-
What tests are affected by hemolysis? Which is the most important? Why?
- Potassium, LDH, Phosphorous
- Potassium - high or low amounts will cause cardiac arrest (small range)
-
What molecules must be maintained at critical levels in the blood? (Too much or too little will cause problems)
Glucose, Potassium, Calcium, Sodium
-
What molecules indicate critical problems if there is too much in the blood?
CK - 1 and CK - 2 and Bilirubin (infants)
-
What tests do you have to fast before?
-
What is a BUN test?
Blood urea nitrogen
-
What were the first instruments to analyze blood samples?
SMA 6/60, SMA 12/60 and SMAC
-
What two methods are used for most of a biochemical profile?
Colorimetry and Enzymes
-
How does Colorimetry work?
Based on Beer-Lambert Law: Color is directly proportional to concentration
-
What are the two ways enzymes can be measured?
- Rate at which substrate is converted to product
- Rate at which a substrate is depleted
-
What does Electrophoresis do?
Separate similar substances into individual components
-
What are the 5 tests electrophoresis is used for?
- Hemoglobin - detecting abnormal forms
- Protein - Total protein or serum protein electrolyte (TPE or SPE) ex. multiple myeloma
- Immunophoresis (immunofixaton electrophoresis) (IFE or IEP) - done when their is an immunoglobulin spike in SPE
- Lipoprotein - ex. hyperlipidemia
- Western blot - confirmatory test (3 bands)
-
What are the immunoglobulins? Which is the most prevalant? Which arrives first? Which lasts the longest?
- IgG - 85%, 2nd to arrive, lasts longest
- IgA
- IgM - largest, first to arrive
- IgE
- IgD
-
What are the 5 types of antigen-antibody complex formation tests?
- Precipitation tests
- Agglutination tests
- Neutralization tests
- Fluorescent antibody tests (Immunofluorescence)
- Complement fixation
-
What is the RPR a screening test for? What type of test is it?
-
What is immunoprecipitation?
A newer version of precipitation in which there is a well in the center and arcs will form around it if a reaction occurs
-
What is another name for agglutination tests? What is the most common type? What is a common example?
- Agglutination Inhibition/particle inhibition
- Latex agglutination
- Heterophile antibody test (for mono)
-
What are three nutralization tests and what do they test for?
- ASO titer (anti-streptolysin O) - strep
- Anti-DNAaseB (ADB) - strep
- AHT (antihyaluronidase) - strep
-
What are the 4 most common strep pathologies?
- Rheumatic fever
- Acute Post strep Glomerulonephritis
- Erythems nodosum
- Acute bacterial endocarditis
-
What is erythema nodosum? What can cause it?
- red nodes on legs (usually pre-tibial)
- Strep, mono, birth control, chron's
-
What are the two most common Fluorescent antibody tests and what do they test for?
- FTA (Fluorescent treponemal antibody) - syphilis
- FANA (Fluorescnet anti-nuclear antibody) - SLE
-
What test was done for SLE before FANA?
dsDNA antibody (ds = double stranded)
-
What is a complement fixation test?
- Tests for the presence of an antibody or antigen
- Negative test --> complement binds to and lyses sheep RBCs
- Positive test --> complement binds to antibody-antigen complex and sheep RBC's remain intact
-
What is RIA?
Old antigen-antibody test, replaced by EIA (faster, more sensitive)
-
What is ELISA?
- Enzyme-linked immunosorbent assay
- Screening test for many antibodies (strep, HIV, hepatitis)
- Antibody in well, immunoglobulin binds then antibody with detection marker binds
-
What is Nephelometry?
Measures the rate of turbity which indicates the quantity of serum proteins (highest when antigen = antibody concentration) - particles scatter light --> positive
-
What is Western blot?
- Confirmatory test for many antibodies
- Electrophoresis (color reaction occurs)
-
What tests indicate a musculoskeletal problem?
- Calcium (#1)
- Phosphorous
- Uric acid
- Alkaline phosphatase (#2)
-
What is calcium an indicator of?
Parathyroid function and various malignacies
-
What are the 3 forms of calcium?
- 50% free/ionized
- 45% bound
-
What does acidosis promote?
Increased ionized/free calcium
-
What does PTH do to calcium blood levels?
Increase
-
What does calcitonin do to blood levels of calcium?
Decreases (puts it in the bone)
-
How does estrogen affect calcium?
Puts calcium in bone
-
How will hyperthyroid or hyper adrenal glands affect calcium?
hypocalcemia, bone decalcification
-
Causes of Hypercalcemia?
- Primary hyperparathyroid (#1)
- Malignancy (#2)
- Metastatic bone tumors
- PTH producing tumors (lungs or renal)
- Vitamin D intoxication
-
What are the symptoms of hypercalcemia?
- Neurological (irritability, memory loss)
- Peptic ulcers
- Bone lesions
- Anorexia
- Kidney stones
-
Causes of hypocalcemia?
- Malnutrition (#1)
- Hypoalbuminemia (#1)
- Renal disease/failure
- Secondary hyperparathyroidism
- Rickets
- Osteomalacia
- Vitamin D deficiency
-
What is a major cause of secondary hyperparathyroidism?
renal osteodystrophy
-
What are the symptoms of hypocalcemia?
- Increased neuromuscular excitability
- Altered cardiac function
- Tetany
-
What are three signs of Tetany?
- Chvostek's - tap on parotid gland near facial nerve --> face contracts if positive
- Main d'accoucher - tetany of wrist
- Trousseau's - blood pressure cuff causes involuntary spasm of hand
-
What are some follow up tests for calcium?
- Ionized calcium test
- PTH assay
- X-ray or protein electrophoresis - multiple myeloma
- Chest x-ray if coughing - sarcoidosis, TB
- Cortisol - Cushings
- Thyroid
- Vitamin D levels
-
How do Calcium and phosphorus levels affect each other?
- When one goes up, the other goes down (body tries to maintain constant product of the two)
- Exception - vitamin D deficiency
-
Causes of Hyperphosphatemia?
- Hypoparathyroidism
- Renal failure/osteodystrophy
- Secondary hyperparathyroidism
- Excess vitamin D intake
-
Causes of hypophosphatemia?
- Primary hyperparathyroidism
- Rickets
- Osteomalacia
- Malabsorption syndromes
- Alcoholism
-
What are the two main pathologies with high uric acid levels?
Gout (#2) and Renal Calculi (#1)
-
Causes of Hyperuricemia?
- Excess purine consumption
- Excessive cell breakdown/catabolism on nucleic acids
- Excessive cell production and destruction (ex. leukemia, multiple myeloma, P. vera)
- Renal disease (inability to excrete urea)
-
What drugs can cause hypouricemia?
- Allopurinol - purine blocker
- Asprin - purine blocker
- Colchicine - excretes purines
-
Primary vs. secondary gout?
- Primary - from overproduction of uric acid or impaired renal tubular excretion
- Secondary - excessive uric acid from increased nucleic acid turnover or acquired renal problems decreasing excretion
-
What are the three main isoenzymes of alkaline phosphatase (ALP)?
- Bone (osteoblasts) (highest concentration) (#1)
- Liver (#2)
-
Causes of increased ALP?
- Liver infection/cancer/disease
- Bone pathologies (including fractures)
- Growth
- Last tri of pregnancy
-
What is septic arthritis?
Infectious arthritis - bacterial invasion of a joint --> inflammation, destruction
-
Labs for septic arthritis?
Arthrocentesis (pus in joint fluid), increased WBC count, C-reactive protein and ESR
-
What is gout?
Gouty arthritis - metabolic disease where urate deposits in joints, usually feet and legs
-
Labs for gout?
- Arthrocentesis (monosodium urate crystals)
- Uric acid blood levels increased
-
What is osteoarthritis?
- Most common arthritis
- Deterioration of joint cartilage, formation fo reactive new bone at margins and subchondral areas
-
-
What is osteomyelitis?
Pyogenic bone infection that can be acute or chronic, can stay local or spread
-
Labs for osteomyelitis?
increased WBCs, ESR, C-reactive protein, blood cultures
-
Differential diagnosis for osteomyelitis?
- Rheumatic fever
- Myositis
- Bone fracture
- Poliomyelitis
-
What is Paget's?
- Osteitis deformans
- Slow progressive metabolic bone disease
- Initial excess resorption of bone followed by bone formation
- Affects males > 40 years
-
Labs for Paget's?
- Serum alkaline phosphatase
- Anemia
- Urine: 24 hour hydroxyproline
- X-ray/bone scan
-
What is muscular dystrophy?
A group of congenital disorders characterized by progressive symmetrical wasting of skeletal muscles without neural or sensory defects
-
What are the two main types of muscular dystrophy?
- Duchenne's - childhood form, deficiency in dystrophin (protein)
- Limb girdle - affects upper arms and legs, cardiovascular problems
-
Tests for muscular dystrophy?
- CK-3 (CK-MM) - elevated
- Electromyography
- Muscle testing
- Pre-natal testing
-
What is osteoporosis?
Metabolic bone disorder in which the rate of bone resorption accelerates and formation decreases
-
Labs for osteoporosis?
- Calcium - normal
- Phosphorous - normal
- Alkaline phosphatase - normal
- PTH - possible elevation
- Urine - collagen
- Dexa scan
-
What tests on the biochemical profile indicate a problem with the liver?
- Alkaline phosphatase
- AST (SGOT)
- ALT (SGPT)
- SGGT
- LDH
- Bilirubin
- Albumin/total protein
-
What follow up liver tests are there?
- Ammonia
- CEA
- Bile salts/acids
- Vitamin K/PT/PTT
- Alpha fetoprotein
- Alpha 1-antitrypsin
- BSP dye
- Hepatitis tests
-
What is AST? What do elevated levels of AST indicate?
- Aspartate aminotransferase or Serum Glutamin Oxaloacetic transaminase
- Indicates Liver (hepatitis, infectious mono, hepatic metastasis, tumor, alcoholism) or heart (MI, surgery) problem
-
What is ALT? What organ has the highest concentration of ALT? What would a greatly increased ALT indicate? What would a moderately increased ALT indicate?
- Alanine aminotransferase or Serum Glutamic Pyruvic transaminase
- Liver has hghest concentration of ALT
- Significant increase: Hepatitis, hepatic necrosis, hepatic ischemia
- Moderate: Cirrhosis, cholestasis (bile duct is blocked), hepatic tumor, obstructive jaundice
-
What issues are indicated by AST/ALT >1?
Alcoholic cirrhosis, liver congestion, metastasis to liver
-
What issues are indicated by AST/ALT <1?
Acute hepatitis, viral hepatitis, infectious mono
-
What enzyme is most sensitive to alcohol usage?
SGGT
-
What does an increase in SGGT indicate?
- Liver disease
- Alcohol intake
- Mono
- obstructive jaundice
- Meds: Dilantin and Phenobarb
-
How would you DDX liver disease from skeletal disease?
- Both: Increased AST, Alk Phos, LDH
- Liver only: Increased ALT, SGGT, Bilirubin
-
What is LAP? What does an increased LAP indicate?
- Leucine Aminopeptidase
- Liver disease
-
How many LDH isoenzymes are there? What is the most abundant? What does each indicate?
- 5
- LDH 2 is the most abundant
- LDH 1 indicates MI or renal
- LDH 2 indicates reticuloendothelial
- LDH 3 indicates lungs or lymphocytes
- LDH 5 indicates Liver, skeletal muscle
-
What is a flipped or reversed LDH? What does it indicate?
LDH 1 > LDH 2 --> MI
-
Which LDH will be elevated during strenous exercise?
1,2 and 5
-
What type of bilirubin is higher in the blood?
Unconjugated
-
What is another name for unconjugated bilirubin?
Indirect
-
Where is bilirubin conjugated?
liver
-
Where does bilirubin come from?
RBC breakdown (porphyrin ring of heme)
-
What is another name for prehepatic jaundice? What is its cause?
- Hemolytic
- Increased RBC breakdown (hemolytic anemia, sickle cell, Pernicious anemia, erythroblastosis fetalis/hemolytic anemia of the newborn, Resolution of large hematoma, hepatitis, cirrhosis, neonatal hyperbilirubinemia, Gilbert's disease/Crigler-Najjar syndrome G6PD deficiency)
-
What is kernicterus?
Accumulation of bilirubin in baby's brain causing mental retardation
-
A person with bilirubinuria and elevated direct probably has?
Post-hepatic jaundice (obstructive) (gallstones/ cholelithiasis, pancreatic carcinoma, tumors, duct obstruction/cholestasis) - failure to excrete conjugated bilirubin
-
Neonatal jaundice gives increased?
Unconjugated bilirubin, cause by immature liver (hepatic jaundice)
-
Hemolytic ds of newborn gives increased?
Unconjugated bilirubin, mom is breaking down baby's RBCs (Rh- mom and Rh+ baby)
-
What type of bilirubin is increased in Gilbert's ds? What is it commonly misdiagnosed as?
-
What type of bilirubin can be found in the urine? Why?
Conjugated, it is water soluble
-
Elevated direct and indirect bilirubin can occur wit?
Liver damage (hepatitis, alcoholism, cancer)
-
Increased urobilinogen in the urine reflects increased _____ in the blood?
Unconjugated bilirubin (the U's go together)
-
What will the urine findings be in a liver problem?
Increased urobilinogen and presence of conjugated bilirubin
-
What fraction of bilirubin is conjugated?
- 15 to 20%
- 70 to 85% is unconjugated
-
What does decreased albumin lead to?
Edema (swelling)
-
What can decrease albumin levels?
Malnutrition/malabsorption (Crohn's, Whipple's), Liver disease, inflammatory diseases, 3rd degree burns, protein-losing kidney disease (nephrotic syndrome)
-
What can increased albumin levels?
dehydration
-
Are PT/PTT and Vit K used for liver testing?
No, but they will be affected by many liver pathologies
-
What clotting factors are vit. K dependent? What clotting pathways are affected?
- 2, 7, 9, 10
- Intrinsic, Extrinsic and common
-
What clotting factors are in the intrinsic pathway? extrinsic? common?
- Intrinsic: 9,8,11,12
- Extrinsic: 3,7
- Common: 1,2,10
-
What is the problem with testing for ammonia?
Ammonia is very volatile, must be placed on ice right away
-
What causes increased ammonia levels?
- Advanced liver failure:
- Primary hepatocellular disease
- Portal hypertension
- Severe heart failure with congestive hepatomegaly
- Reyes syndrome
- Hepatic encepalopathy
- Hepatic coma
- Genetic metabolic disorder of urea cycle
-
What is Reyes syndrome?
Brain and liver damage caused by asprin in young children
-
What happens if bile acids/salts are decreased?
- Gallstones (cholesterol precipitates)
- Impaired fatty acid absorption
-
What is AFP? What is it used for?
- Alpha-fetoprotein - made by fetal liver and yolk sac
- Pre-natal testing and detection of liver cancer
-
What is AAT? What does it do?
- Alpha 1-antitrypsin
- Protein made by the liver which keeps protesases from destroying the lungs and liver
-
What does a deficiency in AAT cause?
- Emphysema (early onset, panacinar, more in lower 1/3rd of lung)- proteseases make holes in cells --> decreased surface area for oxygen exchange forming an air bulla/blister
- Low serum proteins
- Neonatal respiratory distress sydrome
-
What is CEA? What is it an indicator for?
- Carcinoembryonic antigen
- Tumor marker (particularly colon and breast)
-
What are acute phase reactants? Which is abnormal?
- Proteins which increased in the liver during inflammation
- C-reactive protein is not normally present
-
What are the most common types of hepatitis?
- Viral (IV drugs, STD)
- Alcohol
- Bacterial
-
How is hepatits spread?
- Fecal-oral (A and E)
- Blood borne (B and C)
-
Which immunoglobulin is the 1st to be made? Which one lasts the longest?
- IgM is first
- IgG is longest
-
What are the symptoms and lab findings for hepatitis?
- Fever, flu, possible jaundice
- Bilirubin, LDH, SGGT, ALT, AST and ALP are elveated, neutropenia, lymphopenia followed by lymphocytosis
-
How contagious are you when you are showing symptoms of hepatitis?
- Decreasing contagiousness the longer you have symptoms (peak of contagiousness comes before symptoms show)
- Contagious when have antigens not antibodies
-
What is another name for HAV? What is another name for HBV?
- Infectious hepatitis
- Serum hepatitis (Dane particle)
-
What are the parts of hepatitis B? Which one is in the gap period?
- C (core), E, S (surface)
- C is in the gap or window period or serological negative period
-
What is the seroconversion period?
Period when antibodies (HBsV) become present
-
What tests are included on a hepatitis panel in order of production?
HBsAg, HBeAg, HBcAb, HBeAb, HBsAb
-
What does a positive HBsAg indicate?
- 1st indicator of infection (acute)
- Person is infectious
- Chronic carrier
-
What does a positive HBsAg indicate?
- Immunity
- Previous exposure
- Vaccination
-
What does a postive HBcAb indicate?
- Past infection
- 1st antibody to appear
-
What does a positive HBeAg indicate?
- Index of infectivity (highly contagious)
- Early and active HBV
-
What does a positive HBeAb indicate?
- Low infectivity
- Acute phase is over
-
Which hepatitis B test will distinguish between acute infxn, vaccination and chronic?
Core antibody (HBcAb)
-
What tests are positive for Acute HBV?
-
What tests are positive in a vaccination?
Anti-HBs
-
What tests are positive after recovery from acute HBV?
- Anti-HBs
- Anti-HBc (IgG)
- Possibly Anti-HBe
-
What tests are positive for chronic HBV low infectivity?
- HBsAg
- Anti-HBc (IgG)
- Anti-HBe
-
What tests are positive for chronic HBV high infectivity?
-
What tests are used for HCV?
- c22p
- NS3
- NS4
- NS5
- Core antigen
- EIA
-
What is liver cirrhosis?
- Chronic hepatic disease, destruction and fibrotic regeneration (note: fibrotic tissue is not functional)
- Caused by alcohol or other liver infection/damage
-
What labs are increased in liver cirrhosis?
- Ammonia
- Bilirubin
- Globulin
- PT
- PTT
- AST
- ALT
- LDH
- ALP
-
What is the most common cause of portal hypertension? Other cuases?
- Cirrhosis is most common
- Budd Chiari syndrome
- Schistosomiasis
- Sarcoidosis
- Portal vein thrombosis
-
What is budd chiari syndrome?
hepatic venous or inf. vena cava is obstructed --> spider web venous collaterals form on skin and on x-ray, ascites, hepatomegaly, abdominal pain, esophageal varices
-
What are the signs of hepatocellular failure?
- Jaundice
- Hepatic encephalopathy
- Ascites
- Bleeding diathesis (susceptible to hemorrhage)
-
What is hepatic encephalopathy?
Chronic liver disease interfers with ammonia catabolism and ammonia enters circulation and goes to brain, causing damage
-
What labs will be elevated for hepatic encephalopathy?
Ammonia, bilirubin, PT
-
What is another name for wilson's disease? Symptoms?
- Hepatolenticular disease
- Excess copper retention:
- Kayser-Fleicher rings (lenticular opacities) - only present when ds has progressed beyond the liver
- Hepatic disease
- Neurological changes
-
What is the most common symptom of gallbladder disease?
nausea and vomiting
-
What is cholelithiasis?
Gall stones (calculi) - 90% of all gallbladder ds
-
What is choledocholithiasis?
Gallstones in the common bile duct causes obstruction --> jaundice, persistent itching, retention of bile salts
-
What is cholecystitis?
inflammation of gallbladder
-
What is gallstone ileus?
gallstone ulcerates through gallbladder into intestine and causes obstruction
-
What is biliary cirrhosis?
Ascending infection of the biliary system leads to obstructive jaundice
-
What are gallstones made of? How are they diagnosed?
- Cholesterol, bile pigment stones
- HIDA scan (track flow of bile from liver to SI)
- Echography/x-ray
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