To determine how polymorphism of transporter associated with antigen processing 1 and 2 (TAP1 and 2) alleles contributed to the pathogenesis of systemic lupus erythematosus (SLE) in Japanese patients.
TAP1 and TAP2 typing was carried out in 52 Japanese patients with SLE and 95 normal subjects by the PCR-RFLP (restriction fragment length polymorphism) method. HLA-DR typing and HLA-DRB1*15 genotyping were carried out by the PCR method and PCR-SSCP (single stranded DNA conformation polymorphism) method, respectively.
No particular TAP 1 allele was associated with Japanese SLE or with immunological subgroup of SLE. TAP2H showed a tendency towards increased frequency in SLE (5.8% v 0% in control), but the corrected P value was not significant. No other particular association of TAP2 allele was observed. Furthermore, these was no evidence for linkage disequilibrium between any TAP1/TAP2 alleles and HLA-DRB1*1501--which is reported to be weakly but significantly association with Japanese SLE--in either the normal control or the SLE patient group.
Neither the TAP1 nor the TAP2 gene appears to determine disease susceptibility to SLE in Japanese, and these results are in keeping with those reported in Caucasian SLE patients.