Serology Flashcards
Serology
The diagnostic identification of antibodies in the serum
HIV anitbody Testing
All US tests detect HIV-1 and some HIV-2
HIV 1 - most common in US
HIV 2- Africa
Sensitive - ELISA
Specific - Western Blot
Screening test - ELISA
Western Blot Testing
immunoassay test method that detects specific proteins in blood or tissue.
combines an electrophoresis step with a step that transfers (blots) the separated proteins onto a membrane.
often used as a f/u test to confirm the presence of an antibody and to help diagnose a condition such as HIV or Lyme Disease testing.
Hepatitis A, B, C
Inflammation of the liver, can lead to liver cancer and transplant need.
Active Test - Antigen - HsAg
Prior Exposure - Antibody - HsAb
HEP A (HAV)
Aquired through food or water
There is a Hepatitis A Vaccine
Symptoms may include jaundice and severe stomach pains and diarrhea
Self-limiting
HEP A Test Results
HAV-Ab IgM- exposed. Antibodies will begin 2-3 weeks after first being infected and persist about 2-6 months
HAV-Ab IgG-produced 1-2 weeks after IgM and persist for life
HAV-Ab total-may help determine if you have been infected and have some immunity to the disease
HEP B
not as common, generally self-limiting
Can create a “Chronic-active” state in some people who recover from symptoms but are still contagious and never fully recover.
contracted through blood, blood products, and sex
*STI-like
HEP B Testing
HBV-Ag
HBV-Ab
HBV-D
Hepatitis B tests may be used for a variety of reasons.
detect antibodies produced in response to HBV infection
detect antigens produced by the virus
detect viral DNA.
HEP C (HVC)
Hepatitis C infection is caused by the hepatitis C virus (HCV).
Hepatitis C is transmitted by blood and sexual activity
**very infectious
Exposure may occur:
After a needle stick or sharps injury If blood from someone who has hepatitis Ccontacts a cut on your skin or contacts your eyes or mouth
People at high risk for HEP C
Inject street drugs or share a needle with someone who has hepatitis C
Have been on long-term kidney dialysis
Have regular contact with blood at work (such as a health care worker)
Have unprotected sexual contact with a person who has hepatitis C
Were born to a mother who had hepatitis C
Received a tattoo or acupuncture with needles that were not disinfected properly after being used on another person (risk is very low with practitioners who have a tattoo license or permit or an acupuncture license)
Received an organ transplantfrom a donor who has hepatitis C
Share personal items such as toothbrushes and razors with someone who has hepatitis C (less common)
Received a blood transfusion (rare in the U.S.)
Clearance rates for HEP A, B, C
90% clear Hep B, 95% clear Hep A, 95% of people DO NOT clear Hep C
HEP D
Hepatitis D virus (HDV) is found only in people who carry the hepatitis B virus.
**If someone is taking a long time to clear HEP B - suspicious of D.
HDV may make a recent (acute) hepatitis B infection or an existing long-term (chronic) hepatitis B liver disease worse.
It can even cause symptoms in people who carry Hepatitis B virus but who never had symptoms
Hepatitis D infects about 15 million people worldwide.
It occurs ina small numberof people who carry hepatitis B.
HEP D Risk Factors
Abusing intravenous (IV) or injection drugs
Being infected while pregnant (the mother can pass the virus to the baby)
Carrying the hepatitis B virus
Men having sexual intercourse with other men
Receiving many blood transfusions
Cystic Fibrosis
Autosomal recessive genetic disorder
Delayed growth, Clay or pale colored stools, coughing, sinus pain, recurrent respiratory infections
In CF, thick mucus can obstruct pancreatic ducts and prevent trypsinogen from reaching the intestine. Blood IRT levels will be elevated in newborns with CF, but positive results must be followed by confirmatory testing.
CF Testing
ACMG recommends a panel of 23 of the most common CFTR mutations be used to screen general or targeted populations for cystic fibrosis and CF carrier status.
Trypsin/chymotrypsin: stool test, screening for pancreatic insufficiency
Immunoreactive Trypsinogen (IRT): This test is a newborn screening tool for trypsinogen, which is produced in the pancreas and transported to the intestine, where it is activated to form the enzyme trypsin.
CF Sweat Chloride Test
the sweat of a person with CF may be up to five times saltier than normal.
Positive sweat chloride test results should be confirmed and followed with CF gene mutation testing whenever possible
ASO Titer
<200 IU/mL
Streptococcal Infections (pharyngitis, scarlet fever, rheumatic fever, poststreptococcal glomerulonephritis)
RA
Other collagen diseases
Monospot
normal= negative
POSITIVE-
Mononucleosis
Viral Hepatitis
RA
Infectious mononucleosis, commonly called mono, refers to an infection caused by the Epstein-Barr virus (EBV). This test detects proteins in the blood called heterophile antibodies that are produced by the immune system in response to an EBV infection.
No sports for 6-8weeks - splenic enlargement
Heterophile Antibody Testing
specifically refers to a rapid test for antibodies produced against the Epstein-Barr virus (EBV), the causative agent of infectious mononucleosis
Epstein Barr/ Herpesvirus 4
Someone w/neg. monospot
Also associated with cancers: Hodgkin’s lymphoma, Burkitt’s lymphoma, nasopharyngeal carcinoma and lymphomas associated with HIV