Pancreatitis is in the news. With opposition leader Mark Latham struck down by this painful condition, we look at the role of the pancreas and at HIV-related pancreatitis.

Remember the newsroom scene in Deep Impact, just after US President Morgan Freeman has announced that a comet is going to hit the Earth? “Get me geologists, climatologists,” the news editor screams. “Graphics. I need GRAPHICS!”

I imagine similar scenes occurred recently when the word came over the wires that the federal opposition leader had been taken to hospital with acute pancreatitis. After all, it’s not every day a national political figure gets struck down by a malady few people have ever heard of.

But if you’re HIV-positive, you quite probably have heard of pancreatitis, and hearing the word may have triggered a nasty memory. Because if you or anyone you know has had this condition, you’d probably remember, and the recollection is unlikely to be pleasant.

So while wishing Mr Latham a speedy and complete recovery, let’s take a background look at the enigmatic, charismatic, pancreatic pancreas, and let’s share the story of the dog who gave his life so that Mark Latham could live.

Located deep inside your abdomen, behind your stomach and nestled in amongst your duodenum, kidneys and spleen, the pancreas is a long, spongy, glandular organ, about 12-15 cm in length and weighing 60-100g — about the size of your hand.

The pancreas has two functions: it produces hormones including insulin and glucagon, which your body uses to create, manage and use blood sugar, and it produces “[pancreatic juices]” which contain vital digestive enzymes which break down food in the digestive tract. The pancreas is unusual in that it belongs to both the endocrine system (secreting into the bloodstream) and the digestive stystem.

The organ was discovered in 336 BC by a Greek anatomist called Herophilus, but it took a long time before anyone could figure out its function. The name ‘pancreas’ comes from Greek and means ‘all flesh’, a reference to the view in those early days that it had no function except to cushion the large blood vessels immediately behind it. Despite being wrong, this misunderstanding persisted for the next millennium and a half.

Fast-forward to the mid-seventeenth century, when scientists began to wonder whether the pancreas might serve a greater purpose than taking up space. In 1642, Johann Wirsüng discovered the pancreatic duct, a thin tube which runs from the pancreas to the duodenum. Wirsüng wondered what the duct was for, and may well have figured it out except he was murdered by one of his students a few months after the discovery.

It wasn’t until the late 19th century that the function of the pancreas, and its relationship to diabetes, a disease that had been around for thousands of years, was discovered. In 1889, a pair of German doctors removed the pancreas from a dog and the unfortunate pooch promptly developed diabetes, went into a coma and died.

Thanks to the sacrifice of that ill-fated, anonymous canine, the mysteries of the pancreas were gradually revealed over the next few decades.

In the 1920s, Canadian researchers discovered insulin and demonstrated, again with the help of some laboratory dogs, that insulin injections could reverse diabetes. This enabled type 1 (‘insulin dependent’) diabetes to move from being a life-threatening condition to a ‘chronic manageable illness’ — just as HAART has made HIV infection, for many people, a manageable, rather than life-threatening, condition.

We couldn’t have done it without Fido, and Spot, and their friends.

Along with diabetes, some of the serious illnesses associated with the pancreas include cystic fibrosis (a hereditary disease in which the body produces abnormal amounts of thick mucous which accumulate in the pancreas and lungs) and pancreatic cancer (a relatively common form of cancer which is notoriously difficult to detect and treat).

Pancreatitis is a generic term meaning inflammation of the pancreas, which can arise from many different causes.

In the general community, the most common causes of pancreatitis are gallstones, which can block the pancreatic ducts, preventing enzymes from leaving, and alcohol abuse, which can damage the pancreas over long periods of time. Not all cases of pancreatitis are due to these factors, but they are the most common.

In people with HIV, pancreatitis is relatively rare, and when it does occur the most likely causes are the same as in the general community: heavy alcohol use is a common cause. But there are several HIV-specific causes.

Pancreatitis is a serious, but thankfully uncommon, side effect of the anti-HIV drug ddI (also known as didanosine, Videx, or Videx EC). Other HIV drugs in the same class as ddI (such as d4T, AZT, 3TC, and abacavir) have also been associated with pancreatitis, but the main offender is ddI.

There have also been reports of pancreatitis associated with very high levels of blood fats ([triglycerides]). Protease inhibitors and efavirenz can cause high triglyceride levels, so it’s possible for anyone on HIV treatment to develop this condition, even if they aren’t taking ddI.

Opportunistic infections can affect the gall bladder or pancreas and cause pancreatitis, too. These include CMV, Cryptosporidium, MAC, and salmonella.

The symptoms of pancreatitis include feeling sick (nausea), vomiting, and pain in the middle of the chest at the point where the ribs join. Sometimes this pain can be excruciating, but not everyone with pancreatitis experiences pain. The abdominal area may feel tender and sore to the touch.

Because pancreatitis affects the ability of your body to digest food, weight loss and pale, foul-smelling diarrhoea are possible symptoms of less severe, chronic (long-term) pancreatitis.

If your doctor suspects pancreatitis, blood tests can be done which measure the levels of the enzymes produced by the pancreas, and X-rays and ultrasound or CT scans can be used to see if the pancreas is inflamed and enlarged.

The consequences of pancreatitis can range from the relatively trivial (there may be no outward symptoms) to the very serious. In the most serious cases, pancreatitis can be fatal. There have been several reports of deaths due to ddI-related pancreatitis.

People who experience severe ddI-related pancreatitis usually need treatment in hospital, due to the amount of pain involved and the need to minimise dehydration. The pancreatitis itself usually goes away when the cause — ddI — is stopped or replaced with another HIV drug. In some cases, people who have had a bout of acute pancreatitis may be at risk of long-term effects and may be more likely to develop pancreatitis in the future.

Even if you’re taking ddI, the risk of developing pancreatitis is fairly low. In a large American study, the risk of developing pancreatitis for people taking ddI was less than one in a hundred.

The risk may be higher if you have other risk factors such as heavy alcohol use, if you have a history of pancreatitis, if you’re overweight or if you take medications that increase the levels of ddI in the blood, such as hydroxyurea or tenofovir, or if you’re undergoing treatment for hepatitis C (with interferon and ribavirin). People with very low CD4 counts (below 50) are also at increased risk of this condition.

People taking HIV/AIDS treatments usually have regular blood tests (every three or six months) which include blood tests for pancreatic enzymes. Increased levels of these enzymes may indicate pancreatitis, but moderately elevated levels may be no cause for concern. An Italian study reported in 2001 suggested that as many as one-third of people taking antiretrovirals have high pancreatic enzymes from time to time, but few of them developed pancreatitis.

If you’re concerned about pancreatitis, or if you experience any of the symptoms described in this article, see your doctor.

References

¹ Manfredi, R, 2001: “A Survey of Pancreatic Abnormalities (PA) during HIV Disease, in a Cohort of around 1000 Patients” ICAAC 2001, Abstract I-252.

² Dragovic C et al. “Incidence of pancreatitis in HIV/AIDS – patients receiving nucleoside reverse transcriptase inhibitor drugs”. Second International AIDS Society Conference on HIV Pathogenesis and Treatment, Paris (Antiviral Therapy 8:1), abstract 920, 2003.