Mendley oversees research related to acute and chronic kidney diseases that affect children, including congenital and acquired renal disorders. (Photo courtesy of NIDDK)

A workshop hosted last month by the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) and NIEHS focused on chronic kidney disease of unknown origin (CKDu). A broad range of experts joined the Chronic Kidney Diseases in Agricultural Communities workshop June 25-26 in Bethesda, Maryland to discuss the global health problem.

The organizers’ goal was to identify gaps in knowledge and develop a coordinated scientific research agenda. Ultimately, this collaborative effort could lead to a better understanding of the causes of this epidemic, as well as potential treatments and intervention strategies.

Attacking from all angles

“We planned the workshop with the goal of bringing together a broad range of scientific expertise to permit new ideas to be introduced, to help divergent perspectives align, and to create a collaborative space for constructive discussion,” said Susan Mendley, M.D., a program director in the NIDDK Division of Kidney, Urologic, and Hematologic Diseases (KUH). “From the feedback we have received, I think we succeeded.”

Mendley led planning of the meeting, along with NIDDK co-organizers Paul Kimmel, M.D. and Kevin Abbott, M.D. KUH Division Director Robert Star, M.D., and NIEHS Division of Extramural Research and Training Director Gwen Collman, Ph.D., provided opening remarks.

Joubert oversees research in molecular epidemiology, cardiovascular, respiratory, metabolic, immune, and kidney epidemiology, as well as statistical methods development. (Photo courtesy of Steve McCaw)

Bonnie Joubert, Ph.D., a program director in the NIEHS Population Health Branch, co-organized the event with NIDDK and other experts from NIEHS. “An interdisciplinary group of participants addressed the clinical, scientific, and social complexities of this important topic,” she said. “The nephrologists, pathologists, epidemiologists, toxicologists, and other scientists each brought a distinct perspective.”

Joubert expressed hope that the workshop would encourage and strengthen collaborative partnerships.

An enigmatic epidemic

Chronic kidney disease is a condition in which the kidneys are damaged or cannot filter blood normally. As a result, excess fluid and waste from the blood remain in the body and may cause other health problems, including heart disease, stroke, and infections. The main risk factors for chronic kidney disease include diabetes, heart disease, high blood pressure, and infections.

But these traditional risk factors do not account for all cases, particularly in agricultural communities. Over the past few decades, there has been an increase in Sri Lanka and Central America of recognized cases of CKDu among young adults. Although the worldwide extent of the disease is not known, affected areas include Egypt and India.

Importantly, the causes are unknown and may vary from one region to another. Despite the growing prevalence of CKDu, there remains no universal set of criteria, or case definition, for deciding whether an individual has the disease.

The experts who gathered for the workshop recognized the lack of consensus and definitive data to support a single cause. They discussed possible explanations such as exposure to heat, pesticides, herbicides, fertilizers, and cadmium, arsenic, and other toxic heavy metals. Potential contributing factors include dehydration, malnutrition, and excess sugar consumption.

“Public health efforts are ongoing, but can be strengthened by clearer coordination of research and prevention efforts across countries,” Joubert said.

Sparking public health strategies

Currently, NIDDK and NIEHS fund national and global research on the role of environmental exposures and genetics in CKDu. Some projects aim to identify early biological markers or underlying cellular mechanisms. Others are focused on developing new therapies.

Toward this goal, participants in the June workshop focused on creating a common case definition of CKDu and identifying potential causes. They also discussed how to overcome research barriers, facilitate collaboration among investigators, and properly design long-term epidemiological studies. NIDDK, with the assistance of NIEHS, will plan a series of workshop reports on these topics.

(Janelle Weaver, Ph.D., is a contract writer for the NIEHS Office of Communications and Public Liaison.)