Investigating the cause of clinical symptoms ordinarily doesn’t involve organoid research. But this was no ordinary patient.

“Sam” was born in 2015 without a pancreas due to a homozygous genetic mutation in PDX1, the gene that is essential for the development of pancreatic exocrine and endocrine cells. He was discharged from the Cincinnati Children’s neonatal intensive care unit on insulin therapy and followed by pediatric endocrinology and pediatric gastroenterology. When his care team could not determine the cause of symptoms such as chronic diarrhea, poor weight gain and abdominal pain, Mansa Krishnamurthy, MD, MSc, recruited him to a research study for patients with rare genetic forms of diabetes and congenital hyperinsulinism.

Krishnamurthy, a physician-scientist in the Division of Endocrinology, uses basic and translational approaches in the lab to better understand how rare genetic mutations affect insulin production and secretion. Her work is made possible in part by resources from the hospital’s Center for Stem Cell and Organoid Medicine (CuSTOM). The Center specializes in technologies such as patient-derived induced pluripotent stem cells, CRISPR/Cas9 genetic correction and organoid modeling. Organoid model systems contain all the various cell types one would expect to find in patients, making them an excellent tool to study disease.

A Surprising Discovery

“Researchers know PDX1 is important for the pancreas, but we don’t know how a mutation in the gene affects the gastrointestinal (GI) tract,” says Krishnamurthy. Hoping to shed light on the pathophysiology and potential source of the child’s symptoms, she worked with her research mentor, Jim Wells, PhD, to generate organoids from the patient’s stem cell line representing different regions of the GI tract (mainly the stomach and intestine).

What she discovered surprised her. “We found bits of intestine in the stomach organoids and bits of stomach in the intestinal organoids—a condition referred to as gastric and intestinal metaplasia,” Krishnamurthy says. “This prompted a re-examination of recent biopsies from the patient that my gastroenterology colleagues had obtained, which also showed evidence of the metaplasia.”

Krishnamurthy shared her discovery with Joe Palermo, MD, PhD, Sam’s pediatric gastroenterologist at Cincinnati Children’s. Palermo had observed abnormalities in the patient’s previous biopsies and was interested in Krishnamurthy’s more detailed investigation. He suggested that at the child’s next scheduled endoscopy, he would biopsy tissue from the stomach and duodenum, avoiding the transition zone where stomach and intestine cells often coexist. Those biopsy results confirmed Krishnamurthy’s initial findings.

Capturing Information a Biopsy Could Not

“Our discovery didn’t shed light on what was causing Sam’s GI symptoms, but it did change his treatment plan,” Krishnamurthy says. “The presence of metaplasia raises his risk of getting gastric and intestinal cancers, so we will monitor him over time with an increased number of endoscopies with biopsies. In a sense, the organoids we created were diagnostic and captured valuable information that a biopsy could not.”

In the midst of her organoid study, Krishnamurthy discovered that a relative of Sam’s had the same PDX1 mutation and was receiving care at C.S. Mott Children’s Hospital at University of Michigan Health. She collaborated with pediatric endocrinologists and gastroenterologists there to enroll that child in her study and analyze biopsied tissue. Both children had the same finding of gastric and intestinal metaplasia.

Sam, now 8, is taking proton pump inhibitors to alleviate his pain symptoms and is doing well. He continues to be seen by Krishnamurthy and Palermo for ongoing care.

“Our work on behalf of children with rare mutations associated with neonatal diabetes and congenital hyperinsulinism is gaining momentum,” Krishnamurthy says. “We hope to enroll more patients with these conditions and build a biobank to better understand how mutations in critical genes cause severe pathologies in patients. It’s a very understudied area, but we must improve how we diagnose and clinically manage these patients and help them enjoy the best quality of life possible.”

To learn more, contact Mansa.Krishnamurthy@cchmc.org.

Krishnamurthy published the findings from the organoid study in Gastroenterology (October 2022).