HLA-DRB1,-DQA1,-DQB1 and DPB1 susceptibility alleles in Cameroonian type Idiabetes patients and controls

It is known that certain combinations of alleles within the human leucocyte antigen (HLA) complex are associated with susceptibility or resistance to type 1 diabetes. Variable associations of DR and DQ with type 1 diabetes ar e documented in Caucasians but rarely in African populations; however, the role of HLA-DP genes in type 1 diabetes remains uncertain. In order to inve stigate the HLA class It associations with type 1 diabetes in Cameroonians, we used sequence-specific oligonucleotide probing (SSOP) to identify DRB1, DQA1, DQB1 and DPB1 alleles in 10 unrelated C-peptide negative patients wi th type 1 diabetes and 90 controls from a homogeneous population of rural C ameroon. We found a significantly higher frequency of the alleles DRB1*03 ( chi (2) = 17.9; P = 0.001), DRB1*1301 (chi (2) = 37.4; P < 0.0001), DQA1*03 01 (<chi>(2) = 18.5; P = 0.001) and DQB1*0201 (chi (2) = 37.4; P < 0.001) i n diabetes patients compared to the control group. The most frequent allele s in the control population were DQA1*01, DQB1*0602 and DRB1*15. The DRB1*0 4 allele was not significantly associated with type 1 diabetes in our study population. We observed no significant difference between patients and con trols in DPB1 allele frequency. In conclusion, the data in Cameroonian diab etes patients suggest the existence of HLA class II predisposing and specif ic protective markers, but do not support previous reports of a primary ass ociation between HLA-DP polymorphism and development of type 1 diabetes.