Interpretation of Lab Tests

1. Interpretation of Lab Tests Barb Bancroft CPP Associates Chicago IL www.barbbancroftcom

2. Rule number one … • Various methods of testing and various “normal ranges”… • Know what’s normal for the lab YOU are using • And, the normal ranges are usually on the lab slip

3. Platelets • Quantitative Platelet Counts (how many?) 150,000 to 450,000 (wide range)—too few platelets is called thrombocytopenia; too many platelets is called thrombocytosis • Qualitative Platelet Counts—(how well do they work?) • How well do they “plug a hole”? Measure the bleeding time (3-6 minutes)

4. Manifestations of platelet deficiency or platelet dysfunction • Superficial bleeding is the rule with platelet dysfunction or deficiency • Mucous membrane bleeding—easy bruising, nose bleeds (most common cause?), gum bleeds, blood in the urine (hematuria), blood in the stool (occult blood) –

5. Causes of platelet bleeding • Quantitative? Too low? Thrombocytopenia, ITP (Immune Thrombocytopenic Purpura), Lupus, leukemia, lymphoma, chemotherapy, HCV, EBV/mono, heparin, severe pre-eclampsia • Qualitative? Drugs are the usual culprit; over-the-counter such as NSAIDS, ASA; the G’s—gingko, ginseng, glucosamine, garlic, ginger; HIV

6. Other drugs that inhibit platelet function… • Anti-platelet therapies—ASA, NSAIDs, clopidogrel/Plavix, pasugrel/Effient, ticagrelor/Brilinta

7. Anti-coagulant therapy • Anticoagulation therapies—warfarin/Coumadin, • rivaroxaban/Xarelto • apixaban (Eliquis), • dabigatran/Pradaxa

8. Warfarin (Coumadin) • Atrialfibrillation, prevention of DVT and PE • Inhibits vitamin K-dependent activation of II, VII, IX, X which are formed in the liver • When adding or subtracting a drug, check the INR within 4 days • What is the INR? International Normalized Ratio • Standard therapeutic range for patients on warfarin is 2-3; mechanical heart valves? 2.5-3.5

9. While we’re talking about warfarin • $80 per month (with INR monitoring) vs. newer rivaroxaban/Xarelto ) ($200+) and apixaban (Eliquis), dabigatran (Pradaxa) • Good news? Cheaper • Bad news? Lots of drug interactions making warfarin either MORE effective (bleeding) or less effective (clotting) • Good news? Vitamin K antidote for warfarin bleeding; Bad news? No antidote for other anticoagulants

10. The lipoproteins • High-density lipoprotein (HDL) • Low-density lipoprotein (LDL) • Very-low density lipoprotein (VLDL)—the lipid on this protein is known as triglyceride • The newest finding is that as far as heart disease is concerned, the LDL fraction is the most important to predict cardiovascular disease; the higher the LDL, the greater the risk of cardiovascular disease

11. LDL guidelines • HIGH RISK: with CAD or a risk equivalent (stroke or previous TIA, peripheral arterial disease, abdominal aneurysm); calculated 10-year risk > 20% • the LDL goal should be <100 mg/dL (<2.85 mg/dL), ideal would be <70 mg/dL (2.0 mmol/L or even lower to 1.8 mmol/L) • Risk calculator: http://hp2010nhlbihin.net/ATPiii/calculator.asp?usertype=prof

12. LDL guidelines • MODERATELY HIGH RISK: two+ risk factors (smoking, HBP or being treated for HBP, family history of CAD (first degree relative male under 55, female under 65), your age (over 45 for males, over 55 for females); calculated 10-year risk 10-20% • <130 mg/dL (ideal would be <100 mg/dL (<2.85 mmol/L)

13. LDL guidelines • MODERATE RISK: 2+ risk factors; calculated 10 year risk less than 10% • < 130 mg/dL • Lower risk: 0-1 risk factor; < 160 mg/dL

14. Risk factors for increased LDLs • Diet high in trans and saturated fats • Smoking • High iron levels • High insulin levels • Couch potato • Fat around the belly

15. Say YES to statins—the “statin” sisters… • The statins inhibit the enzyme in the liver responsible for producing LDL-cholesterol • Since the liver works overtime at night, giving the statin drugs in the evening provides an even greater reduction in LDLs • Statins decrease plaque formation, stabilize plaques, prevent plaque rupture

16. Did your MD or NP start you on lipid-lowering medications? • If so, how much should your LDL go down? • Atorvastatin/Lipitor 10 mg = 39% • Fluvastatin/Lescol 40 mg BID = 36% • Fluvastatin XL/Lescol 80 mg = 35% • Lovastatin /Mevacor 40 mg = 31% • Pitavastatin/Livalo 2 mg = 36% • Rosuvastatin/Crestor 5 mg = 45% • Simvastatin/Zocor 20 mg = 38% (Circulation 2004;110:227-239

17. WBC (white blood cell count) and DIFFERENTIAL (types) • 5 types of mature WBC’s and one immature WBC circulate in the “cold, cruel world” known as peripheral blood • Normal range 5,000 to 10,000 (3500-12000) (5 to 10 with a range of 3.5-12)

18. The List… • Neutrophil (segs (57-63%) of the total white count; acute inflammation, acute necrosis, acute bacterial infection(1.51-7.07) • Lymphocytes (30%)-first responder to viruses; cells of the immune system (0.65-2.8) • Monocytes (4%)—cells of chronic inflammation (0.00-0.51) • Eosinophils (3%)—cells that respond to parasites and allergies (0.00-0.42) • Basophils (less than 1%)—who cares? Contain histamine (0.00-0.16)

19. 5 types of WBCs • Neutrophils (seg)—(phagocyte)-- only job in the world is to EAT until it dies • Cell of acute inflammation • First responder to bacterial invasion • Loves acute necrotic tissue • 57-63% of total WBC (1.51-7.07)

20. Neutrophils • Neutrophils (segs) are produced in about 8-10 days; leave the bone marrow and live in the blood for 5-6 hours; migrate into tissues and eat for 36-72 hours; • released rapidly in response to virulent organisms such as strep, staph, E. coli, H. flu, meningococcus, Pseudomonas • Acute necrosis—MI, gangrene of the bowel, acute appendicitis

21. Clinical conditions with an increased neutrophils in the WBC • GABHS (group A beta hemolytic strep) • Pyelonephritis • Acute appendicitis • Bacterial meningitis

22. Drugs and neutropenia (too few neutrophils) • Chemotherapy (all patients)—ONCOLOGIC EMERGENCY and usually has two words in front of it…LIFE-THREATENING • Cimetidine (Tagamet), ranitidine (Zantac) • Carbamazepine (Tegretal); phenytoin • Captopril (Capoten), enalapril (Vasotec), amiodarone, quinidine • Zidovudine (Retrovir) • Clozapine (Clozaril) • Metronidozole (Flagyl) • Gentamicin, clindamycin, imipenem, PCNs, tetracyclines • Azothiaprine (Imuran) • PTU

23. ACUTE STRESS can increase the total white blood cell count • Screaming kids • 24-hours post-op • Last trimester of pregnancy • No bands

24. Cells of the immune system--lymphocytes

25. 3 types of lymphocytes • B lymphocytes (16%)—bone-marrow derived • T lymphocytes (70%)—thymus-derived • NK cells (14%)—Natural Killer cells (innate immunity—part of the first line of defense) • Specific tests are needed to determine the numbers of each type of cell in the blood • Not routinely performed

26. Cell-mediated immunity—T cells are the first responders to: • Viruses • Fungus’ • Parasites • Protozoa • Cancer • Transplants

27. B lymphocyte turns into plasma cell • B lymphocytes are triggered by a foreign pathogen • Turn into a mean, green antibody producing machine called a plasma cell • Takes 7 to 21 days to produce antibodies with the initial response • Memory response? Minutes to hours

28. Measuring antibody levels for various diseases or “types” of antibodies • Did you ever have chickenpox as a child? Varicella titers • Are you making antibodies to your very own tissues? Autoimmune diseases will have specific antibodies— • Anti-nuclear antibodies—lupus • Anti-microsomal antibodies – Hashimoto’s thyroiditis

29. Plasma cells produce antibodies… • IgM—first antibody formed to an infection “acute titers”—HSV-IgM (acute phase of infection) • IgG—second antibody formed to an infection; lasts “forever”; crosses placenta; “convalescent titers”—HSV-IgG (reactivation of earlier infection)

30. Plasma cells produce antibodies… • IgA—barrier antibody; saliva, tears, urine, breast milk • IgD--??

31. Immunoglobulin E • IgE—antibody of allergies • Drills a hole in the mast cell— releases primary granules full of histamine

32. RBC’S AND ANEMIAS Barb Bancroft, RN, MSN, PNP www.barbbancroft.com barb@barbbancroft.com

33. 3 major tests for anemia • Reticulocyte “retic” count– tells you if you are actively making red blood cells • Hemoglobin—O2 carrying protein; contains iron • MCV—mean corpuscular volume or mean cell volume—tells you the size of the red blood cell

34. Patient with a high retic count but is still anemic • High retic count means that the bone marrow is making RBCs, but something is destroying them rapidly—either in peripheral blood or bone marrow (hemolysis) and the bone marrow is working overtime to produce more

35. Known as hemolytic anemias • Sickle cell? Genetic hemoglobinopathy • Thalassemia? (as above) • G6PD deficiency?(as above) • Autoimmune hemolytic anemia (lupus, drugs) • Hemolytic uremic syndrome (drugs, E.coli)

36. Low retic count • Underproduction anemia • Usually due to a deficiency of a nutrient • Iron, B12, folic acid

37. The most common anemias have to do with deficiencies of substances needed to make RBCs • Iron • Vitamins B12 and folic acid

38. You also need specific hormones to make RBCs • Thyroid hormone • Erythropoietin produced by healthy kidneys

39. Good genes are needed to make healthy RBCs • Who’s your momma? Who’s yo’ daddy?

40. Iron and RBCs • How do we get iron? • Food—especially as children for vertical growth • Food—not so much in adults as we are not growing vertically and we usually get plenty of iron from our diet (only need 1 mg from diet of the 20 mg used per day—the other 19 mg is recycled through the senescence of old RBCs) • Pregnancy -- need extra iron to grow a baby

41. How do we become deficient in iron? • Bleeding—anywhere; women have 20% less blood than men, hence, lower iron stores and a greater risk of iron deficiency anemia; also have periods premenopausally which increases risk of iron deficiency due to RBC depletion (and depends on type of period) • Bleeding—ALWAYS THINK GI, GI, GI

42. Iron absorption • Fact: You need a healthy duodenum to absorb iron and you need iron to grow vertically as a child • Celiac disease primarily involves the duodenum; consider a child with short stature with possible celiac disease • Gastric by-pass surgery and duodenal exclusion surgeries—consider iron deficiency

43. B12 (200-800 pg/mL) for RBC production • Stored in the liver for 5-7 years 2,000 to 5,000 mcg is stored; Use about 1 mcg per day for maintenance • Takes 5-7 years of no B12 intake to deplete stores in the liver

44. Functions of B12 • Growth and differentiation of RBCs in the bone marrow • Maintenance of CNS myelin, PNS myelin, and is a co-factor in the production of serotonin (happy) • Not enough B12? You’re anemic, demented, depressed with a peripheral neuropathy

45. Notes on B12 • Foods high in B12? Animal protein, eggs, brewer’s yeast—Dietary deficiency • Glycoprotein in the stomach, intrinsic factor, binds to B12—stomach problems • Tumbles into the small intestine where it is absorbed in the ileum—absorption problems • Transported to liver for storage, bone marrow for RBC production nervous system –storage problems

46. High risk groups(200-800 pg/mL) • Over 55 years of age (problems with absorption) • Lack of IF (intrinsic factor)—autoimmune gastritis (pernicious anemia), gastrectomy patients • No animal protein in diet—vegetarians or Tea and Toasters • Liver failure • Lousy diet (alcoholics)—no B12 in booze • Malabsorption (Crohn’s disease, celiac disease, gastric by-pass surgery) • Metformin; PPIs

47. Folic acid (greater than 3 mg/mL)and Dr. George Herbert • 40 days and 40 nights • Maintenance of healthy RBCs • Don’t forget the neural tube, young ladies!! • Green leafys and citrus fruits, fortified cereals and breads

48. Some other numbers… • Normal RBC count is 4.5 million to 6 million mm3 • Hemoglobin adult females (11-15.5 g/dl) (110-155 g/L) males (13-17.3)(130-173 g/L) What is anemia defined as? Hemoglobin under 11 g/dl for females and under 13 for males

49. The size of the red blood cell also helps define anemias • Mean Cell Volume (MCV) – 90 (83-97) fL • microcytic anemia (RBCs are too small), • Normocytic anemia (RBCs normal size) • Macrocytic anemia (RBCs too large)

50. Serum Enzymes…lab test interpretation