Mesoamerican Nephropathy (MeN): What We Know so Far

Figures & data

Figure 1 Mesoamerican Nephropathy: Early timeline. During the first years after the initial description of the disease, the progress of knowledge was slow, mainly due to the plight of the developing countries where it occurs.

Figure 2 Mesoamerican Nephropathy: Clinical presentation and evolution. From suspected case to progression, the clinical aspects of the management of these patients are similar in all countries of the region.

Abbreviations: V, and/or; GFR, glomerular filtration rate; CKD, chronic kidney disease; GN, glomerulonephritis; HBP, high blood pressure; SCre, serum creatinine.

Table 1 Definition of CKDu

Suspected CKDu

1. eGFR<60 mL/min/1.73m^2.

2. and or albuminuria>30mg/g

3. and or proteinuria>150 mg/g

All Any of the above in the absence of HT, DM, AKI.

Exclusion criteria; proteinuria >2g/g excludes the diagnosis

Probable CKDu

1. Fulfill the criteria of “Suspected CKDu”

2. Hypokalemia and/or hyperuricemia

3. 1 AND 2 in the absence of autoimmune disease, glomerular disease, congenital kidney disease, obstructive kidney disease

Confirmed after repeat assessment at week 12

Confirmed CKDu

All of the above-mentioned criteria for probable CKDu

AND histopathological features consistent with CKDu on kidney biopsy (pyelonephritis and interstitial nephritis caused by specific etiology should be excluded from the definition).

* In those cases where kidney biopsy is not possible, CKDu can be clinically confirmed with the above mentioned criteria for probable CKDu

Note: Adapted from Anupama YJ, Sankarasubbaiyan S, Taduri G. Chronic kidney disease of unknown etiology: case definition for India – a perspective. Indian J Nephrol. 2020.²⁸

Figure 3 Mesoamerican Nephropathy: Risk factors and pathophysiology. The four elements on which MeN’s physiopathology focuses. The community exposed to agrochemicals, heat stress, dehydration and the third factor that could correspond to genetic and epigenetic alterations, appear as a constant and repetitive stimulus that generate tubular damage and accelerate the progression towards CKD. Those elements develop in the context of disease’s social factors who accompany the process.

Figure 4 Mesoamerican Nephropathy: Conceptual model. A conceptual model on the influence of social determinants of disease.

Figure 5 The multicausal phenomenon of Mesoamerican Nephropathy. The community is exposed to social determinants of poverty, genetic and epigenetic changes. It is located at less than 300 meters above sea level and is exposed to heat, contaminated water. However, there is a group of agricultural workers who, in addition, are exposed to heat stress, exercise, dehydration, agrochemicals and Silica particles. All circumstances are given in this group to develop the perfect storm that triggers and accelerates the entire physiopathological process of the MeN.

Table 2 Recommendations for Clinical Management of Patients with CKDu by Healthcare Providers

1. Ensure adequate access to safe drinking water and promotion of appropriate hydration.

2. Encourage pursuing frequent rest breaks and reducing heat exposure in the occupational setting (rest and shade).

3. Emphasize avoidance of nephrotoxic medications, especially NSAIDs and over the counter medications not requiring oversight by a healthcare provider

4. Emphasize avoidance of all herbal medications

5. Encourage minimization of alcohol consumption, with a focus on avoidance of home-brewed alcohol

6. Counsel on using appropriate personal protective equipment and avoiding agrichemical exposures

7. Establish regular care with physicians, ideally nephrologists, who can diagnose early the presence of kidney dysfunction and manage sequelae of chronic kidney disease including electrolyte and acid-base disturbances

8. There is insufficient evidence at present to support the use of pharmacotherapy to prevent progressive kidney function decline in CKDu, including ACEIs and ARBs, allopurinol, and corticosteroids. However, use of these and other medications in appropriate clinical situations arising concurrently with CKDu may be appropriate for some patients.

Note: Clinical Considerations surrounding Chronic Kidney Disease of Undetermined Etiology (CKDu): A report from the Third International Workshop of CKDu, San Jose, CR, March 2019.⁶²

Anupama YJ, Sankarasubbaiyan S, Taduri G. Chronic kidney disease of unknown etiology: case definition for India – a perspective. Indian J Nephrol. 2020.

 Web of Science ®Google Scholar

Crowe JL, Joubert BR, Brooks DR, Eds. Report From the Third International Workshop on Chronic Kidney Diseases of Uncertain/Non-Traditional Etiology in Mesoamerica and Other Regions, SALTRA, 20 March - 22 March 2019, San José, Costa Rica

 Google Scholar