Introduction:
There are over 400 rare kidney diseases (RKDs) encompassing various genetic and acquired kidney disorders, affecting both children and adults. Due to their rarity, RKDs remain poorly characterized in the literature. While multiple networks, registries, and cohort databases have been created to help better understand the epidemiology and natural history of RKDs, they are often limited to specific geographic regions, making disease estimates from these regions potentially not generalizable. Estimating the global burden of RKDs is further complicated due to diverse data sources, differing case ascertainment methods, and the absence of a standardized coding system. The aim of this scoping review is therefore, to systematically map the burden of kidney disease from RKDs globally, investigate which RKDs are described, from which countries the research originates, what epidemiological indicators (if any) are reported, and what types of studies are being published (e.g., case reports, cohort studies).
Methods:
A scoping literature review was conducted in MEDLINE to understand the burden of RKDs using a complex search string that combined search terms for RKDs developed using the Orphanet database (e.g. renal or urinary tract malformation, glomerular disease, thrombotic microangiopathy, genetic cystic disease, nephropathy secondary to a storage or other metabolic disease, rare renal tubular disorder, rare causes of hypertension, and inherited renal cancer-predisposing syndromes), epidemiological keywords (e.g. incidence, prevalence, case reports, case series), and terms related to kidney disease (e.g. chronic kidney disease, proteinuria, kidney failure). Articles published in English between December 2013 and 2023 were included. Articles were excluded if they were randomized control trials, case-control studies, cross-sectional studies, or without original results. All studies were uploaded into Covidence, a systematic review software, and duplicates were removed. Titles and abstracts were independently screened by two authors against the eligibility criteria, with conflicts resolved by a third author. The full text of selected studies will now be assessed against the eligibility criteria and data extracted using a data extraction tool. Descriptive statistics will be used to describe the data.
Results:
The literature search yielded 10,810 references, of which over 7,200 references will need full-text review. During this stage, case reports, case series, and cohort studies that did not report the incidence or prevalence of RKDs will be excluded. For these excluded studies, information such as rare disease group, country of origin, and whether there was a genetic component to the study will be extracted. For included studies, additional information that will be extracted will include the aim of the study, the specific RKD reviewed, the type of epidemiological indicator, and reported incidence/prevalence data.
Conclusions:
Our review will provide a snapshot of the global research activity on RKD in the past decade. To the best of our knowledge, no other review of RKDs to this scale has been conducted. We believe that this study will highlight gaps in literature and provide targeted areas for more research in RKDs.
I have potential conflict of interest to disclose.
This project is supported by Novartis.
I did not use generative AI and AI-assisted technologies in the writing process.