Blood Bank Exam 1

In acquired (adaptive immunity) a specific response is enlisted. The cells involved have the ability to recognize the specific agent and mount a powerful response

• Innate (natural immunity) is nonspecific and provides the first line of defense against invading pathogens
• skin
• mucous membranes
• pH in skin
• acid in stomach

• Elicited on first exposure to a foreign antigen
• Lag phase of 5-7 days before antibody can be detected in the host
• Following the lag period, antibody levels rise, plateau, and then decline
• IgM antibodies are produced first then IgG are producted

Also called anamnestic response because there are memory cells

Happens within 1-2 days of Ag exposure with significant amount of antibody production

Principal antibody is IgG, unlike primary response in which IgM is the principal antibody

1,000 times more antibody and slow decline

• Goodness of fit
• Strength and rate of reaction
• Size, Shape, and Charge
• Affinity: The strength of binding between a single antibody and epitope of an antigen
• Avidity: The overall strength of reactions between several epitopes and antibodies

Epitope made of sugar and lipids

The concentration of antibody exceeds the antigen concentration

• Maximum agglutination occurs when the concentrations of antigen and antibody are in the zone of equivalence
• Same amout of antibody and antigen

The concentration of antigen exceeds antibody concentration

• 4+ red cell button is a solid agglutinate, with a clear supernatant background
• 3+ red cell button breaks into several large agglutinates, with a clear background
• 2+ red cell button breaks into many medium sized agglutinated, clear background, no free RBC
• 1+ red cell button breaks into many small clumps barely visible macroscopically, background is turbid with many unaggutinated red cells
• 0 no agglutinated red cells visible, red cells are observed flowing off the red cell button during the process of grading

First class of antibodies produced by B cells or plasma cells when an Ag is encountered

Pantamer shape, 5 units held together by J chains

Can agglutination of red cells in saline at room temp

Constitutes 5%-10% of total serum antibody

Consists of a single four chain unit

Does not agglutinate red cells in saline

Reacts optimally at 37 degrees C

Can cross the placenta and cause HDFC

Makes up 80% of Ab concentration in the serum

Heavy chain constant region has the function of the class. The variable region is unique and gives it specificity

Detect IgG antibodies on the red cell. Differ between direct and indirect

• Identify red cells that have been sensitized to IgG or complement in vivo
• cells must be washed to remove excess antibody so it doesn't neutralize the AHG (Coombs) reagent
• No incubation necessary because the reaction has already occured in vivo

• Designed to detect in vitro sensitization of red cells
• Two step method by which serum is incubated at body temp (37 degrees) with a red cell source allowing for binding of antibody
• Excess antibody is thoroughly washed and the AHG reagent is added
• Aggulitination indicates a positive result

• A created clone that contains antibodies of a defined specificity
• Monoclonal antibody is produced in vitro

• Usually derived from the injection of animals or humans with purified antigens
• Polyclonal product contains several clones of B-cell antibody

• If a high protein anit-D is used then a Rh control required
• This is to verify positive reaction
• Make sure it is not caused by some additive or reagent
• This is the reason to use monoclonal
• If there is a positive reaction with anti-D and the D control is also positive then the test is invalid

Polyspecific AHG reagents are used primarily in direct antiglobulin testing (DAT) and contain antibodies to both IgG and C3d

Monospecific reagents are preparedd by separating the polyspecific products into either IgG, AHG, or C3d AHG

AHG is commercially available as polyclonal or monoclonal serum based

• Used in antibody screen tests
• Obtained from type O individuals
• Available as two or three vial sets
• FDA requires that the cells detect the most clinically significant antibodies

Serologic testing determines the presnece or absence of antigens on red cells

The phenotype is the physical expression of inherited genes

More specifically the antigens found on red cells

The actual genes inherited from each parent

Can be inferred only from the phenotype

Family studies are required to determine the actual genotype

Predicting the genotype from a phenotype is important in paternity studies or when determining a fetus' probable phenotype

• Examination of family history
• Allows the important elements of patterns to become more visibly apparent
• Can illustrate the difference between genotype and phenotype

Illistrate the probabilities of phenotypes from known or inferred genotypes

Figuring out blood types

Refers to different blood system alleles from each parent (AO)

Both parents contributed the same gene, giving a double dose of antigen (AA, BB)

Exchange of genetic material during meiosis between chromosomes

• Ensures the safety and efficiency of blood, blood components, and testing reagents
• Requires licensing of manufactureres and products
• Regulates labeling and facilities
• Penalties for violation
• FDA inspections

• OSHA passed by congress in 1970
• Defines biosafety levels based on potential exposure to infectious material
• Ensures a safe, healthful work environment
• All accidents must be reported

• Introduced in 1987
• Introduced to reduce the risk of occupational exposure to blood borne disease
• Treat all substances are potentially infectious

Became involved in the assessment of medical waste in 1988

Required to determine types, numbers, and sizes of generators of medical waste in the US

Examines present or potential threat of medical waste to human health and the environment

DOT regulates diagnostic materials and etiologic agents shipped between states and foreign countries

Governs all ground transportation

Accrediting agency by which orginizations elect to be inspected and accredited

Blood bank included in inspection

Safety requirements incorporate general safety, hazardous chemicals, and equipment

Voluntary

Standards for blood bank and transfusion services, provides the basis for inspection and accreditation

High standards

Safety is a large component of the inspection process

Voluntary

• Provides peer reviewed accreditation for labs
• Recognizes accreditation by CAP as equivalent to it's standards
• Includes inspection and observation of safety compliance
• Uses comprehensive checklist