1	CLSC320 Principles of Immunology Diagnostic Laboratory Immunology Program for Clinical Laboratory Science Unit - 08 Scope of Laboratory Testing
2	Unit – 08 Guidelines Reading assignment: Pages 174 - 191 of textbook Learning objectives: Those listed on page 175 of textbook Key terms: Those listed on page 175 & 176 of textbook
3	Indications for Immunologic Testing Detection of immune response to infections agents y Evaluation of immune competence y Detection of deficiencies of the immune system y Evaluation of hyperactivity of the immune system y Diagnosis of malignancies y Pre-Transplantation testing y Monitoring of therapy
4	Detection of Immune response - 1 Detection of Infections: Umost widely used tests are those that detect antibody response to a specific organism. Disease Organism involved Name of Ag Name of Ab Diphtheria Corynebacterium diphtheriae Diphtheria toxin specific antitoxin Legionella or Legionnaire=s Legionella pneumophilia polyvalent ag (4 strains) anti-Legionella Lyme disease Borrelia burgdorferi borrelia ag anti-borrelia Gonorrhea Neisseria gonorrhoeae gonococcal LPS ag LPS = lipopolysaccharides anti-LPS Rheumatoid fever Group A Beta- hemolyticStreptococci Streptolysin O ag anti-ASO DNase (B) isozyme anti-DNase (B)
5	Detection of Immune Response - 2 Detection of Infections: continued Udetection of antigen-specific antibodies when an infectious disease is suspected has two major clinical applications: ediagnosis of primary (recent) infection -antigen-specific IgM must be present in specimen collected during 1st week of symptoms -recent infection confirmed by a four-fold or higher increase in antigen-specific IgG titer between acute and convalescent specimens
6	Detection of Immune Response - 3 Detection of Infections: continued ediagnosis of immunity (past infection) -antigen-specific IgG is detectable within 1 - 2 weeks after primary infection -antigen-specific IgG levels peak at 4 - 8 weeks and then declines. It remains at detectable levels the rest of the patients life. -immunity to a specific antigen can be conferred through immunizations -re-infection produces low titer IgM and a higher titer IgG -congenital infection has detectable IgM or IgA in fetal, cord, or newborn blood. Detectable IgG in these specimens is of maternal origin.
7	Detection of Immune Response - Vaccination Detection of Infections: continued eImmunizations in which seroconversion confirmation is recommended: Vaccine given Antigen-specific IgG detected Hepatitis B surface Ag HBs antibodies Chickenpox Varicella zoster antibodies Hepatitis A Ag Hepatitis A antibodies Measles Rubella antibodies
8	Lab Testing for Viral Infections - 1 eDetection of antigen-specific antibodies is method of choice because: especialized isolation techniques required (EBV & herpes) egrowth and propogation of virus is dangerous (HIV) eCommon screening panels for viral infections include: Name of Panel Infectious agent detected Antibodies detected Hepatitis A, B, & C Hepatitis C anti-HCV Hepatitis A anti-HAV(IgM & Total) Hepatitis B (immunity) anti-HBsAg Hepatitis B (active if alone) anti-HBcAg EBV panel EBV-capsid ag anti-EBV-VCA EBV-EA ag (early) anti-EBV-EA EBV-NA ag (nuclear) anti-EBV-NA
9	Lab Testing for Viral Infections - 2 Laboratory Testing for Viral Infections: (Cont=d) Name of Panel Infectious agent detected Antibodies detected TORCH panel Toxoplasma gondii anti-Toxoplasma Rubella virus anti-Rubella Cytomegalovirus (CMV) anti-CMV Herpes simplex virus (HV) anti-HSV MMR/VZV panel Rubeola virus anti-Rubeola Mumps virus anti-Mumps Rubella virus anti-Rubella Varicella-Zoster virus anti-V-Z
10	Lab Testing - Bacterial Infections - 1 Ubased on positive cultures Ubased on positive results using Arapid test@ kits Ubased on immunological tests for confirmation of past infections: eIgM positive = eIgG positive = current infection past infection Uexample: epositive test for anti-streptolysin O (ASO) demonstrates the presence of post-streptococcal infection as seen in: rheumatic fever glomerulonephritis caused by group A streptococci
11	Detection of Immune Competence Definition: immune competence is the ability of an individual=s immune system to produce a normal humoral and cell-mediated response to a specific antigen. Indications for laboratory evaluation of immune competence: UOn patients who are immunosuppressed due to drug or radiation exposure UOn patients who are immuno-reconstituted due to bone marrow grafting or cancer therapy UOn patients who are immunized due to vaccinations UOn patients who have autoimmune or immunodeficiency disorders
12	Testing Panel – Immune Competence - 1 UScreening tests: eComplete Blood Cell count (CBC) eTotal T lymphocytes count (CD3) eT_Helper lymphocyte count (CD4 & CD3) eT_Cytotoxic lymphocyte count (CD8 & CD3) eT_Helper to T_Cytotoxic lymphocyte ratio (CD4:CD8) eTotal B lymphocytes count (CD19) eTotal NK lymphocytes count (CD16 & CD56)
13	Testing Panel – Immune Competence - 2 UNon-specific tests that evaluate immune response: USpecific tests that evaluate immune response: eTests for Humoral immune response: serum immunoglobulin levels (IgG, IgM, & IgA) eTests for Cell-mediated immune response: number and type of leukocytes (WBC differential) skin test (lymphocyte response)
14	Types of Immunodeficiencies UPrimary immunodeficiencies USecondary immunodeficiencies ehereditiary or congenital ebecomes evident in infancy or early childhood eincreased susceptibility to infections eB cell, T cell, or B & T cell deficiencies eneutrophil dysfunction ecomplement dysfunction eDiGeorge=s syndrome (T cell) eSCID = severe combined immunodeficiency (T & B cells) eacquired (AIDS) edevelops in later life edevelops secondary to infection edevelops secondary to: _infection, cancers, immunosuppressive therapy _diabetes, burns, or malnutrition echaracterized by increased susceptibility to: _tumors, infections with opportunistic microorganisms
15	Screening for Immunodeficiencies Parameter measured Method by which measured # & type of lymphs # of neutrophils Neutrophil function ANCA ANCA = antineutrophil cytoplasmic autoantibodies B cell function T cell function Complement CBC and WBC differential CBC and WBC differential NBT test, chemiluminescence NBT test = Nitroblue tetrazolium test IFA and EIA IFA = immunofluorescence antibodies EIA = enzyme immunoassay measurement of immunoglobulin production flow cytometry and skin tests (DTH) CH₅₀ and serum C3 levels
16	Complement Deficiencies & Disease Disease Complement component deficient LE-like syndrome LE = Lupus Erythematosus Severe recurrent infections Neisseria infections Recurrent bacterial infections C1q or C4 C3 C5 Factor H and I Testing for Malignancy: eDefinitions: emalignant tumor ecancer ecarcinoma terms used to describe a malignancy a clone or a mass of transformed cells derived from normal host tissue
17	Classification of Tumor Markers eTumor-associated markers: surface molecules on normal or malignant cells of same cell line eTumor-specific markers: surface molecules on tumor cells but not on normal cells
18	Non-specific Tumor Markers Tumor marker present Disease CEA CEA = Carcinoembryonic antigen Primary colorectal cancer, breast cancer, Gastrointestinal tumors, ovarian, prostatic, lung, liver, and pancreatic AFP AFP = Alpha-fetoprotein Non-seminomatous testicular cancer Primary hepatocellular carcinoma HCG HCG = Human chorionic gonadotropin hydatiform mole, choriocarcinoma testicular neoplasm
19	Specific Tumor Markers Tumor marker present Disease CA 27.29 (CA 15-3) CA = Cancer antigen Breast carcinoma CA 125 Ovarian carcinoma CA 19-9 Gastrointestinal cancer PSA PSA = Prostate-specific antigen Prostate cancer Calcitonin Thyroid medullary malignancy
20	Immunotyping in Leukemia & Lymphoma eB cell-associated antigens: _sIg sIg = surface immunoglobulin _CD10 or CD = cluster of differentiation CALLA CALLA = common acute lymphoblastic leukemia associated on normal immature & ALL B cells not on mature circulating B cells eT cell-associated antigens: _CD3 _CD4 _CD8 _CD9 on T cells and T cell neoplasms on T_Helper cells, macrophages, and T cell neoplasms on T_Cytotoxic cells and subsets of NK cells on cells of ALL (immature T cells) eMiscellaneous marker: _TdT TdT = Terminal deoxyribonucleotidyl transferase on cells of ALL and lymphomas (immature B cells)
21	Histocompatibility in Transplantation Complete tissue compatibility: UOnly if between identical twins UHave same histocompatibility (HLA) antigens Graft rejection occurs: Ubecause of foreign HLA antigens Uthe greater the mismatch of HLA antigens the higher the risk of rejection Pre-transplantation testing: UTissue typing: UCrossmatch: UHLA antibody screening/identification: eidentification of HLA class I and HLA class II antigens edetects the presence of antibodies (anti-HLA) in patient that react with HLA antigens of donor edetects the presence of antibodies (anti-HLA) in patient and identifies the type of antibody.
22	Hyperactive Immune System Hyperactivity of immune system results from: UInappropriate response to self-antigens (autoimmune disorders) UHeightened immune response to harmless antigens (allergies) UAbnormality of antibody-producing cells (B or plasma cells) Autoimmune diseases: UOccurs when there is a loss of self-tolerance and antibodies produced against self-antigens UClassifications of autoimmune disorders: eorgan-specific eSystemic _autoantibodies show specificity for antigens expressed on a particular organ _autoantibodies directed against various cellular components and react with a variety of organs
23	Organ-Specific Autoantibodies Disease Organ involved Multiple Sclerosis Myelin protein of axons Myasthenia gravis Acetylcholine receptors Goodpasteur=s syndrome glomerular basement membrane of kidneys Grave=s (hyperthroidism) thyroid-stimulating-hormone receptors Hashimoto=s thyroiditis Thyroid tissue Diabetes mellitus (insulin dep) beta cells of pancreas
24	Systemic Autoantibodies Disease Autoantibodies to which structures Lupus erythematosus ds-DNA, Sm, nRNP ds-DNA = double-stranded DNA Sm = Smith antigen nRNP = nuclear ribonucleoprotein Rheumatic fever Pernicious anemia intrinsic factor, parietal cells, intestinal receptors Autoimmune hemolytic anemia variety of red cell antigens Scleroderma Scl-70, centomere Scl-70 = scleroderma antigen
25	Immunoproliferative Disorders - 1 Most common causes: UAbnormalities in B lymphocytes UPlasma cell dyscrasias Clinical findings: Uabnormal or excessive production of monoclonal antibodies eseen in malignancy (@monoclonal gammopathy@) Uexcessive production of total immunoglobulins eseen in benign response to stimulus (@reactive cell proliferation@) Plasma cell dyscrasias: UMultiple myeloma eclonal proliferation of plasma cells eM protein or paraprotein produced esingle light chains or single heavy chains produced
26	Immunoproliferative Disorders - 2 Plasma cell dyscrasias: continued UWaldenstrom=s macroglobulinemia emalignant production of B lymphocytes ecells are called Aplasmacytoid lymphocytes@ eproduce large amounts of monoclonal IgM eincreased serum viscosity Laboratory Diagnosis of Plasma cell dyscrasias: UProtein electrophoresis UImmunoelectrophoresis (IEP) UImmunofixation electrophoresis (IFE)
27	Immediate Hypersensitivity Clinical findings: UIncreased IgE caused by: ehay fever econtact dermatitis eeczema easthma Laboratory Evaluation of allergic reactions: URadioimmunosorbent test (RIST) UEnzyme immunoassay (EIA) URadioallergosorbent test (RAST)
28	The End of Scope of Laboratory Testing Press the ESC key to end program