lab med final lecture 18

Acute Phase Reactant

proteins whose plasma concenrations increase or decrease by at least 25% during inflammatory states

- infection

- trauma

- tissue infarction

- autoimmune dz

- neoplasms

what can cause APR

utility

levels generally reflect the presence and intensity of an inflammatory process

ESR

Nonspecific test used to detect illnesses associated with acute and chronic infection, inflammation, advanced neoplasm, tissue necrosis, or infarction

ERP

measurement of rate at which RBCs settle in saline solution

non specific

is ESR specific or non specific

RBC sedimentation

what increases when inflammatory processes increase fibrinogen content of plasma

utility ESR

Part of evaluation for vague symptoms (ex: Irritable Bowel Syndrome vs. IBD) and Monitor disease course for inflammatory/autoimmune diseases

- anemia

- pregnancy

- menstruation

- meds

- obesity

- smoking

what can flasly elevate an ESR

- autoimmune disease

- infection

- tissue injury

- malignancy

- diseases w increased proteins

what can cause in increase in ESR

CRP

Nonspecific test used to detect illnesses associated with acute and chronic infection, inflammation, and tissue necrosis

CRP

Protein produced by the liver during acute inflammatory process

CRP

which test is more sensitive ESR or CRP

CRP

which test is faster ESR or CRP

CRP

which acute phase reactant will show a rise rapidly when you have an acute infection

ESR= none

CRP= elevated

what are the lab results for ESR and CRP:

acute paronychia

elevated ESR and CRP

what are the lab results for ESR and CRP:

chronic osteomyelitis

detect inflammation or infection

what is the utility of CRP

cardiovascular

what can CCRP be a marker for in the future

- noninfectious inflammatory response

- autoimmune disease

- tissue damage

- MI

- bacterial infection

- malignancy

what will cause in elevation in CRPs

false: bacterial causes a rise not viral

True or False:

viral infection will cause a rise in CRP but not bacterial

- HTN

- high BMI

- metabolic syndrome

- chronic infection

- cig smoke

- alcohol

- meds

what can cause a false elevation or CRP

ANA

type of autoantibody that targets substances inside the nucleus of cells

low

what is the specificity for ANA

ANA

which test is most commonly used to screen for autoimmune disease, specifically connective tissue disease

pre test

what is a key clinical factor for ANA

True because high sensitivity in SLE

true or false:

Nearly everyone with SLE will have positive ANA

true

true or false:

Many healthy people will have false positive ANA

ANA

this test is reported as a titer and a pattern

a high positive test rate

if you have a high titer what does that mean for the rate

Rheumatoid Arthritis

A 45-year-old woman presents with a 6-month history of symmetric joint pain, stiffness, and swelling, primarily affecting the wrists, MCPs, and PIPs. She reports morning stiffness lasting over an hour, which improves with activity. She also notes fatigue and unintentional weight loss. On exam, she has tenderness and synovial thickening in multiple small joints of the hands bilaterally, with limited grip strength. No skin rash or back pain is noted. Hand Xray as below.

Labs reveal: Elevated ESR and CRP

Positive Rheumatoid Factor

Positive Anti-CCP antibody

What is your most likely diagnosis?

rheumatoid arthritis

Chronic autoimmune disease affecting targeting synovial joints that cause inflammation, joint destruction and deformity

- Symmetric polyarthritis, particularly in small joints

- Morning stiffness lasting > 1 hour

- Extraarticular manifestations

clinical features of rheumatoid arthritis

abnormal antigenic IgG antibodies against Fc portion of antigenic IgG

what abnormalities in the antibodies are seen with RA

- rheumatoid factor

- Anti CCP

which labs can help us determine the diagnosis of RA

test for anti CCP

what lab should you do next if RF is positive

rheumatoid factors

antibodies directed against the Fc portion of Immunoglobulin G (IgG)

greater likelihood that its true rheumatic disease

what does a high level of RF mean

uric acid and serum

what lab can help aid in the diagnisis of gout

false, you need uric acid AND synovial fluid analysis

true or false:

you can diagnose gout off uric acid levels

Gout

Hyperuricemia -> monosodium urate crystals deposited in joints -> pain and inflammation

decreased renal excretion or overproduction

what can gout be provoked by

2 weeks

how long does it take for a complete resolution of flare to normalize

allopurinol

what is the treatment if there are frequent/severe gout flare ups

wait 2 weeks and if no changes AFTER 2 weeks than you may change the dose

when should you change the dose for gout

<6.0

what is the therapeutic goal for gout

There should be no changes in his therapies currently

Patient returns for a follow-up. He is continuing appropriate anti-inflammatory medications. He has been compliant with low-purine diet and urate-lowering therapy (allopurinol). His symptoms completely resolved 5 days ago.

Repeat uric acid level is 8.9 mg/dL

Which of the following is true?

The patient needs to increase his allopurinol dose by 100 mg

Patient returns for a follow-up 3 weeks later. He has been compliant with low-purine diet and urate-lowering therapy (allopurinol). His symptoms completely resolved 26 days ago.

Repeat uric acid level is 8.0 mg/dL

Which of the following is true?

D dimer

what lab value tells us about the presence of a clot

D dimer

Degradation product from lysis of cross-linked fibrin

D dimer

this value is used to identify intravascular clotting and some prognostic value in COVID 19

- DVT

- PE

- DIC

what are some causes for increased D dimer

sensitive; non specific

D dimer is highly --- and highly -- ---

imaging

if a D dimer is positive what should you do next

- pregnancy

- surgery

- malignancy

- infection

- stroke

- MI

- liver disease

- renal failure

- advanced age

what can cause a false positive for D dimer

CTPA

what is the gold standard image for PE

D dimer

what test requires that you MUST consider pre-test probability prior to ordering

modified wells criteria and PERC

what criteria is used for patients risk of PE

patients who are extremly low risk

when should you not order a D dimer

extremely high risk patients

when should you not order a D dimer