Scientists have decoded an extremely rare case in which a Chinese woman with diabetes was hospitalised periodically for severe vomiting episodes of over 30 times on some days.
The 27-year-old woman, according to a study published last month in the journal Frontiers in Endocrinology, suffers from type 1 diabetes (T1D), an autoimmune disorder in which a person’s immune system attacks the healthy cells in their own pancreas that produce the hormone insulin.
An additional autoimmune disorder due to genetic factors and dysregulated immunity is suffered by one in five individuals who have T1D, pointed out researchers, including those from the University of Hong Kong.
They suspect the woman’s autoimmune disorder could be causing her to vomit, with the volume sometimes found to be in litres.
“The episodes were so severe that the patient had vomiting episodes more than 30 times a day and the vomiting volume could be as large as six litres,” scientists wrote in the study.
The doctors reportedly first examined the patient in 2016. She has since been hospitalised “almost once a month” with primary complaints of vomiting and abdominal pain.
New Research: Type 1 diabetes complicated with cyclic vomiting syndrome and exogenous insulin antibody syndrome: A case report: Every fifth individual with type 1 diabetes (T1D) suffers from an additional autoimmune disorder due to… https://t.co/tds1JZ4Hy3 #Endocrinology #Endo
— Frontiers in Endocrinology (@FrontEndocrinol) November 10, 2022
Each time before the woman experienced a full-blown episode of vomiting, she had an “impending sense of doom” and came to the hospital in a state of panic.
A few hours after admission, she had relentless nausea, vomiting and retching along with abdominal pain, and was in a manic mood due to the “unbearable” pain.
The patient underwent several tests, including intensive whole-body physical examination and imaging diagnoses like ultrasonography, endoscopy, CT and MRI scans to find out if there were any pathogenic factors causing the vomiting and abdominal pain.
But doctors did not discover any significant findings from these assessments.
The woman’s gastric emptying tests – that assess the time it takes for food to empty out from the stomach – were normal. Her blood cell counts and urine and stool examinations were normal as well.
In her blood plasma, doctors found extremely high levels of antibodies against an enzyme produced by the pancreas, despite it being almost 12 years since she was diagnosed with T1D.
They diagnosed the 27-year old with “cyclic vomiting syndrome” (CVS) – a disorder in which patients experience attacks of sudden vomiting interspersed with long periods without symptoms.
While the patient’s vomiting subsided over a few days following hospitalisation, her blood sugar would plummet and stay low for days, researchers pointed out.
Scientists are still trying to uncover the exact mechanism behind the 27-year-old’s symptoms, especially what seemed to be causing her blood-sugar levels to drop.
“We observed an unusual phenomenon of ‘insulin recycling’ in this patient, where the hormone was reentering the bloodstream rather than being efficiently broken down by cells,” Aimun Xu, one of the authors of the case study, told Live Science.
“Although it is extremely rare, antibodies against both endogenous and exogenous insulin are capable to induce intractable hypoglycaemia via binding with insulin and disrupting its normal function,” researchers explained in the study.
Doctors then tried Rituximab, a drug that tags some immune cells that produce antibodies for destruction.
They found that it reduced the number of antibodies attacking the patient’s insulin-producing cells.
It also corrected her low blood sugar and reduced episodes of cyclic vomiting.
“Treatment with Rituximab to suppress the IAs [an antibody type] was associated with a striking amelioration of hypoglycaemia. Unexpectedly, the episodes of cyclic vomiting were also dramatically reduced,” scientists wrote in the study.
Researchers suspect CVS could be a separate autoimmune disorder that needs to be studied further and hope to conduct clinical trials with Rituximab against the condition.