Lupus Nephritis: A Different Disease in European Patients?

Abstract

Background: Lupus nephritis (LN) is still associated with significant mortality and substantial risk of progression to end-stage renal failure. Its outcome is related to the class and severity of LN and response to treatment, and it is poorer in patients with renal relapses. Ethnicity has a relatively well-defined impact on the outcome of the patients and their response to treatment and must always be taken into consideration in treatment decisions. Summary: In this article, we provide a review of the impact of ethnicity on the prevalence of systemic lupus erythematosus (SLE), the proportion of patients with SLE developing LN, outcomes of SLE and LN and response of LN to treatment. In European patients, the prevalence of SLE and the proportion of SLE patients with LN are lower and the outcome of LN is better than in nonwhite populations. European patients may respond better to some modes of treatment [e.g. cyclophosphamide (CYC) or rituximab] and may be less frequently refractory to treatment compared to black patients with LN. Although these differences may be largely genetically driven, socioeconomic factors (poverty, education, insurance, access to health care and adherence to treatment) may also play a significant role in some disadvantaged patients. Key Message: Treatment of LN may be different in patients with different ethnicity. Less aggressive disease in European patients may better respond to less aggressive treatment. Treatment of LN in nonwhite patients may require newer (more effective) therapeutic approaches, but targeting negative socioeconomic factors might be even more effective. Facts from East and West: (1) The prevalence of SLE is lower among Caucasians than other ethnicities. A higher prevalence is observed among Asians and African Americans, while the highest prevalence is found in Caribbean people. The prevalence of LN in Asian SLE patients is much higher than in Caucasians as well. However, the 10-year renal outcome and renal survival rate appear to be better in Asians. (2) Polymorphisms of genes involved in the immune response, such as Fcγ receptor, integrin alpha M, TNF superfamily 4, myotubularin-related protein 3 and many others, might be partly responsible for the differences in prevalence between the different ethnic groups. European ancestry was shown to be associated with a decrease in the risk of LN even after adjustment for genes most associated with renal disease. (3) Access to health care is a key determinant of disease progression, treatment outcome and the management of complications such as infections, particularly in South Asia, and might also explain disparities between clinical outcomes. (4) The efficacy of low-dose CYC combined with corticosteroids for induction treatment of LN was proved in European Caucasian patients. This treatment is also used in Asia, although no formal evaluation of efficacy and safety in comparison with other treatment regimens exists in this population. The efficacy of mycophenolate mofetil (MMF) is similar to that of CYC, and similar between Asi...

Incidence of glomerulonephritis and non-diabetic end-stage renal disease in a developing middle-east region near armed conflict

“…FSGS appears to be increasing in many countries of the Middle-East and replacing SLE as the most common type of GN [ 31 – 33 ]. SLE is well known to have geographic, racial, and ethnic variations [ 13 , 34 , 35 ]. Some of the geographic differences are undoubtedly due to biopsy practices.…”

Genetic contributions to lupus nephritis in a multi-ethnic cohort of systemic lupus erythematous patients

“…Hispanic, African American, and Asian patients develop SLE at a younger age and more severe manifestations including LN, than patients of European descent [ 2 ]. The etiology of these ethnic disparities is a matter of ongoing debate, with genetic and non-genetic factors being implicated [ 3 ]. Previous work has shown that European ancestry is protective for LN whereas Amerindian and African ancestry contributes to risk [ 4 , 5 ].…”

Urinary MCP-1 and TWEAK as non-invasive markers of disease activity and treatment response in patients with lupus nephritis in South Africa

“…This could suggest that these biomarkers can be useful for monitoring renal disease ares which are more aggressive and often more frequent in non-Caucasian populations. [30] The usefulness of these biomarkers for monitoring are of LN have been demonstrated in some studies [31,32] while others have also shown their bene t with monitoring response to treatment. [25] A study has suggested that combining both uMCP-1 and uTWEAK might be useful as potential predictors for proteinuria in LN.…”