What is Asplenia?
Asplenia is a condition where a person doesn’t have a spleen. This can be because the spleen is physically absent or because it’s not working properly due to other diseases. The spleen, one of the body’s main organs of the immune system, is located in the upper left part of the belly. Under normal circumstances, you shouldn’t be able to feel the spleen, and it’s usually about 10.65 by 5.16 cm in size. However, the size of the spleen can change based on different factors such as gender and racial background. For instance, spleens are generally larger in men compared to women, and white individuals typically have larger spleens compared to African American individuals.
The primary function of the spleen is to filter and process old blood cells, mainly red ones. It also helps protect our bodies from certain types of bacteria. Inside the spleen, there are two types of tissues: the white pulp and the red pulp. The white pulp is full of immune system tissues that produce antibodies, while the red pulp has a network of small blood vessels that help filter the blood. As the human body’s largest blood filter, the spleen removes old red blood cells and helps eliminate infections.
Beyond the spleen, the body’s lymphatic system – a complex network including lymph vessels, lymph nodes, and other organs such as the thymus, tonsils, and appendix – plays a vital role in defending the body from disease.
Asplenia can occur when there’s damage to either the white pulp or red pulp, or both. The spleen can be negatively affected by various underlying diseases or infections. Understanding the risk factors related to having no spleen is important, such as the increased risk of infections by specific types of bacteria. Certain bacterial infections, if left untreated in people with asplenia, can become life-threatening. Patients without a spleen are around 200 times more likely to pass away from septicemia, a serious bloodstream infection, compared to those with a functional spleen. Sadly, there have been many reports of patients with asplenia losing their lives to infectious diseases. Therefore, it is important to recognize that the rate of serious bacterial infections and death in people with asplenia is significantly higher.
What Causes Asplenia?
You can lose your spleen in several ways. It could be removed surgically, it could stop functioning even though it’s still physically present, or you could be born without one. The most common reason people lose their spleen is because of an operation or injury. According to a survey in the US in 2005, about 22,000 spleen removal surgeries were performed. The main reason for these surgeries was trauma. A study looking at why these surgeries were performed in the past showed that around 41.5% were due to injury, around 15.4% were due to blood cancers, and another 15.4% were due to a decrease in blood cells.
There are several blood disorders, both non-cancerous and cancerous, that could lead to the need for removing the spleen. Some examples include hereditary spherocytosis, sickle cell disease, thalassemia major, immune thrombocytopenia (ITP) that doesn’t respond to treatment, severe myeloproliferative disorders, certain types of autoimmune hemolytic anemias, lymphoproliferative disorders, and rarely in a disease known as thrombotic thrombocytopenic purpura (TTP). There’s also a condition known as congenital asplenia where a person is born without a spleen. This can happen on its own or because of rare conditions such as Ivemark syndrome. This syndrome involves spleen problems, heart defects, and abnormal placement of chest and abdominal organs.
Besides these more commonly known causes, many other reasons for spleen malfunctions have been reported in medical literature. These include gastrointestinal disorders like Celiac disease, Whipple disease, and inflammatory bowel diseases. Infections and immune deficiency syndromes, including HIV, can also affect the spleen. Liver problems like alcoholic liver disease, cirrhosis, portal hypertension, and hepatorenal syndrome can also cause spleen issues. Lastly, rheumatologic conditions such as systemic lupus erythematosus (SLE) have been associated with decreased spleen function.
Risk Factors and Frequency for Asplenia
Asplenia, a condition where the spleen doesn’t function as it should, can occur due to different reasons. All patients suffering from sickle cell anemia are likely to develop asplenia, putting them at a high risk of serious infections after spleen removal. Similar conditions as sickle cell anemia – known as hemoglobinopathies – can also cause splenomegaly (an enlarged spleen), which may require spleen removal, or asplenia over time.
There are also some diseases that lessen spleen function, even when the spleen is not removed. These conditions include celiac disease, Whipple’s disease, and alcoholic liver disease.
- All patients with sickle cell anemia (hemoglobin SS disease) are likely to develop asplenia.
- People with similar conditions to sickle cell anemia, known as hemoglobinopathies, may develop an enlarged spleen or asplenia as their disease progresses.
- Certain diseases reduce spleen function, including celiac disease (33% to 76% prevalence), Whipple’s disease (47% prevalence), and alcoholic liver disease (37% to 100% prevalence).
- Remark syndrome, another condition associated with asplenia, is quite rare, occurring in 1 out of every 10,000 to 40,000 cases.
Signs and Symptoms of Asplenia
Asplenia is a condition in which a person does not have a spleen, or the spleen is not functional. Some people with asplenia may not show any symptoms, while others may feel unwell, tired, have a fever, or suffer from encephalopathy, which is a general term for brain disease that alters brain function or structure. When a doctor examines a patient, they usually can’t feel a normal-sized spleen located in the left upper abdomen. However, if the spleen is enlarged, which is not the case in asplenia, it can typically be felt below the rib cage when the person takes a deep breath.
People without a working spleen may also show symptoms of an infection. The most common bacterial infections in asplenic patients usually involve Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria meningitides. Therefore, it’s crucial to check for a stiff neck in these patients if they have a fever because it may be a sign of meningitis, a potentially life-threatening infection of the membranes surrounding the brain and spinal cord. Pneumococcal meningitis, in particular, can be four times more deadly in asplenic patients than other types of bacterial meningitis and over 6 times more likely to result in severe health problems.
Testing for Asplenia
Your doctor may examine a sample of your blood under a microscope to check for Howell-Jolly bodies, which could be a clue to a problem with your spleen such as a congenital (present at birth) abnormality or a functional issue.
To further investigate and confirm their findings, your doctor might use imaging methods like abdominal ultrasound, computed tomography (CT), magnetic resonance imaging (MRI) or spleen scintigraphy. These can not only identify if your spleen is present or absent, but they can also measure its size.
Using ultrasound, CT, or MRI can also provide a better picture of any possible inborn or blood vessel-related abnormalities. Spleen scintigraphy is a unique method that uses a type of radioactive substance that, specifically, attaches to spleen tissue. If the test shows no uptake or adherence of this substance to any area, that would mean there is no spleen present.
Treatment Options for Asplenia
People without a spleen, or “asplenic”, are at a higher risk of severe infections, especially from bacteria known as encapsulated microorganisms. Consequently, healthcare professionals have been working to prevent, detect, and treat these infections more effectively in asplenic patients. Interestingly, the most common source of infection in people without a spleen is a type of bacteria called Streptococcus pneumoniae. In fact, one research study found that in up to 87% of cases, asplenic patients were infected with this bacteria type.
To prevent sickness, everyone without a spleen, regardless of the reason for their condition, is strongly advised to get vaccinated against these encapsulated bacteria. Vaccinations are recommended both before and after a surgery to remove the spleen, known as a splenectomy. Similarly, those who have a poor-functioning spleen are also urged to maintain regular vaccination schedules.
In preparation for a splenectomy, patients are advised to take the PCV-13 pneumonia vaccine 8 weeks ahead, as well as the PPSV-23 pneumonia vaccine, a vaccine for a type of Haemophilus influenzae (Hib), and a meningococcal conjugate vaccine 2 weeks prior to surgery. Vaccination should also continue after surgery, with the PPSV-23 pneumonia vaccine and meningococcal conjugate vaccine scheduled for 5 years post-surgery and again at the age of 65. People with a weakened immune system may need to be tested to determine their immunity levels.
In addition to the specific vaccines mentioned, yearly flu shots are also recommended. Furthermore, children without a spleen might need to take preventative antibiotics, also known as prophylactic penicillin, until they reach 5 years old. However, this preventative measure isn’t usually recommended for adults without a spleen. Instead, they should have quick access to antibiotics if they show symptoms of an infection, as any delay could make things worse.
After a splenectomy, it’s not uncommon for infections to rapidly get worse, particularly in children under 16 because their immune systems are still developing. If an asplenic patient develops signs of an infection, they should immediately start taking a broad-spectrum antibiotic until tests can identify the specific bacterial cause. According to the Surviving Sepsis Campaign guidelines, patients suspected of having sepsis, a severe response to infection, should start taking antibiotics within an hour to prevent bad outcomes. Aggressive intravenous hydration should also be established right away, along with standard sepsis management. Since people without a spleen are at a higher risk of developing septic shock, which causes low blood pressure, they may also need vasopressors to maintain their blood pressure. In some severe cases, mechanical ventilation may be necessary if the patient develops respiratory failure.
What else can Asplenia be?
When a doctor is trying to diagnose asplenia, which is the absence of a functional spleen, another medical condition, called hyposplenia, may be considered. Hyposplenia, which is a reduced function of the spleen, shares many of the symptoms with asplenia and can evolve into asplenia over time. However, unlike asplenia, hyposplenia can sometimes be reversed by treating the condition that caused it. For example, if a person has Celiac disease and the condition has caused hyposplenia, their spleen may start working normally again if the Celiac disease is managed properly.
What to expect with Asplenia
When asplenia, or lack of a functioning spleen, is not detected, it can lead to serious health issues. Without proper treatment, people with asplenia are more susceptible to infections. It’s advised that these individuals receive vaccinations and take preventative antibiotics to manage their condition. This is especially important for those who have weakened immune systems combined with asplenia.
Without immunizations, individuals with asplenia are at very high risk of severe bacterial infections, potentially leading to life-threatening conditions like sepsis, septic shock, and even death. There have been unfortunate instances recorded where patients with asplenia passed away from infections despite receiving standard medical care. An example is a 45-year-old man who had his spleen removed during his childhood and later contracted a serious type of infection known as pneumococcal meningitis. Despite receiving appropriate medical treatment, his condition rapidly worsened and he sadly died of sepsis. Such cases underscore the urgent need for preventative care in asplenic patients.
Possible Complications When Diagnosed with Asplenia
People who have had their spleen removed (asplenic patients) often experience a serious condition known as overwhelming post-splenectomy infection (OPSI). Asplenic individuals are more prone to infections from certain types of microorganisms, often resulting in an intense flood of bacteria in their bloodstream. The origin of the infection is not easy to pinpoint, and it often progresses rapidly into severe septic shock. If not managed properly, OPSI can lead to death in 60% to 70% of cases.
A healthy spleen performs crucial blood filtration roles. It helps to remove old red blood cells and aids in the defense against certain parasites. In the absence of a spleen, patients are more likely to contract parasitic infections such as babesiosis and malaria. Moreover, with the spleen serving as the largest single-source B cell generator, which is essential for our immune response, asplenic individuals may suffer severe illnesses due to a lack of these immune cells.
The spleen also plays a vital role beyond immune function. It is crucial in vascular health. Patients with specific blood disorders may encounter vascular complications due to a lack of spleen. Some of these patients have been found to have an increased rate of occurrences like stroke, heart attack, and coronary artery disease.
Because of the lack of spleen, patients are at a higher risk of blood clotting. As a result, they may develop complications like pulmonary hypertension. Other complications often seen in asplenic patients are:
- Adrenal hemorrhage, also known as Waterhouse-Friedrichsen syndrome
- Purpura fulminans, a disorder causing sudden and severe clotting
It’s crucial for doctors to quickly recognize and manage these conditions to prevent further health issues and even death.
Preventing Asplenia
In simple terms, for people without a spleen, the most important thing is to ensure they’re taking preventive measures to protect their health. These individuals need to be aware of the potential complications that can arise, including a high risk of severe infections that can sometimes be fatal. A crucial part of preventing these complications is keeping up to date with vaccinations and potentially taking preventative antibiotics in certain cases.
Those without a spleen should keep their vaccinations for pneumococcus, meningitis, influenza, and Haemophilus up-to-date. As for preventative antibiotics, amoxicillin and penicillin are commonly recommended. In some situations, like young kids without a spleen or adults with weakened immune systems, it’s important to properly educate these individuals on how to use these preventative antibiotics.
Moreover, if they are traveling to parts of the world where parasitic infections like malaria or Babesia are widespread, they should be aware that they’re at a higher risk of infection. Depending on where they’re traveling and which infections are common there, preventive treatments such as anti-malarial medication may also be necessary.
