Polyagglutination Flashcards
What is polyagglutination?
Agglutination caused by ABO compatible sera due to altered RBC membrane that exposes crytantigens. Polyagglutination does not occur with cord blood sera
What are polyagglutinins?
Naturally occurring IgM antibodies found in most adult sera such as anti-T and anti-Tk
How is polyagglutination detected?
Rarely seen with the use of monoclonal reagents.
Not detected in the crossmatch because it is red cell problem (unless donor is polyagglutinable; rare)
Clinical condition suspected when patient is hemolyzing
DAT and Auto are often negative
What conditions is associated with T activation?
T activation is found in patients with CARCINOMA, malignant breast tissue, septicemia, GI dissorders, and wound infections
Often caused by Pneumococci, Clostridium perfringes, Vibro, and influenza virus
More common in children
May be an early marker for HUS
How does T activation occur?
bacteria produce neuraminidase that cleaves both NANA from SGP and exposes T receptor.
M, N, and Pr antigens are lost
Can create artificial T cells with neuraminidase
Enzyme treatment removes MN so anti-T will not react
What is Th polyagglutination?
Early stage of T activation caused by neurominidase
Found in patients with septicemia assoc. with E. coli, Clostridia, Bacteroides, and Proteus
How does Tk poly agglutination occur?
Bacteria that produce endo-beta-galactosidase remove galactose residues exposing GluNAc on paraglobloside. ↓ ABO, Lewis, Ii, and P1.
Acquired B is often seen w Tk.
Normal paraglobside = Gal-GluGal-Gal-Glc-Cer
What lectins will react with T polyagglutination?
Glycine soja and Arachis hypogaea
What lectins will react with Th polyagglutination?
Arachis hypogaea
What lectins will react with Tk polyagglutination?
Arachis hypogaea and Griffonia simplicifolia
What causes Tk polyagglutination?
Caused by Bacteroides fragilis, Aspergilus niger, and C. albicans
Assoc. w/ GI infection, septicemia and wound inf.
What is VA polyagglutination?
Possibly caused by microbial infection. Depressed H antigens may be caused by a a-fucosidase. Assoc. w/ hemolytic anemia.
What is Tx polyagglutination?
Rare; 1st described in children with pneumococcal infections
What is acquired B?
A1 cells with B like activity due to bacterial deacetylation of the A antigen. Acetyl group removed from GalNAc and galactosamine remains that is similar to the B antigen.
What causes Tn polyagglutination?
An acquired somatic mutation on X chromosome leads to poor synthesis of sialic residues on the MN SGP. M/N reduced.
Lacks B-3-D galactosyltransferase. No terminal NANA and Gal results in exposure of GalNAc that human anti-A will react with.
What are the characteristics of Tn polyagglutination?
Enzyme treated cells will not react because M/N is removed.
May see MF agglutination because only cells from mutated clone are affected
Assoc. w/ leukemia and causes hemolytic anemia,
↓ PLT’s, ↓WBC’s
What lectins will react with Tn cells?
Glycine Soja (reduced Sialc acid) Dolchos biflorus (GalNAc) Salvia sclarea and Salvia horminum
What causes Cad postitive cells?
Inherited autosomal dominate known as Super Sda. Very strong Sda expression on RBC’s is agglutinated by autoantibody in normal adult sera. Cells carry and additional GalNAc M/N SGP glycosylation.
What lectins react with Cad positive cells?
Glycine Soja (reduced GPA) Dolchos biflorus (GalNac) Salvia horminum
What is HEMPAS?
Inherited autosomal recessive disorder. Hereditary erythroblastic multinuclearity with a positive acidified serum lysis test and is caused by congenital dyserythropoietic anemia type II. RBC’s react with anti-I and anti-i. Poly agglutination occurs at low temperature w/ naturally occurring IgM antibody. Abnormal RBC have 2 membranes that have increased susceptibility to complement mediated lysis and have compensated anemia
What lectins will Hempas react with?
Positive acidified serum lysis test ad reacts with Glycine soja
What is NOR?
Autosomal dominate inheritance. Part of P1PK blood group. Have normal P and P1 antigens. Polyagglutination inhibited by hydatid cyst fluid and avain P1 substance.
What is M-hemoglobin Hyde park?
Inherited; Discovered in 12 healthy members of mixed race family in S. Africa. Hemoglobin M-hyde park = methemoglobin
Disalylation results in exposure of GalNAc.
What is Glycine Soja lectin?
Agglutinates red cells that are sialic acid (Anti-T,-Tn,-Cad) deficient
Reacts with enzyme treated cells
Made from Soy beans
