PH 166 Clinical Chemistry 1 Introduction PDF

PH 166: CLINICAL CHEMISTRY 1 Introduction to Clinical Chemistry Asst. Prof. Raycha Lei Concess M. Rama-Sabandal | January 23, 2025 ​ Fluid is collected while the fetus is still in the uterus...

PH 166: CLINICAL CHEMISTRY 1 Introduction to Clinical Chemistry Asst. Prof. Raycha Lei Concess M. Rama-Sabandal | January 23, 2025 ​ Fluid is collected while the fetus is still in the uterus OUTLINE A.​ Clinical Chemistry Saliva a.​ Specimen ​ May also be used as a specimen b.​ Analyte c.​ Specimens and Analytes d.​ Assay Synovial Fluid e.​ Phlebotomy ​ Fluid found in joint cavities B.​ Brief History of Clinical Chemistry ​ Arthrocentesis: process of getting synovial fluid specimen a.​ Ancient Times ○​ Used for the molecular diagnosis of infectious b.​ Middle Ages diseases c.​ Renaissance d.​ 18th Century e.​ 19th Century Pleural Fluid f.​ 20th Century ​ Fluid from the sac surrounding the lungs (pleural cavity) C.​ Role of Clinical Chemistry in Medicine and Public ​ Thoracentesis: the process of acquiring pleural fluid Health ​ Usually for describing tumor markers and concentration of a.​ Clinical Chemistry in Medicine certain enzymes b.​ Clinical Chemistry in Public Health D.​ Review Questions E.​ References Pericardial Fluid ​ Fluid from the sac surrounding the heart (pericardial cavity) CLINICAL CHEMISTRY ​ Pericardiocentesis is assisted by ultrasound ​ “Encompasses centralized analytical activity concerning the chemical composition of biological material such as Peritoneal Fluid blood, urine, tissue, secretions, excretions, etc., necessary ​ Also called ascitic fluid for the diagnosis and treatment of and research into ​ Fluid from the abdomen diseases.” (Poul Astrup) ​ Acquired through Abdominal Paracentesis or ○​ Analytical: systematic Peritoneocentesis ○​ Centralized: Focused or concentrated, concerns the analysis of chemicals and instrumentation. ANALYTE ​ Instrumentation: How you go about the process ​ Substances found in specimens ○​ Primarily deals with the chemical compositions of ​ The ones being measured/analyzed biological materials. ​ Measurement (concentration) has a diagnostic meaning ○​ Done in a logical sequence (methodological) and is compared to reference intervals (i.e. normal values) ​ 200-300 analytes routinely tested in laboratories SPECIMEN ​ 1000 total analytes in total are being studied ​ Also known as “Sample” ​ The main goal is to measure a certain analyte and compare ​ Taken for testing or examination it to a reference range. This can determine if it is normal or ​ Bodily fluids are the main specimen used abnormal (high/low) Blood ​ Serum: Obtained using red tube, NO anticoagulant. The liquid part of the blood without clotting factors ​ Plasma: Obtained using purple tube, contains anticoagulant for centrifuged separation. The liquid part of the blood with clotting factors ​ Whole Blood: Unsegregated cellular and liquid blood Urine ​ 24-hour collection: usually used for Clinical Chemistry ​ Describes kidney status ​ All urine excreted within a set 24-hour period is collected ​ Urinalysis: First morning urine is preferred for more concentrated constituents. Mid-stream catch is used. Cerebrospinal Fluid (CSF) Figure 1. Hypothetical Typical Chemistry Test Results. ​ Obtained via Lumbar Puncture ​ Used for glucose and protein analysis (e.g. diagnosis of ​ Analytes could be any of the following: infection or malignancy) ○​ Substances that are normally present in a bodily function or circulation Amniotic Fluid ​ e.g. Electrolytes, Vitamins, and Hormones ​ Acquired through Amniocentesis (procedure) which is ○​ Metabolites/End products of metabolism ultrasound-assisted ​ e.g. Glucose, Urea, Ammonia ​ Used for diagnosing problems in unborn children, such as ○​ Substances released by cells due to cell damage or genetic disorders and fetal infections abnormal cell function #MagkabigkisBenteSais Group 1 | 1 of 6  ​ e.g. Tumor markers, Proteins, Enzymes SPECIMENS AND ANALYTES ○​ Drugs/Toxic Substances ​ Most specimens contain the same analyte of interest (e.g. ​ Drugs of abuse and Therapeutic drugs glucose in blood and urine, especially in diabetics) ​ However, analytes have different physical and chemical properties within various specimens Table 1. List of Common Analytes Seen in the Clinical Chemistry Laboratory. ○​ Differences in fluid characteristics of analytes are IONS, SALTS, AND MINERALS termed matrix differences ​ Potassium ​ Laboratory tests need to be appropriate not just for a ​ Sodium particular analyte but also for a particular specimen ​ Calcium ○​ Procedure for an analyte is dependent on the ​ Chloride specimen in use ​ Magnesium ○​ There is a specific test for a specific analyte found in a ​ Phosphorus specific specimen (procedure would vary for a ​ Carbon Dioxide specimen in blood vs a specimen in urine) ​ Lead ​ Other analytes presented: Hemoglobin, Uric Acid, Vitamin ​ Iron E, Folate, Thyroid Hormones (T3 and T4) SMALL ORGANIC MOLECULES ​ Can more than one analyte be found in a specimen? Yes. ​ Glucose Table 2. Examples of Multiple Analytes from a Single Specimen. ​ Cholesterol ​ Urea Specimen Analyte Results ​ Lactic acid ​ Normal ​ Glucose Metabolites ​ Bilirubin Blood ​ Abnormal (High ​ Cholesterol or Low) ​ Creatinine ​ Triglycerides ​ Tetrahydrocannabinol ​ Presence ​ Ammonia Urine (a.k.a. cannabis, ​ Absence marijuana metabolite) ​ Cystatin C ​ Vancomycin ​ Theophylline General Scheme of Clinical Chemistry Tests Therapeutic Drugs ​ Digoxin 1.​ Starts off with an obtained specimen (e.g. blood) ​ Phenytoin 2.​ Specimen is processed to analyze certain analyte (e.g. ​ Valproic acid glucose) by identifying its concentration ​ Alcohol (ethanol) 3.​ Analyte concentration is compared to reference values Toxicology ​ Salicylate (aspirin) (given in kit, manual, or print-out of machine) ​ Acetaminophen ​ Find out if the specimen has a normal or abnormal (high or low) value (Quantitative test) ​ Cocaine ​ Find out only presence or absence of analyte ​ Barbiturates (Qualitative test) Drugs of Abuse (DOA) ​ Amphetamines ○​ Ex. Drug testing (If presence is detected, it is ​ Opiates further screened) ​ Cannabinoids LARGE MACROMOLECULES ASSAY ​ Albumin ​ A system or set of procedures and processes ​ Transferrin performed to analyze an analyte Transport Proteins ​ Haptoglobin ​ Some procedures are more complicated and rigorous than ​ Ferritin others while others are simple ​ Total Protein ​ An analyte can be tested using more than one assay, ​ Lipase depending on the employed principle ​ Amylase ○​ Main goal: To ascertain how much of the analyte is ​ Alanine Aminotransferase there in the specimen (ALT) ​ Analytes can be tested differently within laboratories Enzymes ​ Aspartate Aminotransferase ○​ Reference values/range vary per lab (AST) ​ Alkaline Phosphatase (AlkP) QUALITATIVE ​ Lactate Dehydrogenase (LD) ​ Creatine Kinase (CK) ​ Determine the physicochemical properties of analytes ○​ Chemical reactivity, solubility, molecular weight, ​ Immunoglobulins (IgA, IgG, melting point, radiative properties (emission, IgM) absorption), mass spectra, nuclear half-life, etc. Specific Proteins ​ Complement C3 ​ “Yes/No” ​ Complement C4 ​ C-Reactive Protein (CRP) QUANTITATIVE ​ High Density Lipoprotein ​ Determine the weight, volume, or concentration (HDL) ○​ Typically used in clinical chemistry Lipoproteins ​ Low Density Lipoprotein ​ Exception: Assay of tetrahydrocannabinol (LDL) (marijuana) only indicates its presence or absence ​ Lipoprotein (a) ​ Concentration is most vital in clinical chemistry Diabetes Marker ​ Hemoglobin A1c (HbA1c) ○​ Compared to reference/normal values ○​ Most assays are quantitative PH 166 | Introduction to Clinical Chemistry 2 of 6  only and not all 4 humors PHLEBOTOMY ​ Called Diabetes → "Diarrhea of Urine" ○​ An atypical symptom ​ Act of drawing blood specimen from a blood vessel ○​ When one has diabetes, he/she has ​ Phlebotomist: Medical professional trained in drawing excessive urination (polyuria) blood ​ Noted the relationship between fluid ​ Venipuncture: Collecting blood from a vein intake and urine volume ○​ Most common method of collecting blood samples ○​ If a person is healthy, liquid ○​ Tip: Press on puncture wound longer to lessen severe ingested = urine expelled bruising afterwards MIDDLE AGES From BSPH 2025 Trans: ​ Deep influence of religion in medical practice ​ Vein is typically used because the artery pulsates and is ​ Disease was believed to be a punishment for sin, a difficult to control blood flow (due to high pressure) while result of witchcraft or possession capillaries are too small ​ Uroscopy reached new levels of diagnostic ​ Arterial Blood Puncture: Collecting blood from an artery dominance →​Puncturing the wrist area perpendicularly and allowing ○​ Urine = gold standard (often examined) the blood to flow into the syringe ○​ Urine flask = emblem of medieval medicine ​ Capillary pricking: Collecting blood from a capillary ​ In Jerusalem, it was a law that when a doctor does ​ Blood gasses are different between arteries and veins not examine the patient's urine, he/she is criticized (sometimes exposed to public beatings) as urine BRIEF HISTORY OF CLINICAL CHEMISTRY examination is a part of diagnosis ○​ Patients bring their urine to doctors, where it is Table 3. History of Clinical Chemistry compared to the urine wheel or urine chart based Historical Figure Contribution on its color, density, and clarity ​ Sometimes, excreta or semen were used for ANCIENT TIMES diagnosis ​ “Father of Medicine” ​ Humoral Theory or Theory of Humors ○​ 4 Humors: ​ Blood ​ Phlegm ​ Yellow Bile (vomit) ​ Black Bile (from kidney and spleen; causes melancholy and sadness) ○​ Each humor originates from a different region of the body Hippocrates ○​ Humor balance is disrupted → (300 B.C.; disease Greece) ​ Original uroscopist (studies urine) ○​ Hypothesized that urine was a filtrate of humors ○​ "Bubbles floating on the surface of Figure 3. Urine wheel or urine chart the urine denotes affections of the kidneys and that the disease will be ​ Adding heat to urine might present long" — Aphorisms, Section VII, more insight, invented the first Number XXXIV Protospatharius documented laboratory technique ​ This observation is true to some ​ Protein is precipitated through heat → extent because frothy urine Cloudiness → Proteinuria (cloudiness) indicates that there is a kidney ​ Utilized vinegar to bring out cloudiness problem due to protein excretion ​ Acid, like heat, will precipitate or ‘cook’ Paracelsus proteins (denaturation) ​ Founder of Experimental Physiology ○​ Boiling an egg ​ Combined Humoral Theory + Theory of Four Elements RENAISSANCE ○​ Phlegm = Water ​ Uroscopy ○​ Black Bile = Earth ○​ Used to diagnose chlorosis among young women ○​ Yellow Bile = Fire ○​ Blood = Air ○​ Sometimes used as a test for chastity ​ An increasing number of physicians were diagnosing from urine alone Jean Baptiste ​ Introduced gravimetric analysis of Galen Van Helmont urine (180 B.C.) ​ Observed protein in urine after Frederik boiling it with acetic acid Dekkers of ​ Combined the methods of Leiden Protospatharius and Paracelsus ​ Noticed the sweet taste of a diabetic’s urine ​ Differential diagnosis of diabetes Thomas Willis Figure 2. Four humors of the body and the four mellitus vs diabetes insipidus elements ○​ Diabetes insipidus - large volume of dilute urine ​ Theorized that urine is a filtrate of blood PH 166 | Introduction to Clinical Chemistry 3 of 6  18TH CENTURY ○​ 1895 ​ A chemist and a non-practicing ​ William Pepper Laboratory of Clinical physician Medicine ​ Interested in the application of ​ Attached to the University of Pennsylvania chemistry to medicine in Philadelphia ​ Proposed that a chemical laboratory ○​ 1898 Antoine must be located near the hospital François De wards ​ Ayer Laboratory of the Pennsylvania Fourcroy ○​ For immediate chemical analysis of Hospital urine and other excretions LEADERS IN CLINICAL SCIENCE (1900-1920) ​ Was able to classify hundreds of Name Workplace Field urinary calculi (urine sediments) GERMANY despite inadequate availability of Embden Hamburg Metabolism of fats (COH) chemical methods Myerhof Hanover Chemistry of muscle ​ “It is in the blood that we must look for Willstatter Karlsruhe Enzymes many important modifications in Thomas Aschoff Berlin Tissue pathology connection with disease.” Hodgkin Fischer Munich, Berlin Specificity of Enzymes ​ While others were focused in urine, he explored blood as a specimen ENGLAND London ​ Father of Hematology Hopkins Glutathione; chemistry of ​ Explained that the coagulation process William Hewson London, body fluids in blood is caused by a “coagulable Haldane Cambridge, Hemoglobinometry lymph” (now known as fibrinogen) Edinburgh ​ Treated physiologic processes as chemical reactions in his experiments U.S. ​ Wrote “Animal Chemistry” Welch Baltimore Bacteriology (Staph. albus) ○​ Stimulated interest in clinical Folin Boston Chemistry of blood chemistry because it introduced a Benedict New York Chemistry of blood glucose quantitative method into Van Slyke New York Blood gasses & Justus Liebig physiological chemistry electrolytes ​ His theory on metabolism involving 20TH CENTURY chemical processes was attractive, but some were antagonized by his wishful ​ America’s First Clinical Biochemist thinking and speculative excesses ​ His method for quantifying creatinine ​ Had an analytical laboratory in Giessen, in urine using Dubosq-type Germany colorimeter is said to have “ushered the modern era of clinical chemistry” 19TH CENTURY ​ Developed quantitative methods for ​ Specific diagnostic signs became known: Otto Folin urea, ammonia, creatinine, uric acid, ○​ Proteinuria total nitrogen, phosphorus, chloride, ○​ Glycosuria total sulfate, and acidity ○​ Glucose and bile pigments in blood ​ First to publish normal values for uric ​ There was anticipation for finding other “diagnostic acid, nonprotein nitrogen (NPN), and protein in blood signs” and heightened interest in applications of ​ Eventually, chemical measurements chemistry to medical problems were found to be an indispensable part ​ Approximately 1400 organic compounds discovered of the diagnosis and treatment process ​ 1840s - origin of the discipline of ‘chemical of medicine pathology’ or ‘pathological chemistry’ ​ Contemporaries in medicine and clinical ​ 1850s - new diagnostic instruments were introduced Frederich science expressed the need for ○​ Stethoscope, ophthalmoscope, laryngoscope, Boerner & determining values and characteristics microscope, spirometer, ECG William that constitute the so-called “norm” Sunderman Sr. ○​ No attempts were made to gather ​ Wrote “Clinical Chemistry” (1883) such comprehensive set of data yet ​ “In spite of the disparagements of such ​ Were persuaded by publishers and eminent clinical teachers as Graves and colleagues to write “Normal Values in Trousseau, chemistry has become more Clinical Medicine: and more important to the physician as ○​ Published after World War II a means of elucidating many ​ Invented the AutoAnalyzer pathological conditions, or of ○​ The first completely automated Charles Henry determining the character of the morbid system for analyzing blood samples Ralfe changes effected in tissues or ○​ First measured urea, then blood secretions. Indeed, it is becoming more sugars and more evident that we must ○​ In 1957, Skeggs published a eventually look to Chemistry for continuous flow method for information with regard to the primary colorimetric analysis of blood urea alterations that occur in fluids and nitrogen, which was more reliable tissues, and which are the first step in Leonard Skeggs and as accurate as manual every disease” methods HISTORY OF CLINICAL LABORATORIES ​ The Story of the AutoAnalyzer ​ Clinical laboratories became an essential unit of a ○​ Skeggs realized from control hospital samples that results were not very ​ Munich, Germany (1886) reliable and often misleading ○​ First clinical laboratory attached to a hospital ○​ He developed the idea of automated analysis in flowing ○​ Established by Hugo Wilhelm von Ziemssen streams ​ United States ○​ Loaned $5000 by his boss, Skeggs PH 166 | Introduction to Clinical Chemistry 4 of 6  created the first continuous flow ​ Process of detecting disease early before the onset of analyzer in his home signs and symptoms ○​ Despite good results, it took him 3 ​ Early intervention is done to slow down or halt disease years to find a willing manufacturer progression (Technicon Company) and the ​ Recommended for those with family history of certain company took another 3 years to manufacture it diseases ​ 1957 - only 50 units sold ​ E.g. Newborn screening ​ 1969 - 18,000 units sold in that ○​ Some enzymes in the breast milk may not be okay for year alone the baby’s consumption (allergy or intolerance); hence CONTINUED DEVELOPMENTS diet adjustments are necessary ​ Sigma Chemical Co. ○​ Registry of newborn illnesses ○​ Introduced repacked, ready-to-use assay reagent kits Establishing Severity of Disease ​ Tietz ​ Identifying extent of physiological disturbances caused ○​ Listed 13 automated analytical systems by disease ​ Introduction of vacutainer tubes, electrophoresis, ​ Can be used to determine treatment radioimmunoassay ○​ E.g. Palliative care or undergoing procedures ​ Organizations, publications, programs, and services ​ Applicable in diseases that are categorized into stages firmly established the “professional status of the (cancers) clinical chemist” ○​ Tumor markers ​ High levels may indicate remission, extent (stage) of disease and/or the patient’s prognosis (likely outcome or course of disease) Figure 4. First Continuous Flow Analyzer (L), Model IV AutoAnalyzer (C), Sequential Multiple Analyzer Computer (R), Fully Automated Discrete Analyzers (B) ROLE OF CLINICAL CHEMISTRY IN MEDICINE AND Figure 5. Tumor Markers. PUBLIC HEALTH Providing Prognosis CLINICAL CHEMISTRY IN MEDICINE ​ Predicting outcome of disease Confirming or Excluding A Disease Table 4. Clinical Chemistry in Medicine Summary ​ Confirming a disease Clinical Chemistry in Medicine Summary ○​ Making a diagnosis Confirming Making a diagnosis ​ Excluding a disease Excluding Ruling out a disease ○​ Ruling out a disease Assisting proper selection, ​ Referring to reference values and patterns of disease can Monitoring monitoring, and adjusting of aid in correct diagnosis and rule out other diseases treatment ​ Correct test selection and right timing of test will Assisting establishment of shorten the time to diagnose a disease and immediately Screening disease in the absence of start treatment clinical signs or symptoms Identifying extent of Establishing Severity physiological disturbances Monitoring Treatment caused by disease ​ Assisting proper selection, monitoring, and adjusting of Providing Prognosis Predicting outcome of disease treatment ​ Checks effect of the current treatment CLINICAL CHEMISTRY IN PUBLIC HEALTH ○​ Provides physicians basis for adjusting, continuing, or ​ Monitoring the impact of intervention and changes in risk discontinuing treatment factors ​ Determine the recurrence of disease (applicable in ​ Diagnosing disease at an early stage (screening) cancers) ​ Lessen burden disease ​ E.g. Regular testing for chronic illnesses to determine how ​ Prevent complications and premature death the treatment should proceed ​ Lessen out-of-pocket expenses of patients ​ Lessen cost of health care system Screening ​ Assisting establishment of disease in the absence of Patient 1 vs Patient 2 diagnosed with Type 2 Diabetes at the clinical signs or symptoms same time ​ “Catch it early” ​ Patient 1: No monitoring, NO PHI ​ Secondary prevention ○​ Year 1-5: Discontinues glucose monitoring, eyes and kidneys unchecked PH 166 | Introduction to Clinical Chemistry 5 of 6  ○​ Year 10: ↑ blood glucose, ↑ blood pressure, ↑ LDL c.​ Both A and B cholesterol, kidney damage d.​ None of the above ○​ Year 15: Undergoes leg artery bypass, ↑ medication 5.​ Who utilized vinegar for precipitating protein in urine? for cholesterol, blood pressure and kidney swelling a.​ Protospatharius ○​ Year 20: Undergoes dialysis and amputation of leg b.​ Paracelsus ○​ Total Healthcare Expenditure: Php 4 000 000 c.​ Hippocrates d.​ Thomas Willis 6.​ Who published “Normal Values in Clinical Medicine?” a.​ Otto Folin and Leonard Skeggs b.​ Frederich Boerner and William Sunderman Sr. c.​ William Hewson d.​ Charles Henry Ralfe 7.​ Who invented the AutoAnalyzer? a.​ Hippocrates Figure 6. Patient 1 without monitoring and public health monitoring post Type 2 b.​ Justus Liebig Diabetes diagnosis. c.​ Galen ​ Patient 2: With monitoring and PHI d.​ Leonard Skeggs ○​ Year 1-5: Monitors glucose levels, regular kidney, liver, 8.​ This instrument is the first automated system for and urine tests analyzing blood samples. What is it called? ○​ Year 10: Daily glucose monitoring, takes oral meds for diabetes ○​ Year 15: Careful diabetes management, continues medicine, doctor adjusts medication ○​ Year 20: Regular diabetes tests, modest ↑ in blood pressure, careful dose management ○​ Total Healthcare Expenditure: Php 90 000 (Controlled diabetes) a.​ Fume hood b.​ Centrifuge c.​ AutoAnalyzer d.​ Moisture Analyzer 9.​ Who combined the Humoral Theory and the Theory of Four Elements? a.​ Galen b.​ Protospatharius c.​ Thomas Hodgkin Figure 7. Patient 2 with monitoring and public health monitoring post Type 2 d.​ Otto Folin Diabetes diagnosis. 10.​ Which of the following is not an analyte? ​ The patient with consistent monitoring and public health a.​ Blood intervention has significantly lesser total healthcare b.​ Chloride expenditure c.​ Glucose d.​ Amylase REVIEW QUESTIONS ANSWER KEY 1.​ What substances are found in specimens and are the 1.​ C 6.​ B ones being measured? 2.​ TRUE 7.​ D a.​ Sample 3.​ Refer to Table 1 8.​ C b.​ Reagent 4.​ C 9.​ A c.​ Analyte 5.​ B 10.​ A d.​ Assay 2.​ TRUE OR FALSE: Sodium and potassium are examples REFERENCES of analytes. ​ Rama-Sabandal, R. (2024). Introduction to Clinical Chemistry [Lecture]. 3.​ Give two examples of analytes. https://drive.google.com/file/d/1JSZJ80jiaROEED0pq69WBHr5Xr4 4.​ The image below is called a _____. fpp_4/view?usp=drivesdk. a.​ Urine wheel b.​ Urine chart PH 166 | Introduction to Clinical Chemistry 6 of 6