rheum diagnostics

Question 1

what are the different types of rheumatology diagnostics

Answer 1

1. blood tests
2. joint(synovial) fluid analysis
3. imaging tests: xrays, ultrasound,ct,mri

Question 2

basic blood tests in rheumatology

Answer 2

fbc
urea and electrolytes
liver function tests
bone profile
erythrocyte sedimentation rate
c reactive protein

Question 3

what are the 3 main types of arthritis

Answer 3

osteorthritis
inflammatory
septic

Question 4

what would you expect to see in fbc of inflammatory arthritis

Answer 4

low (in anaemia) or normal hb
normal mcv
usually normal wcc
normal/high platelets

Question 5

what would you expect to see in fbc of osteoarthritis

Answer 5

normal hb
normal mcv
normal wcc
normal platelets

Question 6

what would you expect to see in fbc of septic arthritis

Answer 6

usually normal hb
normal mcv
high wcc - leukocytosis
normal/high platelets

Question 7

why might anaemia and therefore low hb occur in inflammatory arthritis

Answer 7

long standing uncontrolled inflammation can suppress bone marrow leading to less production of red cells

Question 8

what are u&es ?

Answer 8

urea
creatinine
sodium
potassium

Question 9

what does a higher creatinine suggest and why is it relevant to rheum

Answer 9

higher cr = worse renal clearance indicating kidney problem

rheum disease can affect kidneys

Question 10

what can sle do to kidneys

Answer 10

can cause lupus nephritis - which is kidney inflammation

Question 11

what can vasculitis do to kidneys

Answer 11

glomerular nephritis

Question 12

what can chronic inflammation in poorly controlled inflammatory disease cause

Answer 12

high levels of serum amyloid (saa) protein leads to saa deposits in organs (aa amyloidosis)

Question 13

what effects do NSAIDs e.g ibuprofen do to kidneys

Answer 13

can cause kidney impairment

Question 14

what are the lfts

Answer 14

bilirubin
alanine aminotransferase
alkaline phosphatase
albumin

Question 15

why are lfts a relevant test in rheumatology

Answer 15

dmards e.g methotrexate can cause liver damage

*patients on methotrexate need regular blood tests (e.g every 8wks)

Question 16

what is low albumin a sign of?

Answer 16

can either reflect problem of synthesis (in liver) or problem of leak from kidney e.g in lupus nephritis

Question 17

what is pagets disease

Answer 17

disease caused by abnormality of high bone turnover

Question 18

what are the clinical features of pagets disease

Answer 18

bone pain, excessive pain growth

fracture through area of abnormal bone

Question 19

when would you expect the alp to be very high

Answer 19

pagets disease of bone

Question 20

what might you see in bone profile of osteomalacia (soft bone due to vit d def)

Answer 20

normal/high alp

normal/low ca and po4

Question 21

what is osteoporosis

Answer 21

low bone density

Question 22

bone profile seen in osteoporosis

Answer 22

usually ca, po4 and alp are normal

Question 23

what are some other reasons esr may be high.

Answer 23

elevated immunoglobulin level
paraprotein (myeloma)
anaemia
tends to rise with age

Question 24

what is the rule of thumb in sle

in regards to esr and crp

Answer 24

esr usually high but crp normal
exception: crp high in sle if significant synovitis/inflammatory pleural or pericardial effusion
if crp high in lupus - suspect infection

Question 25

what if esr/crp are elevated and there is evidence of inflammatory arthritis what bloods should be done

Answer 25

look for 2 types of antibodies in blood: - rheumatoid factor: antiIgG antibody - cyclic citrullinated peptide antibodies

Question 26

why is ccp helpful

Answer 26

more specific thanrf | associated with worse prognosis

Question 27

what are anti nuclear antibodies

Answer 27

antibodies directed at nuclear component of cell

Question 28

what is ana use in rheumatology

Answer 28

high titre ana in combination with correct clinical features may indicate autoimmune connective tissue diseases e.g sle, sjogrens, scleroderma

Question 29

how can we interpret anas

Answer 29

negative test rules out sle | postive test - doesnt necessarily mean sle, other clinical features needed to support diagnosis

Question 30

what to do if ana comes back positive

Answer 30

ena test of 5 autoantibodies: ro,la,rnp,smith,jo1

Question 31

which of the 5 autoantibodies would be positive in lupus

Answer 31

ro,la,rnp,smith

Question 32

which of the 5 autoantibodies would be positive in sjogrens syndrome

Answer 32

ro,la

Question 33

what does positive jo1 on test mean

Answer 33

polymyositis

Question 34

why is double stranded dna antibodies a useful test

Answer 34

highly specific for lupus, associated with renal involvement, useful for tracking lupus activity over time

Question 35

when are c3 and c4 complement levels useful

Answer 35

may be low in active lupus

Question 36

what are the 2 indications for joint aspiration

Answer 36

diagnostic - to obtain synovial fluid for analysis | therapeutic - to relieve symptoms

Question 37

how is synovial fluid obtained

Answer 37

by aspirating fluid from joint

Question 38

what are the 2 main diagnostic uses for aspiration

Answer 38

1. suspected septic arthritis - gold standard for diagnosis - send for mc and s - enables causative organism to be identified - sensitivities from culture guide antibiotic choice 2. diagnosing crystal arthritis

Question 39

key differences in septic and reactive arthritis

Answer 39

sa - positive synovial fluid culture whilst sterile in reactive antibiotic therapy needed in septic arthritis joint lavage needed in septic arthritis

Question 40

imaging test in rheum

Answer 40

x rays - first line, cheap, widely available ct scans - more detailed bony imaging mri - best visualisation of soft tissue, best for spinal imaging, expensive and time consuming us - like mri good for soft tissue, good for smaller joints, less good for large/deep joints

Question 41

what is the most useful diagnostic test in oa

Answer 41

xrays

Question 42

what are radiographic features seen in osteoarthritis

Answer 42

joint space narrowing subchondral bony sclerosis osteophytes subchondral cysts

Question 43

what are some radiographic features found on xrays of ra

Answer 43

soft tissue swelling peri articular osteopenia boney erosions - aim is to treat before erosions

Question 44

us is much better at detecting synovitis. us changes in ra:

Answer 44

synovial hypertrophy increased blood flow - doppler signal may detect erosions

Question 45

radiographic features of gout

Answer 45

juxta articular 'rat bite' erosions - at mtpjs