Serology Tests for Diseases, Autoimmune, Tumor Markers

treponemal tests

1. darkfield microscopy

   a. for motile org, in 1ry & 2ry lesions

2. fluorescent trep Ab absorption test (FTA-Abs)

   a. react serum w Nichol’s strain of T. pallidum

3. T. pallidum immobilization test (TPI)

   a. rgt live T. pall immobilized by pt Ab = expensive

4. microhemagglutination assay for T. pallidum (MHA-TP)

   a. if Ab → agglutination

nontreponemal tests (reagin)

1. VDRL: venereal dz research laboratory

2. rapid plasma reagin test (RPR)

VDRL

microflocculation

Ag = cardiolipin + lecithin + 0.9% cholesterol

Ab (reagin) = IgM or IgG directed against damaged tissue or org

serum req heat inactivation

test of choice for screening CSF

false pos in malaria, SLE, RA, hepatitis, pneumonia, aging, IM

RPR

microflocc & coagglutination of charcoal particles

more sensitive, less specific than VDRL

Ag = cardiolipin + charcoal

no heat inactivation needed

black clumps form in reactive test

false pos - same as VDRL

syphilis test sensitivity

1ry stage

• FTA-Abs (all stages)

• RPR

• VDRL

2ry — all tests equally sensi

late stage

• FTA-Abs, MHA-TP, TPI = equal sensi

• reagin tests = poor sensi

syphilis work up

rheumatoid arthritis (RA)

production of IgM or G Ab directed against IgG

dx req radio, clin, and lab findings

RA lab find

1. high titers of rhematoid factor

2. low titers of complement

3. pos anti-cyclic citrullinated peptide (anti-CCP)

RA screen & confirmation

RF screen

• test for serum IgM

• pos = agglutination

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confirmation: anti-cyclic citrullinated peptide assay (anti-CCP)

• ELISA

• allows earlier dx

celiac disease (celiac sprue)

hypersensi to gliadin (protein component of gluten) found in grains

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lab find

• tissue transglutaminase Ab (best) (tTG-IgA/G)

• endomysial AB (EMA-IgA)

• antigliadin Ab (AGA-IgG/A)

infectious mononucleosis (IM) screen

caused by EBV

screen for heterophile Ab

• rapid diff slide test

• 2 serum aliquots, absorb one w guinea pig or horse kidney cells and other w beef rbc

• react each aliquot w sheet or horse rbc (indicator)

• pos for IM = greater agg in beef rbc absorbed serum

• false pos: leukemia, CMV, Burketts lymphoma, RA, viral hepatitis

or

rapid ELISA slide test

IM confirmation

EBV specific Ab testt

a. immunofluorescent assays for IgM & G anti-viral capsid Ag

• anti-VCA - IgM or G

• anti-EA

• anti-EBNA

current/recent infn =

• IgM anti-VCA;

• anti-EA;

• IgG anti-VCA w/o anti-EBNA

past infn = anti-EBNA or IgG anti-VCA w/o IgM anit-VCA

Streptococcus Group A infn: Streptozyme

Streptozyme = slide agglut test to screen for Ab to 5 Ag

• Ag on rgt srbc: streptolycin, streptokinase, DNase, NADase, hyaluronidase

• pt serum + rgt srbc → agglut

GAS anti-DNase- B test

high specific neutralization test

better than ASO tests for cases of glomerulonephritis (anti-streptolysin O is often not produced in GNitis)

DNase B rgt hydrolyzes DNA-methyl green conjugate rgt → green → colorless

so if anti-DNase B in pt serum → rgt neutralized → green color persists → grade from 2+ to 4+

AIDS sero tests

HIV-1 retrovirus attacks CD4 cells (T helper & macrophages)

T helper to T suppressor ratio is dec

clin manifestations → pneumococus pneumonia, Kaposi sarcoma, reccurent infns

screen: ELISA for HIV1 Ab

confirm: Western blot (pos if bnads for p24, gp41, and gp120 or gp160 present)

Cytomegalovirus (CMV) includes __

Herpes virus

• usually causes asympto infn

• may be serious in i-compromised pt & infants rec’ing tx

  • presence of Ab doesn’t present re-infn

HAV test

anti-HAV (IgM) = recent acute Hep A infn

HCV test

anti-HCV = Hep C infn

order of HBV

HBsAg

HBeAg

anti-HBc

anti-HBe

anti-HBs

(surface, envelope, ANTI-core, env, surface)

if pos HBsAg and HBeAg

acute HBV infn, highly contagious

if hbsag, hbeag, anti-hbc

chronic HBV, carrier state

if have 3 anti-HB everything

immunity to HPV due to past infn

if only pos for anti-HBs

immunity to HBV due to vaccination

multiple sclerosis

autoAb to myelin sheath of nerves or myelin basic protein

oligoclonal IgG bands in CSF but not in serum

Grave’s dz

autoAb for receptors for TSH

Goodpastures dz

autoab to basement membrane (kidney, lung)

Hashimoto’s thyroiditis

autoab to TPO or microsomal

Myasthenia Gravis

autoab to acetylcholine receptors at neuromusc jxns

rheumatoid arthritis autoab to

IgG (Fc) - 19s anti-IgM autoab = Rheumatoid factor

Sjogren’s syndrome autoab to

salivary duct / tear duct

chronic granulomatous dz dysfxn

ineffective phagocytosis

Chediak-Higashi syndrome dysfxn

impaired neutrophil fxn

DiGeorge’s syndrome

T cell defic (absence of thymus)

Wiskott-Aldrich syndrome

partial combined immunodefic

AFP

cancer of liver, ovary, testes (teratoblastoma)

CEA

colon, breast, lung

CA-15-3, BR 27.29, HER2/neu

breast

CA 125

ovary

CA 19-9

pancreas

estrogen/progesterone receptors = tumor marker in

breast cancer

PSA

prostate