Chronic kidney disease of undetermined etiology around the world

Background: Epidemics of chronic kidney disease of uncertain etiology (CKDu) are occurring on the Pacific coast of Central America, in Sri Lankan and Indian agricultural communities, and in other hotspots around the world. CKDu primarily affects male agricultural workers, and traditional risk factors such as diabetes and hypertension are not involved in the pathogenesis. Although a causal factor has not yet been identified, culprits include repeated volume depletion-induced kidney injury, as well as exposure to agrichemicals, heavy metals and nephrotoxins contained in drugs, beverages, and traditional medications. Multiple risk factors may interact in a synergistic fashion thus resulting in chronic kidney damage. The absence of undefined protective factors may amplify the risk. Summary: This review focuses on the current understanding of CKDu by analyzing epidemiology, potential risk factors, and clinical and pathological features as well as geographical peculiarities of each disease. We also focus our attention on the etiology of these conditions in which multiple factors may synergistically contribute to the development and progression of the disease. The last part of the manuscript is dedicated to the research agenda and practical recommendations. Key Messages: Since renal replacement therapy is not extensively available in areas where CKDu is widespread, prevention by avoiding all known potential risk factors is crucial. Innovative healthcare solutions and social policies in endemic areas along with collaborative clinical research projects are needed to better identify factors involved in disease promotion and progression.