Blood Bank Units #1-2

FDA

regulatory agency, enforces regulations

CDC

Makes reccomendations to OSHA for safety of disease transmission

AABB

voluntary accrediting agency, publishes guidelines, standards for blood banks, quality essentials

OSHA

ensures safe and healthy working conditions

EPA

involved in assessing medical waste

QA

comprises the combined activities performed by an organization to ensure quality of products and services

Document Control

should specify and describe acceptable media, types of docs, record-retention intervals

Record Keeping

if it was not recorded then it never happened

Audit Trail

Internal evaluation that recreates every step in the production and distribution of a unit of blood and its components

Computerized Record Guidelines

traces original entry, person making correction, requires backup method

Validation

a process or system that is checked before implementation. Ensures consistency

Personnel Training

provided during poor performance, procedure changes, and new employee orientation

Root-Cause Analysis

investigation and identification of factors contributing to an error

Recalls

issued by manufacturers to remove faulty products

Calibration

standardizes an instrument for accuracy

Quality Control

tests for accuracy and precision

Preventative Maintanence

maintenance to decraese downtime and enhance reliability

CAP

administers proficiency testing to labs

Universal Precautions

applies to blood, bodily fluids, nonintact skin, and mucous membranes. Not sweat

Radiation Safety

nuclear regulatory commission requires training for all using irradiators

Antigens

molecules that bind to antibodies or T cell receptors

Allogeneic

non-self antigen

Autologous

self antigen

Hapten

partial antigen that require a carrier molecule

Antibodies

glycoprotein made of 4 polypeptide chains joined by disulfide bonds. 2 heavy and 2 light chains

Constant region

determines antibody class. heavy chain

Variable Region

binds the antigen on the antibody. Light and heavy chain

IgG

2 binding sites, 4 subclass, monomer

IgM

10 binding sites, pentamer held together by J chain

Primary Response

first exposure to antigen, lag phase of 5-10 days, IgM dominant

Secondary Response

second exposure to antigen, 1-3 days, IgG dominant

IgG

react at 37 C

IgM

react at 22 C

Complement

series of enzymatic reactions, C3 is central to both pathways, end result cell lysis

Classical Pathway

activated by Ag-Ab complexes

Alternative Pathway

activated by foreign cell surface constituents (bactiera)

Sensitization

antibody binds to antigen, no visible agglutination occurs

Lattice Formation

antibody-coated cells cross-link to form visible agglutinaton

Prozone

antibody excess, false negatives

Postzone

antigen excess, false negatives

Reagnet RBC

commercially prepared, known source of antigen

Patient or Donor RBC

usually unknown source of antigen, blank is tested with commercial antisera to determine id

Reagent Antisera

commercially prepared, known source of antibody

Patient or donor serum/plasma

usually unknown, blank tested with commerical RBC

Reagent specificity

recognition of the antigenic determinant and its corresponding antibody

Reagent Potency

strength of the reaction

Polyclonal Antibodies

made from several different clones of B cells, recognize multiple epitopes

Monoclonal Antibodies

made from single clones of B cells that secrete the same specificity

Monoclonal Antibody Examples

Anti-A, Anti-c, and anti-IgG

D antigen Typing

Rh group system contains several antigens, but this is the most important

High Protein Reagents

Anti-D reagent. contains polyclonal antibodies, 20% bovine albumin

Low Protein Reagents

Anti-D Reagent. contains monoclonal antibodies, 6% bovine albumin

Antiglobulin Test

commercial antibody with a specificity toward human globulins is used to agglutinate antibody coated RBC

Antiglobulin Reagents

IgG and Complement

Direct Antiglobulin Test (DAT)

detects IgG or complement bound in vivo. AHG is added after RBC are washed. Agglutination demonstrates attachment

Transfusion Reaction

donor cells coated with IgG

Hemolytic Disease of Newborn

fetal red cells coated with IgG

Autoimmune Hemolytic Anemia

IgG or C3 on patient red cells

Drug-related mechanisms

IgG-drug complex attached to cells

Indirect Antiglobulin Test (IAT)

detects IgG or complement bound to RBC in vitro

Antibody Screening

detects antibodies with specificity to red cell antigens

Antibody identification

identifies specificity of red cell antibodies

Crossmatch

determines serologic compatibility between donor and patient before transfusion

Antigen Typing

identifies a specific red cell antigen in a patient or donor

False Positives

Red cells are agglutinated before washing step, dirty glassware, improper centrifugation

False negatives

faliure to wash cells, testing is delayed, failure to identify weak rxn, loss of reagent, faliure to add reagent, improper centrifugation, inappropriate red cell concentration

Polyspecific AHG

contains both anti-IgG and anti-C3d antibodies. Derived from polyclonal or monoclonal sources

Monospecific AHG

contains either anti-IgG or anti-C3d, not both.

IgG Sensitized Cells

Used to confirm that a test is negative

Low-ionic strength saline (LISS)

increases rate of antibody uptake

Polyethylene glycol (PEG)

concentrates the antibody in the test environment in LISS

Proteolytic enzymes (papain and ficin)

removes negative charges from the cell membrane reducing zeta potential

Bovine Serum Albumin (BSA)

reduces the repulsion between cells but does not shorten incubation time

Lectins

seed extracts that have specificity toward certain RBC antigen

Gel Technology

uses dextran acrylamide gel particles to trap agglutinated cells

Microplate

A 96-well microtiter plate replaces test tubes.

Solid Phase

uses microplate wells with immobilized reagent. Cells adhere to sides and bottom are positive

Blood Group System

one or more antigen governed by a single gene or complex of two or more closely linked genes

Gene

basic unit of inheritance

Locus

specific site where gene is located on a chromosome

Allele

alternative form of a gene found at its locus

Antihetical

antigens produced by opposite alleles

Polymorphic

multiple alleles at a single locus

Rescessive

gene expressed only when inheritied by both parents

Codominant

equal expression of two different alleles, most blood groups

Dominant

gene expressed over another gene

Amorph

gnee that does not express a detectable product

Independent Segregation

occurs when one gene from each parent is passed to offspring in a predictable way

Independent Assortment

different genes are separately resulting in a mix of genetic material

Linkage

two genes that are in proximity are inherited together

Halpotype

a set of linked genes

Linkage disequilibrium

haplotypes occur at higher frequency then unlinked genes

Xg genes

only found on the X chromosome

Cis

alleles on the same chromosome

Trans

alleles on opposite chromosome

Homozygous

a perosn who inherits identical alleles

Heterozygous

a person who inherits different alleles

Phenotype

physical expression of traits

Genotype

actual genetic makeup

Dosage Effect

homozygous results in double dose (stronger rxn) while heterozygous results in singe dose