Summary of four articles on connections to Africa in African-Americans with lupus
| Author, year | N | Objective | Results | Conclusions | Level of evidence |
|---|---|---|---|---|---|
| Fraser et al, 200073 | 18 | To define the haplotypes with C4A-deleted alleles in African-Americans | Haplotypes HLA-DRB1p1503, HLA-B53, B44031 or B18 and HLA-DRB1p0301 and HLA-B53 and B8 were observed in conjunction with C4A gene deletions. | This is the first study to define the HLA haplotypes bearing C4A gene deletions in populations of sub-Saharan African ancestry | III |
| Gilkeson et al, 201155 | 184 | To define whether a lupus gradient exists between African-Americans and Africans | The prevalence of serum antinuclear antibodies in the two cohorts was comparable, though there was a significantly increased prevalence of antiphospholipid and anti-Sm antibodies in the Sierra Leone cohort. Seropositivity for common viral infections was significantly higher in women from Sierra Leone, while serum 25-OH vitamin D levels were drastically lower in the Gullah population. | While the prevalence of autoimmunity is similar in the two populations, there are significant environmental differences that may impact progression to autoimmune disease | III |
| Kamen et al, 200874 Lodolce et al, 201075 | 472 513 | To define the genetic and environmental factors contributing to SLE in the Gullah population To examine two non-synonymous coding polymorphisms in the deubiquitinating domain of TNFAIP3: F127C, which is in high-linkage disequilibrium with reported SLE-risk variants, and A125 V, which has not been previously studied | The severity of lupus in the Gullah population was similar to that in other African-American populations, whereas skin disease and familial disease prevalence were increased in the Gullah. Authors discovered a new African-derived risk haplotype that is separate from previously reported risk variants (OR 1.6, p=0.006), along with a rare protective haplotype defined by A125V (OR 0.31, p=0.027). | Findings suggest that there is an increased genetic influence on overall disease in this cohort compared with that in other African-American cohorts, which confirms the unique nature of this cohort This is the first report of an association between TNFAIP3 polymorphisms and autoimmunity in African-Americans | III III |
SLE, systemic lupus erythematosus.