Introduction

Felty syndrome is a rare complication of rheumatoid arthritis that is characterised by the triplet of splenomegaly, neutropenia, and rheumatoid arthritis.¹ Splenomegaly is having an abnormally enlarged spleen, neutropenia is when an individual has abnormally low levels of the white blood cells called neutrophils and rheumatoid arthritis is painful inflammation in the joints.^1,2 These are known as extra-articular manifestations, meaning they are symptoms of arthritis that present outside of your joints. Approximately 2% of individuals with rheumatoid arthritis develop Felty syndrome and almost all of these people are seropositive, meaning they possess the rheumatoid factor antibody. It is suggested that both Felty syndrome and rheumatoid arthritis are associated with genetic facts and therefore could be partially hereditary. Similarly to rheumatoid arthritis, it is three times more common in those assigned female at birth than those assigned male at birth. Felty syndrome typically develops later in life and mostly affects those between the ages of 50 and 70 years.²

Symptoms of felty syndrome

The symptoms of Felty syndrome typically align with those of rheumatoid arthritis. Individuals with the syndrome suffer from stiff and painful joints, fever, fatigue, swollen lymph nodes, dry eyes and weight loss.1,2 In some cases, there may also be discolouration of the skin, ulcers on the lower leg and an abnormally enlarged liver. They may also have an increased frequency of infections, anaemia, vasculitis or thrombocytopenia.¹

What is splenomegaly?

Splenomegaly is when the spleen is enlarged and can refer to mass or size which can vary depending on height, mass and sex assigned at birth.^3,4 A normal adult spleen is usually between 70 g and 200 g in mass and measures up to 12 cm in length and measurements above 400 g and over 12 cm indicate splenomegaly.³ The spleen belongs to the immune system and lymphatic system.⁵ It has many critical functions including storing red blood cells and platelets, which help blood clot, filtering out and destroying damaged blood cells, and preventing infection. It does this by producing white blood cells called lymphocytes and acting as a defence mechanism against disease-inducing organisms. An enlarged spleen will perform these functions less effectively.⁴

Causes of splenomegaly

There are multiple potential causes of splenomegaly, with many including conditions and disorders^3,4,5:

• Acute or chronic infections (such as mononucleosis, HIV and malaria) can stress the immune function of the spleen, causing it to overproduce antibodies
• Cirrhosis and other liver diseases can lead to pressure buildup in the blood vessels in the liver and spleen, which is known as portal hypertension
• Blood disorders (such as haemolytic anaemia) that destroy red blood cells early and overload the spleen
• Metabolic disorders (such as Niemann-Pick disease and Gaucher disease) that cause substance build-up in the blood and then stored in organs can infiltrate the spleen
• Autoimmune conditions (such as sarcoidosis or lupus) can trigger spleen hyperplasia or an overactive immune response
• Blood cancers (such as leukaemia or lymphomas) can infiltrate the spleen with fast-multiplying cells.
• Focal lesions (such as abscesses, cysts and metastasis)
• Venous thrombosis is when there is pressure or blood clots in the veins within the spleen or liver

Mechanisms of splenomegaly in felty syndrome

Splenomegaly can be classified based on its mechanism. These include congestive, infiltrative, immune and neoplastic. Congestive is when portal hypertension occurs, infiltrative is when foreign cells invade the spleen, immune is when the spleen becomes overactive and destroys blood cells too much and neoplastic is when cells within the spleen develop into a neoplasm such as lymphoma.³

Symptoms of splenomegaly

An enlarged spleen typically does not cause many symptoms and is usually discovered during physical examinations. However, if symptoms do arise, they can include:^4,5

• Bleeding or bruising easily
• Pain in upper left stomach that can spread to left shoulder and back
• Frequent infections or colds
• A feeling of fullness after eating a little amount or not eating at all (due to spleen pressing on stomach)
• Anaemia (low red blood cells), including weakness and fatigue

Diagnosis of splenomegaly

Someone with splenomegaly usually goes to their healthcare doctor with symptoms of abdominal discomfort or symptoms associated with their underlying condition. The doctor typically finds an enlarged spleen by accident while performing a routine examination, as they will likely be able to feel it. Medical tests are then performed to confirm an enlarged spleen and identify the cause. Imaging tests, such as ultrasounds or CT scans, can identify the size of the spleen and provide information on the severity of enlargement, whether a lesion is present and whether it is affecting any other organs. MRI scans can be used to trace the blood flow through the spleen. Blood tests can investigate causes by testing for various diseases, and blood disorders including anaemia, liver function and cancers. Bone marrow may also be analysed via aspiration or biopsy to find the blood cell content in bone marrow tissues to provide information on how well the spleen is functioning, as well as give an indication of specific disorders.⁵

Treatment and management of splenomegaly

Treatment of an enlarged spleen is directed towards the cause and underlying condition. Some conditions such as infections may go away without any help and therefore so will the enlargement. The patient may be treated with medications to help remedy the condition or blood treatments. If the cause has no cure, the patient may be treated with low-dose radiation therapy to reduce the size of the spleen or surgery to remove it.⁵ This requires much consideration because, although you can live a healthy life without a spleen, the risk of life-threatening infections increases. To reduce your risk of infection after spleen removal, you should have a series of vaccinations to prevent infections such as pneumonia, blood, bone and joint infections and meningitis. Antibiotics should also be taken when your healthcare professional suspects an infection and you should avoid travelling to places where malaria is common.⁶

Prognosis of and living with splenomegaly

An enlarged spleen can affect your life depending on its severity. Some people live a healthy life with suitable management, while some people must make lifestyle changes. It is important to avoid contact sports to reduce the likelihood of a ruptured spleen, as well as always wearing a seatbelt in the car for protection in an accident.⁶ The spleen may also lose its functionality or become overactive, therefore you should look out for signs of anaemia, such as fatigue or paleness. While it is unsure whether diet affects your spleen, it affects your immunity and, as you are more susceptible to infections, you can protect your immunity with food. It is recommended that processed foods be minimised, as well as highly inflammatory foods. Beneficial and anti-inflammatory foods include unsaturated foods, such as fish and nuts.⁵

FAQs

When should I consult my doctor if I suspect an enlarged spleen?

If you notice increased pain in the abdomen or left shoulder, seek medical attention as soon as possible, especially if it hurts more when you breathe in. A rupture is more likely to occur with trauma but can also occur by itself and therefore the earlier an enlarged spleen is treated, the more manageable it is, and the underlying condition can be investigated.⁵

Are there any risk factors that contribute to splenomegaly?

Children and young people with infections are more at risk, as well as those with metabolic disorders that affect the liver and spleen. People who visit or live in areas where malaria is prevalent also pose a higher risk.⁴

What are the complications of an enlarged spleen?

An enlarged spleen may become overactive and remove too many blood cells from circulation, leading to a lowered number of platelets and red and white blood cells, therefore causing more frequent infections. In rare scenarios, a severely enlarged spleen can potentially rupture due to a direct impact and cause life-threatening internal bleeding.⁴ An enlarged spleen may also outgrow its blood supply and be unable to reach the tissues, meaning the tissues will stop functioning.⁵

Summary

In Felty syndrome, splenomegaly is linked to rheumatoid arthritis and neutropenia and is when a spleen is over 400 g in mass and 12 cm in length. It can have various causes, including blood disorders and autoimmune conditions, and act via different mechanisms. Diagnosis involves imaging and blood tests, while treatment includes medication and surgical removal. If you show any symptoms mentioned above, consult a healthcare professional immediately to live a healthy life.