Immunodef. Flashcards
B-cell defects
Individuals healthy 7-9mths postpartum, then there are transient low IgG levels. Suseptible to recurrent bacterial and fungal infections.
Aggamaglobulinemia
Low Ig levels. Diagnosed by ELISA and quanitity B cell number.
Bruton’s XLA
Bruton’s X-linked agammaglobulinemia. More prevalent in males, greatly reduced number of B cells due to them being immature.
Lack enzyme for B cell maturation due to mutant tyorosine kinase.
Non-Bruton’s aggamaglobulinemia
Equal in men and women.
Autosomal defects in B cell maturation signalling.
Hyper IgM syndromes
All defects in class switching, many in hypermutation.
Most common defect in CD40L/CD40 so can’t interact with Th cells.
Lack of IgG and IgA, so opportunistic infections.
CVID
Common variable immunodeficiency.
Impaired Ab response.
Low levels of IgA and IgG.
Hyper IgE-aberrant isotype.
SCID
Severe combined immunodeficiency diseases.
No effective T/B cell response.
Inevitably fatal untreated without BMT/HCT.
Possible Th defects.
With Th1, Th2, T-reg cells.
MHC defects.
Autoimmune lymphoproliferative disease
Excess proliferation of B and T cells and immature thymocytes
Dye to defects in apoptopic machinery
X-linked lymphoproliferative disease
Excess IFN-gamma leads to excessive Th1 skew and proliferation of B lymphocytes after EBV infection.
Leukocyte adhesion deficiency I-III
Lack mechanism for migration
Chronic granulomatous disease
Can’t produce superoxide for phagasome killinh
Chediak-Higashi Syndrome
Defect in organelle fusion, some immune cells can’t kill
When do autoimmune disease occur>
Tolerance breaks down.
Trauma releases previously unseen antigens, e.g the eye.
Molecular mimicry.
Genetic factors.
Insulin dependent diabetes
Beta islet cells damaged by inflammatory macrophages. C, T or beta cells destroy T cells reactive against insulin found in islet cells.
