Resolving the enigma of the mesoamerican nephropathy: a research workshop summary.

The First International Research Workshop on Mesoamerican Nephropathy (MeN) met in Costa Rica in November 2012 to discuss how to establish the extent and degree of MeN, examine relevant causal hypotheses, and focus efforts to control or eliminate the disease burden. MeN describes a devastating epidemic of chronic kidney disease of unknown origin predominantly observed among young male sugarcane cutters. The cause of MeN remains uncertain; however, the strongest hypothesis pursued to date is repeated episodes of occupational heat stress and water and solute loss, probably in combination with other potential risk factor(s), such as nonsteroidal anti-inflammatory drug and other nephrotoxic medication use, inorganic arsenic, leptospirosis, or pesticides. At the research workshop, clinical and epidemiologic case definitions were proposed in order to facilitate both public health and research efforts. Recommendations emanating from the workshop included measuring workload, heat, and water and solute loss among workers; quantifying nephrotoxic agents in drinking water and food; using biomarkers of early kidney injury to explore potential causes of MeN; and characterizing social and working conditions together with methods for valid data collection of exposures and personal risk factors. Advantages and disadvantages of different population study designs were detailed. To elucidate the etiology of MeN, multicountry studies with prospective cohort design, preferably integrating an ecosystem health approach, were considered the most promising. In addition, genetic, experimental, and mechanistic methods and designs were addressed, specifically the need for kidney biopsy analysis, studies in animal models, advances in biomarkers, genetic and epigenetic studies, a common registry and repository of biological and demographic data and/or specimens, and other areas of potential chronic kidney disease experimental research. Finally, in order to improve international collaboration on MeN, workshop participants agreed to establish a research consortium to link these Mesoamerican efforts to other efforts worldwide.