A study conducted on 61 SLE patients in Pakistan who met at least 4 American College of Rheumatology (ACR) criteria stated that there was an increased frequency of several HLA-A, HLA-B and HLA-DRB1 among SLE patients, reflecting a positive association of those alleles with SLE [42]. Here, HLA-DRB1 is linked to systemic lupus erythematosus.