With the aid of methods of polymerase chain reaction / sequence specific primers （PCR/SSP） and polymerase chain reaction-restriction fragment length polymorphism （PCR/RFLP）

the allelic polymorphism of HLA-DR and TNFB loci and susceptibility to systemic lupus erythematosus （SLE） in northern Chinese Han nationality were studied. The genetic analysis of 51 patients with SLE and 106 healthy controls indicated that frequencies of DR2 and DR3 alleles were significantly increased in SLE patients（P< 0.05 and <0. 005

relative risks of 1.77 and 4.01 respectively）

which represent candidate susceptible genes or useful marker for SLE. The frequency of DR5 was found to decrease in SLE patients compared with control population （P<0. 025

relative risk = 0. 38）. It might be an antagonistic or protective allelle or a marker for such allele. Analysis of 51 patients with SLE and 80 healthy control also revealed that the frequency of TNFB’ 2 allele was significantly increased（P<0. 05

RR= 1. 70）. Therefore TNFB’ 2 gene may also be a susceptibility gene or a marker gene for SLE in northern Chinese Han nationality. It was also investigated the association between HLA-DR

TNF B alleles and Patient plasmic SC5b-9 levels

auto-antibodies （anti-SSA

SSB

Sm

RNP

ds DNA and ANA） and SLE complications （SLE nephritis

SLE pneu-monitis and SLE encephalopathy）

no relationship was found.