platelets, granulocytes and HLA

Question 1

define refractory

Answer 1

failure to achieve an acceptable platelet count following platelet transfusion

Question 2

describe the expected platelet increase after transfusion for
- 1 apheresis
- 6 whole blood concentrates

Answer 2

both expected to increase by 30,000-50,000/uL

Question 3

define the platelet CC (clinical cound increment)

Answer 3

[(post transfusion PLT count)-(pre transfusion PLT count) * BSA]/number of plts transfused (10^11)

Question 4

describe what happens to platelets while stored

Answer 4

• ATP released
• aggregation
• increase glucose consumption
• increase lactic acid
• decrease in pH = platelets swell

Question 5

how does continuous agitation impact storage

Answer 5

facilitates oxygen transfer in bag to maintain pH

Question 6

describe impact of platelet cold storage (improper storage)

Answer 6

irreversible spherical shape change

Question 7

describe platelet additive solution (PAS)
- alternative storage

Answer 7

reduced plasma stored with platelets

Question 8

describe frozen platelet storage

Answer 8

DMSO stored up to 2 years
- 33% viable

Question 9

describe pathogen inactivation

Answer 9

• UV light or alkylating = impair replication via DNA damage

Question 10

when are platelets tested for bacterial contamination and how

Answer 10

through blood culture or virax
- 3 days after collection

Question 11

define the composition of platelet pheresis product

Answer 11

single donor = platelets 3*10^11

Question 11

define the composition of platelet pool product

Answer 11

4-6 donors with 5.5*10^11/50mL

Question 12

at what pH do platelets need to be maintained

Answer 12

> 6.2

Question 13

list donor requirements for platelet pheresis

Answer 13

• PLT >150,000
• not taking aspirin (2 days def) or plavix (14 day)

Question 14

describe granulocyte cellular product

Answer 14

• simulated with corticosteroids or colony stimulating factor
• directed donation: transfues w/in 24 hrs of collection
• minimum dose of 1*10^10
• must be irradiated by not reduced

Question 15

describe hematopoietic progenitor cellular product

Answer 15

• donor given GH prior to collection
• collected by apheresis or bone marrow
• used to stimulate cellular growth after chemotherapy or immune depression

Question 16

list pre transfusion testing for platelets

Answer 16

• just ABORh type on patient on admission
• match plt label to patient

Question 17

on what chromosome is HLA located

Answer 17

6

Question 18

true or false
HLA co-dominantly express 2 alleles for each locus

Answer 18

true

Question 19

describe class I HLA

Answer 19

• A, B and C
• on all nucleated cells
• heavy alpha chains present to t cells binding CD8
• transplant and platelet testing
• present changes from endogenous attack

Question 20

describe class II HLA

Answer 20

• T and B cells, antigen presenting cells
• paternity testing
• heterodimers of alpha and beta chains
• bind CD4
• present changes from exogenous attack

Question 21

when is HLA crossmatch ordered

Answer 21

• platelet match
• recipient plasma and potential donor product

Question 22

when is an HLA antibody screen ordered

Answer 22

• HLA screen aganst known cells to determine if refractory

Question 23

when is HLA match used

Answer 23

• platelets and stem cells typed
• B< or large organ transplant

Question 24

describe cross reactivity

Answer 24

• CREG
• if reactive to one antigen in group, reactive to all antigens in group

Question 25

what 4 methods are used for HLA testing

Answer 25

• ELISA
• flow
• molecular
• microlymphocytotoxicity

Question 26

which diseases are HLA of increased importance

Answer 26

• diseases with specific HLA linked to disease
• ankylosing spondylitis, celiac, narcolepsy, RA