MLS serology exam 2

First marker for Hepatitis B

Hepatitis B surface antigen (HBsAG), indicator of active infection, peaks during acute stages of infection, declines with development of host antibody response, remains elevated during chronic infection

Second marker for Hepatitis B

Hepatitis Be antigen (HBeAG), core of HBV, marker of active viral replication, appears shortly after HBsAG and levels decline before HBsAg, may remain elevated during chronic infection, indicates high degree of infectivity

Third marker of Hepatitis B

Anti-HBc, directed against hepatitis B core antigen, IgM anti-HBc appears first and indicated current or recent acute infection, consists mostly of IgG and can indicate current or past infection, can persist for a lifetime

Fourth marker of Hepatitis B

Anti-HBe, directed against HBeAg, indicates recovery from Hepatitis B

Last marker of Hepatitis B

Anti-HBs, directed against HBsAg, indicates immunity to hepatitis B

Which Hep B markers can persist for years

Anti-HBe and anti-HBs persist for years and help protect against subsequent infection

Acute HBV

Chronic HBV

What markers are positive for past Hepatitis B infection

Anti-HBeAg and anti-HBs

Which hepatitis b marker means immune due to vaccination

Positive for Anti-HBs

What are the early antigen markers for mono

EA-D- anti-EA-D present in acute IM and EA-R

What are the late markers for mono

Viral capsid antigens (VCA), IgM anti-VCA (best marker for IM) appears at the onset of clinical symptoms and persists for 2 months, IgG anti-VCA (acute or past IM)

What are the latent-phase markers for mono

EBV nuclear antigens (EBNA), anti-EBNA (convalescent IM), latent membrane proteins (LMP-1, LMP-2A, LMP-2B)

Serological test result for acute EBV

Anti-VCA IgM, anti-VCA IgG, anti-EA-D, could be anti-VCA IgA and heterophile antibody IgM

Serological test results for past EBV

Anti-VCA, anti-EBNA

Serological test results for reactivated EBV

Anti-VCA IgG, anti-EBNA, could be anti-EA-R or heterophile antibody IgM

Serological test results for never infected EBV

All negative

Serological test results for chronic EBV

Very positive for Anti-VCA IgG, anti-EA-D, anti-EA-R, could be anti-EBNA

Transmission for CMV

Close, prolonged contact with infectious body secretions, sexual contact, blood transfusions and solid organ transplant, mother to infant

Symptoms for CMV

Healthy people: asymptomatic to mild IM-like illness, immunocompromised/suppressed: severe disease involving GI tract, CNS, blood, virus remains dormant but can be reactivated later in life

Complications in CMV

Infection is dangerous for immunocompromised patients, transplant patients have an increased risk of reactivation and previously CMv negative patients have high risk of GVHD, major opportunistic pathogen in AIDs patients, in neonates congenital infection, platelet dysfunction, CNS involvement, hearing loss

Testing for CMV

Organs screened for CMV, neonates receive CMV negative blood, molecular methods to detect CMV DNA, serological assays for CMV IgG to detect path infections, assays for IgM have limited value

What is measles?

Morbillivirus paramyoxoviridae, rubeola, RNA virus

Symptoms of measles

Subacute sclerosing panecephalitis (SSPE)

What is transmission in measles

Respiratory droplets

What is the testing for measles

RT-PCR to detect virus, capture ELISA to detect antibodies IgM or IgG, titers for healthcare works to confirm immunity

What is Mumps?

Rubulavirus paramyxoviridae, single stranded RNA virus

Mumps transmission

Respiratory droplets

What does mumps cause

Parotitis

What is the testing for mumps

RT-PCR or viral culture to detect virus, ELISA to determine current infection, recent infection, or immunity, PCR is used to monitor viral load for HTLV I/II

What kind of virus is Varicella Zoster?

DNA, Herpesviridae

Transmission of Varicella zoster

Primarily through inhalation of infected respiratory secretions, contact with or inhalation of aerosols from skin lesions, mother to fetus

What diseases does varicella zoster cause

Varicella (chickenpox), herpes zoster (shingles)

What is varicella zosters life long laten state?

Dorsal root, autonomic, and cranial ganglia, T cell-mediated immune response keeps virus in latency

Lab diagnosis for varicella zoster

Based on characteristic clinical findings, real-time PCR is main method to detect VZV DNA, titers (health-care workers, pregnant women, organ transplant candidates), ELISA detects immunity- total VZV IgG and automation helps provide objective results

What is Rubella

Rubrivirus togaviridae, RNA virus

What does Rubella cause

German measles

Transmission of Rubella

Respiratory droplets, mom to fetus (across placenta), CRS= congenital rubella syndrome

Testing for rubella

RT-PCR to detect viral antigens, serological assays to determine immunity or current infection, ELISA- best sensitivity and specificity, IgM- primary infection, IgG- past infection or immunity

What kind of virus is Human T-Cell lymphotropic virus (HTLV)

HTLA I/II are closely related retroviruses, RNA, posses reverse transcriptase

Transmission of HTLV

Bloodborne, sexual contact, mother to child (primarily breast feeding)

What disease is HTLV-I associated with

Adult T-cell leukemia/lymphoma

Testing for HTLV

ELISA used to screen, western blot used for confirmatory, all blood donors screen for HTLV I/II

Which cell is the main target for HIV infection?

CD4+ T cells- macrophages, monocytes, dendritic cells, Langerhans cells, and microglial brain cells can also be affected due to CD4 expression

How does the HIV virus attach to the target cell?

Coreceptor required (chemokines), CXCR4- T lymphocytes, CCR5- macrophages

Primary infection for HIV infection

Acute, early infection, may be asymptomatic or have flu-like syndrome that resolves, high level of viremia and decrease in CD4 T cell-number

Clinical latency of HIV infection

Absence of clinical symptoms, decrease in viremia and increase in CD4 T cell number, long-term nonprogressors (LTMP)- patients that remain asymptomatic for more than 10 years without antiviral therapy, normal or mildly decreased CD4+ counts, and low viral load

Clinical course of AIDs

Resurgence of viremia and decrease in CD4 T cell number, profound immunosuppression, with appearance of life-threatening opportunistic infections and malignancies

Clinical course of HIV

What is stage 0 for HIV

Patient with early HIV infection, have one positive HIV test, followed by negative or indeterminate test within 6 months, reclassified into one of the other categories 180 days or more after initial diagnosis

What is stage 1 of HIV staging

CD4 count: >/= 500 cells/microliter, CD4 count/= 26%

What is stage 2 of HIV

CD4 count: 200-499 cells/microliter, CD count: 14-25%

What is stage 3 of HIV

CD4 count: </= 200 cells/microliter, CD4 count: </= 14%, indicative of any opportunistic illnesses present in patient

What is unknown stage of HIV

When CD4 data is missing

What test methodology is used to stage HIV infection?

CD4 T cell enumeration through flow cytometry, HIV viral load through PCR and branched chain DNA, drug resistance testing through genotype and phenotype resistance assay

What is the fourth generation ELISA test for HIV being tested for?

Measures the optical absorbance of a patient HIV1/HIV2 antibodies and p24

What is the conjugate used in fourth generation ELISA test for HIV?

Enzyme labeled anti-p24 and HIV-1/HIV-2 antigens

Which type of ELISA is the fourth generation test for HIV?

Combination, sandwich ELISA

List the bands that must be present for a positive Western blot HIV test?

P24, gp41, gp120/gp160

List the test methods used to test for resistance in drugs used to treat HIV?

Genotype resistance assay: detects mutation in reverse transcriptase and protease from RNA in patient plasma, amplified RT-PCR, nucleotide sequenced products entered into database and analyzed with software for mutations, reported as resistance, possible resistance, no level resistance

Phenotype resistance assays: determine ability of HIV from clinical samples to grow in presence of antiretroviral drugs, direct measure of drug susceptibility, create recombinant virus from patient plasma and reference lab strain using mammalian cells, advanced procedure

Discuss HIV testing in infants

Less than 18 months of age, maternal antibodies in infant serum can complicate serologic test results, use molecular methods of diagnosis, qualitative HIV-1 DNA PCR (preferred), serologic testing at 12-18 months of age used to confirm

Describe the test methodology for the fluorescent ANA test

HEp-2 cells are fixed on the slide patient serum added to the slide and incubated, wash, add secondary fluorescent marker, wash, examine under microscope. If patient has the ANA it will bind w/the HEp-2 cells and the fluorescent marker will bind to this structure and glow. If the patient does not have ANA, it will not bind and everything will be washed away with no glowing

Homogenous pattern; SLE, drug-induced lupus, autoimmune hepatitis, juvenile idiopathic arthritic, antibodies to dsDNA, histones, nucleosome

Speckled pattern; SLE, sjogren’s syndrome, SSc, other SARDs, antibodies to ENAs, DFS70/LEDFG

Nucleolar pattern; antibodies to RNA and RNP, SSc and other SARDs

Nuclear dot pattern; broad spectrum autoimmune disease

Centromere pattern; antibodies to centromeres of chromosome, CREST syndrome (limit cutaneous SSc)

What is systemic lupus erythematosus (SLE)

Inflammatory disease that affects multiple organs including skin, joints, renal, neurological, and cardiac, anti-ds DNA (lupus-specific), anti-ss DNA, anti-histones and nucleosomes detected by immunofluorescent assay immunoblotting (western blot), EIA

What does systemic lupus erythematosus have antibodies to?

Centromere or nucleolar components, anti-ENA (anti-SM specific for lupus detects by IIF, immunodiffusion, immunoblotting, immunoprecipitation, EIA), anti-RNP, anti-SS-A, anti-SS-B

What plays a key role in rheumatoid arthritis

TNF-alpha plays a key role in process

What organs are affected in rheumatoid arthritis

Joints and bones

What is tested for in rheumatoid arthritis

Rheumatoid factor- IgM autoantibodies reacts with Fc portion of IgG, anti-CCp- autoantibody against cyclic citrullinated peptide and highly specific, ANAs, ESR, CRP, and complement assays

What does graves’ disease cause?

Hyperthyroidism

In graves’ disease what does TRAbs produce?

Autoantibodies to thyroid stimulating hormone (anti-TSHR)

Lab results of graves disease

Low TSH, high FT4, antibodies to TPO and Tg, antibodies to TSHR

What happens in Hashimotos thyroiditis?

Immune destruction of the thyroid gland produces hypothyroidism

Lab results of hashimotos thyroiditis

Normal or high TSH, low free T4, antibodies-TPO, antibodies-Tg

What are autoantibodies directed against in hashimoto’s thyroiditis

Thyroglobulin (anti-thyroglobulin)

What part of the body does myasthenia gravis affect

Neuromuscular junction = weak skeletal muscle

What are antibodies against in myasthenia gravis

Antibodies to acetylcholine receptors and block binding of ACH to its receptor and transmission of nerve impulses that activate muscle, anti-ACHR autoantibodies can be detected

What is affected in multiple sclerosis

Inflammation and destruction of the central nervous system by destroying the myelin sheath

What are antibodies against multiple sclerosis

Against myelin basic protein

Lab findings in multiple sclerosis

Lesions seen on magnetic resonance imaging, increased immunoglobulins in spinal fluid and increased IgG index, oligoclonal bands on protein electrophoresis of CSF

What part of the body is affected in goodpasture’s syndrome

Basement membranes lining the renal glomeruli and lung alveoli

What are antibodies directed to in goodpasture’s syndrome?

Basement membranes

What is Type I diabetes mellitus?

Endocrine disorder characterized by hyperglycemia

What are antibodies directed against in type I diabetes mellitus

Autoantibodies destroy beta cells in pancreas causing insulin deficiency

Laboratory results in type I diabetes mellitus

Increased blood glucose level, elevated HGBA1c, autoantibodies to glutamic acid decarboxylase (GAD), insulinoma antigen 2 (IA-2), islet cell antibodies(ICA)

What part of the body is affected in celiac disease

Affects small intestine and other organs

What autoantibodies form in celiac disease

HLA-DQ2 or HLA-DQ8- gliadin (component of gluten) and DGPs, tissue transglutaminase (tTg IgA), endomysium (EMA)

Mechanism of type I hypersensitivity

Sensitization phase: APCs process allergens and present them to help T cells, helper T cells induce production of allergen-specific IgE, IgE binds to high-affinity receptors on mast cells and basophils

Activation phase:allergen cross-links adjacent cell-bound IgE, mast cells and basophils degranulate, chemical mediators are released and bind to target organs, allergy symptoms are produced

Type I hypersensitivity mechanism

Example of type I hypersensitivity

Allergies

Examples of Type II hypersensitivity

Transfusion reactions, HDFN, autoimmune hemolytic anemia, goodpasture’s syndrome, hashimoto’s disease

Mechanism of Type II hypersensitivity

Triggered by antigen found on cell surface (IgG or IgM, altered self antigen or heteroantigens), antibody binds to macrophages, neutrophils, eosinophils, NK cells, results in cell destruction and lysis

Type II hypersensitivity

Type III hypersensitivity reaction examples

Arthus reaction, serum sickness, SLE, RA, reaction to bee stings, drug reactions, sequelae to infections

Mechanism of type III hypersensitivity

Antigen-antibody complexes precipitate out and deposit in tissues, immune system in overwhelmed, complexes deposit in tissues where they bind complement, immune complex deposition typically occurs in glomerular basement membranes, vascular endothelium, joint lining, pulmonary alveolar membranes, complement binds to complexes in tissues

Examples of type IV hypersensitivity

Infections with intracellular pathogens, skin test for TB, contact dermatitis, hypersensitivity pneumonitis, mycobacterium tuberculosis, mycobacterium leprae, pneumocystsis carinii, leishmania species, herpes simplex virus

Mechanism in type IV hypersensitivity

Delayed cell mediated hypersensitivity, involved sensitized Th1 cells and macrophages, antibody and complement are not involved, Th1 cells release cytokines that attract and activate macrophages, macrophage induce inflammation, cytotoxic T lymph are recruited and destroy target cells, hypersensitivity peaks 48 to 72 hours after antigen exposure