Ih Discussion Outline (midterms).docx

MAJOR BGS: RH (7 TH AND 8 TH MEETING) OBJECTIVES: At the end of this unit, the learners must be able to: 1. discuss the discovery of the Rh-hr system; 2. explain the nomenclature of the Rh-hr system; 3. compare and contrast the genetic pathways for the inheritance of the Rh antigens to those of ABO; 4. discuss the significance of the RH phenotypes; and 5. identify the techniques in Rh grouping.

A.

Historical Perspective a. Before 1939 - Morbidity and mortality in ABO compatible transfusions b. Levine and Stetson – antibody from mother c. Landsteiner and Weiner – antibody from guinea pigs and rabbits transfused with rhesus monkey RBCs d. Levine and co-workers – said the two antibodies are the same e. Renaming to anti-LW f. 1940’s – 5 antigens g. 50 different specificities

B.

Inheritance a. Chromosome 1p36.11 b. Codominant c. RHD and RHCE d. Polymorphic e. Gene codes for the antigen or blood factor itself (Depends on the terminology)

C. Nomenclature and Terminology a. Postulated Genetic Mechanism i. Fisher-Race: The DCE terminology 1. Closely-linked genes: D, d, C, c, E, e 2. Antigens: D, d, C, c, E, e 3. “d” represents the absence of D antigen 4. Disadvantages: Cannot report 5. Newer Rh antigens 6. Rhmod and Rhnull ii. Wiener: The Rh-Hr terminology

1. Rh gene produces at least 3 factors within an agglutinogen 2. Fisher-race can be converted to Wiener b. Presence or absence of Ag i. Rosenfield and Coworkers: Alpha/Numeric Terminology 1. Rh1 – D 2. Rh2 – C 3. Rh3 – E 4. Rh4 – c 5. Rh5 – e a. Ex: Rh: 1, 2, 3, -4 Rh: 1, 2, 3, -4, -5 c. Working Party on Terminology for Red Cell Surface Ag i. ISBT: Numeric Terminology D.

Antigens A. Transmembrane polypeptides B. Non-glycosylated proteins C. Highly immunogenic

D. E. F. a. b. c. d.

D is most potent D>c>E>C>e Weak D (Du phenotype): Genetic weak D C in Trans with D Partial D (mosaic) – must be given Rh (D) negative Del

E.

Antibodies A. Immune antibodies B. IgG class

F.

Clinical Significance A. Delayed HTR B. HDFN (especially on the 2nd pregnancy), becomes severe in ABO compatible pregnancies i. Etiology 1. Destruction of RBCs of the fetus by antibodies produced by the mother 2. IgG class 3. GOOD - To provide immunity against pathogens 4. BAD – if IgG is directed against RBCs, fatal

ii. Factors affecting severity 1. Antigenic exposure and antigenic sites 2. Host factors 3. Immunoglobulin class a. IgG transport begins in 2nd trimester b. Efficiency: IgG1 and IgG3 > IgG2 and IgG4 4. Antibody specificity

5. Rh > Kell > others 6. Influence of ABO group iii. Diagnosis: 1. Acid elution method for fetal hemoglobin (transplacental hemorrhage) 2. Amniocentesis and chorionic villi sampling 3. ABO and Rh testing 4. Antibody screen 5. Antibody identification 6. Paternal phenotype 7. Amniocyte testing 8. Antibody titers 9. Elution and DAT iv. Pathogenesis 1. Hemolysis 2. Erythroblastosis fetalis 3. Severe anemia 4. Hypoproteinemia 5. Cardiac failure 6. Generalized edema, effusions and ascites (hydrops fetalis) 7. Bilirubin (kernicterus)

8. Decreases upon delivery but persists several days up to weeks after delivery (half-life of IgG is 25 days) v. Management 1. Rho gam/Rh Ig 2. Exchange transfusion 3. Intrauterine transfusions 4. Premature delivery 5. Exchange transfusion 6. Phototherapy

G. Laboratory Methodology A. Reagents a. Saline-based b. High protein-based c. Low protein-based d. Chemically modified e. Monoclonal f. Blends of monoclonal H.

Rare phenotypes A. Cw B. f(ce) C. rhi(Ce)

D. E. F. G. H. I. J. K. L.

G Rh:13, Rh:14, Rh:15, Rh:16 Hro Rh:23, Rh:30, Rh:40 Rh:33 Rh:32 e Variants V, VS Deletions

OTHER BGS (9 TH AND 10 TH MEETING) Objectives: At the end of this unit, the learners must be able to: 1. explain the importance of other blood group systems to blood transfusions; and 2. characterize the blood group system disease associations;

Relative Importance of BGS is determined by: 1. Frequency of antibodies 2. Characteristics of antibodies a. Subclass

b. Thermal range c. Ability to fix complement d. Capacity Tabulation of OBGS: ISBT SYMBOL

CS

KEL DUFFY JK LU

LE I M&N

Yes Yes Yes Lua – No Lub – Yes No No No

S&s

Yes

Ab Optimal Reaction Effect of Class Temp phase Enzymes in ºC IgG 37 AHG No effect IgG 37 AHG Destroyed IgG 37 AHG Enhanced IgM RT RT No effect IgG

37

AHG

IgM IgM IgM

RT, 37 RT 37

IgG

37

AHG RT RT AHG AHG

• Inactivated by enzymes – Duffy – MNS – Xga • Enhanced by Enzymes

Enhanced Enhanced Destroyed Variable

– – – – – –

Rh Kidd Lewis P I ABO

Note:  See also accompanying excel file on OBGS. LEUKOCYTE ANTIGENS (11 TH MEETING) At the end of this unit, the learners must be able to: 1. comprehend the concept of human leukocyte antigens; and 2. become aware of the relevance of these antigens in blood transfusion. A. Historical Perspective a. Patients who have been previously transfused have alloantibodies b. Alloantibodies were directed against alloantigens not present in recipient c. MAC – initials of the three volunteers

d. Implicated in FNHTR e. Advent of HLA typing f. Genetics was elucidated B. Nomenclature and Genetics a. Polymorphic b. HLA genetic region on chromosome 6 i. Determines major histocompatibility factors ii. Recognition and elimination of foreign tissues c. Also known as the MHC region d. 35 to 40 genes physically grouped in three regions located on the short arm of chromosome 6 e. Related genes: Glyoxalase-1 (GLO) and

phosphoglucomutase-3 (PGM-3) are also linked

f. Class I region gene – classic transplantation molecules i. HLA-A ii. HLA-B iii. HLA-C iv. HLA-E, HLA-F and HLA-G (non-classic) g. Class II region gene i. HLA-DR ii. HLA-DP iii. HLA-DQ h. Class III region

i. C2 and C4, Bf (complement factors) ii. 21-hydroxylase iii. Tumor necrosis factor

C.

Significance a. SELF vs NON-SELF b. Pre-transfusion and transplantation c. Platelet refractory therapy and random platelet donors d. Disease correlation e. Paternity testing f. Anthropologic studies g. FNHTR h. TA-GVHD i. Clinical presentation 1. 4-30 days after the transfusion 2. Typical symptoms include: fever, erythematous maculopapular rash, which can progress to generalized erythroderma, toxic epidermal necrolysis in extreme cases 3. Other symptoms can include cough, abdominal pain, vomiting, and profuse diarrhea (up to 8 liters/day).

Upon transfusion of blood to someone who is not genetically identical (different HLA types): 1. Transfused lymphocytes mount an immune response 2. Recipient with normal immune system counterattacks

D. Prevention of TA-GVHD Gamma irradiation 15-25 Gy (US, Philippines) 25-50 Gy (Australia & New Zealand) Radioisotopes (Cesium-137 or Cobalt-60)

PLATELET ANTIGENS (11 TH MEETING) At the end of this unit, the learners must be able to: 1. comprehend the concept of human platelet antigens; and 2. become aware of the relevance of these antigens in blood transfusion. A. Definition a. HPA are polymorphisms in platelet antigens b. can stimulate production of alloantibodies in recipients of transfused platelets from donors with different HPAs B. Significance a. Antibodies cause: i. neonatal alloimmune thrombocytopenia ii. post-transfusion purpura iii. some cases of platelet refractoriness

REFERENCES: A. Textbook: a. Harmening, Denise M. Modern Blood Banking and Transfusion Practices (2012). 6th Edition. F.A. Davis Company. B. Reference Books: a. Blaney, Kathy D and Howard, Paula R. Basic and Applied Concepts of Immunohematology (2008). 2nd Edition. Mosby, Inc. . b. AABB Committee (2011). Standards of Blood Banks and Transfusion Services. 27th Edition. USA: American Association of Blood Banks. c. Fung, Mark K; Grossman, Brenda J; Hillyer, Christopher D; and Westhoff, Connie M (2014). 18th Edition. Technical Manual (AABB). Maryland, USA. d. Mcpherson, Richard A. and Pincus, Matthew (2017). Henry’s Clinical Diagnosis and Management by Laboratory Methods. 23rd Edition. Philadelphia: Elsevier Inc. C. Related Websites and other materials: a. American Association of Blood Banks. Available at: http://www.aabb.org/Pages/Homepage.aspx. Accessed on November 6, 2017. b. American Red Cross. Available at http://www.redcross.org/ Accessed on November 6, 2017. c. Department of Health. Available at http://www.doh.gov.ph Accessed on November 6, 2017. d. Human Blood. Available at http://www.fi.edu/learn/heart/blood/blood.html. Accessed on November 6, 2017. e. Hematology-Blood Bank Links to Related Sites. Available at http://www.lhsc.on.ca/lab/bldbank/links.htm. Accessed on November 6, 2017. f. International Society of Blood Transfusion. Available at http://www.isbtweb.org/. Accessed on November 6, 2017. g. Medical Laboratory Observer. Available at http://www.mlo-online.com. Accessed on November 6, 2017. h. World Health Organization. Available at http://www.who.int/en/. Accessed on November 6, 2017.

Note: Regarding the pictures presented in this document, these fall into one of the following types: photographs personally taken by the document’s author, downloaded from the internet under creative commons license, or scanned/downloaded from the references listed; unless otherwise stated in the photograph or caption.

Prepared by: CRIZELDA L. SALITA, MS, RMT