Ii

Question 1

What Gene codes for I antigen

Answer 1

IGnT
B6-cetylglucosaminyltransferase that adds a GlcNAc to type 2 precursor chains
i is blood group collection 207

Question 2

What chromosome is I gene located on?

Answer 2

Chromosome 6

Question 3

i (adult) phenotype

Answer 3

w/o cataracts = I antigen not on RBC but still in tissues
w/ cataracts = no I antigen on RBC’s or Tissues
- occurs in Asiansq

Question 4

What chain is i antigen on?

Answer 4

H2 chains - Type 2 precursor straight unbranched chains

Question 5

What chain is I antigen on?

Answer 5

H3 and H4 chains - Type 2 precursor branched chains

Question 6

How are ABH, Lewis, and P1 related to I structure?

Answer 6

I is the precursor for A, B, H, Lewis, and P1

Question 7

Anti-I and -IH linked to ABO group?

Answer 7

Anti-I is formed in Group O

Anti-IH is formed in Group A

Question 8

H antigen vs I antigen

Answer 8

The H antigen present the less I antigen
Except Group has Lots of I and H antigen
Cord cells have lots of H and very little i

Question 9

Ii antigen charactersitics

Answer 9

I is poorly developed on cord cells and considered I negative and i positive
Enzymes enhance I expression
Resistant to DTT and EGA
Amt of I antigen present is variable

Question 10

What age is I antigen fully developed

Answer 10

By 2 years of age

Question 11

Where else is I found in body?

Answer 11

Amniotic fluid, hydatid cyst fluid, urine, saliva, human milk, leukocytes and plasma

Question 12

Adult i phenotype

Answer 12

occurs 1 in 10,000
Recessive mutation that forms enzyme unable to form branched chains
Often make anti-I

Question 13

Characteristics of i1 phenotype

Answer 13

most i and least I

Anti-I will react with i cord and i2, but not other i1 cells

Question 14

Characteristics of i2 phenotype

Answer 14

Less i and most I

Anti-I reacts with i cord cells and not other i2 or i1 cells

Question 15

Anti-I characteristics

Answer 15

found in nearly all sera if tested at 4C

Classically, Anti-I reacts with all adult cells and weakly with cord cells and adult i cells

Question 16

Auto vs Allo anti-I

Answer 16

If enough autoantibody is attached to patients RBC’s then patient may type as I negative

Question 17

Anti-Lectin

Answer 17

Aplysia depilans

Question 18

Disease associated with anti-I

Answer 18

Mycoplasma pnuemoniae

Question 19

Disease associated with anti-i

Answer 19

Infectious mononucleosis (transient but POTENT)
Reticulosis
Alcoholic cirrhosis
Myeloid leukemia

Question 20

Anti-i characteristics

Answer 20

Rare antibody

stronger reaction with cord cells

Question 21

What are antibodies to compound antigens?

Answer 21

Specificity of antibody is not a mixture of antibodies but both antigens must be present for antibody to react
Ex) anti-IA will react with A cells with I

Question 22

Anti-I(f)

Answer 22

Anti-I(f) reacts with both adult and cord cells

Causes cold hemagglutinin disease

Question 23

Anti-I(D)

Answer 23

Most common form of anti-I
Much stronger reactions with Adult cells and very weak titer with cord cells and i adult cells
Found in adult i people
can be inhibited with human milk

Question 24

Anti-I(T)

Answer 24

T= transitional
Reacts with cord cells better than adult I and adult i cells
Found in Melanesians and Venezuelans

Question 25

Cold auto adsorption

Answer 25

Treat cells with ficin to enhance antibody binding | Time consuming, requires a lot of sample, and patient must not be recently transfused

Question 26

What is RESt?

Answer 26

Rabit Erythrocyte Stroma contains I and i antigens and can be used to adsorbed cold antibody May also adsorb out anti-D, -E, and -K Can't be used for ABO typing because will adsorb out anti-B

Question 27

Characteristics of pathological auto anti-I in CHD?

Answer 27

Reacts at 32C and activates complement at 30-37C Titer is > 500 at 4C and >128 at room temp Will hemolyze enzyme treated cells at low pH Antibody is typically monoclonal or idiopathic

Question 28

Characteristics of benign auto-I?

Answer 28

Reacts at <25C and activates Complement at <25C Titer is < 64 at 4C and <16 at room temp Antibody is polyclonal

Question 29

Pr antibodies

Answer 29

antibodies will NOT react with enzyme treated cells React equally with Adult I, i, and cord cells Isolated membrane SPG's can neutralize antibodies Suspected with enzyme treated cell fail to adsorb autoantibody

Question 30

Gd antibodies

Answer 30

IgM antibody reacts equally with adult I, i, and cord cells Not destroyed by enzymes Antigen is inactivated by neuraminidase

Question 31

Effect of Proteases and Neuraminid on I and i

Answer 31

I and i are enhanced

Question 32

Diseases and Ii concentration

Answer 32

Increased I and i is found in chronic hemolytic disorders and is a sign of stresses erythropoiesis - Thalassemia major - Hypoplastic anemia - CLL - Acute leukemia - Bombay phenotype

Question 33

I substance is found in the following

Answer 33

Urine, Human milk, Saliva