1 / 32

Rh System

Rh System. Antibody Identification. Rh System. Most important blood group system in blood transfusion medicine. (after ABO). Rh Discovery. 1939 – Levine and Stetson 1 st discovered antibody 1940 – Landsteiner and Weiner discovered

dolan-macias
Télécharger la présentation

Rh System

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Rh System Antibody Identification

  2. Rh System • Most important blood group system in blood transfusion medicine. • (after ABO)

  3. Rh Discovery • 1939 – Levine and Stetson 1st discovered antibody • 1940 – Landsteiner and Weiner discovered antibody developed by using Rhesus monkey cells. • 1960’s- Discovered the antibody produced by the pregnant woman and the Rhesus monkeys were actually two different, distinct antibodies.

  4. Rh Nomenclature • Fisher Race – D, C, E, d, c, e • 3 sets of genes produce the antigens • Examples: • DCe/dce • DcE/DCE • Weiner – R1, R2, r • Inheritance of all Rh antigens lies under control of one gene • Examples: • R1R2 • R1r’ • R0r

  5. Rh ISBT Nomenclature • International Society of Blood Transfusion • Uniform nomenclature both eye and machine readable • D = RH1 • C = RH2 • E = RH3 • c = RH4 • e = RH5

  6. Rh Genetics • RHD and RHCE genes located on Chromosome 1 • Over 100 RHD and 50 RHCE alleles have been identified • RHAG (RHAG) Rh associated glycoprotein located on Chromosome 6 • LW gene located on Chromosome 4

  7. Rh Genetics • PS1 RHAG PS2 CDE LW RH genes LW genes

  8. Rh Biochemistry • Extends 12 spans of the RBC membrane • Integral part of the red cell membrane • Linked to membrane skeleton

  9. Rh Antigens • D antigen is comprised of multiple epitopes • Persons with one or more epitopes missing from the red cells can produce an immune response when exposed to the common form of the D antigen • Cells generally type normally as D+ since typing reagents are designed to detect multiple epitopes

  10. Rh Antigens • Classification of Partial D Epitopes

  11. Rh Typing Reagents • Early reagents relied on antibodies produced by women sensitized by pregnancy or in hyperimmunized volunteers. • Monoclonal antibody technology was introduced in the 1980’s. • But monoclonal antibodies are specific for a single D epitope • Does not detect all D-positive red cells.

  12. Rh Typing Reagents • Current reagents are blends containing monoclonal IgM antibody plus monoclonal or polyclonal IgG antibody • IgM allows for RT reactivity • IgG allows for AHG testing and detection of Weak D • Must read package insert to see which variants it detects • Gammaclone – reacts at AHG with DVI, DBT, DHar, Crawford • Immucor Series 4 and 5 reagents do not react with Crawford • OrthoBioclone does not react with Dhar or Crawford

  13. Rh Antibodies • Enhanced by enzymes • Not affected by DTT, Chloroquine, EGA treatment

  14. Rh Antibodies • Anti-D vs Anti-LW • Anti-LW reacts with all adult cells • Reacts stronger with Rh+ cells • Reacts weaker with Rh- cells • Anti-LW reacts strongly with Rh+ or Rh- Cord cells • Anti-LW destroyed by DTT

  15. Anti-LW

  16. Rh Antibodies • Anti-f • f antigen is expressed on RBCs having c and e on the same haplotype (cis). • R1r DCe/dce • f antigen is not expressed when c and e occur on separate haplotypes (trans). • R1R2 DCe/DcE • 65% Caucasian population, 92% African Americans, 12% Asians

  17. Anti-f

  18. Rh Antibodies • Anti-G • Inseparable anti-CD • G antigen is present on ANY cell with the C or D antigen, or both • But there have been cases of D-C-G+ and D+G- • Must perform adsorb/elution studies to confirm presence • Patient can have both anti-G plus anti-D or anti-C.

  19. Anti-G

  20. Anti-G • Ro (Dce) • Will adsorb out true anti-D while leaving separate anti-C • Antibody will be coating cells after adsorption • Perform elution to harvest coating antibody • Perform antibody identification on eluate • If shows anti-D plus anti-C pattern = ANTI-G • If shows only anti-D, then have separate anti-D and anti-C antibodies

  21. e Variants hrs hrb e mosaic e V/VS

  22. e Variants • The e antigen is considered to be a mosaic • Correct terminology is Partial • The antigens in the mosaic are • e, hrs ,hrb, V, and VS

  23. e Variant Antibodies • hrs antibody is similar to anti-ce • hrb antibody is similar to anti-Ce • Anti-VS can be naturally occurring

  24. Anti-hrs

  25. Rh Antibodies - Detection • Saline • Albumin • Enzyme • 37°C Incubation • AHG

  26. Rh Antibodies

  27. Enzymes • Enzymes: Ficin, Papain, Bromelin • Rh antibodies show enhanced reactivity with enzyme-treated cells • Enzyme treatment removes structures from the red cell membrane that otherwise interfere with the antigen-antibody complex

  28. Rh Antibodies • Other sources of Rh antibodies • RhIg • WinRho • IVIg • Rutuximab/Rutixan • Other sources of red cell stimulation • Renal transplantation • Red cells still in organ • B cells in graft producing anti-D • Bone grafts • Needle sharing

  29. Rh Antibodies • RhIg/WinRho • Used for the treatment of ITP • Used as a prophylaxis in Rh negative mothers • May contain anti-A, anti-B, anti-C, anti-E, Duffy and Kidd antibodies

  30. Rh Antibodies • IVIg • Manufactured from a pool of 1000 to 100,000 donors • May contain anti-A, anti-B, anti-D, and other antibodies • Used for treatment of WAIHA • Cost - $10,000 a dose (220 lb person @ 2g/Kg)

  31. Rh Antibodies • Rutuximab (Rituxan) • Antibodies directed against CD20 (B cell marker) • Used for treatment of TTP, lymphoma, leukemia, transplant rejection, autoimmune diseases

  32. On the Horizon • Partial RhD typing kit • BioarrayRh Variant BeadChip • CICBC should have the new Bioarray kit available by end of next year.

More Related