Immunology Flashcards
What immune disease is charactertized by:
Presents approximately 2-6 months of age (after maternal antibody wanes)
Extremely low or absent immunoglobulin levels (IgG <200 mg/dl)
Recurrent upper respiratory infections, Giardia infestations
Bruton’s aggamaglobulinemia
The correct term now is Bruton’s Thymidine Kinase (BTK) Deficiency
CD19 positive B cells are absent in peripheral blood. Most common defect is in a B cell progenitor kinase, located on the long arm
of chromosome X (Xq22)
Treated with intravenous Immunoglobulin
An autosomal recessive form of this syndrome exists and is related to defects in the genes encoding the u heavy chain gene, CD79A and CD179B
How do you differentiate Bruton’s agammaglobulinemia from transient hypoalbuminemia of infancy?
Trans Hypoalb will present approximately 5-6 months
IgG and IgA low, IgM may be normal to low
Recurrent upper respiratory infections
CD19 positive B cells ARE present
Hypogammaglobulinemia may last up to 2 years.
Cause is undefined
What immune disease may be a B or T cell defect and can cause a Th1 imbalance with elevated IL12 and gamma interferon and it is autosomal recessive and from ICOS defect?
*These patients get recurrent upper and lower respiratory infections, intestinal bacterial overgrowth and Giardia intestinalis infection
CVID
B cells can’t differentiate into plasma cells
Germinal centers are HYPERplastic
What immune disease presents in the first year of life, IgM levels are normal to elevated (100-1000 mg/dl), IgG, IgA and IgE levels are low, CD4 cell increase may occur and it is due to a defect is in the gene (Xq26 ) coding for the T cell protein, CD154 (CD40 Ligand) molecule?
CD40 Ligand Deficiency (used to be called Hyper IgM Deficiency)
CD154 binds to CD40 initiating class switching in B cells. This defect prevents T cells from inducing B cells to undergo a class switch. Thus the B cells produce IgM, without switching to another isotype. Autosomal recessive form does exist, involving the TNFRSF5 gene
What is the mutation in DiGeorge syndrome?
Tbx1 mutation
Chromosome 22q11.2 missing in DiGeorge,
What immune disease is characterized by IL-2 receptor gamma chain mutation, (Xq13); also affects receptors for IL-4, 7, 9, 15 and 21. Phenotype is T- B+ NK+or-?
SCID
What immune disease is characterized by not having ANY T, B or NK cells (ie what the boy in the bubble had)?
Adenosine deaminase deficency
What genes are involved in 1) MHC Class I deficiency and 2) MCH Class II deficiency?
Autosomal recessive disorder
– Class 1 deficiency- TAP1, TAP2 genes
– Class II deficiency- RFXAP, RFXANK genes
What immune disease is characterized by:
Defect in CD18 gene (INTGB2 gene, 21q22.23), preventing proper LFA-1 adhesion molecule formation. This molecule is important in allowing neutrophils to migrate out of blood vessels into the tissues. It is autosomal recessive disease and causes recurrent soft tissue infections; impaired
wound healing?
Leukocyte Adhesion Deficiency, Type I
This cell is a neutrophil engulfed Ab coated cell
nucleus. What disease can this be seen in (not real life but on boards)?
Lupus
What ANA pattern is seen here and what antigens are present?
HOMOGENOUS
Antigens: DNA, histone, dsDNA, ssDNA
Associations: SLE, drug-induced lupus, RA
What ANA pattern is this and what antigen is it associated with?
Anti dsDNA quantitation with Crithidia luciliae
The kinetoplast staining is positive dsDNA and will appear as two (sometimes three) dots. The only staining that is important is the KINETOPLAST
The other two dots that are staining regardless are the basal body and the nucleus but the nucleus is usually poorly visualized even if sera is ANA positive.
What serum markers help differentiate lupus from mixed connective tissue disease?
MCTD will be positive with anti-RNP but NOT anti-smith
Lupus will be positive for both
What ANA pattern is this and what antigen is it associated with?
SPECKLED
Antigen: SSA (Ro), SSB (La), Smith, U1-RNP, PCNA, Scl-70 (fine speckling)
Associations: SLE, MCTD, Sjogren, Scleroderma
What immunologic findings do scleroderma patients display in regards to levels of CD4, CD8 and B cells?
Normal CD8 suppressor activity
Increased CD4 TH activity
Increased lymphokines
Increased B cell activation
What ANA pattern is seen here and what antigen is this associated with?
NUCLEOLAR pattern
Antigens: RNA polymerase I, U3-RNP (fibrillarin), PM-Scl
*NOTE* if you see the nucleolar pattern with prominent green background staining, that is most likely specific to fibrillarin (U3-RNP)
Associations: Scleroderma, Polymyositis/Scleroderma overlap
What ANA pattern is seen here and what antigen is it associated with?
Centromere
Antigens: CENP-A, B and C
Associations: scleroderma (with CREST syndrome), Raynoud
*NOTE* the mitotic cells show a speckled pattern whereas in the normal speckled pattern, you won’t see these mitotic figures
What vasculitis is immune complex mediated?
Polyarteritis nodosa (secondary to SLE, HepB)
What autoimmune vasculitis is antibody mediated?
Kawasacki disease (necrotizing vasculitis, primarily pediatric disease)
Name three diseases associated with pANCA.
Churg Strauss
Microscopic polyangiitis
IBD (60-70% with UC, 40% with Crohn’s)
*Anti-Saccharomyces ceriviseae Ab (ASCA) is asssociated with Crohn’s
Regarding c-ANCA and p-ANCA, what are these antibodies against?
cANCA is usually antibody to proteinase 3
pANCA is usually antibody to myeloperoxidase
*HINT* Remember that P ANCA does NOT go with P protein
What is atypical (X) ANCA and what is it associated with?
UC and primary sclerosing cholangitis
Possible antigen targets: lactogerrin, cathepsin G, histone H1, BPI (bacterial permeability increasing protein)
BQ! Explain the technical process for ANCA evaluation (actually pretty interesting process and according to OSLER guy, this shows up commonly on boards).
FIRST: Screen on ETOH fixed neutrophils
–Cytoplasmic speckling indicates cANCA
–Perinuclear or nuclear staining indicates either pANCA, ANA or
aANCA
SECOND: Run specimen on formalin fixed neutrophils
*why? Because during ethanol fixation, the granules in neutrophils coalesce around the nucleus where in formalin fixed neutrophils they stay out in the cytoplasm so on a FF slide there is NO difference in a C or P ANCA that is why screening is done on ethanol slides because you can tell the difference
–Cytoplasmic staining on FF fixed neutrophils suggest pANCA
– MPO remains in the cytoplasm during formalin fixation
–Negative result suggests ANA or xANCA
– Anti DNA may remain positive on FF neutrophils
THIRD: Run on Hep-2 to rule out ANA
Shown are ethanol fixed neutrophils. What is this diagnostic of?
c-ANCA
*in ethanol fixed neutrophils, c-ANCA is cytoplasmic whereas perinuclear staining could be either p-ANCA, ANA, or atypical ANCA because the granules coalesce around the nucleus so if you get cytoplasmic staining on ethanol fixed, you have c-ANCA but if you have perinuclear staining, you have to then test formalin fixed neutrophils where BOTH c-ANCA and p-ANCA will stain the cytoplasm but will be negative if ANA or atypical ANCA is the culprit. So then follow it with Hep2 cells to check for ANA and if that is neg, you have atypical ANCA by exclusion.
Therefore cytoplasmic staining in ethanol fixed is c-ANCA. Perinuclear staining on ethanol fixed followed by cytoplasmic staining in formalin is p-ANCA. Perinuclear staining on ethanol followed by negative formalin followed by positive ANA Hep2 is ANA and if Hep2 is negative its atypical ANCA
This is a mouse kidney. What antibody is this?
Anti-mitochondrial antibody
85% of PBC
Reactive with the cytoplasm of parietal cells of the staomch and renal tubular cells in the mouse stomach/kidney substrate
*note AMA also seen in 10-15% of autoimmune hepatitis
What antibodies are seen in autoimmune hepatitis (there are two types)?
Type 1- Anti-Smooth muscle Ab, ANA
Type 2- Anti-Liver Kidney Microsomes (Cytochrome P450 D26)
What immunodeficiency is more common in patients with Celiac disease?
IgA deficiency occurs more frequently in celiac
disease than in the general population.
– 1/700 in normal population
– App 4% in celiac disease patients
This is monkey esophagus. What is the antibody?
Anti-endomysial antibody (Celiac)
What is the single best test for celiac disease?
IgA anti TTG is the best single test for Celiac Disease
IgA Anti TTG and Anti Deamidated Gliadin appear to be the most useful combination of serological assays
– If the above tests are negative, and the patient is IgA deficient, or if clinical suspicion of Celiac is still high, then an IgG anti TTG and IgG anti d-Gliadin is in order
HLA Typing- DQ2 and DQ8
What chromosomes are the following found:
1) kappa light chain genes
2) lambda light chain genes
3) heavy chain genes
4) HLA proteins
1) Chr 2
2) Chr 22
3) Chr 14
4) Chr 6p
What is the gold standard for detecting HLA antigens, HLA antibodies and performing HLA crossmatching?
Complement dependent cytotoxicity assay (CDC)
What do the following luminex values correspond to in HLA testing:
1) >5,000 MFI
2) >10,000 MFI
1) correlates with a positive T cell and B cell flow crossmatch
2) correlates with a positive CDC, indicating hyperacute rejection is likely if organ is transplanted
What immune disease typically appears in the 2nd or 3rd decade of life and is characterized by recurrent upper and lower respiratory tract infections, intestinal bacterial overgrowth, Giardia infection, bronchiectasis, low IgG, low IgM, low IgA and variable T cell deficiency?
CVID
These patients will have lymphoid hyperplasia with decreased/absent plasma cells on biopsy
What disease have increased IgE (3) and decreased IgE (2)?
Increased IgE: Wiskott-Aldrich, Job syndrome (hyper-IgE) and Nezelof syndrome
Decreased IgE: Bruton agammaglobulinemia and Ataxia-telangectasia
What immune disease has been linked to in utero exposure to Accutane?
DiGeorge Syndrome
Microdeletions involving chr 22q11.2
What immune disease is characterized by deficient IgA (hint I am not getting at IgA def here), VERY HIGH serum AFP and CEA, and is due to mutations in the ATM gene on 11q22.3?
Ataxia telangectasia
*opposite of DiGeorge which is 22q11 and this disease is 11q22
What disease is from mutations in autoimmune regulator gene (AIRE) on chromosome 21q22.3?
Chronic mucocutaneous candidasis
What disease causes a fulminant and often fatal immune response to EBV, has inverted CD4:CD8 ratio, hypogammaglobulinemia and the underlying abnormality is from mutation of SH2D1A gene Xq25 which codes for an SH2 domain on a signal transducing protein called SLAM associated protein (SAP)?
Duncan disease (X linked lymphoproliferative disorder)
What anomaly is characterized by fat vacuoles in leukocytes?
Jordan anomaly
What are the lab findings in C1 esterase inhibitor deficiency (hereditary angioedema)?
Urinary histamine levels and serum C1 levels are elevated during attacks while serum CH50, C4 and C2 are decreased.
Between attacks, C4 is always low while C2 levels are normal
Treatment: used to be FFP but in 2008 recombinant C1 esterase inhibitor concentrate became available which is now first line therapy
What is the MHC gene association for hereditary hemochromatosis?
HLA A3
What is the MHC gene association for 21 hydroxylase deficiency?
HLA C4
What is the MHC gene association for ankylosing spondylitis and Reiter’s syndrome?
HLA B27
What is the MHC gene association for Behcet’s disease?
HLA B51
What is the MHC gene association for celiac sprue?
HLA DQ2, DQ8
What is the MHC gene association for DM type 1?
HLA DR3 or DR4
What is the MHC gene association for multiple sclerosis?
HLA DRB1, DQB1
What is the MHC gene association for narcolepsy?
HLA DQ6
What is the MHC gene association for RA and pemphigus vulgaris?
HLA DR4
What mneumonic helps to remember what drugs cause drug induced lupus?
“SHIPP, May Day”
Sulfasalazine
Hydralazine
Isoniazid
Procainamide
Penicillin
Methyldopa
Dilantin
A patient is very likely to have what disorder if they have positive ANA, positive SS-A but negative SS-B?
Lupus nephritis
Other than sarcoidosis, what disease have elevated ACE?
Gaucher
Leprosy
PBC
PBC and autoimmune hepatitis both have hypergammaglobulinemia due to a polyclonal increase of which antibody (different for each)?
PBC polyclonal IgM
AIH polyclonal IgG
The lesion shown is characteristic of what disorder?
HINT: it involves medium sized vessels and typically spares the lungs and involves the kidney, nerves, mesenteric vessels and skin?
Polyarteritis nodosa
Pic is showing the characteristic lesion of segmental fibrinoid necrosis of the vessel wall
The segmental nature of involvement with active and healing lesions next to normal segments of blood vessel is highly characteristic
Name this disease.
Autosomal recessive disorder caused by anomalies in the MEFV gene on chromosome 16 which encodes pyrin/marenostrin protein and is characterized by paroxysms of fever and pain related to inflammation of the serosal membranes (peritoneum, pleura, synovium, or tunica vaginalis) and amyloidosis with renal failure is a complication (AA type)?
Familial Mediterranean Fever
this is the prototype “autoinflammatory fever syndrome”
Q from Q book but I have trouble remembering this concept:
Which of the following is NOT an example of type IV hypersensitivity?
a) contact dermatitis
b) multiple sclerosis
c) myasthenia gravis
d) rheumatoid arthritis
e) type I DM
Myasthenia gravis (it is a type II hypersensitivity)
These type IVs don’t make sense to me because by definition they are not supposed to be antibody mediated yet almost all these diseases have characteristic autoantibodies– so just memorize
Type IV hypersensitivity: contact dermatitis (ie poison ivy), multiple sclerosis, rheumatoid arthritis, type I diabetes, Crohn’s disease and Hashimoto’s
What are the serum antibody patterns seen in Wiskott-Aldrich?
Serum IgG normal
IgM low
IgA and IgE high
What immune disease is characterized by leukocytes being deficient in C3b receptors and their red cells often bear the McLeod phenotype (absence of Kell antigen, Kx)?
Chronic granulomatous disease
McLeod phenotype shows red cells with acanthocytosis
Other disease associated with McLeod phenotype: a late onset type of muscular dystrophy (“neuroacanthocytosis”) and retinitis pigmentosa
What is the CD4 count of an HIV patient with CMV retinitis?
<50
The hemodialysis associated systemic form of amyloidosis is associated with which amyloid protein?
Aß2M
ß2 microglobulin is a component of the MHC class I molecule that is deposited in patients undergoing long term dialysis
Other types:
AL = primary amyloidosis resulting from conditions like myeloma and other monoclonal B cell proliferations
AA or serum amyloid associated protein = produced in the liver and is associated with secondary amyloidosis from chronic inflammatory conditions such as RA, AS, IBD, heroin abusers as well as neoplasms such as RCC and Hodgkin’s
Transthyretin (TTR) = protein that transports retinol and thyroxine and its mutant form is deposited in familial amyloid polyneuropathies and senile systemic amyloidosis
Aß (ß amyloid protein) = forms the core of cerebral plaques in Alzheimer’s
What are the following amyloid proteins associated with?
1) Aß2M
2) AL
3) AA
4) Transthyretin
5) Aß
Aß2M = ß2 microglobulin is a component of the MHC class I molecule that is deposited in patients undergoing long term dialysis
AL = primary amyloidosis resulting from conditions like myeloma and other monoclonal B cell proliferations
AA or serum amyloid associated protein = produced in the liver and is associated with secondary amyloidosis from chronic inflammatory conditions such as RA, AS, IBD, heroin abusers as well as neoplasms such as RCC and Hodgkin’s
Transthyretin (TTR) = protein that transports retinol and thyroxine and its mutant form is deposited in familial amyloid polyneuropathies and senile systemic amyloidosis
Aß (ß amyloid protein) = forms the core of cerebral plaques in Alzheimer’s
What cells express MHC Class I antigens? MHC Class II?
Class I: Surface of most nucleated cells
Class II: B cells, monocytes, macrophages, dendritic cells and activated T lymphocytes
There are 3 main targets of acute GVHD, what are the histologic findings?
- Skin
- Intestinal tract
- Hepatobiliary tract
Acute GVHD occurs within the first 100 days with most cases presenting within the first 30 days
- Skin–erythematous pruritic rash, erythema multiforme like apoptosis that is most pronounced at base of rete ridges
- Intestinal tract–diarrhea, histologically ectatic crypts with attenuated enterocytes, crypt abscesses and striking apoptosis within the crypt epithelium
- Hepatobiliary tract–liver involvement presents with jaundice char by mononuclear portal inflammatory infiltrates with endothelialitis, ductitis and ductopenia
Chronic GVHD happens after the first 100 days and in addition to above shows mucosa and respiratory tract involvement. They get extensive cutaneous sclerosis similar to progressive systemic sclerosis pts. They may experience esophageal strictures, bronchiolitis obliterans, scarring ocular lesions and chronic liver damage.
This is different from TA-GVHD where the primary target is bone marrow and 90% of these pts die and this can be prevented by irradiated units
What is the most common inherited immunodeficiency disease?
Selective IgA deficiency (1 in 700)
What are the IgG4 related sclerosing diseases?
- Sclerosing mediastinitis
- Idiopathic retroperitoneal fibrosis
- Riedel thyroiditis
- Sclerosing cholangitis
- Orbital pseudotumor
- Sclerosing pancreatitis
What antibody is this staining?
Anti-smooth muscle
Autoimmune hepatitis
