Immunology - Diseases & Specific Findings Flashcards Preview

Step 1 > Immunology - Diseases & Specific Findings > Flashcards

Flashcards in Immunology - Diseases & Specific Findings Deck (32):
1

SS-A (anti-Ro) / SS-B (anti-La)

Sjogren's Syndrome

2

Dermatomyositis - Clinical and Histological Findings

Malar / heliotrope rash
'Shawl sign'
Gottron's papules / 'mechanic hands'

Histology shows perimysial CD4 inflammation

3

Polymyositis - Histology

Histology shows endomysial CD8 inflammation

4

Nitroblue tetrazolium (NBT) test

Negative in chronic granulomatous disease

Looks for production of superoxide anion which reduces the test indicator to produce blue color

5

Catalase positive bacteria

Pseudomonas
Listeria
Aspergillus
Candida
E. Coli
S. aureus
Serratia

6

Pathogens associated with Guillian-Barre Syndrome

Campylobacter jejuni
CMV

7

Pathogens associated with Hyper-IgM syndrome

Pyogenic infections, especially:

Pneumocystis
Cryptosporidium
CMV

8

Pemphigus Vulgaris - Antibody, IF, special sign

anti-demoglein

IF shows antibodies surrounding epithelial cells in a 'reticular' arrangement

Positive Nikolsky sign = separation of the epidermis with mechanical stroking

9

Direct Coomb's Test

Used to detect the presence of anti-RBC antibodies in a patient's serum sample

RBCs from patient serum are incubated with anti-IgG antibodies; if RBCs agglutinate then RBCs were bound by antibody

10

Indirect Coomb's Test

Used to detect antibodies in patient serum, i.e. prior to blood transfusion

Patient's serum is mixed with donor RBCs; if antibodies are present in the serum which bind donor RBCs then addition of anti-IgG to the solution causes agglutination

11

Seronegative arthropathies - HLA association

HLA B27

Psoriatic Arthritis
Ankylosing Spondylitis
IBD-related arthritis
Reactive arthritis

12

Celiac Disease - HLA Association

DQ2
DQ8

13

Diabetes Mellitus Type 1 - HLA Associations

DR3
DR4

14

Which cytokines are secreted by Th2s?

IL-4 - Enhances class switching to IgE and IgG

IL-5 - Enhances class switching to IgA; stimulates growth and differentiation of eosinophils

IL-10 - Inhibits differentiation of T cell progenitors into Th1

15

Which cytokines are secreted by Th1s?

IL-2 - Provides 2nd signal for activation of CTLs

IFNy - Stimulates macrophages

16

Rheumatoid Arthritis - HLA Association

HLA DR4

17

SLE - HLA Association

HLA DR2
HLA DR3

18

Edrophonium challenge test

Edrophonium is a short-acting AChEI used to diagnose Myasthenia Gravis; symptoms of myasthenia gravis improve with administration of edrophonium

19

Anti-phospholipid antibody

AKA 'Lupus anticoagulant' - acquired anti-phospholipid antibody; bind to platelet phospholipids, making them accessible to clotting factors and leading to recurrent venous and arterial thrombosis

Inhibits the function of exogenous platelet phospholipids used in PTT assay causing false elevation (looks like a bleeding disorder)

Requires lifelong anti-coagulation therapy

Reacts with cardiolipin antigen used in syphylis serology, causing false positives for syphilis

20

What antibodies are most specific for SLE?

anti-Smith
anti-double stranded DNA

21

Which auto-antibody causes false positives in syphylis testing?

Anti-phospholipid antibody (Lupus)

22

What antibodies are seen in Churg-Strauss Syndrome?

anti-MPO
p-ANCA

23

ANCA-associated vasculitidies

Churg-Strauss Syndrome
Wegener's Granuloamotosis
Microscopic polyangiitis

24

Negatively Birefringent crystals

Crystals are yellow under parallel light, blue under perpendicular light

Characteristic of monosodium urate (MSU) crystals seen in Gout

25

Gout

Inflammatory monoarthritis caused by precipitation of monosodium urate (MSU) crystals in joints, secondary to hyperuricemia (90% due to under-excretion of urate)

Presents as asymmetric appearance of painful, red, swollen joint, classically the MTP of the big toe (Pedagra); 20% eventually develop Gouty Nephropathy due to MSU deposition in adrenal medulla, uric acid renal stones causing renal failure

Findings: Needle-shaped, negatively birefringent crystals in joint fluid

Acute treatment = NSAIDs / Colchicine, Glucocorticoids

Chronic treatment = Xanthine Oxidase inhibitors (Allopurinol)

26

Drug-Induced Lupus

Seen in men and women equally, associated with anti-nuclear antibody (ANA) and anti-histone; not associated with anti-DNA antibodies (anti-dsDNA, anti-Smith)

Caused by:
Hydralazine
Isoniazid
Procainamide
Phenytoin

27

Lambert-Eaton myasthenic syndrome

Autoimmune production of antibodies directed against the pre-synaptic voltage-gated Ca2+ channel at the NMJ; often occurs as paraneoplastic syndrome of small cell lung cancer

Presents as proximal muscle weakness, diplopia, decreased DTRs; muscle weakness improves with exercise due to accumulation of pre-synaptic Ca2+

28

Kaposi Sarcoma

Neoplasm of vascular endothelial cells caused by HHV-8; seen in the setting of immunosuppression (AIDS, transplant)

Presents as dark, flat or papular lesions on the skin; may also affect GI tract and lungs

Treated with alpha interferon

29

Chronic mucocutaneous candidiasis

T cell dysfunction resulting in deficient or absent T-cell proliferation response to Candida antigens

Presents as recurrent oral / esophageal thrush, vulvovaginitis

Treated with fluconazole / capsofungin (for oral/esophageal) and topical -azole (for vulvovaginitis)

30

X-linked (Bruton's) hypogammaglobulinemia

X-linked defect in BTK tyrosine kinase causing failure of B cell maturation and immunoglobulin production

Presents with recurrent pyogenic bacterial infections after 6 months (once maternal IgG is depleted)

Labs: Normal CD19+ B cell count, decreased Ig of all classes, absent/scanty lymph nodes and tonsils

31

Selective IgA deficiency

Most common primary immunodeficiency

Majority asymptomatic but can see airway or GI infections, as well as anaphylaxis to IgA-containing blood products

Labs: Low IgA with normal IgG, IgM

32

Severe Combined Immunodeficiency (SCID)

Autosomal recessive defect in adenosine deaminase enzyme; accumulation of ATP and dATP imbalances nucleotide pool via feedback inhibition of ribonucleotide reducetase, preventing DNA synthesis and decreasing lymphocyte count

Presents with failure to thrive, chronic diarrhea, thrush; repeated bacterial, viral, fungal, and parasitic infections

Findings: Absent thymic shadow on CXR, absent germinal centers on lymph node biopsy, low IgG/IgM, low / absent T cells