Lupus Nephritis among Arabs - Differences with other Races; Emphasis on Clinicopathological and Serological Perspectives

Abstract

Data on ethnic differences of lupus nephritis (LN) are extremely scattered in the literature. Furthermore, most of the publications on LN in Arabs have in fact discussed the condition within the general frame of systemic lupus erythematosus (SLE) disease in mixed, but Arab-dominated groups of patients, and fewer, in exclusively Arab individuals. Lupus nephritis however, seems to be common, occurring in 37-69% of SLE patients in the Arab dominated groups and in 50% of the exclusively Arab group. In two out of three groups who reported their renal biopsy results, WHO class III was the most common histopathological type (36% and 54% respectively). Interestingly, the relatively high prevalence of nephropathy in the two groups was associated with a low prevalence of discoid lupus. Arabs with LN who have been studied for serological correlation, did not exhibit any specific or distinctive entity of autoantibody profile. Nonetheless, contradictory data have been noticed in relation to dsDNA antibodies, as they significantly correlated with LN in some of the Arab dominated groups, but not in the uniformly Arab group. Anti-RNP antibodies significantly correlated with non-nephritic SLE patients in the latter group, suggesting a possible protective role of these antibodies. The previously reported correlation between anti-Sm antibodies was not confirmed in the Arab groups. Like the other features of SLE, the differences related to LN in various populations are very likely to be multifactorial rather entirely being ethnical. Lupus nephritis in Arabs however, requires further demarcation by evaluating larger number of patients preferably through multicenter studies.

Keywords

• Lupus nephritis
• Arabs
• Ethnicity.