cryoglobulins and streptococcus testing

cryoglobulins

abnormal proteins that precipitate when cooled and dissolve when heated

-auto-immune type rxn

cold saline

what precipitate is resuspended in for protein electrophoresis

gamma

region of protein electrophoresis to focus on in cryoprecipitation

type I

-monoclonal

-one peak on prot electrophoresis

-IgM, IgG

-multiple myeloma (IgG), Waldenstrom’s macroglobulinemia (IgM), lymphomas, leukemias, B cell lymphoproliferative diseases

IgM, IgG

Ab can be elevated in type one cryoglobulinemia

monoclonal

type I cryoglobulinemia

peak

graph feature in gamma region with type I cryoglobulinemia

type II

-mixed

-2 or more Ig elevated, one is monoclonal

-inc in total antibody and peak

-”hump and peak”

-RA, SS, lymphoproliferative diseases, connective tissue diseases

mixed

Ig elevated in type II cryoglobulinemia

hump and peak

graph feature in gamma region with type II cryoglobulinemia

type III

-polyclonal

-no monoclonal pattern → inc in Ig

-SLE, infections (hepatitis, IM, CMV)

hump

graph feature in gamma region with type III cryoglobulinemia

cryoglobulinemia

-many asymptomatic

-symptoms induced by cold

-Raynaud’s

-pain, purpura, ulceration, skin sloughing, bleeding

-T of precipitation more important than amount

temp

the temp/amount of precipitation in cryoglobulinemia is more important

GAS pyogenes

-gram pos cocci

-bacitracin: S

-throat and skin inf

-produces streptolysin O and DNase B

-can result in rheumatic fever or acute glomerulonephritis

streptolysin O

GAS pyogenes hemolysin

rheumatic fever

-follows strep pharyngitis

-results in endocarditis (Ab produced from strep inf recognize proteins similar to mitral valve → cross rxn → endocarditis)

acute glomerulonephritis

-follows strep pharyngeal or pyodernal inf

-edema, hematuria, inc BUN, inc creatinine

-urine: WBC, RBC, casts

anti streptolysin O Ab (ASO)

-increased levels following severe GAS pyogenes inf

-inactivated when oxidized

-lytic when reduced

-inhibits hemolysis

-measured in neutralization procedure, agglutination procedure, or rapid Ag test

neutralization

Ag possesses biologic activity that is inhibited with addition of Ab 

active (lytic), reduced

streptolysin O is active/inactive when reduced/oxidized

inactive

streptolysin O is active/inactive when oxidized

ASO neutralization

-incubate serum + streptolysin O reagent

-sheep RBCs added

-sample is spun and read for hemolysis

-last tube with no hemolysis is titer

streptolysin O reagent

added to patient serum to detect ASO Ab

sheep RBCs

added to incubated serum+streptolysin O reagent for hemolysis reading

not

hemolysis is/not seen with ASO Ab presence in patient serum

is

hemolysis is/not seen with no ASO Ab presence in patient serum

<85

normal ASO Ab level in preschool and adult populations (Todd units)

<170

normal ASO Ab level in pediatric populaiton (Todd units)

inc

ASO titer inc/dec in pediatric population compared to preschool and adult populations

high

ASO titer is high/low in glomerulonephritis and rheumatic fever

indirect agglutination

-latex particle coated in streptolysin O

-detects ASO Ab in patient serum based on visible rxn