Clinical Chemistry Int MT

Dr. Brown

Class Notes for Midterm I

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Midterm I Material – Material – Urinalysis  Urinalysis How do lab values fit into the scheme of things? Patient usually undergoes a battery of of tests before a diagnosis is made Lab tests do not make a diagnosis, people do! Labs only confirm diagnostic impressions   

Diagnostic procedure I. History Taking o List of yes/no questions (impersonal) (impersonal ) o Personal consultation is better o 3 types  Very brief  Comprehensive history* Patient doesn’t know what is wrong with them As a lot of questions to obtain your history Comprehensive Geriatric Assessment (CGA)  II. Physical Examination III. Compile a list of positive findings based on patient history and physical examination (must be linked to patient complaint) IV. Compose/Create differential diagnosis o Anything that could cause those positive findings o The longer the list, the better V. Go through each item on your differential diagnosis list very carefully and rule things out (process of elimination) o aka Working / Preliminary / Tentative Diagnosis VI. Confirm potential diagnosis with labs, x-rays, or biopsies 

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Wellness Screening Screening on the basis of the patient’s age o 18 years old – old  – pap  pap smears on all female patients, and every year after o 20 years old – old  – cholesterol  cholesterol on all patients, and every 5 years after o 45 years old – old  – blood  blood glucose on all patients, and every 3 years after o 50 years old – old  – guiac  guiac test (occult blood in stool) in all patients, and every 4 years after o 50 years old – old  – PSA  PSA level on all male patients, and every year after PSA = prostatic specific antigen not a good 

rectal exam should be done

marker for prostatic cancer

Risk Screening Screening on the basis of high risk patients for specific disease o  Anemia – Anemia – infants being raised on exclusively cow’s milk, lower socioeconomic status, immigrants, pregnant, elderly (native americans) o  Diabetes – Diabetes – positive  positive family history, obese, Afro/Hispanic/Indian-Americans, females who show gestational diabetes o  Hypertension o Coronary Heart Disease – Disease  – men,  men, positive family history, cigarette smokers, hypertensive patients, diabetics, PAD, severely obese o  Bacteruria – Bacteruria – preschool  preschool children, UTI history, men with benign prostatic hypertrophy, > 65 years old, diabetics, morbidly obese, female with gestational diabetes during pregnancy 

Dr. Brown

Class Notes for Midterm I

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Non-Disease Sources of Influence on Lab Values Timing - cortisol in morning, testosterone in m orning Problems related to specimen collection o Failure in adequate preservation o Too much time between collection and analysis o Not enough of the sample o The wrong sample o Improper sample myocotic fungus sample of dermatophytes - Keratin KOH sample collection of the wrong portion of the skin o Improper labeling of the sample specimen Problems which are intrinsic to the patient without presence of disease  Biological False Positives o  Age + Rheumatoid Factor without clinical evidence for arthropathy  ANA (antinuclear antibody) without clinical evidence for collagen-vascular disease  Increased ESR  Male PSA without evidence of disease  VDRL without clinical evidence venereal disease research laboratory  Increased alkaline phosphate in children due to bone development  In older people, it would indicate bone or liver disease heat stabilization test vs enzyme test to differentiate o  Gender Males tend to have a high serum uric acid level  o  Race at risk for sickle cell anemia African-Americans tend to have a high creatine phosphokinase level  Problems related to patient activity o  Diet  ↑TGs with high fat diets or after a meal  ↑Creatine levels with diets high in cooked meats  Fasting 24-48 hours with ↑serum bilirubin, TGs, and ↓blood glucose  Caffeine lowers cholesterol, but raises cortisol and non-esterified FAs, influences glucose tolerance test decaf raises triglycerides! Alcohol abuse  Short term – hypoglycemia and ↑uric acid Long term - ↑TGs o  Tobacco  Chronic >2 packs/day will lead to polycythemia (↑RBC, WBC, platelets, Hb, and crit) o  Drugs Side effects on other organs  ↑Vitamin C can cause BFP of guiac test no red meat, fish, aspirin  o Posture (i.e. bed bound) Tissue fluids move to vascular compartment and dilutes the blood (↓blood cells,  electrolytes, serum proteins) o  Exercise  Short term ↑blood glucose, serum uric acid, RBC count Long Term  hematuria and proteinuria with long runner exercise ↓serum uric acid and RBC count 

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Dr. Brown

Class Notes for Midterm I

 Abnormal Lab Findings Fluid imbalance first significant o Hemoconcentration v. dehydration Taking of drugs second significant o Probably the most common reason or altering of lab tests

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Nsaids diuretics antibiotics

Urinalysis Renal Artery pressure o 80 – 180 mmHg o Autoregulation within renal arteriole system will keep pressure lows as not to damage the structures o Pressure tends to push water out of the glomerulus o Colloidal osmotic pressure tends to bring it back in   Effects o SSNS  Overall / generally there is no appreciable effect  It can (theoretically) be stimulated by Exposure to a very cold environment   Exercise   Hemorrhage   Pain   Emotions  all increase vasoconstriction o  Hormones Epinephrine and Norepinephrine can cause vasoconstriction on afferent and efferent  arterioles affecting filtration No real affect  o  Autocoids Endothelium from damaged capillary endothelial cells on afferent and efferent arterioles    Pregnancy Chronic uremia  Angiotensin II can affect efferent arterioles  No real affect 

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Glomerular Filtration cell walls are negatively charged Bowman’s Capsule o Capillary wall of glomerulus with fenestrations/openings within the epithelium and basement membrane o Most substances that travel through the blood that are negatively charged have a difficult time getting through  i.e. albumin is small enough to pass through the slits, but it is negatively charged slit pores o However, positively charged particles pass much easier   GFR o 125mL/min is the normal rate of blood creatine clearance   7500mL/hr   180,000mL/day 

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Dr. Brown

Class Notes for Midterm I reabsorbed*

A lot of that is being absorbed by the renal tubules (178,500mL/day)  1500mL/day (750-2000mL/day normal range) in the urine production Significant measure of renal function  eGFR calculator – blood creatinine, age, gender, and race of patient  60 – good renal function, normal, refers to 1500mL/day   30-59 – moderate renal damage   15-29 – severe renal damage   2 hours without refrigeration)  As it sits, it darkens because urobilin is present (oxidation)   Sediment – many things have deteriorated (i.e. cells, casts, etc.)  Ketone bodies seen in diabetics would have dissipated  Bacteria will have multiplied  Bacteria will also eat any glucose that may have been present  Shift in pH to a more alkaline urine Normally it should be 4.8-8.0 Urea breaks down to ammonia with lots of hydroxyl ions Becomes cloudy because of bacterial multiplication  Amorphous structure precipitation  

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Dr. Brown

Class Notes for Midterm I

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Urine Evaluation   Macro Chemical Routine UA   Micro Culture, if indicated    

Macro Evaluation Measure the amount using a graduated cylinder (+/-400mL with early morning clean catch) o Result: Polyuria >2000mL/day  Fluid overload  Caffeine / diuretics may not be true polyuria Emotional reasons  Diabetes mellitus/Insipidus    Polydipsia  Renal disease (UTIs or pyleonephritis) o Result: Oliguria < 400mL/day   Dehydration bladder outlet obstruction - BPH, stone eg. in AM Lack of ingestion Vomit / diarrhea Too much salt ingestion  ↑S ANS ↓CO and renal perfusion causing hypotension Bladder Outlet obstruction  Prostatic hypertrophy Renal disease  Glomerular nephritis o Result: Anuria < 100mL/day Complete bladder outlet obstruction  very severe hypotension Early stages of acute glomerular nephritis  Tubular necrosis  Cortical necrosis  Observe the color of the urine o Urochrome (yellow pigment) + uroerythrin (red pigment) = pale yellow  – amber colored urine is normal o Colorless urine (looks like water)  Untreated diabetes with increased water intake  Patients on diuretic therapy  Increased fluid intake (water-holics) o Orange-colored urine (very concentrated)  Bladder overstay  Excessive sweating  Very low fluid intake  Febrile patients rhabdomylitis  Vitamin intake o Reddish-Brown/Red-colored urine (presence of Hb or myoglobin)   Hemoglobinemia 

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Dr. Brown

Class Notes for Midterm I

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Rule: If hematuria is bright red, it is from the lower GI tract. If it is dark red, it ************ urinary tract*** means bleeding from the kidney. Food (lots of beets) Brown - rhubarb Drugs (i.e. Dilantin) pinkish - red 

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compezine -anti-emetic - reddish brown

  Smoky - too many red blood cells o Milky urine caused by presence of WBCs o Fat in the urine also milky o Purulent exudate Observe the scent of the urine o  Normally – characteristic aromatic odor from volatile acids, but is not generally offensive o Old, stale urine – ammonia due to increased breakdown of urea o  Asparagus – o Acetone / Fruity – from ketone bodies in urine   Diabetes sweet urine - Indian taste test which att racted ants   Starvation o  Foul – bacterial infection   UTI o  Fecal – fistula formation (enterovessicular) Observe the transparency of the urine o Can you read newspaper print if you hold it behind the sample? o  Normal – clear o  Abnormal – Cloudy or hazy  Turbid (if you can’t see it at all)  Observe for foam formation upon shaking o  Normal – slight layer of foam o Vivid yellow foam – bilirubinuria o Abundant and very white - proteinuria o

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Example: Reddish-Orange Urine Porphyria Cutanea Tarda (PCT) – missing uroporphyrinogen decarboxylase Signs and Symptoms o Large blisters on dorsum of the hands o Hyperpigmentation of the face o Hypertrichosis (increased hair length) o Maybe liver disease Lab Findings o Add 10% HCl to urine o Observe under Wood’s light o Will fluoresce o Abnormal liver findings Example: Dark Brown / Almost Charcoal colored urine homogenistic oxidase   Alkaptonuria – breakdown of tyrosine produces homogenistic acid due to missing oxidase mimics arthritis Signs and Symptoms o Acid builds up and deposits in spinal joints and large weight bearing joints, sometimes the IVDs o  Ochronosis  Light gray/blue cartilage in ear  

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Dr. Brown

Class Notes for Midterm I  

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Blue on the sclera of the eye Blue on the lenula of the nail plates

Lab Findings o Add 10% NaCl to the urine o Will turn black o You can also get a false positive for sugar in the urine (copper reduction procedure) because the acid is in the urine normal urine smell - distinguishable characteristics from volatile acids, not normally off ensive stale smell from bacteria breaking down urea to ammonia fruit like smell suggests ketone bodies foul smell - bacterial infection fecal smell - fecovesicular fistual

Chemical Evaluation Determine the pH of urine o  Normal   4.8 – 8.0 Should be slightly acidic  If it has been sitting around and bacteria is present, urea will be broken down to  ammonia and become more alkaline/basic Minor importance because it neither identifies nor excludes a disease  Only time it matters is if it is extremely acidic or basic  o < 4.8 High protein diets (↑phosphates and sulfates)  Excessive physical exertion    Diseases – severe diarrhea; ketonuria from uncontrolled diabetes, starvation, or febrile children; respiratory acidosis; renal TB  Certain crystals like to form in acidic urine Uric acid Calcium oxalate   Cysteine o > 8.0  Patient has just eaten (post paraneal alkaline tide)  Patient has high fruit and vegetable diet  Stale sample  Bacteria may be present  Bladder overstay  Disease states – UTIs (pseudomonas and proteas), severe vomiting, hyperventilation, metabolic acidosis  Crystal formation Calcium phosphate Determine specific gravity o Urine density Amount of dissolved substances within the urine  Tells us about the state of hydration  Parallels the osmolarity of the blood  High volume would show a low specific gravity (and vice versa)  o Chem Sticks Incomplete evaluation  Only tells us the ionic concentration  o Refractometer / Urometer   Cylinder 

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Dr. Brown

Class Notes for Midterm I

Read meniscus  Measures all things   Normal – 1.003-1.035 (read as ten oh three  – ten thirty five); first morning void 1.020  Renal Failure – fixed specific gravity at 1.010; kidney is dysfunctional or dead  < 1.003 Excessive fluid intake   Diuretics Inadequate mineral intake Diabetes Insipidus  > 1.035   Dehydration Excessive perspiration Febrile state (especially kids) Diabetes mellitus Glomerular nephritis Protein in Urine Some small molecular proteins can get filtered, but are usually reabsorbed  Tamm-Horsefall Protein – secreted by tubular epithelium and is released; acts as  substrate and forms casts Slight to moderate proteinuria, usually in the AM, is normal    Causes   Functional – no association with disease entity (systemic or renal in nature) o Orthostatic (most common) o Excessive exercise o Exposure to cold o Pregnancy (usually first pregnancy and < 25 years old, especially if labor > 12 hours)   Glomerular – damage to glomerulus (basement membrane increases filtration); problem becomes peripheral edema with decreased albumin and liver can’t compensate, causing hypoalbuminemia, ascites, and pulmonary edema o  Toxins o Immune reactions o  Infections i.e. Strep Pharyngitis Group A β -hemolytic: sore throat can cause  post strep infection in the kidney  i.e. Nephrotic Syndrome: loss of copious amounts(3-4g) of protein/day; 2/3 are idiopathic, 1/3 are amyloidosis, diabetes, or SLE o Vascular diseases Tubular Damage – small proteins aren’t reabsorbed o  Pyleonephritis o Acute tubular necrosis o Heavy metal intoxication o Polycystic kidney disease o Wilson’s disease 

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Dr. Brown

Class Notes for Midterm I

Lower Urinary Tract Pathology o Ureter infection o  Cystitis o  Urethritis o  Disease o Vaginitis / prostatitis Blood in the Urine (hematuria)  Sometimes, colors can suggest blood in the urine Smoky urine can mean RBCs Pink or reddish brown urine Occult blood doesn’t show any obvious color change  Positive dipstick RBCs in urine Free Hb in urine Myoglobin in urine  RBCs seen under microscope Bleeding from somewhere o Renal disease (anything from infection to a tumor) o Kidney stone o  Smoking Bleeding disorder   Anti-coagulents Hb seen under microscope (no presence of RBCs)  Intravascular hemolysis due to parasite infestation  Myoglobin seen under microscope Very rare (myoglobin is usually rapidly cleared in urine)   Rabdomyolysis Bacteria in the Urine *Must have bladder stay for at least 4 hours to see the bacteria!!   Nitrite Test Must be in the form of nitrate From vegetable sources in the diet Positive test suggests gram negative bacteria (not proteus or e.coli)  Leukocyte Esterase WBC in the urine to fight infection Positive test suggests there is bacteria present Glucose in the Urine / Blood  Anything above the normal range would suggest diabetes  From the stand point of the blood chemistry, we would assume diabetes at 126mg%, regardless of absence of any other symptoms 100-126 mg%: prediabetic state 180 mg%: renal threshold for glucose (at this point you begin to spill sugar, no symptoms) 200 mg%: symptoms appear 3.5mg%) Excessive urobilinogen and stercobilinogen (and stercobilin) in the intestines will cause the stool sample to be very dark 3 Abnormal Findings o Increased bilirubin in the blood o Increased urobilinogen in urine o Very dark stool Portal Jaundice  Diseased liver is the problem Only some free bilirubin can get in and become conjugate Whatever can get into the liver will follow the normal pathway, but only some urobilinogen is formed Can’t get back into the liver (blocked) Instead, it goes to the kidney via the blood to form urobilinogen Some stercobilinogen will only be able to form some stercobilin in the intestines Abnormal Findings o Slightly more urobilinogen than expected o Very pale stool    

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Dr. Brown

Class Notes for Midterm I

Obstructive Jaundice Problem is in the bile duct o Spasm of the sphincter of Oddi o Stricture within the common bile duct o Stone/tumor in pancreatic head can push against the duct Constant regurgitation into sinusoids Gets picked up by the blood and goes to the kidney No urobilinogen because none goes to the intestines Abnormal Findings o Normal free bilirubin in the blood o Evidence of conjugated bilirubin in the blood o No urobilinogen o Stool will be chalk white Porphyrins in the Urine (uroporphyrins)  Patients with porphyria  Normally, there shouldn’t be any Abscorbic Acid (Vit B) in the Urine  Normally not done in the analysis  Can interfere with some lab tests  Hematuria Test would be show negative when  Glucose in urine there really is some present! 

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Microscopic Evaluation   Microscopes o Bright field microscope  Works best for stained samples  i.e. Sedi / Kova Stain – crystal violet and saferin-o  i.e. Toalladene blue o Phase contrast microscope  Do not need stains  Easier seen than with bright field microscope Hyaline casts Mucous cells Negative Biophringent  – do not bend light   Bacteria o Polarizing microscope  Determine biophringents  How do they bend light?  Identifies the crystals that are present   Fat Starch fibers Differentiates specimens from phase contrast microscope    Samples o Centrifuge 10mL of urine for 10 minutes o Decant the supernant o Remove sediment and place on slide o Apply a stain (Sedi or Kova) and a cover slip o Observe for cells (organized part of the sediment)   

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Dr. Brown

Class Notes for Midterm I o

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Sediment 1. Organized = Cells 2. Unorganized = casts, crystal

RBCs o o o o

Ideally, you shouldn’t find any However, 0-3 cells per high powered field is normal > 3 suggests a pathology Observe the morphology of the cells   Dysmorphic – distorted and irregular in shape Glomerular bleeding  Round / Swollen – can rupture, especially with a more alkaline pH; will see Ghost Cells / Shadow Cells (RBC membrane with no traces of Hb) Hypotonic urine with low specific gravity (dilute) due to increased intake, diuretic use, and diabetes Insipidus   Crenated – shrunken RBCs Hypertonic urine with high specific gravity and a concentrated urine due to dehydration, fever, diabetes mellitus, or glomerular nephritis Observe the number of RBCs Whole bunch of normal looking RBCs  Diseases of the ureter, bladder, or urethra (tract, not the kidney) Pyleonephritis (possible)   Prostatitis Systemic diseases such as TB or malaria 

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WBCs Ideally, we should see none o However, 0-4 cells per high powered field is normal o > 5 indicates pathology   Pyuria – infection in the kidney, tract, or prostatitis   Febrile Excessive exercise  o Neutrophil / Glitter Cell Hypotonic urine  Granules are scintillated  Seen in lower UTIs  Long standing pyleonephritis  o  Eosinophil Reddish-orange granules  Must use Hansel stain  Drug hypersensitivity (i.e. penicillin)  RBCs + WBCs o If you see a mixture, there is always a predominance of RBCs Aspirin overdose / toxicity    Trauma   Tumor   Anti-coagulants Epithelial Cells o  Males – membranous portion is composed of pseudocolumnar epithelium o  Males – lower portion is composed of columnar epithelium o

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Dr. Brown

Class Notes for Midterm I

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  Female – entire urethra is composed of squamous epithelium with islands of pseudocolumnar epithelium  If they are crusted they are called Clue Cells  – bacterial vaginitis(gardenella vaginallis) o Findings do not suggest anything  Other possible cells o Budding yeast cells  Candida albicans indicates a yeast infection o  Sperm o Trichomonas vaginalis o  Bacteria – not easily seen o Schistisoma hematobium eggs These can be present 6-12months before any symptoms can appear (massive  hematuria) o Diaoctophyma renale – giant kidney worm eggs from infected fish   Casts – unorganized portion of the sediment o Tamm-Horsefall Protein  Increased acidity of urine  Increased osmolarity of filtrate (increased solutes) Proteins from plasma  Tubular stasis  o Morphology of casts   Cylindrical Parallel sides with equal diameters These are ideal, but they change shape as  Longer than they are wide they travel through the tubular system.  Rounded tips at the end  o  See Difficult to see  Should use a stain  Phase contrast microscope  o  Classifications Plain Casts – nothing inside, but Tamm-Horsefall protein    Hyaline – clear o  Dehydrated o  Diuretics o Stress reaction   Waxy – slightly more granular due to degraded protein matrix o Advanced renal failure  Inclusion Casts – Tamm-Horsefall protein with something in it RBCs (no nucleus is present) o Glomerular nephritis o Runners with hematuria WBCs (can differentiate because they are nucleated) o  Pyleonephritis Epithelial Casts o Tubular injury o Nephrotic syndrome o Patients with glomerular nephritis o

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Dr. Brown

Class Notes for Midterm I

Granular Casts – protein + cell debris (RBC + WBC + epithelial) o Strenuous exercise o  Dehydration o  Etc. Pigment Casts o Hemolysis (free Hb) o Rabdomyolysis (myoglobin) Fatty Casts – missing α galactosidase A enzyme (Fabry’s Disease) o Nephrotic syndrome   Mixed – RBCs, WBCs, epithelial, etc. (lots of stuff is present) o Glomerular nephritis   Crystal o Metabolic disorder o Stone formation (calculi)   Bacterial o  Pyleonephritis

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Crystals o Probably the most abundant thing in sediemtn o Pretty, but pretty insignificant o Can be seen in perfectly normal patients o Uric Acid (most common) Always in acidic urine < 6.0 pH  Many morphologies  Present in gouty arthritis  o Calcium Oxalate Crystals pH > 7.0  Calculus formation  Particular foods such as spinach and rubarb Excessive Vit C intake Ethylene glycol poisoning o Calcium Phosphate   Cystitis  Benign prostatic hypertrophy o Triple Phosphate Crystals / Coffin Lids  Urinary stasis Urinary Cultures   Methods o Clean catch o  Catheterization o Suprapubic aspiration   Time o Takes a day to grow o Takes a day to analyze  Acquiring the sample o Calibrated loop o Calibrated micropipette o  CFUs – colony forming units   

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