71531
| Question | Answer |
| who gets repeated bacterial infections? | pts with:1. low phagocyte numbers (or defective) 2. complement defects 3. humoral immunity defects |
| macrophage defects in IFNy signalling | autosomal recesive, fatal unless tx with IFNy |
| symptoms dx and tx of complement defs | symp: recurrent bacterial infections, dx: symp + CH50 levels, tx: antibiotics |
| defects in CMI (cell mediated immunity) usually result in recurrent... | ...fungal protozoan intracellular bacterial and viral infections |
| inherited complement defs | rare, most common are C3 and C2, if C5 through C9 no MAC formed |
| phagocytic dysfunction | 1 low neutrophil numbers from defective production during haemopoieses, 2. life threatening, 3. tx=recombinant granulocyte colony stimulating factrs |
| The WHO classifies immunodeficiencies into 5 groups | 1. phagocytic dysfunction, 2. complement ab+def 3. B cell (humoral) ab+def 4. T cell (CMI) ab+def 5. combined B&T cell ab+def |
| B cell (humoral) defs | 1. brutons x linked agammaglobulinaemia 2. common variable immunodef CVID 3. hyper IgM immunodef |
| brutons x linked agamaglobulinaemia symp dx and tx | symp: normal first 6 months then recurrent pyogenic infections, susp to giardia, dx: low b cell count tx: antibiotics and monthy gammaglobulin transfusions |
| Chediak-Higashi syndrome | 1.autosomal recessive mutation in LYST protein 2. recurrent bacterial infections 3. partial albinism 4. phagocyte granules impotent 5. infiltration of organs by lymphocytes |
| why is the cause of immundef sometimes hard to identify? | 1. normal values have wide range, 2. complex inter relationships between components, 3. sometimes difficult/expensive to test for |
| 2 types immunodeficiency | congenital or acquired |
| three diseases associated with defective intracellular killing of ingested bacteria | 1. chronic granulomatous disease CGD 2. Chediak Higashi syndrome 3. macrophage defects in IFN signalling |
| primary (congenital) | defects in structural components or developmental stages of immune system. May be masked at birth by abs from mother. |
| causes of secondary (acquired) immunodeficiency | 1. infectious disease (HIV) 2. cancer 3. stress 4. excessive exercise 5. malnutrition 6. drug tx |
| leukocyte adhesion defs (LADs) | LFA-1 is two chain molecule that allows neutrophils to stick to endothelial wall. If either chain defective, cannot migrate to site of infection |
| symptoms of LAD | 1. recurrent bacterial infections 2. absence of neutrophils at infected sites leading to large abcesses |
| Diagnosis of LAD | detection of defect in CD11 and CD18 |
| Hyper IgM immunodeficiency | 1. rare x linked 2. defect gene coding for CD40 ligand essential to class switching 3. |
| warning signs of primary immunodef | 1. family hx 2. recurrent serious infections 3. infant failure to thrive 4. persistent thrush 5. need for IV antibiotics |
| treatment for LAD | antibiotics |
| Hyper IgM symp dx + tx | symp: boys, bacterial infections. dx: def IgG and IgA, no CD40 ligand. tx: antibiotic and gammaglobulin transfusions |
| 3 combined B and T cell defs | 1. SCID 2. ADA adenisine deanimase def 3. xlinked SCID |
| chronic granulomatous disease CGD | NADPH oxidase is defective=no superoxide ions to kill intracellular bacteria |
| what is most common cause for CGD | defect in cytochrome b |
| ADA (adenosine deanimase) def symp dx &tx | symp: all types infections. dx: low peripheral T count, detection of ADA, low serum levels of 3 major Igs. tx: bone marrow transplant, gene tx, |
| x linked SCID | lethal. defect in gene for gamma chain of IL-2 receptor. Need bone marrow transplant or gene tx |
| types of acquired deficiencies | 1. malnutrition. 2. cancer. 3. stress. 4. exercise. 5. v young/old. 6. immunosupression 7. infections |
| malnutrition | impaired functions due to lack of selenium copper and fe, lymphoid system particular affected, worldwide issue |
| what is future tx for cgd | gene replacement therapy |
| Dx of CGD | neutrophils stained with nitro-blue tetrazolium remain pale yellow rather than blue |
| cyclophosphamide | acts by covalent alkylation with active metabolites, cross links with DNA, result marrow toxicity-->lymphocyte numbers /function |
| Tx of CGD | antibiotics |
| glucocortcoids | inhibition of b cells, t cells and cytokines |
| AIDS stats | leading cause of death in africa. ~1 million dx in US. |
| four components of immune system | T cells, B cells, phagocytes, complement |
| HIV symp dx | 1.70-80% asymptomatic 3-12 weeks after exposure, 2. fever, rash, cervical lymphadenopathy, aseptic meningitis, encephalitis, myelitis, polyneuritis, 3. fall in CD4 counts to 300-400, 4. depletion of CD4 cells leaves susp to infections, 5. lymphatic tissue is main reservoir of HIV |
| list of x linked immunodef diseases (5) | 1. CGD, 2. wiskott aldrich syndrome, 3. SCID, 4. x linked agammaglobulinaemia, 5. hyper IgM immunodef |
| defect in CGD | intracellular phagocytic killing and inability to produce bacterial cytolysins |
| defect in wiskott aldrich syndrome | thrombocytopenia and low serum IgM, low CD23 expression causes abnormal B cell development |
| defect in SCID | defect in both humoral and cel mediated immune responses |
| defect in Hyper IgM | defective CD40 ligand on lymphocytes prevent isotope switching therefore low serum levels of all immunoglobulin classes except IgM |
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