakness typically

occurs later in the disease.

Myasthenia gravis The presence of anti muscular specific

kinase (MuSK) antibodies in patients lacking anti-acetylcholine receptor antibodies may identify a subgroup of MG patients.

Reversibility of clinical symptoms with anticholinesterase inhibitors in MG is another hallmark of diagnosis.

Once a diagnosis has been made, computed tomography or magnetic resonance imaging of the chest should be done to exclude an associated thymoma, which is apparent in about 10% of the patients.

Myasthenia gravis

MG is a prototypic autoimmune disease> its antibody-mediated pathogenesis is exclusively directed to the post synaptic membrane of the neuromuscular junction.

 Graves disease

Graves disease is defined as a form of hyperthyroidism associated with a diffuse hyperplastic goitre.

prevalence is approximately 1% of the general population.

the disease is more prevalent in females than in males (female to male ratio 7:1).

 Graves disease

usually presents with thyroid-toxicosis, due to the released of preformed thyroid hormones from the damaged tissue, and a diffusely enlarged thyroid.

Disease is often accompanied by exophtalmos.

 Graves disease

Patients with graves disease have diffuse lymphocytic infiltration of the thyroid gland, resulting in thyroid destruction and produce antibodies to a multitude of antigens (thyroid peroxidase, TSH receptor and thyroglobulin)

 Graves disease

Diagnosis> based on clinical and biochemical manifestations of hyperthyroidism. >The hyperthyroidism is due to the continuous stimulation of the thyroid-stimulating hormone receptor by auto-antibodies.

 

Graves disease

Treatment is generally with radioiodine therapy or antithyroid medication.

Hashimoto thyroiditis Chronic progressive autoimmune

thyroiditis Is an inflammatory disorder that results

in progressive destruction of the thyroid gland.

The prevalence of hashimoto disease is 0.5-1.0%. but subclinical hyperthyroidism is much more common, affecting 4% of the general population, with higher rates among women and with increasing age.

Hashimoto thyroiditis Females make up the vast majority of patients

(female to male ratio 8:1) The clinical disease is marked by initial

thyrotoxicosis, which is invariably followed by progressive hyperthyroidism and myxoedema.

Clinical diagnosis>based on the presence of a firm, rubbery, painless goitre with initial eythyroidism, but later clinical signs of hypothyroidism and often a combination of high titres of antithyroid peroxidase, and/or antithyroglobulin antibodies.

Hashimoto thyroiditis T cells are considered to play a critical

role in thyroid destruction by interacting with the follicular cells as well as the extracellular matrix.

T cells can destroy thyroid tissue by direct cytotoxicity or indirect by cytokine secretion.

Journal

Sjogren’s syndrome?by: Nancy schoofs, RN, PhD

Dry eyes and mouth are just two of the many symptoms that can develop as a result of this common but little-known autoimmune disease that gradually destroys the exocrine glands. Because the effects are so far-reaching, it’s important to familiarize yourself with diagnostic and treatment options as well as the special care needs of the patients.