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43 Cards in this Set
- Front
- Back
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when is the age of onset for B-cell defects?
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after the maternal antibodies have disappeared ~ >6 months
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what types of infections do b-cell deficient people have an increased risk for?
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g+,-; encapsulated bugs, mycoplasma, giardia,cryptosporidium, campylobacter, enterovirus
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clinical findings of a b-cell deficient patient?
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-rcrrnt resp. tract infections
- drrha - malbsrptin - ileitis,cholangitis, colitis - arthritis, dermatomyositis - meningioencephalitis |
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what studies are important to order to rule in/out b-cell def?
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- IgA msrment --> if abnormal--> order IgM
- isohemaglutinins - ab titers to tetanus, dip, h.flu and s.pneumo |
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examples of bcell disorders?
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-brutons aggamglobulinemia
- common variable immunodeficiency - selective iga deficiency - hypogammaglobulinemia of infancy |
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treatmetn for b-cell defects?
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- ivig
- antibiotics - bone marrow transplant for cd40 ligand defect XLp |
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What are the 5 main types of immunodeficiencies?
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b-cell defects, t-cell defects, phagocytic cell defects, complement deficiencies, combined b/t-cell deficiencies
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when are t-cell defects normally seen?
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early infancy
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what bugs are seen in tcell def?
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viruses --> cmv, ebv
- systemic post bcg vaccination - fungal infections - pneumocystis carinii |
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presentation of t-cell def. in an infant?
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-poor growth
-ftt - candidiases - skin rashes - sparse hair - opportunistic bugs - graft vs. host disease after transplant |
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what test would b good to order in a t-cell deficiency?
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-candida skin test
- absolute lymphocyte count |
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examples of t-cell deficiencies?
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-Digeorge syndrome
- cd3/cd8 deficiency |
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When do phagocytic cell defects normally present?
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early infancy
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bugs seen?
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gram+,-; catalase + bugs in CGD, especially ASPERGILLUS
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what do u see clinically in phagocytic cell defects?
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-poor wound healing
- skin diseases ; impetigo,abscesses - cellulitis WITHOUT pus - suppurative adenitis - periodontitis - liver abscesses - crohn's disease - osteomyelitis - bladder outlet obstructions |
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what tests would be good for phagocytic cell defects?
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- absolute neutrophil count
- nbt dye test - dhr test |
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examples of phagocytic cell defects?
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- chronic granulomatous disease
- g6p dehydrogenase deficiency - myeloperoxidase deficiency - leukocyte adhesion defiency (LAD) - chediak higashi - asplenia |
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When does a COMPLEMENT deficiency present?
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presents @ any age!
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what bugs are normally seen?
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Neisseria gonorrhea
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findings?
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- rheumatoid disorders
- angioedema - increased susceptibility to neisseria species infections due to late mac complex phase reactants |
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study to determine for a complement deficiency?
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ch50
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examples of complement deficiencies?
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-hereditary angioedema
- deficient complement control |
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what happens with the combined b/tcell deficiencies?
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have a deficiency in both t/bcell mediate immunities... people are not able to mount any time of immune response --> susceptible to everything!
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bugs seen in combined deficiencies?
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bacterial, viral, fungal, protozoal --> frequent infections lead to early death unless treated w/ bone marrow transplant
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examples of combined immunodeficiencies?
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- severe combined immunodeficiency
- adenosine deaminase deficiency - combined immunodef. - wiskott aldrich syndrome - ataxia telangiectasia - hyper ige syndrome |
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rx for sever combined?
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bone marrow transplant or gene therapy
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what is the differential for someone with decreased lymphocytes (b/tcells)
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scid, hiv, bare lymphocyte syndrome, ataxia-telangiectasia, atypical digeorge syndrome
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what is the b/tcell mitogen used to detect if there is an immune response?
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pokeweed
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scid
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cannot produce mature b/t-cells
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what do u see on lab studies? scid
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-absent/low t-cells
- bcells can b normal or absent - nk cells can b low to normal --> failure to mount both humoral and cell mediated responses = high risk for opportunistic infections with intracellular bugs |
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mutations in what subunit and interleukin receptor are most responsible for defects in x-linked severe combined immunodeficiency?
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- gamma subunit of the interleukin 2 receptor
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what other receptors is the gamma subunit also associated with?
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IL-4,7,9,15
- dfctve rcptrs causes dcrsd growth/proliferation of b/tcells - lack of t-cells is mainly IL7 defect |
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what are some other defects associated w/ SCID ?
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- class 2 mhc absence
- dysfunctional ZAP-70 (tcell trnsdctn) - defctvie rag1/2 (tcr/ig recombination) - absent adenosine deaminase or purine nucleoside phosphorylase |
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what deficiency should b suspctd in a case with NORMAL CMI but ABSENT PLASMA IMMUNOGLOBULINS?
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bruton's agammaglobulinemia
- xlinked - boys have few bcells in blood/lymphoid tissue - serum = low levels of ALL IGG'S |
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what kinase is affected in the previous condition?
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- bruton's tyrosine kinase --> needed for maturation of pre-bcells
- maternal ig protects child until 6moa |
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bcell disorder associated w/ anaphylactic transfusion reactions?
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IGA deficiency (mcc one)
- defect in heavy chain isotype switching --> cannot produce iga - pats devlp spcfc IGE agnst fc portion of IgA hvy chain --> anaphylactic rxn to blood products that arent purged of this Ig |
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all cgd defects r from what ?
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mutations in the gene encoding NADPH oxidase
- inability of phagocytes to kill pathogens - cannot catalyze oxygen --> superoxide. - superoxide disumutase cnvrts superoxide --> h202 --> converted to hypochlorite via myeloperoxidase |
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phagocytes cannot kill ingested pathogens..so what happens next?
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bugs persist and a GRANULOMA forms to wall off the bug it cannot kill
- widespread granulomas r found in absence of infection as well (due to unopposed proinflammatory cytokine production) |
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what is a granuloma?
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-collection of epitheliod / giant cells surrounded by a fibrous capsule
- epitheliod cells are MODIFIED MACS - giant cells --> come from FUSED macs (supernumery nuclei) |
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how are granulomas maintained?
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granulomas are maintained via constant secretion of IFN-GAMMA by the local TH1 cells
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Staphylococcal infections (catalase positive) are commonly seen...why?
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catalse positive bugs quickly eliminate the h202 they make and thus r not killed by an oxidative respiratory burst...
- common to see S.Aureus, Serratia, Burkholderia cepacia, aspergillus, candida |
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how does chediak higashi differ from cgd?
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- ar disorder
- lysosomes of neutrophils cannot fuse w/ phagosomes (pockets containing ingested bugs) - rcrrnt infxns of s.aureus, strepto, pseudomonas - normal nitroblue tetrazolium test b/c phagocytic NADPH is normal |
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how does liposomal amp b differ from amp b?
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liposomal amp b has less renal sidefx
- amp b renal side fx related to --> afferent arteriolar constriction and direct damage to the distal tubular epithelium |
