Prevalence of lupus nephritis and the use of serology in a central South African chronic kidney disease patient cohort

Abstract

Prevalence of lupus nephritis and the use of serology in a central South African chronic kidney disease patient cohortTo the Editor: Lupus nephritis (LN) is a frequent kidney manifestation of systemic lupus erythematosus (SLE) and is classified into six histological classes (I -VI), as per the International Society of Nephrology and Renal Pathology Society criteria. [1] Of the six classes, class III, IV and mixed class V are known as the proliferative forms of LN, which have a more aggressive disease course and poorer prognosis. [2] The initial diagnosis of SLE is made based on the Systemic Lupus International Collaborating Clinics criteria and the 2019 European League Against Rheumatism/American College of Rheumatology (ACR) classification criteria. [3][4][5] Accurate statistics regarding the prevalence of LN in sub-Saharan Africa are limited owing to limited availability of kidney histology registries. [6] However, a substantial amount of research has highlighted worse prognostic factors among individuals of African descent, [2,[7][8][9] attributed to multifactorial factors such as apolipoprotein L1 (APOL-1) gene polymorphism, less robust cutaneous manifestations that contribute to delayed diagnosis of SLE and poor access to healthcare. [6][7]10] The delayed identification of LN has become a major underlying cause of chronic kidney disease (CKD) in South Africans. [2] LN research in South Africa (SA) is limited, and although the prevalence is reported as high, [11][12] no representative value has been published for the central SA population. However, the few data that are available indicate that the SA LN population has a consistently poorer prognosis in comparison with other global populations. [11][12][13][14] This therefore necessitates further analysis of this population.It is important to note that our findings form part of the aim of a larger genetic study wherein the human leucocyte antigen (HLA) profiles of patients with biopsy-proven CKD from a single centre in Bloemfontein, Free State Province, were investigated. This was done in order to determine whether specific HLA alleles confer a higher risk for CKD, and therefore, a study population with a welldefined diagnosis was selected. Consequently, as part of the inclusion criteria of the main study, all participants must have undergone a kidney biopsy, and were recruited between January and June 2022. In conducting this research, we were able to determine the distribution of the various chronic kidney diseases in a central SA population, from which we found the prevalence of LN to be noteworthy.Ethics approval was obtained from the Health Sciences Research Ethics Committee of the University of the Free State (ref. no. UFS-HSD2021/1462/2501), as well as permission from the Free State Department of Health (ref. no. FS_202112_005) and the National Health Laboratory Services, in order to conduct the main study.In this study of 100 (n=100) patients diagnosed with biopsyproven CKD from the nephrology clinic at Universitas Academic Hospital, the prevalence ...