What is Systemic lupus erythematosus (SLE)?

Systemic Lupus Erythematosus (SLE), or more commonly known as lupus, is an autoimmune disease in which your own body makes antibodies that attacks various organ system in your body associated with inflammation. It is a disease that follows a relapsing-remitting course and is chronic.

It is estimated that more than 90% of people with SLE are women. It usually begins at childbearing age. In the United States, it has been noted that black women are 2-4 times more likely to have the disease compared to white women.

The diagnosis of SLE can be difficult to make in some cases as the signs and symptoms look a lot like other diseases. There are several tests available to help in making the diagnosis of SLE.

It is important to make the diagnosis of SLE the earlier possible to prevent the occurrence of severe complications.

Causes and risk factors for SLE

 SLE is an autoimmune disease which consists of the inflammation of different organs in the body due to the presence of antibodies (proteins that attach to cells that need to be destroyed by your body’s immune system) against your own body cells. It has been shown that genetics and environment play a crucial role in the development of the disease.

Some triggering factors may include:

• Infections:  It has been documented that some infections can trigger lupus in certain people. If you already have the disease, catching an infection can trigger a relapse.
• Medications: There are some drugs, for example, antihypertensive, anti-seizure and antibiotics that can trigger SLE. The affected individual usually get better after cessation of the offending drug.
• Sunlight: In some people, exposure to sunlight can be a possible trigger.

Furthermore, some factors can increase your risk of having the disease at some point in life including:

• Having a birthweight less than 2500g
• Being born preterm
• Being exposed to pesticides during childhood
• Cigarette smoking
• Use of Estrogen in postmenopausal women
• Being a female

Signs and symptoms

Signs and symptoms of SLE vary from person to person. Besides, the symptoms can also be a lot alike to those of other diseases. The disease also follows a waxing and waning course, meaning that if you have the condition, you will experience periods of flares followed by remission.

The clinical presentation of a person with lupus will depend on the organ systems affected. Common signs and symptoms include the following:

• Weakness and fatigue
• Joint pain
• Swollen joints
• Stiff joints
• Fever
• Butterfly-shaped rash on the cheeks and nasal bridge

• Appearance of skin lesions following sun exposure
• Fingers and toes turning white or blue when exposed in cold environment
• Dry eyes
• Chest pain
• Difficulty to breathe
• Seizures
• Swollen lymph nodes
• Recurrent infections
• Weight loss or weight gain
• Muscle pain
• Stomach ache
• Nausea

Making a diagnosis

SLE is a disease that can affect any organ system of the body. Therefore, to make the diagnosis of SLE, your doctor will begin by asking you a series of questions to get an idea of what are the organs involved and to rule out some other diseases. This will then be followed by a thorough physical examination. Your doctor will examine your joints, skin and other organ system.

A good clinical history, physical examination and a series of tests can help in making the diagnosis of lupus. These tests include:

• Full blood count: This test is done to look for any blood abnormalities such as anemia (low hemoglobin), changes in white blood cells and platelets. All of these can be low in lupus.
• Erythrocyte sedimentation rate (ESR): This is a blood test done to measure how quickly red blood cells settle at the bottom of a testing tube filled with blood. If the red blood cells settle at a faster rate than normal, this indicates that there is the presence of an inflammation in your body.

• Antinuclear antibody (ANA) test: This is a test performed to look for the presence of antibodies produced by your immune system. If you have lupus, the test will most likely be positive. But a positive test does not always mean that you have lupus.
• Liver and kidney function: Blood tests to assess the function of your liver and kidneys may also be requested to check if the disease is affecting these organs.
• Urinalysis: A sample of your urine may be collected for further analysis to look for the presence of red blood cells or protein. If these are present in your urine, this may indicate that lupus is affecting your kidneys.
• Imaging tests: Chest X-ray and echocardiogram may be done to check the lungs and heart respectively depending on your symptoms.
• Kidney biopsy: In some cases where there is deranged kidney function, a biopsy of your kidney may be requested. In this procedure, a sample of your kidney is taken using a specialized technique, and this sample is send for further examination. This will indicate the extent of involvement in your kidneys.

Treatment of SLE

The main goals of the treatment of SLE is to alleviate symptoms, prevent flares and improve the quality of life of each affected individual. Depending on the extent of your symptoms, your doctor will choose among the following treatment options:

• Nonsteroidal anti-inflammatory drugs (NSAIDs): These medications can be obtained over the counter. They work by alleviating pain, fever and swelling of joints. Some examples include naproxen sodium and ibuprofen. However, these drugs cannot be used if you have kidney problems or gastritis.
• Antimalarial medications: These medications can be very effective in the prevention of flare ups. They work particularly on your immune system. An example include hydroxychloroquine. Long term side effect associated with this drug include damage to your retina in your eye. It is advised to regularly have eye check-ups when on these medications.
• Corticosteroids: These medications play an important role in the management of SLE. They have anti-inflammatory effects and can be used to control serious forms of the disease. Some examples include prednisone and methylprednisolone. However, they are known to be associated with a variety of side effects with long term use including weight gain, osteoporosis, increased blood pressure, diabetes and increased risk of having infections.
• Immunosuppressant: Since lupus involves your immune system attacking your own cells, suppressing your immune system helps to keep the disease under control. Some examples include; azathioprine, mycophenolate mofetil and methotrexate. These medications can however be associated with potentially serious side effects such as liver damage, increased risk of having infections and decreased fertility.
• Biologics: These medications are used to decrease symptoms of SLE. An example include belimumab. Side effects include gastrointestinal upset and risk of having infections.

Complications of SLE

Complications of SLE are mainly due to the capacity of this disease to affect various organs in your body. If left untreated, SLE may progress rapidly and lead to the following:

• Kidney failure
• Headaches
• Behaviour change
• Vision problems
• Anemia
• Bleeding tendency
• Lung inflammation
• Pneumonia
• Inflammation of the heart muscles
• Increased risk of having infections

Prognosis

The course and progress of SLE depends from person to person. In some people, it may be benign while in others, it can progress rapidly to serious forms of the disease. Individuals with kidney involvement have a poorer prognosis compared to those who only have musculoskeletal and skin symptoms. The disease is associated with a reduced life expectancy. However, with newer treatment options and new research, the mortality rate from the disease have dropped over the last few decades.

Parveen, K. and Michael, C., 2017. Kumar & Clarks Clinical Medicine. 9th ed. The Netherlands: ELSEVIER.

Bartels, C., 2020. Systemic Lupus Erythematosus (SLE).