week 4 Flashcards
Cold agglutinins
• Used to identify and investigate cold agglutinin syndrome and certain infections such as mycoplasma pneumoniae (secondary Cold agglutinin syndrome)
o Not used for diagnosis of infections (including mycoplasma pneumoniae)
• Includes flu, arthritis, HIV, etc.
• Cold agglutinin syndrome – antibodies to erythrocytes are very high, >1:512; moreSx in cold
Anticardiolipin antibodies
• Often positive in patients with systemic lupus erythematosus (SLE)
• Higher risk of antiphospholipid syndrome [Hughes syndrome] which includes venous/arteria thrombosis, thrombocytopenia, recurrent spontaneous abortions
o Used to see if SLE patients are HIGH RISK of above
• Patient who has had syphilis will have a false-positive result
o False positive has also been seen in patients taking chlorpromazine, hydralazine, PCN, phenytoin, procainamide, quinidine
Anitnuclear antibody, (ANA)
• Used to diagnose SLE and other autoimmune diseases (scleroderma, RA, Sjogren syndrome)
o A negative test means it is not autoimmune dx
• If positive Need additional antibody tests to confirm diagnosis
• Immunofluorescence pattern reported with test results
o Different patterns associated with different disease
• Not specific to SLE
• Many drugs can cause a false positive result
• Steroids can cause a false negative
Anti-DNA antibody
- Used for diagnosis and follow up of SLE
- Found in up to 80% of patients with SLE; rarely seen in patients with other diseases
- Decreases with successful therapy and increases in exacerbations
Anti-SS-A. SS-B, and SS-C antibody
• Used for diagnosis of Sjogrens Syndromes
o Sjogrens immunologic abnormality characterized by progressive destruction of the lacrimal and salivary exocrine glands leading to mucosal and conjunctival dryness
• Anti SS-A and SS-B positive in primary Sjogrens syndrome (solo)
o SS-A can also be found in patients with SLE
o SS-B found only in primary Sjogrens Syndrome
• Anti SS-C used to diagnose Rheumatoid Arthritis (leading to secondary Sjogrens)
o In general higher the titer of anti-SS bodies, the more likely Sjogrens syndrome exists
Alkaline phosphatase
- Monitor diseases of bone and liver
* Elevated levels in RA
C reactive inflammatory markers
- Indicates inflammatory d/o or bacterial disease
- Indicates presence but NOT cause of disease
- More sensitive than sed rate (shows quicker, leaves quicker)
- Also suppressed by anti-inflammatory
- Can be valuable in predicating coronary disease
Erythrocyte sedimentation rate (ESR)
- Detect illnesses associated w/ acute and chronic infection, inflammation, advanced neoplasm, and tissue necrosis or infarction
- Non-specific marker of inflammation
- Similar to CRP; if ESR is inconsistent with clinical complaints then CRP ordered
- Often used in evaluation of vague symptoms
- Used to monitor disease therapy in inflammatory autoimmune diseases
- High ESR = dx worsens; lower ESR = dx improves
HIV RNA quantification
- Used to determine HIV viral load
- Used for prognosis, disease progression, response to antiviral treatment, and need for prophylactic treatment
- Used to screen infants born to HIV+ mothers
- Need to have two separate tests 2-4 weeks apart
- Negative does not guarantee negative; it just means it has fallen below testing limit.
HIV serologic and virologic testing
- Identifies antibodies produced by HIV 1 [USA] and 2 [Africa] infection (detection)
- Virologic tests identify HIV infection 11 days after infection
- Serologic identifies HIV infection after about 3 weeks
- Screening tests VS confirmatory tests
- *NEVER give HIV tests over the phone. Always make appointment for follow up to review results
Human t-cell lymphotrophic virus
- Diagnose certain types of leukemias
- Can be infected with HTLV-1 but never be sick
- Associated w/ adult T-cell leukemia
- Retrovirus similar to HIV however not associated with AIDS
Immunoglobulin quantification
• Detect hypersensitivity diseases, immune deficiencies, autoimmune diseases, chronic infections, malignancies, intrauterine fetal infections
• IgA, IgG, IgM, IgE
o IgA – Respiratory and GI tract, saliva, colostrum, tears
o IgG – Majority of circulating blood antibodies
o IgM – Does not cross placenta (identify fetal exposures)
• ABO blood grouping & rheumatoid facto
• Immunologic reaction to infections
o IgE – Allergic response; detect allergic diseases
Rheumatoid factor assay
• Useful in diagnosis of rheumatoid arthritis
• Reactive IgM and sometimes IgG and IgA make up RF
o Reacts against abnormal IgG antibody
• Positive result in dilution > 1:80; when concentrations are less other connective tissue disorders should be considered
o Negative does not r/o RA
o SLE and Sjogrens considered when <1:80
Vitamin D
- Vitamin D necessary to absorb dietary calcium
- Useful in ensuring postmenopausal women have enough vitamin D to absorb dietary calcium
- Regulates calcium and phosphorus levels
- Inhibits PTH secretion
- Requirements increase w/ age
- Promotes the immune system
White blood cell count and differential count
• Part of all routine laboratory examinations
• Differential helps to identify breakdown of WBCs
o WBCs elevate in response to infection and react against foreign bodies and tissues
• Elderly may not develop increased WBC count even in presence of severe bacterial infection
