The clinical importance of variation within the HLA-Bw4 complex.
BACKGROUND
Antibody screening of a patient with a failed renal transplant showed positive reactions with most, but not all HLA-Bw4-associated B-locus antigens. However, the patient's serological HLA class I type suggested the presence of HLA-Bw4.


METHODS
Standard molecular techniques were used to re-type the patient and donor. ELISA antibody screening helped determine the patient's antibody specificity.


RESULTS
The patient's type was HLA-B*1402,4703;Bw6 and the donor HLA-B*4703,51011;Bw4,6. Analysis of ELISA results identified three amino acids (positions 77,80,81) as the most likely epitope recognised by the patient's serum. These corresponded to HLA-B*51011 amino acid mismatches, explaining the lymphocytotoxic reactivity pattern. This epitope is located on a subgroup of the HLA-Bw4 antigen suggesting anti-Bw4 was not a sufficient description of this antibody.


CONCLUSIONS
This report identifies an antibody to a sub-group of the Bw4 public specificity and also confirms the need for sequence-level analysis in the tissue-typing laboratory to determine future unacceptable mismatches.
Collins
R W
RW
South Thames Tissue Typing, NGH3, Guy's Hospital, St. Thomas Street, London, SE1 9RT, UK.
Harmer
A W
AW
Heads
A J
AJ
Kondeatis
E
E
Page
G
G
Vaughan
R W
RW
D000961:Antilymphocyte Serum / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes; D014644:Genetic Variation; D015235:HLA-B Antigens / Q000032:analysis / Q000235:genetics* / Q000276:immunology*; D006650:Histocompatibility Testing; D006801:Humans; D016030:Kidney Transplantation / Q000276:immunology*; D019520:Living Donors; D017211:Treatment Failure
D000961:Antilymphocyte Serum; D000939:Epitopes; D015235:HLA-B Antigens; C042388:HLA-Bw4 antigen