Lupus nephritis (LN) is a disease with a poor prognosis. The association between LN and the Human leukocyte antigen (HLA) genes has never been studied on a Moroccan population. The aim of this work was to evaluate the distribution of the HLA class II alleles in patients with LN and to determine susceptible and protective HLA alleles/haplotypes in LN. The association between these alleles, disease severity of LN, and age at onset were also investigated. Seventy-five patients with LN were compared with 169 healthy unrelated controls. HLA class II alleles typing was performed by polymerase chain reaction-sequence-specific primers (PCR-SSP). A significant increase of HLA-DRB1*15 allele frequency (p = 0.001) and a significant decrease of the HLA-DRB1*04 allele (p = 0.04) were observed in LN patients. The frequency of HLA-DRB1*15-DQB1*06 haplotype (p = 0.003) was increased in the patients while that of HLA-DRB1*04-DQB1*03 (p = 0.027) was decreased. A significant increase of HLA-DRB1*15 allele frequency (p = 0.0001) and HLA-DRB1*15-DQB1*06 haplotype (p = 0.002) was observed in patients with class IV LN. In the Moroccan population we demonstrated the positive association of HLA class II alleles and haplotypes with LN and with a severe form of nephritis. HLA-DRB1*15 allele does not determine the age of disease onset in LN.
Keywords: Human leukocyte antigen; Moroccan population; lupus nephritis.