Dark Banquet - Bill Schutt [47]
What’s the connection between porphyria and bloodletting? Although drug treatments now exist to alleviate the symptoms of this incurable illness, therapeutic phlebotomy is still employed to reduce blood volume—which decreases the levels of porphyrins in the plasma. This ancient technique has been effective in providing relief from the painful and often mentally debilitating symptoms of porphyria. In fact, therapeutic phlebotomy may have been responsible for George III’s ability to undergo dramatic recoveries from his illness—until his arsenic-laced medications kicked in, that is.
There are several other conditions where bloodletting is still used as a therapeutic measure to reduce iron levels in the blood.
Recently, researchers have found evidence that patients suffering from the viral disease hepatitis C respond better to treatment with interferon if they are first bled to induce a mild state of iron deficiency. Interferons are small proteins naturally produced by cells like macrophages in response to a viral attack on the body. The interferons diffuse into uninfected cells where they act as a shield, interfering with the virus’s ability to enter and infect the cell. Since viruses can replicate only within cells whose reproductive machinery they have hijacked, preventing their entry into uninfected cells is a vital part of the body’s antiviral defense. Interferons also attract and stimulate killer T cells that attack cells infected with viruses. Scientists are still trying to determine why lowering plasma iron concentrations through therapeutic phlebotomy increases the efficiency of interferons (which are used to treat diseases ranging from hepatitis B and C to certain types of leukemia and genital warts).
Bloodletting is also used to treat a specific form of diabetes. Insulin, a hormone secreted in the pancreas, helps to adjust blood glucose levels by enhancing its absorption and use by the body. High plasma concentrations of the iron-containing protein ferritin may damage the cells that secrete or respond to insulin. This leads to a condition called high-ferritin type 2 diabetes (in which elevated iron levels ultimately result in dangerously high blood glucose levels). Studies have shown that insulin resistance in patients with high-ferritin type 2 diabetes improved after three bouts of bloodletting (in which five hundred milliliters of blood was drained every two weeks for a total of six weeks).
Other conditions still treated by therapeutic phlebotomy include hemochromatosis, in which the digestive tract absorbs too much iron (resulting in an overload of tissue-damaging iron deposited in places like the liver and pancreas), and polycythemia, in which blood cells are produced at an uncontrollable rate. In many instances the only way to treat these afflictions is to reduce the amount of blood.
Ultimately, then, there are several relatively rare disorders that appear to benefit from treatments involving therapeutic phlebotomy. But when comparing these instances to the fact that historically, bloodletting was prescribed for basically everything, it’s easy to see that although the practice isn’t quite dead it is certainly a medical relic.
There is, however, a form of medicinal bloodletting that has stood the test of time. Unlike the techniques described thus far, this one utilizes an ancient worm that has been securing blood meals for far longer than its parchment-winged counterparts. Like vampire bats, these creatures do their bloodletting far more efficiently than any technique cobbled together by humans—and recognizing this, Hirudo has been employed medicinally since the time of the pyramids. Nearly abandoned as a therapeutic tool in the twentieth century, the leech has