Single-antigen-expressing cell lines are excellent tools for detecting human leukocyte antigen-C-reactive antibodies in kidney transplant recipients.
BACKGROUND
Human leukocyte antigen (HLA)-C is expressed on nucleated cells and platelets in lower levels than HLA-A,B, and its antigens are in linkage disequilibrium with HLA-B antigens. Therefore, HLA-C antibody detection is difficult. The authors questioned whether HLA-C could serve as a target in clinical kidney transplantation using a newly developed assay.


METHODS
Flow cytometry was performed with sera from patients (n=34) awaiting a kidney retransplant using nine cell lines expressing a single HLA-C antigen (single-antigen lines [SAL]).


RESULTS
The SAL were validated with HLA-C-specific alloantisera and human monoclonal antibodies against HLA-A, -B, and -C. The results were in agreement with the specificities previously reported. Exceptions, because of new HLA-C specificities used here, could be explained by epitope sharing between the antigens. With respect to patient sera, 15 of the 34 patients tested (44%) showed serum reactivity toward one or more HLA-C SAL.


CONCLUSIONS
In contrast to peripheral blood lymphocytes, SAL are excellent targets for detecting HLA-C-reactive alloantibodies by flow cytometry. This preliminary analysis revealed that HLA-C-reactive antibodies are frequently present in sera of retransplant patients, serving as possible targets in clinical transplantation.
Zoet
Yvonne M
YM
Department of Immunohaematology and Blood Transfusion, Leiden University Medical Center, Leiden, The Netherlands.
Eijsink
Chantal
C
Böhmová
Radka
R
Witvliet
Marian D
MD
Kardol
Marrie J
MJ
Franke
Marry E I
ME
Claas
Frans H J
FH
Mulder
Arend
A
Doxiadis
Ilias I N
II
D000906:Antibodies / Q000097:blood; D000941:Antigens / Q000276:immunology*; D015415:Biomarkers / Q000032:analysis; D002460:Cell Line; D000939:Epitopes / Q000032:analysis; D015236:HLA-C Antigens / Q000276:immunology*; D006801:Humans; D016030:Kidney Transplantation / Q000276:immunology*; D007962:Leukocytes / Q000276:immunology*; D018579:Patient Selection; D015203:Reproducibility of Results
D000906:Antibodies; D000941:Antigens; D015415:Biomarkers; D000939:Epitopes; D015236:HLA-C Antigens