Immune Deficiencies Flashcards
Bruton’s aggamaglobulinemia
Type:
**B-cell disorder
Defect:
- *defect in BTK tyrosine kinase gene
- *blocks pre-B cells from forming immature B-cells
- *X-linked recessive
Presentation:
**recurrent bacterial infections after 6 mos (maternal IgG) b/c of opsonization defect
Labs:
- *Nl pro-B
- *decreased maturation
- *decreased # B-cells
- *decreased Ig’s of all classes
Hyper-IgM syndrome
Type:
**B-cell
Defect:
- *defective CD40L on Thelper
- *results in inability to class switch
Presentation:
**Severe pyogenic infections early in life
Labs:
- *increased IgM
- *very decreased Ig-G,-A,-E
Selective Ig deficiency
Type:
**B-cell disorder
Defect:
- *defect in isotype switching
- *deficiency in specific class Ig’s
Presentation:
- *sinus & lung infections
- *milk allergies & diarrhea
- *anaphylaxis on exposure to blood products w/IgA
Labs:
**IgA deficiency most common
Common variable immunodeficiency (CVID)
Type:
**B-cell disorder
Defect:
**defect in B-cell maturation (many causes)
Presentation:
- *can be acquired in 20s-30s
- *increased risk autoimmune dz, lymphoma, sinpulmonry infections
Labs:
- *nl # B-cells
- *decreased plasma cells
- *decreased Ig’s
Thymic aplasia (DiGeorge syndrome)
Type:
**T-cell disorder
Defect:
- *22q11 deletion
- *failure to develop 3rd & 4th pharyngeal pouches
Presentation:
- *tetany (hypocalcemia)
- *recurrent viral/fungal infections (T-cell deficient)
- *congenital heart & great vessel defects
- *facies - maldevelopment of mandible
Labs:
- *thymus & parathyroids fail to develop:
- **decreased T cells
- **decreased PTH
- **decreased Ca2+
- *absent thymic shadow on CXR
IL-12 receptor deficiency
Type:
**T-cell disorder
Defect:
**decreased Th1 response
Presentation:
**disseminated mycobacterial infections
Labs:
**decreased IFN-gamma
Hyper-IgE syndrome (Job’s syndrome)
Type:
**T-cell disorder
Defect:
- *Th cells fail to produce IFN-gamma
- *results in inability of neutrophils to respond to chemotactic stimuli
Presentation:
- *FATED
- *coarse Facies
- *cold (noninflamed) staphylococcal Abscesses
- *retained primary Teeth
- *increased IgE
- *Dermatologic problems (eczema)
Labs:
**increased IgE
Chronic mucocutaneous candidiasis
Type:
**T-cell disorder
Defect:
**T-cell dysfunction
Presentation:
**Candida albicans infections of skin & mucous membranes
Severe combined immunodeficiency (SCID)
Type:
**B & T cell disorder
Defect (different types:)
- *MCC: defective IL-2 receptor (X-linked)
- *adenosine deaminase deficiency
- *failure to synthesize MHC II antigens
Presentation:
- *recurrent viral, bacterial, fungal, & protazoal infections
- *B & T cell deficiency
- *absence of thymic shadow, germinal centers (biopsy), & B-cells
- *Tx: bone marrow transplant
Labs:
**decreased IL-2R –> decreased T-cell activation
**increased adenosine –> toxic to B & T cells
(decreased dNTPs, decreased DNA synthesis)
Ataxia-telangiectasia
Type:
**B & T cell disorder
Defect:
**defect in ATM gene, which codes for DNA repair enzymes
Presentation:
- *Triad:
- *cerebellar defects (ataxia)
- *spider angiomas (telangiectasia)
- *IgA deficiency
Labs:
**IgA deficiency
Wiskott-Aldrich syndrome
Type:
**B & T cell disorder
Defect:
- *X-linked recessive
- *progressive deletion of B & T cells
Presentation:
- *Triad (TIE)
- *Thrombocytopenia purpura
- *Infections
- *Eczema
Labs:
- *increased IgE
- *increased IgA
- *decreased IgM
Leukocyte adhesion deficiency (type I)
Type:
**phagocyte dysfunction
Defect:
**defect in LFA-1 integrin (CD18) protein on phagocytes
Presentation:
- *recurrent bacterial infections
- *absent pus formation
- *delayed separation of umbilicus
Labs:
**neutrophilia
Chediak-Higashi syndrome
Type:
**phagocyte dysfunction
Defect:
- *autosomal recessive
- *defect in lysosomal regulator trafficking gene (LYST)
- *microtubule dysfunction in phagosome-lysosome fusion
Presentation:
- *recurrent pyogenic infections by staph & strept
- *partial albinism
- *peripheral neuropathy
Chronic granulomatous disease
Type:
**phagocyte dysfunction
Defect:
- *lack of NADPH oxidase
- *decreased reactive oxygen species (superoxide)
- *absent respiratory burst in neutrophils
Presentation:
- *increased susceptibility to catalase-positive organisms
- *staph aureus, e. coli, aspergillus
Labs:
**negative nitroblue tetrazolium dye reduction test
