1.
1. Characterize comCharacterize completely thpletely the Rh ane Rh antigens (D,C,E,ctigens (D,C,E,c,e) in ,e) in terms of terms of their btheir biochemical niochemical nature and ature and serologicserologic property
property..
The final result of gene action in RC groups is the production of a biochemical structure! in The final result of gene action in RC groups is the production of a biochemical structure! in the Rh system it is
the Rh system it is a nonglycosylated protein. This means that there are no carbohydrates attached to thea nonglycosylated protein. This means that there are no carbohydrates attached to the protein.
protein.
The gene products of R"D and R"CE are remar#ably similar in that both encode for proteins The gene products of R"D and R"CE are remar#ably similar in that both encode for proteins composed of $1% amino acids that tra&erse the cell membrane 1' times and that their seuence differs composed of $1% amino acids that tra&erse the cell membrane 1' times and that their seuence differs by only
by only $$ base $$ base pairs. The gene pairs. The gene products ofproducts of RHCE, RHCe, RHCE, RHCe, RHce, RHce, andand RHcE RHcE are e&en more similar. Care e&en more similar. C and c differ from one another in four amino acid positions, and one amino acid differentiates E from e. and c differ from one another in four amino acid positions, and one amino acid differentiates E from e. n
nly ly smsmalall l loloopops s of of ththe e Rh Rh prprototeieins ns arare e e*e*poposesed d on on ththe e susurfarface ce of of ththe e RC RC anand d prpro&o&idide e ththee conformational reuirements for the serologic differences bet+een the
conformational reuirements for the serologic differences bet+een the Rh blood types.Rh blood types.
n comparison +ith and ell () blood groups, 1 cells possess appro*imately 1./ 0 1/ n comparison +ith and ell () blood groups, 1 cells possess appro*imately 1./ 0 1/ -antigens, +hereas homozygou
antigens, +hereas homozygous ell cells ha&e /// sites. s ell cells ha&e /// sites. The greatest number of D antigen sites isThe greatest number of D antigen sites is on cells of the rare Rh phenotype D22. (D22 cells carry only D antigen and completely lac# Cc and Ee.) on cells of the rare Rh phenotype D22. (D22 cells carry only D antigen and completely lac# Cc and Ee.) "o+e&
"o+e&er, of er, of the commonly encounthe commonly encountered Rh tered Rh genotygenotypes,pes, R2R R2R' cells possess the largest number of D' cells possess the largest number of D antigen sites.
antigen sites. 3ummary4 3ummary4
Rh antigens are non2glycosylatedRh antigens are non2glycosylated
Rh antigens are transmembrane polypeptides and are an integral part of Rh antigens are transmembrane polypeptides and are an integral part of the RC membranethe RC membrane
"ighly immunogenic4 5e*t to - and "ighly immunogenic4 5e*t to - and D6c6E6C6e
D6c6E6C6e
7eighs appro*imately 1821%$ #D7eighs appro*imately 1821%$ #D
7ell de&eloped in early fetal life7ell de&eloped in early fetal life '.
'. 9i&e a 9i&e a listing listing of the of the Rh antigRh antigens in ens in their ditheir different nomfferent nomenclatures, anenclatures, and their d their freuency ofreuency of occurrencef occurrence
FREQUENCY FREQUENCY
D
D: 85% Caucasians, 92% Blacks, 99% Asians: 85% Caucasians, 92% Blacks, 99% Asians C
C: 68% Caucasians, 27% Blacks, 93% Asians: 68% Caucasians, 27% Blacks, 93% Asians E
E: 29% Caucasians, 22% Blacks, 39% Asians: 29% Caucasians, 22% Blacks, 39% Asians c
c: 80% Caucasians, 96% Blacks, 47% Asians: 80% Caucasians, 96% Blacks, 47% Asians e
e: 98% Caucasians, 98% Blacks, 96% Asians: 98% Caucasians, 98% Blacks, 96% Asians
GROUP 2 GROUP 2
EXPERIMENT NO 11: D (Rh) TYPING – DIRECT, SLIDE METHOD EXPERIMENT NO 11: D (Rh) TYPING – DIRECT, SLIDE METHOD
Researcher4 :-5;<-, Ros&an utch =.
http4>>+++.ncbi.nlm.nih.go&>boo#s>5''?>
@. 9i&e a list of the more common phenotypes and genotypes of the Rh system, including the antigens present and their serologic reactions +ith the 8 antisera.
7E5ER A3"ER2R-CE R1r DCe>dce R1R1 DCe>DCe rr dce>dce R1R' DCe>DcE R'r DcE>dce R'R' DcE>DcE
Researcher4 C-3, Bary -ntonette :.
Reference4 Bodern lood an#ing and Transfusion =ractices by "armening
a. mproper and inadeuate +ashing of the red cell suspension may cause pseudoagglutination due to the presence of serum macromolecules in the suspension. This should cause a positi&e control as +ell.
b. The presence of strong autoagglutinins in the patients or donors serum may cause
agglutination. =roper +ashing and the control are designed to pre&ent or detect this problem. c. -ntibody coating of the red cell (positi&e D-T) can cause a false positi&e reaction, particularly
in the +ea# D test. - D-T +ill detect this occurrence.
d. - false negati&e reaction may be seen due to the bloc#ing phenomenon. This occurs most commonly in "DA5 due to anti2D. 3ince the red cells antigen sites are hea&ily coated +ith maternal antibody, they may not react +ith the antiserum.
e. Aalse positi&e or negati&e reactions may occur in the Rh test due to many of the technical errors..
f. RCs that react +ith one manufacturerFs anti2D reagent but not +ith another may ha&e a partial D antigen.
Researcher4 C-3, Bary -ntonette :.
Reference4 cache42u#<G?8;+#G4 indianinitiati&e.org>+p2content>uploads>'/11>/>'112Rh2 Typing.docHIcdJ$IhlJenIctJcln#IglJph
8. 7hat is the clinical! significance or importance of Rh typing
• Transfusion Reactions
Rh antigens are highly immunogenic. The D antigen is themost immunogenic antigen outside the - system. 7hen anti2D is detected, a careful medical history +ill re&eal RC e*posure through pregnancy or transfusion of products containing RCs. Circulating antibody appears +ithin 1'/ days of
a primary e*posure and +ithin ' to % days after a secondary e*posure.
Rh2mediated hemolytic transfusion reactions, +hethercaused by primary sensitization or secondary immunization, usually result in e*tra&ascular destruction of immunoglobulin2 coated RCs. The transfusion recipient may ha&e an une*plained fe&er, a mild bilirubin ele&ation, and a decrease in hemoglobin and haptoglobin. The direct antihuman globulin test is usually positi&e, and the antibody screen may or may not demonstrate circulating antibody. 7hen the direct antiglobulin test indicates that the recipientFs RCs are coated +ith g9, elution studies may be helpful in defining the offending antibody specificity. f antibody is detected in either the serum or eluate, subseuent transfusions should lac# the implicated antigen.
• "emolytic Disease of the 5e+born ("D5)
"D5 is briefly described here because of the historic significanceof the disco&ery of the Rh system in elucidating its cause. -s stated pre&iously, anti2D +as disco&ered in a +oman after deli&ery of a stillborn fetus. The mother reuired transfusion. The fatherFs blood +as transfused, and the mother subseuently e*perienced a se&ere hemolytic transfusion reaction. :e&ine and 3tetson1 postulated that the antibody causing the transfusion reaction also crossed the placenta and destroyed the RCs of the fetus, causing its death. The offending antibody +as subseuently identified as anti2D."D5 caused by Rh antibodies is often se&ere because the Rh antigens are +ell de&eloped on fetal cells, and Rh antibodies are primarily g9, +hich readily cross the placenta. -fter years of research, a method +as de&eloped to pre&entsusceptible (Rh/ D2negati&e) mothers from forming anti2D, thus pre&enting Rh/(D) "D5. Rh2immune globulin, a purified preparation of g9 anti2D, is gi&en to a D2negati&e +oman during pregnancy and follo+ing deli&ery of a D positi&e fetus.
Researcher4 C-3, <enelei 9race -.
Resources4 "armening, D. B. ('/1'). Modern Blood Banking And Transfusion Practices (th Ed.). A.-. Da&is, '/1'.
. 7hy is it necessary to run the control (+ith 3-) in Rh typing
To assess the &alidity of the high2proteinRh typing results, a control reagent +as manufactured and had to be tested in parallel +ith each Rh test. f the control reacted, the test result +as in&alid and had to be repeated using a different techniue or reagent anti2D.
To assess the &alidity of the high2protein Rh t yping results, a control reagent +as manufactured and had to be tested in parallel +ith each Rh test. f the control reacted, the test result +as in&alid and had to be repeated using a different techniue or reagent anti2D.
o&ine -lbumin is primarily used to enhance the reacti&ity of blood group antibodies, either in direct agglutination tests or indirect antiglobulin test. This fact +as confounded by Cameron and Diamond, 1?$8, +ho established that certain anti Rho (-nti2D) 3era +ould agglutinate Rh positi&e red cells +hen they +ere suspended in albumin, ho+e&er no agglutination +as obser&ed +hen same red cells +ere suspended in 5ormal 3aline medium.
PRINCIPLE: o&ine -lbumin is freuently used as a control for Rh typing. E&ery blood specimen tested by the slide, stic# or modified tube method should be controlled by testing simultaneously +ith a medium such as o&ine -lbumin. 3ince cells coated +ith an autoagglutinin or suspended in serum ha&ing a protein abnormality may gi&e a false positi&e result in Rh typing.
Researcher4 Caiso, <enelei 9race -.
References4 "armening, D. B. ('/1'). Modern Blood Banking And Transfusion Practices (th Ed.). A.-. Da&is, '/1'.
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