MLS Comprehensive Exam

Accuracy

closeness of a measured value to the target/true value

Reliability

Capacity of a method to maintain accuracy and precision

Mean

average of a data set

Range

difference between the largest and smallest data points in a data set

Standard deviation

average distance between the mean of a data set and every value in that data set

Coefficient of variation

SD/Standard deviation expressed as a percentage of the mean

What percentage of data is within 1 SD on a gaussian curve?

68.3%

What percentage of data is within 2 SD on a gaussian curve?

95.4%

What percentage of data is within 3 SD on a gaussian curve?

99.7%

AABB name and function

• American Association of Blood Banks

• Technical standards and accreditation of blood banks

CDC name and function

• Center for Disease Control and Prevention

• Standards and guidelines related to infection control and safe work practices

CLSI name and function

• Clinical Laboratory and Standards Institute

• Standards on all aspects of lab practice developed through voluntary consensus

CMS name and function

• Centers for Medicare and Medicaid Services

• writes regulations for and enforces clinical laboratory improvement amendments of 1988 (CLIA 88)

OSHA name and function

• Occupational Safety and Health Administration

• Regulates employee safety in the workplace

FDA name and function

• Food and Drug Administration

• Regulates market entry of instruments/reagents and production of donor blood and components.

• Licenses blood banks

CLIA ’88 name and function

• Clinical Laboratory Improvement Amendments of 1988

• Foundational U.S. federal law that establishes quality standards for all non-research laboratory testing performed on human specimens

Type 1 Diabetes mellitus

• children

• autoimmune

• insulin deficiency

• Diabetic Ketoacidosis (DKA)

Type 2 Diabetes Mellitus

• gradual

• adults

• insulin resistance (N/increased)

• increased risk for micro/macro complications

• Hyperosmolar Hyperglycemic Nonketotic Syndrome (HHNS)

Diabetic Ketoacidosis (DKA)

• Type 1

• Frequent urination

• Fruity breath

• Kussnal-Kien respirations

• Glucose >250 mg/dL

• Ketones present

Hyperosmolar Hyperglycemic Nonketotic Syndrome (HHNS)

• Type 2

• Confusion (neurological)

• Glucose >600 mg/dL

• Hyperosmolality → dehydration

• No Ketones

Healthy Patient Diagnosis

• FPG: 70-99 mg/dL

• HbA1C: <5.7%

• CSF: 50-80 mg/dL

Pre-Diabetic Diagnosis

• FPG: 100-125 mg/dL

• HbA1C: 5.7-6.4%

• OGTT: 140-199 mg/dL

Diabetic Diagnosis

• FPG: >126 mg/dL

• OGTT: >200 mg/dL

• HbA1C: >6.5%

Major functions of albumin

• maintains osmotic pressure

• blood buffer

• decreased in liver damage

  • less sensitive than prealbumin

Why is albumin considered less sensitive than prealbumin?

Prealbumin has a short half-life, making it a sensitive marker for malnutrition

What can cause hyperalbuminemia?

Dehydration

Alpha 1-antitrypsin

• 90% of alpha-1 globulin fraction

• Inhibits neutrophil elastase → prevents excess tissue damage

Alpha 1-fetoprotein

• screens for fetal abnormalities and fetal distress

• Increased in neural tube defects

• Decreased in down syndrome

Haptoglobin

• binds to free hemoglobin

• decreased in intravascular hemolysis

Wilson’s disease

• ATP7B gene mutation

• Copper accumulates in organs and tissues causing damage

• decreased serum ceruloplasmin, increased serum free copper and increased urinary copper excretion

• Kayser-Fleischer rings in cornea

Menke’s Kinky Hair Syndrome

• ATP7A gene mutation

• Decreased serum ceruloplasmin, total and free serum copper

A2-Macroglobulin

• Protease inhibitor

• Increased in nephrotic syndrome

B2-Microglobulin

• forms light chain of HLA antigens

• Increased in renal failure

Fibrinogen

• Found in PLASMA ONLY

• False positive will show band between beta and gamma regions

What are the results of a patient with a liver disorder?

• Increased total protein

• Increased albumin

• Normal globulins

What are the results of a patient with multiple myeloma?

• Increased Total protein

• Normal/Decreased albumin

• Increased gamma (IgG) sharp peak

What are the results of a patient experiencing dehydration?

• Increased total protein

• Increased albumin

• Increased globulins

SPE Pattern for Nephrotic Syndrome

• Everything decreased

• Increased alpha-2 macroglobulin

SPE Pattern for monoclonal gammopathy

• Sharp peak in gamma region

SPE pattern for Liver Cirrhosis

• Decreased albumin

• Beta-gamma bridging due to IgA

SPE Pattern for acute phase reactants

• decreased albumin

• increased a1 and a2 regions

eGFR

• doesn’t require 24-hour urine

• accounts for sex/age

• corrects for body surface area

CrCl

• requires 24-hour urine

• overestimates GFR by 10-20%

Pre-renal azotemia

• Increased BUN

• Normal Creatinine

• Increased ratio

• Indicates CHF, dehydration, increased protein intake, GI bleed

Renal-azotemia

• Increased BUN

• Increased Creatinine

• Normal BUN/Creatinine ratio

• Indicates renal disease (glomerulonephritis, AKI, CKD)

Post-renal azotemia

• Increased BUN

• Increased Cr

• Increased ratio

• Indicates enlarged prostate, kidney stones

How does plasma Cr and CrCl change in renal dysfunction (impaired renal function)?

• INVERSE RELATIONSHIP

• Plasma Cr increased

• CrCl decreased

Zero Order

• Depends on enzyme concentration

• Substrate in excess

First order

• Reaction rate proportional to substrate: increases as more substrate is added

• Enzyme in excess

When the body compensates for a respiratory or metabolic disorder, the MAIN goal is to achieve:

A normal pH

Primary hemostasis

formation of loose platelet plug, rapid but short term

Secondary hemostasis

Stabilizes loose platelet plug, delayed but long term

Fibrinolysis

Plasmin breaks down clot when its not needed anymore

Average time in circulation of platelets

8-12 days

What glycoproteins are involved in adhesion?

• vWBF with GP 1b95 (1b-IX-V)

• GP VI (6)

What glycoproteins are involved in aggregation?

• GP IIb & GP IIIa - ligand for vWBF and fibrinogen

What factor does von Willebrand factor combine with in circulation?

Factor VIII

Factor I common name

Fibrinogen

Factor II common name

Prothrombin

Factor III common name

Tissue factor

Factor VIII common name

Anti-Hemophilic factor

Which coagulation factors are NOT present in serum?

• 1

• 2

• 5

• 8

• 13

Which coagulation factors are vitamin K dependent and part of the prothrombin group?

• 2

• 7

• 9

• 10

• Protein C

• Protein S

Vitamin K acts upon the _______ group. a deficiency will result in _______, a prolonged ____ and _____.

• Prothrombin

• bleeding

• PT

• aPTT

What is required in all three pathways?

calcium

Which method remains the gold standard for ANA detection?

Slide-based immunofluorescent assay

One risk associated with patients that require chronic transfusions is…

iron overload

What effect may bacterial contamination have on urine pH?

The bacteria may make the pH more alkaline

Vitamin D deficiency causes…

Rickets

Vitamin A deficiency causes…

night blindness

Vitamin B1 deficiency can cause..

Beriberi

Vitamin C deficiency can cause….

Scurvy

Yeast cells are more likely to be seen in a patient with which condition?

Diabetes

Creatine Kinase (CK)

• major sources: skeletal and cardiac muscle, brain

  • CK-BB: brain type

  • CK-MB: cardiac muscle

  • CK-MM: skeletal muscle

• CK-MB >6% = myocardial damage, AMI

Lactate Dehydrogenase (LD)

• major sources: skeletal and cardiac muscle, liver, kidney, RBCs

  • highest elevation in pernicious anemia

• Flipped LD (LD1 > LD2) in AMI and intravascular hemolysis

• LD-4/5 = liver disorder

Aspartate Aminotransferase (AST)

• major sources: skeletal and cardiac muscle, liver

  • highest elevation in hepatocellular disease

Alanine Aminotransferase (ALT)

• major source: LIVER ***MOST LIVER SPECIFIC ENZYME****

  • highest elevation in hepatocellular disease

• AST/ALT > 1 = necrotic liver disease

Alkaline Phosphatase (ALP)

• major source: intestine, liver, bone, spleen, placenta, kidneys

  • increased in hepatobiliary disorders (cholestasis) & bone disorders (paget’s disease)

Gamma-glutamyltransferase (GGT)

• major source: kidneys, brain, prostate, pancreas, liver

  • liver and biliary disorders

• normal in bone disorders and pregnancy

• INCREASED IN LIVER DISORDERS

• >2-3X = ALCOHOLISM

Severe liver disease with synthesizing issue will have what type of lab results?

• increased INR and ammonia

• decreased albumin and BUN (urea)

Predominate increase in AST and ALP may indicate…

hepatocellular functional damage

Predominate increase in ALP and GGT may indicate…

hepatobiliary obstructive damage

Increased ammonia can indicate…

severe liver damage/failure

Amylase (AMY)

• pancreas and saliva

• used for acute pancreatitis

Lipase (LIP)

• major source: pancreas

• MORE SPECIFIC FOR ACUTE PANCREATITIS

Key findings in an AMI

• increased Troponin, CK-MB and myoglobin

Key findings in CHF

Increased BNP

PSA tumor marker

diagnosis for prostate cancer

HE4 tumor marker

diagnosis for ovarian cancer

AFP tumor marker

liver cancer

hCG tumor marker

diagnosis for testicular cancer, and pregnancy

CEA tumor marker

colorectal cancer

CA19-9 tumor marker

diagnosis for pancreatic

CA 15-3 tumor marker

breast cancer

CA 125 tumor marker

ovarian cancer diagnosis

Pharmacokinetics

• The study of movement of drug via absorption, distribution, metabolism, elimination

• 5-7 doses before steady state

How does the body respond to high osmolality?

• triggers hypothalamus to stimulate thirst and secrete AVP (ADH)

Water overload

Normal → excess H2O intake → decreased plasma osmolality → thirst and AVP suppresed → large urine volume excreted → increased plasma osmolality

Water deficient

Normal → deficient H2O intake → plasma osmolality increase → thirst and AVP stimulated → H2O consumed, water reabsorbed → small urine volume excreted → plasma osmolality decreased

• hyperosmolality, hypernatremia

SIADH

• HYPOsmolality

• water retained

• increased urine osmolality, decreased blood osmolality

• hyponatremia