eesohbel's version from 2015-07-18 01:00

Quick review of immunoglobulins

Question Answer
dimeric immunoglobulinIgA
pentameric immunoglobulinIgM
immunoglobulin that binds to mast cellsIgE
antigen receptor on surface of mature naive B lymphocytesIgD
IgG that mediates antibody-dependent cell mediated cytotoxicityIgG


Question Answer
BTK defecttyrosine kinase defect --> BRUTON X linked recessive agammaglobulinemia
no B cells in peripheral bloodBruton's agammaglobulinemia
absent/scanty lymph nodes and tonsilsBruton's agammaglobulinemia
presents after 6 months of life with recurrent bacterial, enterovirus and giardia infectionsBruton's agammglobulinemia
live vaccines must be avoidedBruton's agammaglobulinemia
most common primary immunodeficiencySelective IgA deficiency
recurrent sinus and pulmonary deficiencySelective IgA deficiency
celiac diseaseselective IgA deficiency
when transfused with blood in IgA deficiencyform IgG
22q11 deletion detected by FISHDiGeorge
3rd and 4th pharyngeal pouchesDiGeorge
failure of endodermal developmentDiGeorge
B cell differentiation defect can be acquired in 20s and 30sCVID
low plasma cells and low immunoglobulins CVID
increased risk of bronchiectasisCVID
no thymus and parathyroidsDiGeorge
tetanyDigeorge (from hypocalcemia bc no parathyroid glands)
associated with ToF and truncus arteriosusDiGeorge
absent thyme shadow on CXRDiGeorge, SCID
low IFN gammaIL12 receptor deficiency and Job (hyper IgE)
low Th1 response IL12 receptor deficiency
may present after BCG vaccine administrationIL12 receptor deficiency
STAT3 mutation Job (hyper IgE)
deficiency of Th17 cells Job (hyper IgE)
impaired neutrophil recruitmentJob (hyper IgE)
FATEDcourse Facies, cold non inflamed staph Abscesses, retained primary Teeth, high IgE, Dermatologic eczema (Job hyper IgE)
coarse faciesJob (hyper IgE)
cold abscessesJob (hyper IgE)
baby teeth retained (2 rows of teeth)Job (hyper IgE)
eczemaJob (hyper IgE)
what causes chronic mucocutaneous candidiasisT cell dysfunction, many causes (HIV included)
absent T cell responses to candidaChronic Mucocutaneous Candidiasis
no germinal centers on lymph node biopsy, abscence of thymic shadows, and T cellsSCID
adenosine deaminase deficiencySCID
caused by mutations in the gene coding the common gamma chain shared by IL-2, IL-4, IL-7, 9 and 15SCID
severe recurrent infections, failure to thrive, chronic diarrheaSCID
severe mycobacterial infections and fungal infectionsIL12 deficiency
treat with IFN gammaIL 12 deficiency
cannot make Th1 cells from T0 cellsIL-12 deficiency
X linkedWACH (Wiskott Aldrich, Agammaglobulinemia, CGD, Hyper-IgM)
no thymic shadow on X-raySCID and DiGeorge Syndrome

Section 2

Question Answer
defect of ATM geneAtaxia-Telangiectasia
failure to repair DNA double stranded breaksAtaxia-Telangiectasia
cerebellar defects, spider angiomas, IgA deficiencyAtaxia-Telangiectasia
increased AFPAtaxia-Telangiectasia
cerebellar atrophyAtaxia-Telangiectasia
defective CD40L on Th cells or CD40 on B cellsHyper-IgM
class switching defectHyper-IgM
opportunistic infections with Pneumocystis, Cryptosporidium, CMV early in lifeHyper-IgM
low IgG, IgA, IgEHyper-IgM
WATERWiskott-Aldrich, Thrombocytopenic purpura, Eczema, Recurrent infections
low to normal IgG and IgM, but high IgE and IgAWiskott-Aldrich syndrome
mutation in WAS gene and prone to developing non-hodgkin lymphomaWiskott-Aldrich syndrome
defect in LFA-1 integrin (CD18) protein on phagocytesLeukocyte adhesion deficiency type 1
impaired migration and chemotaxisLeukocyte adhesion deficiency type 1
absent pus formationLeukocyte adhesion deficiency type 1
delayed separation of the umbilical cordLeukocyte adhesion deficiency type 1
high neutrophil count, but absent at infection sitesLeukocyte adhesion deficiency type 1
LYST defect. microtubule dysfunction in phagosome-lysosome fusionChediak-Higashi
microtubule dysfunction in phagolysosome fusionChediak-Higashi
partial albinismChediak-Higashi
giant granules inside neutrophils and plateletsChediak-Higashi
NADPH oxidase deficiencyChronic Granulomatous Disease
increased susceptibility to catalase + organisms especially staph aureus and aspergillusChronic Granulomatous Disease
decreased respiratory burstChronic Granulomatous Disease
abnormal dihydrorhodamine flow cytometry testChronic Granulomatous Disease
nitroblue tetrazolium dye test is negativeChronic Granulomatous Disease (normally turns yellow, but turns blue with CGD)
integrin abnormality of CD18 subunitleukocyte adhesion deficiency
delayed separation of umbilical cordleukocyte adhesion deficiency syndrome
recurrent bacterial infectionslack pus formation

Infections in immunodeficiency

Question Answer
No T cells - bacterial infectionsSepsis
No T cells - viral infectionsCMV, EBV, VZV
chronic infection with respiratory/GI virus
No T cells - Fungi/parasite infxnsCandida
No B cells - bacterial infectionsSHiN SKiS: Streptococcus pneumoniae, H. influenzae type B, Neisseria meningitidis, Salmonella, Klebsiella pneumoniae, group B Strep
No B cells - Viral infxnsEnteroviral encephalitis
poliovirus (live vaccine is contraindicated)
No B cells - fungal/parasite infxnsGI giardiasis (no IgA)
No granulocyte - bacteria infxnsStaphylococcus
Burkholderia cepacia
No granulocyte - viral infxnN/A
No granulocyte - fungal infxnCandida
No complement - Bacterial infxnNeisseria (no MAC)
Major trendB-cell deficiencies produce more recurrent bacterial infections
T-cell deficiencies produce more fungal and viral infections

Immune deficiencies

Question Answer
Recurrent bacterial infections (after 6 months) in BoysBruton's X-linked agammaglobulinemia
Mechanism of Bruton's agammaglobulinemiaNo B-cell maturation d/t defect in BTK, a tyrosine kinase gene
↓ # of B cells
↓ immunoglobulins of all classes
Higher incidence of infections (URI, GI) but mostly asymptomaticSelective IgA deficiency~
IgA<7 mg/dL
False-positive B-HCG testSelective IgA Deficiency
Anaphylaxis to blood transfusion?Selective IgA Deficiency
Mechanism of Selective IgA Deficiency?Autoimmune disease
20-30 y.o. with recurrent URI and lymphomaCommon variable immunodeficiency (CVID)
Mechanism of Common variable immunodeficiency (CVID)Defect in B-cell maturation, but normal # of B cells
↓ plasma cells
↓ immunoglobulins
Recurrent viral/fungal infections + Tetany (hypocalcemia)DiGeorge syndrome
↓ T cells, ↓ PTH, ↓ CaDiGeorge syndrome
Mutation in DiGeorge syndrome22q11 deletion
Mechanism of DiGeorge syndromeFailure of the 3rd and 4th pouches (endoderm) development
Thymic aplasia and parathyroid missing. aortic arch abnormalities, due to 4th arch.
Disseminated mycobacterial (TB) infectionsIL-12 receptor deficiency
Mechanism of IL-12 deficiency↓ Th1 response
↓ IFN-gamma
Cold (noninflamed) staphylococcal abscesse+Coarse facies+Eczema+Retained primary TeethHyperIgE (Job's syndrome)
Mechanism of Job's syndromeTh1 cells fail to produce IFN-gamma → neutrophils can't respond to chemotactic stimuli
↑ IgEJob's syndrome (Hyper IgE)
Candida albicans infections of skin and mucous membranesChronic mucocutaneous candidiasis
T cell dysfn
↑ IgE
Failure to thrive + Chronic diarrhea + all kinds of recurrent infectionsSCID
Mechanism of SCIDDefect in T-cell IL-2 receptors (X-linked) or ~Adenosine deaminase deficiency
No thymusSCID (no T-cells) or DiGEorge
No germinal center in LNSCID (no B-cells) and T cells
T-cell recombinant excision circlesSCID
Treatment for SCIDbone marrow transplant
Cerebellar defects
spider angiomas
IgA deficiency
Mechanism of Ataxia telangiectasiaDefects in the ATM gene which codes for DNA repair enzymes
↑ AFPAtaxia telangiectasia
Severe pyogenic infections early in lifeHyper-IgM syndrome
Mechanism of Hyper-IgM syndromeDefective CD40L on helper T cells → inability to class switch
↑ IgM
↓↓ IgG, IgA, IgE
Hyper-IgM syndrome
Recurrent infections+Eczema+Thrombocytopenic purpura~Wiskott-Aldrich syndrome
Mechanism of ~Wiskott-Aldrich syndromeX-linked mutations T cells unable to recognize actin cytoskeleton
↑ IgE, IgA
↓ IgM
Wiskott Aldrich syndrome
Recurrent bacterial infxns without pus formation+Delayed umbilical cord separation~Leukocyte adhesion deficiency (type 1)
Mechanism of Leukocyte adhesion deficiencyDefect in LFA-1 integrin (CD18) protein on phagocytes → Neutrophils unable to respond to chemotactic stimuli
Recurrent pyogenic Staph and Strep infections+Peripheral neuropathy+Partial albinismChediak-Higashi syndrome
Mechanism of Chediak-Higashi syndromeAR - microtubule dysfunction in phagosome-lysosome fusion
Giant granules in neutrophilsChediak-Higashi syndrome
↑ susceptibility to catalase-positive organisms (Staph aureus, E.coli, Aspergillus)Chronic granulomatous disease
Mechanism of Chronic Granulomatous diseaseLack of NADPH oxidase
Abnormal dihydrorhodamine flow cytometry testChronic Granulomatous disease
Recurrent respiratory infections+DextrocardiaKartagener's
Defect in KartagenerPrimary ciliary diskinesia due to failure of Dynein arms to form correctly
Recurrent respiratory infection + InfertilityCystic fibrosis (Kartagener if dextrocardia is present)
Mechanism of cystic fibrosisDefective CFTR channels
Mechanism of Hyper-IgMImpaired immunoglobulin gene re-arrangement
C3 deficiencycauses defects in opsonization and removal of immune complexes. Patients may develop type III hypersensitivity reactions

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