Pancreatic Insufficiency and Laboratory Testing

 Known as EPI (or Exocrine Pancreatic Insufficiency), pancreatic insufficiency is the inability of the pancreas to produce and/or transport sufficient amounts of the digestive enzymes required to break down food particles in the intestine. 

The pancreas gland is a flat, narrow organ measuring about 6 inches long located deep in the abdominal cavity, below the liver and behind the stomach. It is divided into a head, middle, and tail sections. The head section connects to the first part of the duodenum (small intestine). 

The pancreas produces digestive enzymes and bicarbonate that are sent via small tubes (ducts) to the large pancreatic duct. These digestive enzymes and bicarbonate are carried down the length of the pancreas from the tail to the head section of the pancreas into the duodenum by the pancreatic duct. Also, running through the head section is the common bile duct that carries bile from the gallbladder and liver to the small intestine. The pancreatic and bile ducts join together just before entering the duodenum, sharing a common opening into the small intestine. 

There are two kinds of tissues in the pancreas that perform different functions: 

 The Exocrine tissue in the pancreas is responsible for making, storing, and releasing the powerful enzymes needed to digest proteins, carbohydrates, and fats in the small intestine. These enzymes are normally produced and carried to the small intestine in an inactive form where they are activated as needed. Bicarbonate is also produced and released by the exocrine tissue to allow activation of the pancreatic enzymes and to neutralize stomach acids. 

The Endocrine tissue in the pancreas is responsible for producing hormones like insulin and glucagon and releasing them into the blood. These two hormones regulate the transport of glucose (sugar) into the cells of the body, where it can be used for energy. They also help to maintain healthy blood sugar levels in the body. 

Pancreatic Insufficiency 

Pancreatic insufficiency in adults occurs typically as a result of ongoing and progressive damage to the pancreas brought on by repeated bouts of acute pancreatitis or chronic pancreatitis caused by a variety of different conditions. 

Pancreatic insufficiency in children is most frequently associated with diseases such as CF (or cystic fibrosis) or SDS (or Shwachman-Diamond Syndrome). CF is the most common cause of inherited pancreatic insufficiency, followed closely by SDS as the second most common. In all cases of SDS, there is some degree of pancreatic insufficiency present that began in infancy. 

Conditions That May Cause EPI (or exocrine pancreatic insufficiency) 

EPI may also develop in those suffering from the following conditions: 

  • Diabetes 
  • Celiac disease 
  • Pancreatic cancer 
  • Crohn’s disease 
  • Autoimmune pancreatitis (an immunoglobulin G4-related disease) 
  • Zollinger-Ellison Syndrome is a rare condition that is caused by a pancreatic tumor that stimulates the release of excess acid from the stomach.)  Temporary pancreatic insufficiency may be caused by this excess acid; however, the symptoms usually disappear when the excess acid is treated. 
  • Certain surgical procedures that can affect the function of the pancreas or digestive tract can also lead to EPI. 

Signs and Symptoms of Pancreatic Insufficiency 

The most common symptoms of EPI include: 

  • Abdominal bloating and/or frequent gas 
  • Abdominal cramps and pain, sometimes referred to as epigastric pain as it occurs in the upper-middle part of the abdomen. 
  • Fatigue and general tiredness 
  • Unexplained weight loss and the inability to gain weight in children 
  • Frequent diarrhea or greasy, foul-smelling stools that tend to float 

Those with EPI may also suffer from malnutrition, malabsorption, and vitamin deficiencies. Because symptoms of EPI may not be readily evident or appear similar to those caused by other disorders of the digestive tract, laboratory evaluation is often needed to diagnose the condition. 

Tests for Pancreatic Insufficiency 

Laboratory tests used for the detection of EPI include: 

Stool Elastase to measure the level of elastase enzymes (produced by the pancreas) in a stool sample. It is not as effective at detecting milder cases of EPI but quite effective at detecting moderate to severe cases. Those with EPI will have a reduced amount of elastase in their stool. 

Chymotrypsin tests are used to measure the level of the pancreatic enzyme, chymotrypsin, in a stool sample. In those with EPI, the enzyme chymotrypsin will be absent. 

IRT (or immunoreactivity trypsinogen) measures the level of trypsinogen in the blood. Trypsinogen is an inactive precursor that is produced by the pancreas and converted to the enzyme trypsin, responsible for the digestion of proteins. IRT levels may be elevated in those with pancreatitis, a condition that causes EPI. 

Fecal fat tests are used to detect the amount of excess fat in the stool. Excess fat in the stool is often the first sign of pancreatic insufficiency. This test has largely been replaced by the Stool Elastase test, which is easier to perform. 

The 13C-mixed triglyceride breath test is a newer method used for the diagnosis of moderate EPI. However, it is not yet commonly available or widely used. This test can also be used to evaluate the effectiveness of treatments for people with EPI, such as enzyme therapy for fat digestion. 

Some non-laboratory tests may be employed to diagnose pancreatic insufficiency.  These tests include CT (or computed tomography) scan, ERCP (or endoscopic retrograde cholangiopancreatography, MRCP (or magnetic resonance cholangiopancreatography, and ultrasound. 

Treatment for Pancreatic Insufficiency 

Individuals can manage their pancreatic insufficiency with a few treatments: 

  • PERT (or pancreatic enzyme replacement therapy) by taking enzyme supplements to replace those that the pancreas is not producing anymore.  
  • Good, healthy diet. 
  • Vitamin supplements (particularly vitamins A, D, E, and K) if warranted. 
  • Lifestyle changes, such as reduced alcohol consumption and smoking. 
  • Managing or resolving any underlying cause will also treat EPI. 
  • Unlike cystic fibrosis, SDS may improve with age.  
  • Approximately half of the children with SDS will have an improvement in their pancreatic function and fat absorption and will no longer require ERT.