D. M. Grennan

Polymorphisms of the TAP2 transporter gene in systemic lupus erythematosus.

OBJECTIVES--To determine whether the TAP2 transporter gene, which lies between HLA-DP and HLA-DQ, is involved in determining susceptibility to systemic lupus erythematosus (SLE). METHODS--TAP2 types were determined by ARMS-PCR in 89 white patients with SLE and 156 control subjects. RESULTS--No particular TAP2 dimorphism or allele was associated with SLE or with any clinical/immunological subgroup of SLE. Furthermore, there was no evidence for significant linkage disequilibrium between TAP2 and HLA-DQ/DR in SLE. CONCLUSIONS--These data suggest that TAP2 is not a disease susceptibility gene for SLE and that the disease-predisposing haplotypes do not extend as far as TAP2. This indicates that any HLA-DP association with SLE must be independent of other class II (DQ/DR) associations.

HLA-DP does not contribute towards susceptibility to systemic lupus erythematosus.

OBJECTIVES--To determine whether HLA-DP genes are involved in determining susceptibility to systemic lupus erythematosus (SLE). METHODS--HLA-DPA1 and DPB1 genes were amplified by PCR of DNA samples from a panel of patients with SLE and normal controls. Amplified DNA was blotted on to nylon filters and probed with sequence-specific oligonucleotide (SSO) probes. RESULTS--No DPA1 or DPB1 allele was significantly associated with SLE, or with any immunological or clinical subset of SLE. Evidence was found for only limited linkage disequilibrium between HLA-DP and HLA-DQ/DR variants, and none between HLA-DP and the TAP2 gene. CONCLUSIONS--These data indicate that HLA-DP genes do not contribute towards determining susceptibility to SLE.