immunology rotation

what reactions would you expect you see with guinea pig cells and beef red blood cells for the davidsohn antibody test with an EBV positive pt?

agglutination with guinea pig cells and no agglutination with beef RBCs

what antibodies are absorbed by the guinea pig cells and beef RBCs in the Davidsohn heterophile antibody test?

guinea pig cells absorb Forssmann Ab, while beef cells absorb EBV Ab

what is the indicator used for the Davidsohn antibody test?

sensitized horse/sheep RBCs

what is the source of heterophile antibodies?

activated polyclonal B cells during the acute phase of EBV infection

why are EBV antibodies present for life but not heterophile antibodies?

because as time passes, the concentration of antibodies decrease to be too low to detect for heterophile antibodies; however, IgG EBV Ab will still be present due to memory

what serological tests indicate a positive infectious mono case?

EBNA or VCA antibodies

what two tests are treponemal-specific? what two tests are non-specific?

specific: FTA-Abs and TP-PA

non-specific: RPR and VDRL

list the five components of an RPR test and their purpose

• cardiolipin= antigen

• lecithin= emulsifier

• cholesterol= increased flocculation

• choline chloride= inactivates complement

• charcoal= makes reaction macroscopic

what can cause a false positive for RPR?

autoimmune disease, other infectious diseases, yaws, pinta, bejel, Lyme disease, pregnancy

what can cause a false negative for RPR?

prozone effect, too early to detect, latent syphilis, and treated syphilis

why does VDRL not use charcoal?

microscope is used to view reaction instead

what does a false positive look like for FTA-ABs?

beaded fluorescence that is not homogenous

does a negative RF test indicate the absence of RA? why or why not?

no, may be too low to detect

what clinical presentation is characteristic of RA in comparison to SLE?

pannus formed starting at small joints that gradually becomes asymmetrical and lose function

what test is used to confirm RA?

anti-CCP

why is C3 and C4 decreased in RA?

because complement components are consumed due to inflammation

describe the five ANA patterns: homogenous, rim, speckled, nucleolar, and centromere

• homogenous= smooth color over entire nucleus

• rim= bright color around entire rim of nucleus

• spleckled= starry sky fluorescence with some gaps

• nucleolar= 1-5 spots

• centromere= 46 discrete spots

can cytoplasmic staining be present at the same time as ANAs?

no

correlate the ANA patterns with their autoimmune diseases: homogenous/rim, speckled, nucleolar, and centromere

• homogenous/rim: SLE

• speckled: SLE, Sjogren’s syndrome

• nucelolar: PSS

• centromere: CREST

what ANA antibody is associated with PSS?

Scl-70

what ANA antibody is associated with SLE?

anti-Smith

what does a positive anti-DS DNA look like?

stained kinetoplast

what are the CDC v. ARC requirements for HIV detection?

CDC= 2 bands at least for p24, gp41, and gp120/160

ARC= 3 bands, one of POL, GAG, and ENV

what are the CDC v. ARC requirements for indeterminate HIV?

CDC= 1 band

ARC= 2 bands

what antibodies are associated with Wegener’s granulomatosis?

C- ANCA (anti-neutrophil cytosplasm antibody)

what antibodies are associated with Hashimoto’s?

anti-TPO, anti-TG, and anti-thyroid microsomal

what antibody is associated with Grave’s?

TSH receptor antibody

what antibody is associated with chronic autoimmune hepatitis?

anti-smooth muscle

what antibody is associated with primary biliary cholangitis?

anti-mitochondrial

what titer is required to make a diagnosis of a certain ANA pattern? why?

1:40 because there may be low positive levels in normal patients

what is the proper collection/handling procedure for detection of cryoglobulins?

remove serum from RBCs to allow clotting, split serum so that hald is maintained at 37C for the control and the other half is maintained at 1-4C, if positive cryoglobulins will precipitate in the cold and is reversible when warmed

what conditions are associated with cold agglutinins?

cryoglobulinemia, Raynaud’s phenomenon, Mycoplasma pneumoniae, and lymphoid malignancies

what condition is associated with Raynaud’s syndrome and anti-Scl 70?

PSS

what is the clinical presentation of Wegener’s granulomatosis?

respiratory issues and glomerulonephritis

what lab findings are associated with MS?

increased total protein and myelin basic protein in CSF; oligoclonal bands

what antibody is associated with Goodpasture’s syndrome?

anti-glomerular basement membrane

differentiate between the four types of hypersensitivity

• type 1: anaphylaxis

• type 2: cell damage

• type 3: immune complex formation

• type 4: delayed reaction

list some examples of type 2 hypersensitivity

hemolytic anemia, myasthenia gravis, ITP, and transfusion reaction

what are some examples of type 3 hypersensitivity?

arthus reaction, serum sickness, glomerulonephritis from SLE, and innocent bystander RBC destruction

what are some examples of type 4 hypersensitivity?

• PPD reaction

• contact sensitivity

• transplant rejection

• hypersensitivie pneumonitis

what is the clinical presentation of Bruton’s XLA? what are the lab values?

• clinical presentation: frequent bacterial infections, lymphatic organs are small/absent

• lab values: decrease or absence of all antibody classes with a decrease of B cells

what is the clinical presentation of selective IgA deficiency?

recurrent infections at secretion sites with decreased serum and secretory IgA

what is the primary defect of CVID (common variable immunodeficiency)?

defect in B cells differentiating into plasma cells

what is the clinical presentation of IgG subclass deficiency?

increased vulnerability to encapsulated organisms, normal total IgG, IgM, and IgA normal

what condition is indicated by increased susceptibility to pyogenic bacteria like Neisseria?

complement deficiency

how is GVHD prevented?

irradiation of RBCs and platelets

what condition is indicated by a reduced size/lack of thymus at birth, decreased to absent T cells, and cardiac/chest/neck issues?

DiGeorge’s abnormality (thymic hypoplasia)

what condition is this: inability to form pus with incrreased neutrophils, impaired resolution of infection, and delayed loss of umbilical cords?

LAD

how is chronic granulomatous disease detected?

NBT and DHR

differentiate between hyperacute, early, acute, and chronic rejection

• hyperacute: occurs within 24 hours, due to ABO and MHC-1 antibodies

• early: occurs within 5 days, due to 2nd exposure to HLA Ag

• acute: occurs within a few weeks, due to CD4 and CD8 cells that fully infiltrate graft

• chronic: due to humoral immunity

what are the negative acute phase reactants?

albumin, pre-albumin, and transferrin

what are the normal reactions of the following specimens for a complement fixation assay: complement control, sensitized RBC control, antigen control, antibody control, and positive result

• complement control: lysis

• sensitized RBC control: no lysis

• antigen control: lysis

• antibody control: lysis

• positive result: no lysis

what Ig class is capable of crossing the placenta, is most abundant, participates in the secondary immune response, and reacts best at body temp?

IgG

how does MS affect the IgG/albumin ratio?

increases it without having increased albumin

what lab values are specific to MS?

increased myelin basic protein, positive anti-myelin/neuronal Ab, and oligoclonal bands

what indicates a positive result for ASO neutralization?

no hemolysis

why is anti-ss DNA testing not performed?

too many false positives

how does Wharton’s jelly affect RPR?

may cause a false positive

what reactive values indicate an acute hepatitis b infection?

positive HBsAg, HBeAg, anti-HB core IgM and total

what value is most specific to active Hepatitis B infection?

HBeAg

what values indicates a past Hepatitis B infection?

positive anti-HBsAg, anti-HBeAg, and anti-HB core

what values indicate a chronic hepatitis B infection?

positive anti-HBsAg and HB core total

what causes Waldenstrom’s macroglobulinemia?

overproduction of IgM antibodies

what are the earliest detectable markers of Hepatitis B infection?

HBsAg, HBeAg, and anti-HBc

what Ig class(es) is/are capable of fixing complement?

IgG and IgM

what is the ONLY Ig class that is in the form of a dimer?

IgA

what is the only Ig class capable of crossing the placenta?

IgG