Lab Studies inMusculoskeletal

Diseaseswith 이 승원

명분이 없다 아입니까…. 명분이

Complete Blood Count (CBC)• Anemia: Chronic disease:

Normocytic normochromic, Microcytic hypochromic• Leukopenia: common in SLE: 약 50%에서발생• Thrombocytopenia: mild in SLE• Drug induced Myelosuppression: Methotrexate

Check CBC every 3 months!• Macrocytic anemia: Methotrexate: Folate deficiency

Liver Function Tests (ALT/AST)• Elevated ALT/AST:

MyositisDrugs: Methotrexate, NSAID, Sulfasalazine

류마티스약물을복용하는경우 3개월마다검사

정상범위 2배이상상승시Methotrexate 일시중단Autoimmune Connective Diseases

Kidney Function Test: Bun/Cr

• Abnormal Kidney Function:SLE Vasculitis Gout: Mildly elevated Cr can be reversed with

Hypouricemic agent.Drug: NSAID, Tacrolimus

• eGFR : Cr 은나이,성,몸무게에의해영향을받음

Urine Analysis

• Proteinuria

• Hematuria

• Vasculitis 의유무를확인

Erythrocyte Sedimentation Rate

• Measures how quickly red blood cells fall to the bottom of a test tube

• Elevated in inflammatory conditions: Infection or Rheumatologic diseases

• Sensitivity: HighSpecificity: Very lowNormal ESR: 10% of RA ,20% of PMR patients

C Reactive Protein (CRP)

• Increase and return to normal levels is more rapid • More sensitive in showing variation in disease

activity• Not affected by age and sex. • Normal CRP do not mean that there is no disease

progression: Normal in 10% of Active RA cases • High levels may indicate bacterial infection (> 10

mg/dL):

Anti-nuclear Antibody (ANA)

• 정상인에서양성률1/40 dilution: 31.7% 1/80 dilution: 13%1/160 dilution: 5% 1/320 dilution: 3.3%

• Antibodies against DNA and histones which indicates SLE and other Autoimmune Disease

Anti-nuclear Antibody (ANA)

• SLE: 99~100% Scleroderma: 95%Rheumatoid Arthritis: 45%Dermatomyositis: 35%Mixed connective tissue disease:100%Sjögren’s syndrome: 60%

• IF is the gold standard for ANA identification

ENA Panel

• ANA가양성이면더정확한진단을위해 ENA시행

• Smith antigen (Sm), Ribonucleoproteins (RNP), Ro/SSA or La/SSB, Scl-70, histidyl-tRNA synthetase (Jo-1), and PM1.

Rheumatoid Factor (RF)

• Rheumatoid arthritis환자들의 70-80%에서양성• Indicator of worse prognosis. • Healthy population; 15% may be positive at low

titrations and this rate increases with age• Don’t use for monitoring treatment response and

disease

Conditions causing RF positivity• Systemic lupus

erythematosus (SLE)• Sjögren syndrome• Interstitial pulmonary fibrosis• Hepatitis B, chronic liver

disease, and chronic hepatitis• Essential mixed

cryoglobulinemia• Primary biliary cirrhosis• Infectious mononucleosis and

any chronic viral infection• Bacterial endocarditis• Leprosy

• Sarcoidosis• Tuberculosis• Syphilis• Visceral leishmaniasis• Malaria• Leukemia• Dermatomyositis• Systemic sclerosis• After

vaccination/transfusion in normal individuals

Anti-Cyclic CitrillunatedPeptide (CCP)

• More specific test for Rheumatoid Arthritis

• Specificity of 99%/Sensitivity of 61.6%: Early RA:

• Sensitivity 75.2%: Late RA Overall Sensitivity of 71.7% for all RA

Creatine Phosphokinase (CPK or CK)• Muscle enzyme • Autoimmune diseases affecting the

muscles such as Polymyositis • Medication toxicity (such as from statins

used to treat high cholesterol)

Uric Acid or Urate: Gout?

• 10mg/dL이상이면무증상인경우에도약물치료

• 발작이일어난후 4주지난시점에요산측정

• 가장높게측정된수치를인정

• 통풍환자들은여러성인병들이동반: 콜레스테롤, 간수치, 혈당, Bun/Cr, R-CBC, UA

HLA-B5801

• Allopurinol vs Febuxostat• 알로퓨리놀부작용을예방하기위해시행• 동양인에서많이보유• 보험인정기준알로퓨리놀투여전요산이 9 이상이면서만성신질환(GFR<60)이있는경우

Antineutrophil Cytoplasmic Antibodies (ANCAs)

• PR3(cANCA): High sensitivity and Low specificity (90%, 50% respectively) in Granulomatosis with Polyangiitis(Wegener’s Granulomatosis)

• MPO(pANCA): frequently in pauciimmuneglomerulonephritis, Microscopic polyangiitis,드물게 GPA에서양성

• PR3,MPO: Eosinophilic Granulomatosis withpolyangiitis (Churg-Strauss syndrome)

Antineutrophil Cytoplasmic Antibodies 검사를시행해야하는경우

• Arthralgia, fatigue, fever, urinary abnormalities (an active urine sediment) , purpura,

HLA-B27

• PAIR(Psoriasis, Spondyloarthropathy, IBD, Reactive arthritis)와관련

• 90% of pt with AS: HLA-B27 positiveSmall % of people with HLA-B27 develop AS스크리닝목적으로사용하지말것!

•Relatively Underutilized!

HLA-B27가필요한경우

Axial Spondyloarthropathy Peripheral Spondyloarthropathy

Copyrights apply

Elevated CRP

기타검사들

• VDRL• Hepatitis B Surface Ag/Ab • Antiphospholipid Syndrome

Anticardiolipid antibody IgG : Sensitivity가높다Lupus Anticoagulant: Specificity가높다…….Anti-Beta2 GPI

Complement (e.g. C3, C4)

• measures a group of proteins important to the body’s response to infections

• levels can be low in SLE

• Useless for screening of SLE but is often used to monitor disease activity in patients with SLE.

Thank You