Immunohematology (Laboratory)

IMMUNOHEMATOLOGY (laboratory) TOPIC: Blood Typing TOPIC SUB-TOPIC SUB SUB-TOPIC Blood Typing ●​ Laboratory procedure performed to detect or identify unknown antigen or antibodies using commercially prepared typing sera and laboratory prepared known red cell suspension. ●​ 2 Procedures: 1. Forward Typing 2. Reverse Typing Note: ●​ Kapag gagawa ng red cell suspension, make sure na papalitan ito after 24 hours. Forward/Direct/Cell Grouping ●​ To identify unknown antigen ●​ Specimen is red cell suspension of patient ●​ Reagent used is commercially prepared typing sera Anti- A Typing Sera ●​ Used to detect A antigen ●​ Components 1.​ “B” Serum – Source of monoclonal anti-A antibody. 2.​ Dye – Blue (Patent Blue, Methylene Blue, Thymol, Bromphenol) 3.​ Sodium Azide (0.1%) – Act as a preservative with antimicrobial properties Anti-B Typing Sera ●​ Used to detect B antigen ●​ Components 1.​ “A” serum – Source of monoclonal anti-B antibody 2.​ Dye – Yellow (Tartrazine, Acriflavin) 3.​ Sodium Azide (0.1%) – Act as a preservative with antimicrobial properties Anti-AB Typing Sera ●​ Used as Quality Control for anti-A and anti-B ●​ Used for subgrouping of weak A and B antigen ●​ Components 1.​ “O” Serum – Source of monoclonal antibody 2.​ No dye 3.​ Sodium Azide (0.1%) – Act as preservative with antimicrobial properties Reverse/indirect/Serum Grouping ●​ To identify unknown antibodies ●​ Specimen is serum of the patient ●​ Reagent used is laboratory prepared known red cell suspension Known A RCS ●​ Used to detect anti-A ●​ Components 1.​ “A” RBCs (A and H Antigen) 2.​ NSS - Physiologic suspending or washing solution; Tomato red; Usually 2 to 5% concentration Known B RCS ●​ Used to detect anti-B ●​ Components 1.​ “B” RBCs (B and H Antigen) 2.​ NSS – Physiologic suspending or washing solution; Tomato red; Usually 2 to 5% concentration Known O RCS ●​ Used as QC for anti-H ●​ Should give negative reaction ●​ Positive known “O” RCS is seen in the following: 1. Bombay (Oh) Phenotype 2. Rouleaux formation 3. Technical error Methods of Blood Typing Tube Method ●​ Routine Blood Typing ●​ Forward/Reverse Slide Method ●​ Rapid/Bedside BT Forward edrian p. ●​ Centrifugation is required ●​ The interpretation can be up to 1 hour BT A Substance B Substance H Substance A, H, Se “A” secretor ↑↑ None ↑ B, H, Se “B” secretor None ↑↑ ↑ A, B, H, Se “AB” secretor ↑ ↑ ↑ H, Se “H” secretor None None ↑↑ Genes ●​ The interpretation is within 2 minutes ●​ Neonatal and ICU patients Blood Typing Blood Type Anti-A Anti-B Anti-AB A cells (A,H) B cells (B,H) D cells (H) O (H) – – – + + – A (A,H) + – + – + – B (B,H) – + + + – – AB (A, B,H) + + + – – – Notes: ●​ The first 3 columns (orange) after the blood type, is forward blood typing. ●​ The last 3 columns (yellow) is reverse blood typing. ●​ Sa reverse typing, kung saan siya nag-positive/agglutinate, hindi iyon ang blood type niya. Kaya tinawag na reverse. ●​ Lahat sila ay nagrereact sa H substance dahil lahat sila ay may H substance. Mas marami at mataas ang reaction kay H substance. Test for ABH Soluble Substance Saliva Neutralization Test Principle ●​ Agglutination-inhibition Positive Rxn ●​ No agglutination Negative Rxn ●​ With agglutination Reagents ●​ Anti-sera (Anti-A, Anti-B) ●​ Lectin (Anti-H) ●​ Known RCS (Known A, Known B, Known O) Specimen ●​ Saliva ABH Soluble Substance 3 Genes 1. SeSe (Secretor Gene) 2. H gene (Secretor Locus Gene) 3. ABO Gene SOP 1.​ Saliva must be heated at 56°C for 30 minutes prior to testing to inactivate salivary enzyme 2.​ Saliva must be diluted with NSS before use to decrease non-ABH soluble glycoproteins present in the sample to avoid false reaction. Saliva Neutralization Test ●​ Lahat ng blood type ay may secretor, nagkakaiba iba sa sinisecrete. Without Saliva A cell B cell O cell Anti-A + Agglutination – Agglutination – Agglutination Anti-B – Agglutination + Agglutination – Agglutination Anti-H + Agglutination + Agglutination + Agglutination edrian p. Ex. Patient: “B” Secretor With Saliva A cell B cell O cell Anti-A + Agglutination – Agglutination – Agglutination Anti-B – Agglutination – Agglutination – Agglutination Anti-H – Agglutination – Agglutination – Agglutination Indication: (+) for agglutination-inhibition Ex. Patient: “AB” Secretor With Saliva A cell B cell O cell Anti-A – Agglutination – Agglutination – Agglutination Anti-B – Agglutination – Agglutination – Agglutination Anti-H – Agglutination – Agglutination – Agglutination Indication: (+) for agglutination-inhibition ●​ Dito ang tinetest ay yung red cell ng patient, with addition of saliva ay na-neuneutralize siya. ●​ Red font, naging negative agglutination nung nadagdagan ng saliva, compared sa without saliva. ●​ The indication is that the patient is positive for agglutination inhibition. edrian p.