MED TECH NOTES Blood Banking

Blood Banking   

Deals with the study of immunologic principles applied in blood group antigens and antibodies. Deals with mechanisms of blood typing & crossmatching (compatibility test and coomb’s test) Detection and measurement of anti body, screening of donors, bleeding techniques

Different Tests: 1. 2. 3. 4.

ABO typing & RH typing Compatibility/ Crossmatching Coomb’s Test/ Anti Human Globulin Test Detection & Identification - Antibody screening - Unexpected antibody and identify 5. Screening of donors 6. Blood components preparation - transfused ABO typing  

Anti- A Anti- B

RH typing 

Anti- D

Major Blood Group    

Type O Type A Type B Type AB

Methods to determine Blood Group- done simultaneously 1. Cell typing (direct typing or forward typing)- determines the antigen(surface of RBC) 2 ways: a) Slide method- 1 drop of red cell, 1 drop of anti A within 2 mins must interpret result: agglutination; over 2 mins= false positive result cause dry na yung mixture

b) Tube method- prepare different red cell suspension; 2-5% red cell suspension wash it 3x with NSS (normal saline solution) to remove anti bodies. - Applicator: stick mix (within 2 minutes, you have to determine the result) - Done in immunology / serology *Agglutination – most conspicuous reaction Uses of commerically prepared anti sera: Anti A- blue because added “thymol blue” Anti B- yellow because added “acriflavine” Anti AB- colorless; no dye added PLAIN SERUM IS COLOR YELLOW Antigen= red cell antibody = serum Reagents are expensive so can prepare own anti sera Source of anti A is derived from serum of Group B Source of anti B is derived from serum of Group A Source of anti AB is derived from serum of Group O Red Cells A (antigen A) B (antigen B) AB (antigen AB) O (none)

Anti- A + + -

Anti- B + + -

Anti- AB + + + -

Blood Group A B AB O

*where there is agglutination with the anti sera, yun yung blood group * other hospitals only use anti A and Anti B; Anti AB is only for confirmation of results * O- most common 45%,A- 40%, B- 10% and AB- 5% 2. Serum Grouping- detect the presence/ absence of anti body by using red cells of known specificity 5% A cells- A antigen 5% B cells- B antigen 5% AB cells- AB antigen 5% O cells- none at all Serum A ( anti B) B ( anti A) AB ( none) O ( anti A; Anti B)

5% A cells (A antigen) + +

5% B cells (B antgen) + +

5% AB cells (AB antigen) + + +

5% O cells (none) -

Blood Group A B AB O

*where there is no agglutination, yun yung blood group Blood type A B AB O

Can receive from A, O (packed red blood cells) B, O (packed red blood cells) A, B, AB, O (packed red blood cells) O (whole blood or packed)

Can give to A & AB B & AB AB only A, B, AB, O (PRBC)

PRBC- removed the plasma where anti A and B are present; RBC- has no antigen Different Blood Group Systems 1. ABO- most common 2. Rh- most common 3. MNSs 4. Kidd 5. Kell 6. Duffy 7. P 8. I 9. Lutheran 10. Lewis 11. Xg  Rh blood group system- absence/ presence of D antigen Different antigens and their anti sera: 1. 2. 3. 4. 5.

D antigen = anti D C antigen = anti C E antigen = anti E c antigen = anti c e antigen = anti e

*anti sera are imported so expensive; hospitals only keep anti D *if +, the antigen is present, if - the antigen is absent *(Rh +) antigen D is present, (Rh-) antigen D is absent * if Rh-, not necessarily na sayo na ang anti D. It is only developed when exposed to Rh+  immune antibodies= not present but can be developed unlike in ABO, naturally occurring siya  Antigen D is the most important and primary antigen in Rh. it is also immunogenic??

Compatibility/ Crossmatching- series of procedure designed to ensure the safety of blood for transfusion PURPOSE: *person with multiple transfusions is prone to transfusion reaction so must check compatibility 1. Ensure maximum benefit to the recipient 2. Prevent transfusion reactions due to antibodies SPECIMENS: -

Fresh, not in activated serum, less than 48 hrs old. Serum/ plasma may be used but serum is preferred over plasma. Plasma causes clots na napagkakaalaman na agglutination Blood samples should not be taken from intravenous tubing lines Both donor and recipient samples must be stored only for a minimum of 7 days * clerical error (wrong label of specimen of patient)= most fatal error. It occurs more often than technical error so must always ask name. Shouldn’t rely on the paper list.....

TYPES OF CROSSMATCH - Major Crossmatch (PSDR) patient serum donor red cell = refers to testing the patients serum against 5% red cell suspension of the donor red cell = to detect whether there are anti bodies in the patient’s serum that can destroy transfused red cells - Minor Crossmatch (DSPR) donor serum patient red cell = refers to testing the donor’s serum against 5% red cell suspension on patient’s red cell = to detect whether there are anti bodies in the donor’s serum that can cause red cells adverse (transfusion) reaction to the recipient Broad Spectrum compatibility Test- most used method of choice Coomb’s Test aka Anti Human Globulin test -

Used to detect incomplete anti bodies or non- agglutinating anti bodies Non agglutinating = IgG ; agglutinating = IgM Most useful and universally applied tests employed in blood banks and immunohematology

2 METHODS: 1. Direct antiglobulin- in vivo sensitization (inside the body)

-

Diagnosis of haemolytic disease of the newborn Investigation of transfusion reaction Diagnosis of auto immune haemolytic anemia

2. Indirect antiglobulin- in vitro sensitization (outside the body)??? - Compatibility testing - Investigation of transfusion reactions - Detection and identification pf unexpected anti bodies - Red cell antigen phenotyping BLOOD DONOR SCREENING -

Procedure is done to decrease risk of blood transmissible diseases by careful examination of the potential donors Examples of diseases: HIV, Hepatitic

DIVIDED INTO 3 PARTS 1. Registration - REGISTRATION FORM: NAME DATE OF BIRTH AGE SEX CIVIL STATUS ADDRESS OCCUPATION (if pilot or driver, can’t go back to work at once) 2. Medical History 3. Physical Examination - CRITERIA FOR POTENTIAL BLOOD DONOR 1. Age: 18-60 years old 2. Weight: 110 lbs. (50kg) can donate 450 mL of blood but if underweight can also donate but less than 450 mL 3. Pulse Rate: 50- 100 beats/ min (can’t shortcut and count 30 secs then x2) 4. Blood Pressure: 90-160 mmHg (systolic) 60-100 mmHg (diastolic) 5. Hemoglobin: 125g/L (12.5g/dL) 6. Hematocrit: 38% TYPES OF DONORS: 1. Volunteer Donor- donates without compensation - R.A 7719 National Blood Services Act of 1994: advocates voluntary donation of blood in the Philippines 2. Paid, Professional, Commercial Donor- people who sell their blood - Before it was Php 45 per pack

- Use iodine to screen to prevent professional donors 3. Replacement Donor- replaces blood for a particular purpose for replacing the unit of blood used by the patient. It depends upon the ruling of the hospital 1 is to 2. 1 unit used replace with 2 units. 4. Directed Donor- donors who give blood for a particular patient 5. Autologous Donor- gives blood for himself - Case to case basis for surgical procedure - If unused can give to other patient - Not for anemic patients or those with iron deficiency COMPONENT THERAPY- transfusion of the specific component needed by the recipient -

May defer the donor permanently if positive for HIV _____________________

Blood Components -

refers to products separated from a single unit of whole blood To prepare different blood components, need REFRIGERATED CENTRIFUGE

1. Whole Blood - Easy to prepare cause its blood taken from donor after screening tests - Contains all cellular components like [RBC, WBC, platelet, anti coagulant] whole blood parts INDICATIONS: *to replace the loss of both RBC and plasma volume in actively bleeding patients (massive bleeding) bawal PRBC 2. Packed Red Blood Cells aka Red Cell Concentrate - Prepared by sedimentation or centrification - Tangal na yung plasma INDICATIONS: *increase oxygen carrying capacity in patients with acute and chronic anemia *for patients who cannot tolerate sudden increase in blood volume; congestive heart failure 3. Granulocyte Concentrate & Leukocyte Concentrate (crossmatched) Indications: *severe neutropenia (decreased white blood cells) *Septicemia or bacterial contamination *myeloid hypoplasia of bone marrow 4. Platelet concentrate Indications:

*severe thrombocytopenia (decrease in platelet count) -one unit 5000-10000 per microliter * Disseminated intravascular coagulation *massive transfusion 5. Fresh Frozen Plasma Indications: *to treat multiple coagulation deficiencies in patients with liver failure, vitamin K deficiency, massive transfusion and DIC (Disseminated Intravascular Coagulation) 6. Plasma – Removed RBC | type Specific na dapat -has small amount of factors V & VIII (coagulation factors) Indications: *treatment of stable coagulation deficiency esp. Factor XI *source of plasma for patients undergoing plasma exchange 7. Cryoprecipitate - also called factor VIII - contains at least 80 units of factor VIII - 50% of the Von Willebrand factor -20% of factor XIII - 200mg of fibrinogen as well as fibronectin INDICATIONS *Von Willebrand’s disease * Hemophilia A * Fibrinogen deficiency *Factor XIII deficiency