Pathology

Question 1

SLE lab findings

Answer 1

ANA
anti-dsDNA (poor prog - renal dz)
anti-Smith (against snRNPs)
antihistone
decreased complement (C3, C4, CH50) due to immune complex formation

Question 2

Antiphospholipid syndrome

Answer 2

Often 2ary to SLE

Clinical diag: thrombosis, spontaneous abortion, lab findings (lupus anticoag, anticardiolipin, anti-beta2 glycoprotein)

tx: systemic anticoag

Question 3

Sarcoidosis

Answer 3

autoimmune - noncaseating granulomas all over, elevated ACE, increased CD4/CD8 ratio

main sx often = enlarged ln, esp in hilum and mediastinum (see them on CXR)

can –> restrictive lung dz (interstitial fibrosis), also hyperCa (increased Vit D act in macrophages), erythema nodosum, epithelioid granulomas

tx: steroids

Question 4

Polymyalgia rheumatica

Answer 4

Pain and stiffness in shoulder and hips, often with B sx; no muscle weakness

assoc with GCA

increased ESR, CRP

treat with corticosteroids

Question 5

Fibromyalgia

Answer 5

women 20-50yo

musculoskel pain, stiffness, paresthesias, poor sleep, fatigue

tx: exercise, antidep, anticonvulsants

Question 6

Polymyositis

Answer 6

symm, progressive proximal muscle weakness with CD8 endomysial inflamm

often in shoulders

autoimmune

Question 7

Dermatomyositis

Answer 7

progressive, symm prox muscle weakness (as in polymyositis) + malar rash, heliotrope rash (around eyes), shawl and face rash, gottron papules on hand joints

may suggest occult malignancy

perimysial inflamm with CD4+ cells

Question 8

Polymyositis/dermatomyositis lab findings

Answer 8

Increased CK

ANA, anti-Jo-1, anti-SRP, anti-Mi-2 +

tx: steroids, methotrexate and other immunosupp

Question 9

Complications of SLE

Answer 9

Libman-sacks endocarditis

Lupus nephritis (type III hypersensitivity)

Question 10

MG pathophys

Answer 10

Autoantibodies to postsynaptic ACh receptor

Symptoms reversed by AChE (more ACh in synapse to compete against Ab)

Question 11

Lambert-Eaton pathophys

Answer 11

Autoantibodies to presynaptic Ca++ channel –> decreased ACh release

not affected by AChE

Question 12

Ways to distinguish MG from Lambert-Eaton

Answer 12

MG = much more common

MG worsens with muscle use (less ACh released into synapse to compete with Ab)

vs. L-E improves with use (more Ca in presynaptic cell over time –> increased ACh release)

MG assoc with thymoma/hyperplasia vs. L-E assoc with SCLC

Question 13

Myositis ossificans

Answer 13

Metaplasia of skeletal muscle into bone (usually after trauma)

Question 14

Signs and sx of scleroderma

Answer 14

autoimmunity, noninflamm vasculopathy, collagen deposn with fibrosis

Sclerosis of skin –> puffy and taut, fingertip pitting, sclerosis of visc organs (esp pulm)

Question 15

Two types of scleroderma

Answer 15

Diffuse - anti-Scl-70 (anti topoI) - skin and visc, rapid prog

Limited - skin of fingers and face, anti-centromere; CREST involvement

Question 16

CREST

Answer 16

Calcinosis
Raynaud
Esophageal dysmotility
Sclerodactyly
Telangiectasia