Chronic Interstitial Nephritis in Agricultural Communities (CINAC) in Sri Lanka

Genetic Factors Related to the Development or Progression of Mesoamerican Endemic Nephropathy

Over the past two decades, Mesoamerican endemic nephropathy (MeN) has become a major public health problem in certain regions of Mexico and Central American countries. The etiology of this disease is multifactorial, and important environmental factors have been described, such as chronic heat stress, recurrent episodes of dehydration, infections, and exposure to toxins of chemical and biological origin. Genetic and epigenetic factors have been proposed to play significant roles in MeN. Recent studies have analyzed the role of these factors in MeN. In some cases, these factors appear to be associated with accelerated deterioration of established kidney disease due to preexisting endothelial dysfunction and tubulopathy. In other cases, they appear to be associated with early kidney damage, even before occupational exposure, suggesting that they may play a relevant role in the genesis of the disease. Other factors appear to act as risk reducers for developing MeN in areas with a high prevalence of the disease. Therefore, this disease has a rather complex multifactorial etiology, with possible polygenic contributions, possible epigenetic phenomena, and multiple environmental factors.

Climate change and chronic kidney disease (CKD) among outdoor workers: a systematic review

Global warming was positively related to chronic kidney disease (CKD) among outdoor workers. Based on the present systematic review, we gathered the risk factors (individual, environmental, and occupational) for climate change-induced CKD among outdoor workers up to 2023. There has been a rapid increase of CKD in tropical and subtropical countries with low and middle income. Among the risk factors air temperature, diabetes, hypertension, physically demanding job tasks, age, sex, dehydration, working and living in a hot environment, and body mass index (BMI) were the main contributors to CKD-related. Although the high hot-wet and hot-dry climate conditions related to CKD were high, this trend increased in developing countries. Climate change will adversely impact global kidney health over the century through its effects on temperature and the risk of endemic infections. Outdoor workers may face an elevated risk of CKD, with the male population being more vulnerable. Implementing preventive strategies (cooling techniques, acclimation, work/rest cycles, and appropriate clothing) against heat stress due to global warming is crucial.

Modulation of the thiol redox proteome by sugarcane ash-derived silica nanoparticles: insights into chronic kidney disease of unknown etiology

INTRODUCTION

Chronic kidney disease of unknown etiology (CKDu) is an epidemic which is increasingly prevalent among agricultural workers and nearby communities, particularly those involved in the harvest of sugarcane. While CKDu is likely multifactorial, occupational exposure to silica nanoparticles (SiNPs), a major constituent within sugarcane ash, has gained increased attention as a potential contributor. SiNPs have high potential for generation of reactive oxygen species (ROS), and their accumulation in kidney could result in oxidative stress induced kidney damage consistent with CKDu pathology.

METHODS

In order to characterize the impact of sugarcane ash derived (SAD) SiNPs on human kidney proximal convoluted tubule (PCT) cells and identify potential mechanisms of toxicity, HK-2 cells were exposed to treatments of either pristine, manufactured, 200 nm SiNPs or SAD SiNPs and changes to cellular energy metabolism and redox state were determined. To determine how the cellular redox environment may influence PCT cell function and toxicity, the redox proteome was examined using cysteine-targeted click chemistry proteomics.

RESULTS

Pristine, 200 nm SiNPs induced minimal changes to energy metabolism and proteomic profiles in vitro while treatment with SAD SiNPs resulted in mitochondrial membrane hyperpolarization, inhibited mitochondrial respiration, increased reactive oxygen species generation, and redox proteomic trends suggesting activation of aryl hydrocarbon receptor (AHR) and other signaling pathways with known roles in mitochondrial inhibition and CKD progression.

CONCLUSION

Results suggest that PCT cell exposure to SAD SiNPs could promote glycolytic and fibrotic shifts consistent with CKDu pathology via oxidative stress-mediated disruption of redox signaling pathways.

Occupational risks associated with chronic kidney disease of non-traditional origin (CKDnt) in Brazil: it is time to dig deeper into a neglected problem

In the past decades, an epidemic of chronic kidney disease (CKD) has been associated with environmental and occupational factors (heat stress from high workloads in hot temperatures and exposure to chemicals, such as pesticides and metals), which has been termed CKD of non-traditional origin (CKDnt). This descriptive review aims to present recent evidence about heat stress, pesticides, and metals as possible causes of CKDnt and provide an overview of the related Brazilian regulation, enforcement, and health surveillance strategies. Brazilian workers are commonly exposed to extreme heat conditions and other CKDnt risk factors, including increasing exposure to pesticides and metals. Furthermore, there is a lack of adequate regulation (and enforcement), public policies, and strategies to protect the kidney health of workers, considering the main risk factors. CKDnt is likely to be a significant cause of CKD in Brazil, since CKD's etiology is unknown in many patients and several conditions for its development are present in the country. Further epidemiological studies may be conducted to explore causal associations and estimate the impact of heat, pesticides, and metals on CKDnt in Brazil. Moreover, public policies should prioritize reducing workers´ exposure and promoting their health and safety.

Chronic dehydration induces injury pathways in rats, but does not mimic histopathology of chronic interstitial nephritis in agricultural communities

CINAC-patients present renal proximal tubular cell lysosomal lesions which are also observed in patients experiencing calcineurin inhibitor (CNI) nephrotoxicity, suggesting that CINAC is a toxin-induced nephropathy. An alternative hypothesis advocates chronic dehydration as a major etiological factor for CINAC. Here, we evaluated histological and molecular changes in dehydrated versus toxin exposed rats. Wistar rats were divided in 3 groups. Group 1 (n = 6) had free access to drinking water (control group). Group 2 (n = 8) was water deprived for 10 h per 24 h, 5 days/week and placed in an incubator (37 °C) for 30 min/h during water deprivation. Group 3 (n = 8) underwent daily oral gavage with cyclosporine (40 mg/kg body weight). After 28 days, renal function, histopathology and proteomic signatures were analysed. Cyclosporine-treated rats developed focal regions of atrophic proximal tubules with associated tubulo-interstitial fibrosis. PASM staining revealed enlarged argyrophilic granules in affected proximal tubules, identified as lysosomes by immunofluorescent staining. Electron microscopy confirmed the enlarged and dysmorphic phenotype of the lysosomes. Overall, these kidney lesions resemble those that have been previously documented in farmers with CINAC. Dehydration resulted in none of the above histopathological features. Proteomic analysis revealed that dehydration and cyclosporine both induce injury pathways, yet of a clear distinct nature with a signature of toxicity only for the cyclosporine group. In conclusion, both cyclosporine and dehydration are injurious to the kidney. However, dehydration alone does not result in kidney histopathology as observed in CINAC patients, whereas cyclosporine administration does. The histopathological analogy between CINAC and calcineurin inhibitor nephrotoxicity in rats and humans supports the involvement of an as-yet-unidentified environmental toxin in CINAC etiology.

Prevalence of Chronic Kidney Disease of Uncertain Etiology Within Selected Farming Communities in Rural Sri Lanka

Background

Chronic kidney disease of uncertain etiology (CKDu) is an emergent health concern, particularly in tropical farming communities in several global hotspots, including Sri Lanka. This particular nephropathy is characterized by a progressive decline in kidney function in the absence of conventional chronic kidney disease (CKD) risk factors such as diabetes mellitus, hypertension, and other identifiable kidney disorders. As it is almost asymptomatic at early stages, CKDu is mostly diagnosed at late stages with significant kidney damage. Hence, the identification of disease susceptibility and vulnerable communities at the earliest possible instances is highly important for the management of the disease.

Objective

We aimed to compare kidney health across three different farming communities in Sri Lanka to identify CKDu susceptibilities.

Methods

A cross-sectional study was performed with three selected farming communities: paddy farmers (PF; N = 581), sugarcane farmers (SF; N = 550), and vegetable farmers (VF; N = 244) in comparison with an age-matched control group of nonfarming (NF; N = 225) individuals. A medical examination was performed to investigate health status and medical history, whereas a urinalysis was performed to determine creatinine and albumin contents. Estimated glomerular filtration rate (eGFR) and urinary albumin-creatinine ratio (ACR) were used for assessment of kidney function. CKDu susceptibility was determined based on eGFR, and urinary ACR adhering to the clinical practice guidelines in Sri Lanka.

Results

The median (interquartile range [IQR]) eGFR levels of PF (85 mL/min/1.73 m2 [72-97]) and SF (93 mL/min/1.73 m2 [73-112]) were significantly lower than that of the NF group (103 mL/min/1.73 m2 [87-125]) (P < .0001), whereas eGFR of VF (100 mL/min/1.73 m2 [80-111]) was not significantly different compared with NF. The median (IQR) urinary ACR levels of the study groups, PF, SF, VF, and NF, were 0.59 (0.26-1.45), 0.46 (0.28-0.88), 0.45 (0.34-0.90), and 0.44 (0.34-1.02) mg/mmol, respectively. However, urinary ACR did not differ significantly across the study groups (P > .05). The prevalence of CKDu within PF (13.60%), SF (12.54%), and VF (6.67%) communities was significantly higher (P < .05) compared with the NF (2.67%). Of the total CKD cases, CKDu susceptible cases represented 73%, 69%, 50%, and 25% in PF, SF, VF, and NF, respectively, indicating a high risk of CKDu susceptibility among farming communities. Moreover, a noteworthy association of CKDu was observed with agrochemical exposure (odds ratio [OR] = 3.11, 95% confidence interval [CI] = 1.36-7.09). Concerning the farming practices, sugarcane farming showed the highest association with CKDu prevalence (OR = 3.40, 95% CI = 1.49-7.78).

Conclusions

Compared with the nonfarming group, a significant risk of CKDu was observed in the three farming communities, particularly among paddy and sugarcane farmers. Longitudinal epidemiological studies to identify vulnerable farming communities and associated risk factors are critically needed to develop effective management strategies against CKDu within farming communities.

Chronic Tubulointerstitial Nephropathy of Agricultural Communities

Chronic interstitial nephritis in agricultural communities is an emerging public health concern affecting numerous agricultural communities in tropical countries, including regions in India, with a significant impact on the health and well-being of affected individuals. The affected individuals suffer from various psychosocial, nutritional, and metabolic challenges due to organ failure, which affects their quality of life. The etiology remains poorly understood, and various risk factors, which include various environmental and occupational hazards, have been implicated in its development. The recent discovery of lysosomal proximal tubulopathy has reignited interest in its pathogenesis. Along with the representative feature of chronic interstitial nephritis, changes suggestive of tubular injury have also been reported. It is suggested to use the term “chronic tubulointerstitial nephropathy of agricultural community” instead of chronic interstitial nephritis of the agricultural communities. Chronic tubulointerstitial nephropathy in agricultural communities is a slowly progressive disease that initially does not cause any symptoms in patients and most patients have a delayed onset of symptoms. Several diagnostic criteria have been introduced over the past years and one introduced by the Ministry of Health of Sri Lanka is widely used. The management of this chronic illness is no different from other causes of chronic interstitial nephritis and our focus should be on implementing various preventive strategies to reduce its incidence in agricultural communities and protect the health and well-being of agricultural workers. By disseminating knowledge about chronic tubulointerstitial nephropathy in agricultural communities, we can contribute to the development of evidence-based interventions to reduce the burden of the disease on affected communities. Moreover, we would like to sensitize physicians to this entity to increase awareness and identify potential endemic areas in various agricultural communities.

Randomized control trial of prednisolone and doxycycline in patients with acute interstitial nephritis of unknown aetiology

BACKGROUND

Patients presenting with acute interstitial nephritis (AIN) of unknown aetiology, probably the earliest presentation of chronic kidney disease of unknown aetiology (CKDu), have been treated with oral prednisolone and doxycycline by physicians in Sri Lanka. This trial assessed the effectiveness of prednisolone and doxycycline based on eGFR changes at 6 months in patients with AIN of unknown aetiology.

METHOD

A randomized clinical trial with a 2 × 2 factorial design for patients presenting with AIN of unknown aetiology (n = 59) was enacted to compare treatments with; A-prednisolone, B-doxycycline, C-both treatments together, and D-neither. The primary outcome was a recovery of patients' presenting renal function to eGFR categories: 61-90 ml/min/1.73m2 (complete remission- CR) to 31-60 ml/min/1.73m2 (partial remission- PR) and 0-30 ml/min/1.73m2 no remission (NR) by 6 months. A secondary outcome was progression-free survival (not reaching < 30 ml/min/1.73m2 eGFR), by 6-36 months. Analysis was by intention to treat.

RESULTS

Seventy patients compatible with a clinical diagnosis of AIN were biopsied for eligibility; 59 AIN of unknown aetiology were enrolled, A = 15, B = 15, C = 14 and D = 15 randomly allocated to each group. Baseline characteristics were similar between groups. The number of patients with CR, PR and NR, respectively, by 6 months, in group A 3:8:2, group B 2:8:3 and group C 8:5:0 was compared with group D 8:6:1. There were no significant differences found between groups A vs. D (p = 0.2), B vs. D (p = 0.1) and C vs. D (p = 0.4). In an exploratory analysis, progression-free survival in prednisolone-treated (A + C) arms was 0/29 (100%) in comparison to 25/30 (83%) in those not so treated (B + D) arms, and the log-rank test was p = 0.02, whereas no such difference found (p = 0.60) between doxycycline-treated (B + C) arms 27/29 (93%) vs those not so treated (A + D) arms 27/30 (90%).

CONCLUSION

Prednisolone and doxycycline were not beneficial for the earliest presentation of CKDu at 6 months. However, there is a potential benefit of prednisolone on the long-term outcome of CKDu. An adequately powered steroid trial using patients reaching < 30 ml/min/1.73m2 eGFR by 3 years, as an outcome is warranted for AIN of unknown aetiology.

TRIAL REGISTRATION

Sri Lanka Clinical Trial Registry SLCTR/2014/007, Registered on the 31st of March 2014.

Genetics of Chronic Kidney Disease in Low-Resource Settings

Advances in kidney genomics in the past 20 years has opened the door for more precise diagnosis of kidney disease and identification of new and specific therapeutic agents. Despite these advances, an imbalance exists between low-resource and affluent regions of the world. Individuals of European ancestry from the United States, United Kingdom, and Iceland account for 16% of the world's population, but represent more than 80% of all genome-wide association studies. South Asia, Southeast Asia, Latin America, and Africa together account for 57% of the world population but less than 5% of genome-wide association studies. Implications of this difference include limitations in new variant discovery, inaccurate interpretation of the effect of genetic variants in non-European populations, and unequal access to genomic testing and novel therapies in resource-poor regions. It also further introduces ethical, legal, and social pitfalls, and ultimately may propagate global health inequities. Ongoing efforts to reduce the imbalance in low-resource regions include funding and capacity building, population-based genome sequencing, population-based genome registries, and genetic research networks. More funding, training, and capacity building for infrastructure and expertise is needed in resource-poor regions. Focusing on this will ensure multiple-fold returns on investments in genomic research and technology.

Melatonin ameliorates renal dysfunction in glyphosate- and hard water-treated mice

Chronic interstitial nephritis in agricultural communities (CINAC) is a severe and widespread disease that has been associated with environmental and occupational exposure to glyphosate and hard water. However, the potential underlying mechanisms remain incompletely understood. Melatonin is reported to exert protective effects on the kidney, but whether melatonin can attenuate renal tubular injury in mice exposed to glyphosate combined with hard water is unclear. Here, mice were treated with high doses and environmentally relevant doses of glyphosate (100 mg/kg·bw and 0.7 mg/L, respectively) and/or hard water (2500 mg/L CaCO₃ and 250 mg/L Ca²⁺, respectively) via their drinking water for 12 weeks. We found that high-dose glyphosate or hard water treatment significantly increased the levels of biomarkers of renal damage, including β₂-microglobulin, neutrophil gelatinase-associated lipid carrier protein, and/or albumin, in the urine; these increased biomarker levels were correlated with obvious morphological changes, and all of these changes were also observed in animals exposed to environmentally relevant doses of glyphosate and/or high Ca²⁺ water. Melatonin (10 mg/kg·bw, intraperitoneal injection, daily for 12 weeks) administered concomitantly with high doses of glyphosate and hard water inhibited the glyphosate- and hard water-induced increases in the levels of kidney injury biomarkers and changes in morphology; this result was intriguing. Additionally, glyphosate combined with hard water at both high and environmentally relevant doses significantly upregulated the expression of the endoplasmic reticulum (ER) stress marker proteins Bip, ATF6, and PERK as well as the pyroptosis-related proteins (NLRP3 and caspase 1 signaling proteins) in renal tissues. Similarly, melatonin significantly attenuated the increased ER stress and pyroptosis induced by high doses of glyphosate and hard water. In summary, we conclude that exposure to glyphosate and hard water at both high doses and environmentally relevant doses causes renal dysfunction in mice, and this dysfunction can be attenuated by melatonin, possibly through the inhibition of ER stress and pyroptosis. Our results support the notion that melatonin may have therapeutic potential for the treatment of chronic kidney diseases.

Groundwater-Based Drinking Water Supply in Sri Lanka: Status and Perspectives

Drinking water is largely from groundwater in Sri Lanka, so quality management is of great concern. In order to achieve the 6th goal of United Nations (UN) Sustainable Development Goals (SDG), more efforts are being undertaken to secure drinking water quality. In this paper, the current status, challenges and opportunities of groundwater quality management and improvement in Sri Lanka were reviewed and discussed, based on previous studies. There are Ca-HCO3 type, Ca–Mg-HCO3 type and Na–SO4–Cl type groundwater dominated in the wet zone, intermediate and the dry zone, respectively. Elevated levels of hardness, fluoride, DOC, and alkalinity, and salinity are reported in the groundwater in the dry zone controlled by geology and arid climate. Although groundwater in some regions contain significant levels of nitrates, arsenic, cadmium and lead, the majority remain at acceptable levels for drinking purposes. As for treatment technologies, existing membrane-based drinking water treatment technologies such as RO (Reverse Osmosis) stations can produce safe and clean drinking water to the community, but this has still a limited coverage. To achieve a safe drinking water supply for all, especially in rural communities of Sri Lanka under the 6th goal of the UN SDG, more efforts in building up the infrastructure and man power are needed to monitor and assess groundwater quality regularly so as to develop management strategies. Research and development can be directed towards more cost-effective water treatment technologies. Protection of groundwater from being polluted, and educational and awareness programs for the stakeholders are also essential tasks in the future.

Mesoamerican nephropathy: A not so unknown chronic kidney disease

From 2000, Mesoamerican region has reached an important rate of chronic kidney disease of unknown etiology. Under the name of Meroamerican Nephropathy (MeN) several hypotheses (including dehydration, heat stress, environmental or toxic exposure or even infections) have tried to explain the etiology this new disease. MeN affects young men, agricultural workers exposed to high temperatures. MeN courses with unspecific symptoms as low-grade fever and dysuria and progressive kidney disease with impaired renal function and hydroelectrolyte disturbances. The diagnosis requires kidney biopsy showing tubule-interstitial nephritis (usually at chronic stage). Although MeN conditions a high morbi-mortality in endemic regions, there is a lack of specific treatment and only preventive measures have demonstrated some effect of prognosis (avoid heat stress, constant hydration). In this review we aim to summarize the available information of MeN, illustrating the information in a case report.

Chronic Kidney Disease of Unknown Etiology in India: What Do We Know and Where We Need to Go

Chronic kidney disease (CKD) not associated with known risk factors has been reported from parts of India and is presumed to be similar to CKD of unknown etiology (CKDu) that has been described from Central America. The reports from India have been fragmented without clear description of the disease phenotype or its determinants. This paper summarizes the current state of knowledge around CKDu in India based on a review of literature, multi-stakeholder consultation, and a survey of Indian nephrologists. We also contacted individual research groups to solicit data. Our findings suggest that that CKDu is reported from most regions in India; however, it is interpreted differently from the phenotype described from Central America and Sri Lanka. The differences include lack of a clear demographic or occupation group, older age of affected participants, and presence of mild hypertension and low-grade proteinuria. Well-designed prospective field studies with appropriate diagnostic workup are needed to establish the disease burden and identify etiologies, along with socioeconomic and health consequences, the intersection with the environment, and the public health response. Community-based research should phenotype the entire CKD population rather than be restricted to cases with presumed CKDu based on predefined criteria. Guidelines are needed for clinical evaluation, referral, management, and harmonization of clinical documentation and health records. More data are needed to support the existence of a unique CKDu phenotype in India.

Hantavirus infections in Italy: not reported doesn't mean inexistent

BACKGROUND

Hantaviruses can cause serious human diseases including hemorrhagic fever with renal syndrome (HFRS) and Hantavirus Cardiopulmonary Syndrome (HCPS). European Hantavirus are usually associated with HFRS, and their geographical distribution mirrors the ecology of reservoir host species. Epidemiology of HFRS is well-studied in Western Europe, but data from Italy are fragmentary.

METHODS

We searched into two different databases (PubMed and EMBASE), focusing on studies reporting the prevalence of Hantaviruses in Italy. Data were extracted using a standardized assessment form, and results of the analyses were systematically reported, summarized and compared.

RESULTS

We identified a total of 18 articles, including 12 reports (total population: 5,336 subjects, 1981-2019) and 6 case reports (1984-2019). In total, 200 subjects exhibited some degree of seropositivity, with a pooled seroprevalence of 1.7% (95% confidence interval 0.7%-4.0%) in the general population. Higher occurrence was reported in selected subgroups, i.e. acute (28.7%, 95%CI 22.1-36.2) and chronic (6.6%, 95%CI 4.7-9.1) renal failure, forestry workers (3.0%, 95%CI 1.4-6.5, actual range 0.0 to 10.8%).

CONCLUSIONS

In the last decade, no human cases of hantavirus infection have been officially reported in Italy. However, our analysis stresses the actual occurrence of Hantavirus among general population and in selected population groups. Further studies on hantavirus infection rates in reservoir host species (rodents, shrews, and bats) and virus transmission to humans are needed to prevent outbreaks in the future.

Mesoamerican nephropathy: A not so unknown chronic kidney disease

From 2000, Mesoamerican region has reached an important rate of chronic kidney disease of unknown etiology. Under the name of Meroamerican Nephropathy (MeN) several hypotheses (including dehydration, heat stress, environmental or toxic exposure or even infections) have tried to explain the etiology this new disease. MeN affects young men, agricultural workers exposed to high temperatures. MeN courses with unspecific symptoms as low-grade fever and dysuria and progressive kidney disease with impaired renal function and hydroelectrolyte disturbances. The diagnosis requires kidney biopsy showing tubule-interstitial nephritis (usually at chronic stage). Although MeN conditions a high morbi-mortality in endemic regions, there is a lack of specific treatment and only preventive measures have demonstrated some effect of prognosis (avoid heat stress, constant hydration). In this review we aim to summarize the available information of MeN, illustrating the information in a case report.

A comparative review: Chronic Kidney Disease of unknown etiology (CKDu) research conducted in Latin America versus Asia

INTRODUCTION

The incidence of chronic kidney disease of unknown or uncertain etiology (CKDu) is recognized as a global non-communicable health crisis. The goal of this work is to compare the types of research studies in Latin America and Asia, two regions with increasing CKDu incidence.

METHODS

A comparative literature review was conducted to evaluate the CKDu research design for peer-reviewed articles published from 2015 to 2019. Full texts were reviewed to identify study location, study type, study design, risk factors evaluated, and if applicable, sample type and number.

RESULTS

In Asia and Latin America, 82 and 65 articles were identified in total, respectively, with 55 field studies in Asia versus 34 in Latin America. In Asia, research was focused on drinking water (34), heavy metals (20), and agrochemical product usage (19) as potential risk factors. In Latin America, research focused mostly on heat stress/dehydration (36) and agrochemical product usage (18) as potential CKDu risk factors. Biological samples were collected more frequently than environmental samples, especially in Latin America.

DISCUSSION

Research to pinpoint the risk factors associated with CKDu to date is not standardized and typically limited in geographical scope. The emphasis of CKDu research varies by geographic region, with a greater priority placed on water quality and chemical exposure in Asia, versus dehydration and heat stress in Latin America. Using a harmonized approach to CKDu research would yield improved understanding of the risk factors associated with CKDu and how they compare across affected regions.

Chronic interstitial nephritis in agricultural communities (CINAC) and lysosomal tubulopathy: Is there a place for anti-oxidants?

Chronic Interstitial Nephritis in Agricultural Communities (CINAC) continues to attract controversy in the scientific community. It was previously known as Chronic Kidney Disease of Unknown Etiology (CKDu) and is not associated with the common aetiological factors such as diabetes. There is general acceptance that it is an environmentally induced disorder due to a combination of toxicities: heavy metals from food, fluoride in drinking water, hard water, heat stress and pesticides. The recent findings of a lysosomal inclusion body tubulopathy is of great interest to those attempting to find therapeutic agents to slow or eliminate its renal damage. The paper argues that despite these new findings, oxidative stress could play a key role and proposes that anti-oxidants such as Vitamin C and E be repurposed for treatment.

Other Potential CKD Hotspots in the World: The Cases of Mexico and the United States

Hotspots of chronic kidney disease of unknown etiology (CKDu) have been identified throughout the globe, of which the Mesoamerican nephropathy in Central America is the most conspicuous example. It affects mainly agricultural workers, heat exposure during extenuating shifts leading to sudden dehydration and subsequent acute kidney injury (AKI) episodes is the main hypothesis, with other factors such as environmental and social determinants playing an underlying role. Recent reports have suggested that Mexico and the United States may have newly identified CKDu hotspots. Studies from Tierra Blanca, a rural region in Mexico, have shown that the prevalence of probable CKD is high (25%) among the population, of which almost half of the identified cases had no known risk factor (such as diabetes or hypertension). Studies in Hispanic agricultural workers from California and Florida have shown that heat stress and dehydration is frequent and is correlated with AKI episodes after a work shift (33% of workers in one shift). Because recurrent AKI is an established risk factor for CKD, these studies strengthen the evidence that suggests an association between this occupational exposure and CKD. Whether the etiology responsible for the entities described is the same as in other CKDu hotspots in the world remains unknown. The development of preventative and intervention strategies is the most urgent priority to address this issue.

Genetic and Developmental Factors in Chronic Kidney Disease Hotspots

Chronic kidney disease increasingly is being recognized as an important global public health problem. Interindividual susceptibility to kidney disease is high and likely is dependent on risk modulation through genetics, fetal and early childhood development, environmental circumstances, and comorbidities. Traditionally, the chronic kidney disease burden has been ascribed largely to hypertension and diabetes. Increasingly, evidence is accumulating that nontraditional risk factors may predominate in some regions and populations, contributing to epidemics of kidney disease. Such nontraditional risk factors include environmental exposures, traditional medicines, fetal and maternal factors, infections, kidney stones, and acute kidney injury. Genetic factors may predispose patients to chronic kidney disease in some populations. Chronic kidney disease of unknown origin has its epicenters in Central America and South Asia. Such clustering of CKD may represent either genetic or environmentally driven kidney disease, or combinations of both. Developmental conditions impacting kidney development often are related to poverty and structural factors that persist throughout life. In this article, we explore the possibilities that genetic and developmental factors may be important contributors to the epidemics in these regions and suggest that optimization of factors impacting kidney development hold promise to reduce the risk of kidney disease in future generations.