What Are Immune System Disorders?

Autoimmune Diseases continued...

Psoriasis. In psoriasis, overactive immune system blood cells called T-cells collect in the skin. The immune system activity stimulates skin cells to reproduce rapidly, producing silvery, scaly plaques on the skin. 

Graves' disease. The immune system produces antibodies that stimulate the thyroid gland to release excess amounts of thyroid hormone into the blood (hyperthyroidism). Symptoms of Graves' disease can include bulging eyes as well as weight loss, nervousness, irritability, rapid heart rate, weakness, and brittle hair. Destruction or removal of the thyroid gland, using medicines or surgery, is usually required to treat Graves' disease.

Hashimoto's thyroiditis. Antibodies produced by the immune system attack the thyroid gland, slowly destroying the cells that produce thyroid hormone. Low levels of thyroid hormone develop (hypothyroidism), usually over months to years. Symptoms include fatigue, constipation, weight gain, depression, dry skin, and sensitivity to cold. Taking a daily oral synthetic thyroid hormone pill restores normal body functions.

Myasthenia gravis. Antibodies bind to nerves and make them unable to stimulate muscles properly. Weakness that gets worse with activity is the main symptom of myasthenia gravis. Mestinon (pyridostigmine) is the main medicine used to treat myasthenia gravis.

Vasculitis. The immune system attacks and damages blood vessels in this group of autoimmune diseases. Vasculitis can affect any organ, so symptoms vary widely and can occur almost anywhere in the body. Treatment includes reducing immune system activity, usually with prednisone or another corticosteroid.

Immune Deficiency Diseases

The immune system may be suppressed by medications or illness. Immune deficiency can also be present from birth as a genetic disorder (primary immune deficiency). Immune deficiency diseases result in higher vulnerability to infections. Examples of immune deficiency diseases include: 

Severe combined immune deficiency (SCID). A genetic condition causing severe impairment in multiple areas of the immune system. Babies with SCID die from overwhelming infections, usually before reaching age 1. Bone marrow transplant can cure some cases of SCID. 

Common variable immune deficiency (CVID). Due to a genetic defect, the immune system produces too few antibodies to effectively fight infections. Children with CVID typically have frequent infections of the ears, lungs, nose, eyes, and other organs. Treatment includes replacing the missing antibodies with regular injections of antibodies, called immunoglobulins. 

Human immunodeficiency virus / acquired immune deficiency syndrome (HIV/AIDS). HIV infects and destroys immune system cells that normally fight infections. As the number of immune system cells declines, a person's vulnerability to infections rises steadily. 

Drug-induced immune deficiency. Medicines that suppress the immune system result in an increased chance of infection. People taking immune-suppressing drugs for long periods require careful monitoring to detect and treat any infections that occur. 

Graft versus host syndrome. After bone marrow transplant, the donor's immune system cells may attack the tissues of the person receiving the transplant. Prednisone and other immune-suppressing medicines are used to prevent excessive organ damage caused by the donor's immune cells.