diagnosis of autoimmune diseases assos. prof. gülderen yanıkkaya demirel md, phd yeditepe...
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DIAGNOSIS of AUTOIMMUNE DISEASES
Assos. Prof. Gülderen Yanıkkaya Demirel MD, PhDYeditepe University School of Medicine
Immunology Department, Medical Microbiology Department
Yeditepe University Hospital, Hematology DepartmentDirector of Stem Cell Laboratory
DEFINITION of AUTOIMMUNITY
Sometimes antibodies make a mistake, identifying normal, naturally-
occurring proteins in our bodies as being "foreign" and dangerous.
http://www.rheumatology.org/practice/clinical/patients/diseases_and_conditions/ana.asp
AUTOIMMUNITY TAUTOLOGY
GEOGRAPHICAL DISTRIBUTION AND PREVALANCE of AUTOIMMUNE DISEASES
Disease Prevalance1/100,000
Region
Systemic lupus erytematosus 34 – 150
4245
USA, Spain, GreeceCanadaAustria
Multiple sclerosis177 – 358
10146
USA, CanadaTurkeyNorway
Sjögren Syndrome600110
3500
GreeceDenmarkUnited Kingdom
GEOGRAPHICAL DISTRIBUTION of T1D
GEOGRAPHICAL DISTRIBUTION of MS
GEOGRAPHICAL DISTRIBUTION of UC
INFECTIONS SEEN IN AUTOIMMUNE DISEASES
Disease Infection Agents
Romatoid arthritis Epstein-Barr virus (EBV)Parvo B19Chronic Hepatitis C virus (KHCV)
Multiple sclerosis EBVChlamidopiliya
Type-1 Diabetes Coxsachie virus B (Cox B)CytomegalovirusMumps
Sjögren Syndrome Cox BEBVCHCV
SPECIFIC AUTOANTIBODIES – ANTIGENIC DETERMINANT and
CLINICAL REFLECTIONSAnti-dsDNA dsDNA High specificity for SLE; often correlates
with active severe disease
Anti–extractable nuclear antigens Smith High specificity for SLEAnti-Sm Proteins containing U1-RNA
Anti-RNP MCTD, SLE, RA, scleroderma, Sjögren
syndrome
Anti-SSA (Ro) RNPs Sjögren syndrome, SLE (subacute cutaneous lupus),neonatal lupus,
Anti-SSB (La) RNPs Sjögren syndrome, SLE, neonatal SLE
Anticentromere Centromere/kinetochore region Limited scleroderma, pulmonary of chromosome hypertension, primar biliary cirrhosis
Anti–Scl 70 DNA topoisomerase I Diffuse scleroderma
Anti–Jo-1 (anti-synthetase antibodies) Histidyl tRNA synthetase Inflammatory myopathies with (other tRNA synthetases) interstitial lung disease, fever and
arthritis Anti-SRP Antibody to signal recognition protein Inflammatory myopathies with poor
prognosis
Anti-PM/Scl Antibody to nucleolar granular PM/scleroderma overlap syndrome component
Anti–Mi-2 Antibodies to a nucleolar antigen DM of unknown function
IT IS NOT ALWAYS EASY
TO DIAGNOSE
AN AUTOIMMUNE DISEASE
TOOLS for DIAGNOSIS
HISTORY
PHYSICAL EXAMINATION
LABORATORY DIAGNOSIS
IMAGING TECHNIQUES
LABORATORY DIAGNOSIS• INFLAMMATION MARKERS AND BODY FLUID TESTING
– Blood count – ESR – Erythrocyte Sedimentation Rate– CRP – C-Reactive Protein– Ferritin– Oligoclonal band– Immunophenotyping
• AUTOANTIBODY TESTS– ANA – Anti nuclear antibody– dsDNA – doble stranded DNA– ENA – Anti-extractable nuclear antigen– RF – Rheumatoid Factor– Anti-CCP – Autoantibodies to cyclic citrullinated peptide– Complement– Immunoglobulins– Cryoglobulins
TESTS TO BE REQUESTED AT FIRST VISIT
• Blood count• CRP• ANA (if one is strongly suspicious about AID)
ANA – ANTI NUCLEAR ANTIBODY
The antibodies that target “normal” proteins within the nucleus of a cell
are called antinuclear antibodies (ANA).
WHAT IS AN ANTIBODY or ANA?
Antibodies develop in our immune system to help the body fight infectious organisms.
When an antibody recognizes the foreign proteins of an infectious organism, it recruits other proteins and cells to fight off the infection. This cascade of attack is called inflammation.
Unfortunately, some antibodies make incorrect calls, identifying a naturally-occurring protein (or self protein) as foreign. These autoantibodies start the cascade of inflammation, causing the body to attack itself.
Most of us have autoantibodies, but typically in small amounts. The presence of large amount of autoantibodies or ANAs can indicate an autoimmune disease.
FAST FACTS
A positive ANA test means autoantibodies are present.
By itself, a positive ANA test does not indicate the presence of an autoimmune disease or the need for therapy.
Autoimmune diseases can be treated.
EXAMPLES of DISEASE-TEST RELATION
METHODS for AUTOANTIB0DY MEASUREMENT
What does a positive ANA reading mean?
A negative ANA reading means no autoantibodies are present in the body. However, a positive ANA reading alone does not indicate an autoimmune disease. Why?
The prevalence of ANAs in healthy individuals is about 3-15%. The production of these autoantibodies is strongly age-dependent, and increases to 10-37% in healthy persons over the age of 65. Even healthy people with viral infections can have a positive ANA, albeit for a short time.
Some medications can cause a positive ANA. It is important to talk with your doctor all the drugs you are taking—prescription, over-the-counter and street. Other conditions, such as cancer, can cause a positive ANA.
The positive ANA reading simply tells your doctor to keep looking. In fact, you may have a “false positive” ANA, which means that the evidence is not there to make a diagnosis of lupus or any other autoimmune disease. To make a definite diagnosis, your doctor will need more blood tests along with history of your symptoms and a physical examination. http://www.rheumatology.org/practice/clinical/patients/diseases_and_conditions/ana.asp
ANA ALGORITHM