20-30 MOD 3 Flashcards
Positive and Negative selection
During maturation in the thymus, T cells encounter self peptides bound to MHC Molecules. T cells that display the hosts MHC antigens and T cell receptors for non self antigens are allowed to mature, called positive selection. T cells have a high affinity for host cells are sorted out and undergo apoptosis, called negative selection.
2 General causes of autoimmune diseases
Genetic and environmental factors
How to diagnose an autoimmune disease
-History, physical, and serological findings.
-Following-criteria must be met:
Evidence of autoimmune reaction, immunologic findings are not secondary to another condition, and no other identifiable causes are found.
Graves’ disease
Abnormal stimulation of thyroid glad by thyroid stimulating antibodies (TSH receptor antibodies) that act through normal TSH receptors. State of hyperthyroidism, goiter, and opthalmopathy.
SLE
Systemic Lupus Erythematosus is chronic inflammatory disease termed the great imitator because it can affect almost any organ system
HIV
Retrovirus that selectively attacks the CD4+ T lymphocytes, the immune cells responsible for coordinating the immune response to infection. People with HIV infection are more susceptible to severe infections with ordinarily harmless organisms.
HIV spread
Sexual contact, blood to blood contact, or from mother to child during pregnancy , birth or breast feeding. Not spread via saliva or casual contact.
Seroconversion
Term when an infected persons blood converts from being negative for HIV antibodies to being positive.
Window period
Time between infection and seroconversion is called the window period