Immunology

Question 0

What marker is associated with rheumatoid arthritis or Type 1 DM?

Answer 0

DR4

Question 1

What diseases are often associated with HLA-B27?

Answer 1

PAIR - Psoriatic arthritis, Anklyosing Spondylitis, Arthritis of IBD, reactive arthritis (Reiter’s syndrome).

Question 2

If a pediatric patient has low levels of all the immunoglobulin classes and history of recurrent infection but normal levels of T- cells what immunodeficiency is likely?

What is its inheritance pattern?

Answer 2

Bruton’s Agammaglobulinemia

X-linked. Defect in tyrosine kinase required for production of MATURE B-cell lymphocytes. Note that because CD19 is a regular B-cell marker, its levels are normal in Bruton’s.

Question 3

What is Job Syndrome?

Answer 3

It is hyper Ig-E syndrome caused by a failure of HELPER T cells to produced IFN-gamma. FATED - coarse Facies, cold or non-Inflammed abscesses, retained primary teeth, high IgE levels, dermatological problems.

Question 4

IgA deficiency in the setting of Ataxia and telangiectasias of the eye and skin is concerning for …

Answer 4

Ataxia-Telangiectasias. There are usually normal CD4/CD8 count values.

Question 5

What is the problem in paroxysmal nocturnal hemoglobinuria?

Coombs result?
Treatment?

Answer 5

The issue in PNH is the cell surface ANCHORING molecule (GPI - glycophosphatidylinositol). CD 59 (Membrane attack complex inhibitory factor) and CD55 (decay accelerating factor) merely use GPI as an anchor but they are NOT the issue. The affected gene is the PIG-A gene.

They will be Coombs negative – no antibodies. Complement-mediated hemolysis.

Treatment: eculizumab

Question 6

What does ANCA stand for? In what diseases are these common

Answer 6

Anti-neutrophil cytoplasmic body.

Vasculitides which usually have renal symptoms like hematuria, proteinuria, rapidly progressing GN, renal failure.

Question 7

What is the auto-immune response marker in rheumatoid arthritis? What is it against?

Answer 7

RF factor is Anti-IgG auto-antibody against the Fc region.

Question 8

How does a toxoid vaccine confer immunity towards a toxin?

Answer 8

Cross-reactivity with the toxin. The toxoid itself is a modified toxin that is no longer harmful.

Question 9

In graft vs host disease what happens?

Answer 9

The donor T-lymphocytes recognize the recipient as foreign and mount an immune response. This can happen as quickly as weeks after a transplant.

Question 10

What are anti-Jo1 antibodies associated with?

Answer 10

Dermatomyositis, polymyositis.

Question 11

A patient who has recurrent thrush and recurrent vaginal yeast infections in the absence of other signs of immunodeficiency is concerning for..

What immune cell type is dysfunctional?

Answer 11

Chronic mucocutaneous candidiasis.

T-cell

Question 12

A 25 year old patient who is a heavy smoker develops acute onset fever, malaise, muscle pain, HTN, abdominal pain, bloody stool and pre-renal failure 6 months after recovering from an acute Hep B infection. Diagnosis: ____ Treatment: _____

Answer 12

Diagnosis: Polyarteritis nodosa
Treatment: Cyclophosphamide/ Corticosteroids

Question 13

Anti-myeloperoxidase antibodies are seen in what disease?

Answer 13

Microscopic polyangiitis. These are essentially the p-ANCA genes.

Question 14

What is MHC class II composed of?

Answer 14

2 alpha and 2 beta chains.

Question 15

What is MHC Class I composed of?

Answer 15

Three alpha chains and One beta chain

Question 16

What might one see in the setting of immune thrombocytopenia purpura in the setting of anti-platelet antibodies and a low platelet count?

Answer 16

Enlarged platelets.

Question 17

What HLA is associated with Hashimoto’s and pernicious anemia (B12 deficiency)?

Answer 17

DR5

Question 18

What is the mechanism of action of Edrophonium (tensilon) test in myasthenia gravis?

Answer 18

It is a reversible acetylcholine esterase inhibitor. Thus it temporarily improves myasthenia symptoms by transiently increasing levels of ACh.

Question 19

What is marker is missing in Leukocyte adhesion deficiency?

Answer 19

CD 18. - integrin important for chemotaxis.

Question 20

What disease would a defect in CD40 ligand on T-cells cause?

Answer 20

Hyper Ig-M.

Question 21

If a patient with asthma and allergic rhinitis develops uveitis, conductive hearing loss, and muscle/joint pain, consider diagnosis:

Answer 21

Churg-Strauss syndrome (allergic granulomatosis and angiitis) with p-ANCA markers.

Question 22

What type of hypersensitivity reaction is erythroblastosis fetalis?

Answer 22

Type II

Question 23

What type of hypersensitivity reaction is eczema?

Answer 23

Type I. An environmental antigen binds to a pre-formed IgE complex on the surface of mast cells and basophils.

Question 24

What is the term for the type of rejection that happens on the transplant operating room table? What is its pathophysiology?

Answer 24

Hyperacute rejection. It is mediated by RECIPIENT lymphocytes that are anti-the donor’s organ.

Question 25

What is the pathophysiology of KSHV?

Answer 25

Malignant proliferation a of spindle cells and endothelial cells. GI bleeds are very common meaning dark stools (melena). Also tends to affect biliary tree

Question 26

In what layer of skin are the auto-antibodies in pemphigus vulgaris directed?
Treatment:

Answer 26

They are directed at desmoglein-3, a cell-cell adhesion protein expressed by KERATINOCYTES in the EPIDERMIS. There is sparing of the basal layer in pemphigus vulgaris.
Treatment: steroids

Question 27

What adverse effect do cyclosporine and Amphotericin have in common? What is the mechanism of action of cyclosporine?

Answer 27

Nephrotoxicity.

Mechanism of action of cyclosporine: IL-2 inhibition. (IL-2 is import at for T-cell activation).

Question 28

What disease is associated with the characteristic pathological finding of a vacuole that looks like a tennis racquet or to me looked a little like a bacteriophage?

Answer 28

Langerhans cell Histiocytosis. Causes osteolytic or skin lesions in kids. The cells express S-100 and CD1a. In this disease the Langerhans cells which are usually in the skin are immature and do not effectively stimulate T-cell activation.

Question 29

What is a common inhibitory cytokine or DOWNREGULATOR of the immune system?

Answer 29

TGF-beta

Question 30

Someone who does not have an ileum is less susceptible to which infections that take advantage of which immunologic defense specific to the ileum?

Answer 30

Peyer’s patches are specific to the ileum. Shigella, for example, takes advantage of the fact that M cells sample antigens from the gut. Other bacteria.

Question 31

What drug is best to immediately address lupus nephritis?

Answer 31

Cyclophosphamide.

Question 32

Prolonged stimulation improves results for which of the following two: Lambert-Eaton or Myasthenia Gravis?

Answer 32

lambert-eaton.

Question 33

What syndrome is suggested by low serum IgM levels, pruiritic rash and recurrent pyogenic infections?
What other major laboratory abnormality can be expected?
Pathophysiology?

Answer 33

Wiscott-Aldrich syndrome.
Lab: Thrombocytopenia. Also SMALLER platelets.
These individuals have higher risk of auto-immune disease and of cancer. X-linked. T-cells cannot reorganize actin cytoskeleton.
IgE and IgA can be high.

Question 34

In HIV, intracellular organisms e.g. Listeria, can be very difficult to control because they can only be taken care of by T-cells as opposed to extracellular organisms that can also be neutralized by antibodies and the humoral system.

Answer 34

Repeat.

Question 35

What is characteristic about the levels of C3 in Henoch-Schonlein purpura?

Answer 35

They are normal. Even though IgA and C3 deposits are found in the mesangium.