Evidence that Hy– RBCs express weak Jo^a antigen

Abstract

BACKGROUND: RBCs of the Hy– phenotype have, in the past, been typed as Gy(a+w), Hy–, Jo(a–), and RBCs with the Jo(a–) phenotype type Gy(a+), Hy+w, and Jo(a–). Anti‐Hy and anti‐Joa are difficult to identify mainly because appropriate reagent RBCs are poorly characterized. Historically, anti‐Joa has not reacted with RBCs with either phenotype. This report describes a case of an anti‐Joa that shows Hy– RBCs express some Joa antigen, albeit weakly. CASE REPORT: Anti‐Joa was identified in a serum sample of a 71‐year‐old woman. The antibody reacted 1+ to 2+ by the IAT with all untreated and ficin‐treated panel RBCs and did not react with Gy(a–) RBCs and Jo(a–) RBCs. Unexpectedly, the serum sample reacted weakly with six of eight RBC samples with the Hy– phenotype. The anti‐Joa was adsorbed onto and eluted from Hy– RBCs, indicating the presence of weak Joa antigen. The patient's RBCs typed Gy(a+), Hy+, Jo(a–). DNA studies using PCR‐RFLP analysis showed the patient to be homozygous for the JO allele, which is consistent with the serologically determined Jo(a–) status. CONCLUSION: The DNA and serologic evidence of this case show that Hy– RBCs may express low levels of Joa antigen, which contradicts previously published data concerning the Joa type of Hy– RBCs.

Dombrock gene analysis in Brazilian people reveals novel alleles

“…The Gy(a-) phenotype, associated with Hy-negative and Jo(a-), represents the null phenotype. The Hy-negative phenotype is associated with weak expression of Do b and Jo a antigens, while Jo(a-) is associated with weak expression of the Do a and Hy antigens [1][2][3][4][5][6]. The Dombrock antibodies are weakly reactive and are generally found in serum samples with multiple antibodies; moreover, the antigens can be weakly expressed on the red blood cell membrane [7][8][9].…”

Dombrock Blood Group System

“…Gy(a + w ) Hy -red cells are Jo(a -) [40] , or at least express very low levels of Jo a as determined by adsorption and elution tests [41] (Table 14.2 ). Makers of anti -Jo a are Gy(a + ) Hy + Jo(a -) [40 -43] .…”

A PCR‐based strategy for Dombrock screening in Brazilian blood donors reveals a novel allele: the DO*A‐WL

“…The Gy(a–) phenotype, associated with Hy‐negative and Jo(a–), represents the null phenotype. The Hy‐negative phenotype is associated with weak expression of Do b and Jo a antigens, whereas Jo(a−) is associated with weak expression of the Do a and Hy antigens 1–5. The Dombrock antibodies are weakly reactive and are generally found in serum samples with multiple antibodies; moreover, the antigens can be weakly expressed on the red blood cell membrane 6–8.…”