Molecular & Genomic Investigations

of Red Cell, Platelet and Histocompatibility Antigens

The National Molecular Laboratory is involved in many facets of transfusion medicine as it relates to antigen prediction, matching and discrepancy resolution.

For more information about HLA testing, please visit our Red Cross HLA Testing page.

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Margaret Keller, PhD

Executive, National Laboratories - Adjunct Associate Professor, Thomas Jefferson University

Benefits of Our Investigations

Aids in identification of red blood cell (RBC) donors lacking high prevalence antigens or multiple common antigens and platelet donors lacking HPA-1a and other HPA antigens to support alloimmunized patients
Investigates red cell antigen typing discrepancies including serologic weak D phenotype
Develops new genotyping assays (LDTs) and related methodologies
Identifies novel blood group antigen alleles
Aims to identify compatible blood for Rh alloimmunized patients by matching them with donors with similar RH alleles encoding variant antigens
Evaluates commercial genotyping tests and/or platforms
Develops next generation sequencing reagents for RBC phenotype prediction

Recent Publications

Sandler SG, Flegel WA, Westhoff CM, Denomme GA, Delaney M, Keller MA, Katz L, Queenan JT, Johnson ST, Vassallo R, CD Simon. It’s time to phase in RHD genotyping for patients with a serological weak D phenotype. Transfusion 2015;55(3):680-689.
Fennell K, Hoffman R, Yoshida K, Iwamoto S, Govender L, Vather K, Sookraj A,Jentsch U, Pambrun C, McAuley C, Keller MA, Ochoa-Garay G. Effect on gene expression of three allelic variants in GATA motifs of ABO, RHD, and RHCE regulatory elements. Transfusion 2017; 57(11):2804-8.
Horn T, Hamilton J, Kosanke J, Hare VW, Kluver W, Beres W, Nance S, Keller MA. Assessment of common red blood cell pretreatments to yield an accurate serologic antigen phenotype compared with genotype-predicted phenotype. Immunohematology 2017;33(4):147-151
Keller J, Vege S, Horn T, Keller MA, Leger RM, Aeschlimann J, Lomas-Francis C, Westhoff CM. Novel mutations in KLF1 encoding the In(Lu) phenotype reflect a diversity of clinical presentations. Transfusion 2018;58(1):196-199. doi:10.1111/trf.14378
Fennell K, Hoffman R, Yoshida K, Iwamoto S, Govender L, Vather K, Sookraj A,Jentsch U, Pambrun C, McAuley C, Keller MA, Ochoa-Garay G. Effect on gene expression of three allelic variants in GATA motifs of ABO, RHD, and RHCE regulatory elements. Transfusion 2017;57(11):2804-2808.
Luo X, Keller MA, James I, Grant M, Liu S, Massey KS, Czulewicz A, Nance S, Li Y. Strategies to identify candidates for D variant genotyping. Blood Transfusion 2018;16(3):293-301.
Young GJ, and MA. Keller. Validation of the HemoID™ DQS Blood Group Genotyping Panel. 2015. Transfusion 55(S3):142A.
Arndt PA, Horn T, Keller JA, Young R, Heri SM and MA Keller. First example of an FY*01 allele associated with weakened expression of Fya on red blood cells. Immunohematology 2015;31(3):103-7.Ramsey G, Sumugod RD, Lindholm PF, Zinni JG, Keller JA, Horn T, Keller MA. A Caucasian JK*A/JK*B woman with Jk(a+b-) red blood cells, anti-Jkb, and a novel JK*B allele c.1038delG. Immunohematology 2016;32(3):91-95.
Revilla J, M Keller, Horn T, Keller J, Clemente C, Dossantos, Goldman M, Cote J, Figueroa D, Fennell K, M Stef and G Ochoa ABO alleles with single nucleotide variants. Vox Sanguinis 2019;114 (Suppl 1):182.

Keller M, Horn T, Keller J, Villa A, Revelli N, Isernia P, Kucerakova M, Rosochova J, Fennell K, Stef M and G Ochoa. ABO alleles with intron 1 enhancer variants. Vox Sanguinis 2019;114 (Suppl 1):182.
Sandler SG, Keller J, Horn T, Landenberg A, MA Keller. A model for integrating molecular-based testing in transfusion services. Blood Transfusion 2015;14(6): 566-572.
Keller JA, Horn T, Scholz S, Koenig S, Keller MA. Comparison of ABO genotyping methods: a study of two low-resolution polymerase chain reaction assays in a clinical testing laboratory. Immunohematology 2019;35(4):149-153.
Kacker S, Vassallo R, Keller MA, Westhoff CM, Frick KD, Sandler SG, Tobian AA. Financial implications of RHD genotyping of pregnant women with a serologic weak D phenotype. Transfusion. 2015;55(9):2095-103.
Storry JR, Clausen FB, Castilho L, Chen Q, Daniels G, Denomme G, Flegel WA, Gassner C, de Haas M, Hyland C, Yanli J, Keller M, Lomas-Francis C, Nogues N, Olsson ML, Peyrard T, van der Schoot E, Tani Y, Thornton N, Wagner F, Weinstock C, Wendel S, Westhoff C, Yahalom V. International Society of Blood Transfusion Working Party on Red Cell Immunogenetics and Blood Group Terminology: Report of the Dubai, Copenhagen and Toronto meetings. Vox Sang 2019;114(1):95-102.
Westhoff CM, Nance S, Lomas-Francis C, Keller M, Chou ST. Experience with RHD*weak D type 4.0 in the USA. Blood Transfus. 2019 Mar;17(2):91-93
Chou ST, Evans P, Vege S, Coleman SL, Friedman DF, Keller M, Westhoff CM. RH genotype matching for transfusion support in sickle cell disease. Blood. 2018 Sep 13;132(11):1198-1207.
Storry JR, Castilho L, Chen Q, Daniels G, Denomme G, Flegel WA, Gassner C, de Haas M, Hyland C, Keller M, Lomas-Francis C, Moulds JM, Nogues N, Olsson ML, Peyrard T, van der Schoot CE, Tani Y, Thornton N, Wagner F, Wendel S, Westhoff C, Yahalom V. International society of blood transfusion working party on red cell immunogenetics and terminology: report of the Seoul and London meetings. ISBT Science Series 2016;11(2):118-122.