Introduction
African iron overload is a rare condition where the body has too much iron. It got its name because it was first noticed in parts of sub-Saharan Africa, where people drink a type of homemade beer with a lot of iron in it. Symptoms can differ but may include liver problems like fibrous tissue buildup and scarring. The exact reasons for this condition have yet to be fully understood, but scientists think it is caused by a mix of what people eat and their genetics.
What Is African Iron Overload?
African iron overload occurs when the body absorbs excessive iron from the diet. This surplus iron is stored in different tissues and organs, such as the liver, bone marrow, and spleen. The body cannot naturally eliminate this excess iron, although a small amount may be lost through bleeding or shedding of intestinal cells. The regulation of iron levels in the body primarily depends on controlling iron absorption from food.
This condition is associated with a diet rich in iron, particularly with the consumption of traditional African beer brewed in metal drums, which adds iron to the beverage. Some evidence suggests that genetic factors may also contribute to an individual's susceptibility to absorbing excessive iron.
In African iron overload, the surplus iron typically accumulates predominantly in specific immune cells known as reticuloendothelial cells. These cells include macrophages found in the bone marrow and spleen and specialized liver cells called Kupffer cells, which play a vital role in defending the body against infections. As the condition progresses, iron also accumulates in liver cells. This differs from hereditary hemochromatosis, another iron overload disorder, where excess iron primarily accumulates in liver cells.
What Are the Signs of African Iron Overload?
The symptoms of African iron overload can differ from person to person. Typically, this condition appears in middle-aged or older adults. People affected by it often experience an abnormal enlargement of the liver, known as hepatomegaly. In more severe cases, there may be a buildup of fibrous tissue in the main vein that carries blood to the liver, called the portal vein, leading to high blood pressure in this vein, a condition known as portal hypertension. This can result in fluid retention in the abdomen, causing swelling called ascites. In some instances, the liver may become scarred, a condition called cirrhosis, which can ultimately lead to liver failure.
Other symptoms may also occur depending on where and how much iron accumulates in the body. For instance, iron buildup in the pancreas, a small organ that produces insulin, can lead to diabetes. In this condition, the body either does not produce enough insulin or cannot properly use it.
African iron overload has also been linked to other health issues such as bone thinning (osteoporosis), heart problems, and a higher risk of infections like tuberculosis. People with this condition are more likely to develop esophageal cancer or a type of liver cancer called hepatocellular carcinoma compared to the general population.
What Are the Factors Leading to African Iron Overload?
African iron overload was first noticed in rural areas of central and southern Africa among people who drink a traditional beer brewed in steel drums that release iron into the beer. However, not all individuals who consume this beer develop African iron overload, and not all people of African descent who have iron overload consume the beer. Scientists are looking into genetic differences that might affect who is at risk of getting this condition.
Some studies have found that a certain change in a gene called SLC40A1 increases the risk of having too much iron stored in the body among people of African descent. This change is seen in 5 to 20 percent of African-descended individuals but is not common in other groups.
The SLC40A1 gene gives instructions for making a protein called ferroportin, which helps the body absorb iron. When one eats, iron is absorbed through the walls of the small intestine. Ferroportin then moves the iron from the intestine into the bloodstream, which travels to different body parts. Ferroportin also moves iron out of certain liver, spleen, and bone marrow cells. The amount of iron the body absorbs depends on how much iron these cells have stored and released.
The SLC40A1 gene change found in some studies among people of African descent might affect how ferroportin controls iron absorption in the body. However, scientists say this gene change is not linked to most cases of African iron overload.
What Is the Frequency of African Iron Overload?
African iron overload is frequently found in rural areas of central and southern Africa, affecting up to ten percent of the population in these regions. Men tend to be affected more than women, possibly because of differences in how much iron they consume in their diets and because women lose iron through menstruation and childbirth.
It needs to be clarified how common increased iron levels are among people of African descent in other parts of the world. However, these individuals may have a higher chance of having slightly higher iron levels than those of European descent.
How to Diagnose African Iron Overload?
Doctors diagnose African iron overload by looking for specific symptoms, asking detailed questions about the patient's medical history, and conducting a thorough examination. They may also perform various specialized tests, including blood tests. These tests can indicate whether ferritin levels, a protein that binds to iron and reflects the body's iron levels, are elevated compared to the usual levels in the blood plasma. Another test measures transferrin saturation, a protein carrying iron from the intestines to the bloodstream.
What Is the Treatment for African Iron Overload?
Regularly removing blood through a vein, known as venesection or phlebotomy, is a common treatment for conditions with too much iron. This therapy is expected to help people with African iron overload, although there have yet to be controlled studies on it. Still, many experts consider phlebotomy the standard treatment if the patient can tolerate it. Genetic counseling could be helpful for people with the condition and their families.
Conclusion
In conclusion, African Iron Overload (AIO) is a rare genetic disorder prevalent in populations of African descent, characterized by excessive iron absorption and potential health complications such as liver fibrosis, cirrhosis, and diabetes. The condition is often linked to consuming traditional iron-rich beverages and genetic factors, notably variations in the SLC40A1 gene. Diagnosis typically involves evaluating symptoms and conducting blood tests to assess iron levels. Treatment primarily revolves around phlebotomy, the removal of excess iron through blood removal. Further research and genetic counseling are essential for managing AIO effectively and understanding its implications for affected individuals and their families.
