Systemic lupus erythematosus: causes, symptoms, diagnosis and treatment of SLE

By Cristiano Antonino Last updated May 27, 2023

Systemic lupus erythematosus, abbreviated to SLE and more simply known as lupus, is a chronic autoimmune and inflammatory disease which – depending on its severity – can affect various organs and/or tissues

Currently, a precise cause has not been identified, but it is believed that a genetic predisposition combined with hormonal and/or environmental triggering factors (e.g. UV rays, infections) can determine its onset.

In terms of incidence, it is known that lupus predominantly affects young women: the peak is observed between the ages of 15 and 40, with a female-male ratio of 6-10:1.

The Afro-Caribbean population is more predisposed, with 207 cases per 100,000 individuals, followed by the Asian population with 50 cases per 100,000 individuals and the Caucasian population with 20 cases per 100,000 individuals.

The diagnosis of systemic lupus erythematosus is often delayed due to the fact that the disease can affect different systems and organs, with different degrees of severity.

Three levels of severity of SLE can be identified:

in the mildest form it affects the skin and joints, in the form of inflammation;
in the moderate form it affects the heart, lungs and kidneys;
in the most serious form it affects the nervous system, starting with the brain.

With the use of appropriate immunosuppressant drugs, symptoms can be brought under control.

What is systemic lupus erythematosus

Systemic lupus erythematosus is an autoimmune disease that can cause inflammation of the skin and joints and progress further to affect the blood cells, lungs, kidneys, heart and nervous system.

Although it was identified towards the beginning of the 19th century, Hippocrates already spoke of a disease that caused skin ulcers, calling it “herpes esthiomenos”.

His name consists of three words:

lupus, Latin name for wolf, due to the butterfly-shaped rash that appears on the face of many patients with SLE (and which resembles the white “spot” on the muzzle of wolves), or due to the scarring resulting from the rash similar to wolf scratches;
erythematous, as the skin becomes red as if from a rash;
systemic, indicating that the pathology affects different areas of the body.

The origin of the term lupus dates back to the 12th century, when the Parma doctor Rogerio Frugardi used it to describe a skin manifestation.

In 1872, then, the Hungarian dermatologist Moritz Kaposi identified the systemic manifestations and still later, in 1948, the LE cells, ie the neutrophil granulocytes characteristic of the disease, were identified.

Starting from the end of the 1800s, lupus was treated with quinine, then in association with salicylic acid, with evident results; however, it was during the 20th century that corticosteroid drugs began to be used to manage the disease.

Like all autoimmune diseases, systemic lupus erythematosus also results from a dysregulation of the immune system.

In subjects suffering from diseases of this type, the immune system instead of attacking only viruses and bacteria recognizes some organs or tissues as strangers and therefore “enemies”, producing an inflammatory response that determines the damage – of different types and severity.

Systemic lupus erythematosus: symptoms

Defining a typical and precise symptom picture for systemic lupus erythematosus is very complicated; the manifestations can in fact be different from patient to patient, but above all they can be non-specific and common to those of other autoimmune diseases or other pathological conditions.

For this reason, lupus is sometimes referred to as “the great imitator.”

However, there are some more common symptoms that can manifest themselves progressively, namely:

asthenia (feeling tired, weak or lack of energy);
general malaise;
moderate fever;
lack of appetite resulting in weight loss;
joint pain, swelling and stiffness (90% of people with SLE suffer from it, especially in the wrists, knees and hands): inflammatory arthralgias, arthritis, myalgias/myositis;
deformation of the joints, in 10% of patients;
skin rashes, found in 70% of patients and generally characterized by a “butterfly” rash;
patchy alopecia;
skin hypersensitivity;
redness after sun exposure;
ulcerative lesions on the mucous membrane of the oral cavity and in the nasal cavities;
Raynaud’s syndrome (excessive spasm of peripheral blood vessels, causing reduced blood flow);
red, flaky or scaly patches.

Specifically, skin lesions are divided into:

acute: the so-called “butterfly” rash, an erythematous and edematous rash that can extend from the bridge of the nose to the cheekbones;
subacute: papules or erythematous plaques, sometimes scaling, in photo-exposed areas;
chronic: plaque lesions with a tendency to heal, often localized on the face, auricles, scalp and trunk, but sometimes also generalised.

In the most severe cases, the disease also affects blood cells, lungs and kidneys and – later – the nervous system.

But there are patients who, due to SLE, also suffer from disorders of the spleen, liver, lymph nodes, digestive system, blood vessels and salivary glands.

And finally, there are those who develop other autoimmune diseases over time, such as rheumatoid arthritis or Sjögren’s syndrome.

The onset of symptoms can occur suddenly, sometimes in association with fever so as to suspect an infection, or gradually and over months or even years, with silent phases alternating with phases of exacerbation.

In 70-90% of cases at the onset of the disease there is a sometimes disabling asthenia, although there are patients who suffer intermittently from joint disorders for years, before the onset of other typical symptoms.

If SLE becomes systemic: the symptoms

When systemic lupus erythematosus affects the kidney, a condition called glomerulonephritis can occur, which is an inflammation of the renal glomeruli (the network of arterial capillaries that filters blood to produce urine).

In this condition, blood and urine tests will allow you to make a diagnosis.

Early diagnosis of this disease and therefore the possibility of promptly treating it reduces the risk of acute renal failure to less than 5%.

Blood cell involvement leads to thrombocytopenia (reduction in platelet count) or leukopenia (reduction in the number of white blood cells), or bleeding disorders.

The pulmonary involvement of systemic lupus erythematosus can instead cause pleurisy (acute inflammation of the pleura), pneumonia, interstitial disease, pulmonary hypertension or thromboembolism.

If SLE affects the heart, the patient may complain of chest pain, palpitations or respiratory symptoms, which could be suggestive of diseases such as endocarditis, pericarditis, myocarditis or atherosclerosis up to, in the most serious cases, myocardial infarction.

Nervous system involvement (brain and/or peripheral nerves) usually manifests as severe headaches, confusional states, memory impairment, mood and behavior disturbances, epilepsy, seizures, cognitive problems, vision disturbances, or polyneuropathy .

In the most severe cases, strokes have been observed.

Other symptoms of systemic lupus erythematosus can be

enlarged lymph nodes, spleen, liver and salivary glands;
gastrointestinal disturbances;
vasculitis (inflammation of blood vessels);
miscarriage and preeclampsia in pregnant women.

Systemic lupus erythematosus: causes and diagnosis

To date, a real cause for the onset of systemic lupus erythematosus has not yet been identified. According to the most accredited theories, there are factors predisposing to the onset of the disease:

genetic-hereditary factors: the ethnic groups most affected by SLE are African Americans, Native Hawaiians, Hispanics, Asian Americans and Pacific Islanders;
hormonal factors: in 9 out of 10 cases it is women who are affected; although the role played by estrogen has never been confirmed, the symptoms become more intense during the menstrual cycle and during pregnancy;
environmental factors: these include exposure to ultraviolet rays or silica dust, the use of antihypertensive or antiepileptic drugs or antibiotics (penicillins or amoxicillin), exposure to some viruses (e.g. rubella or Epstein-Brr), vitamin D deficiency and, more generally, stress.

To diagnose lupus erythematosus, you must meet at least 4 of 11 diagnostic criteria established in 1982 by the American College of Rheumatology and revised in 1997:

butterfly-shaped red rash on the face, or other rash characteristic of lupus;
characteristic rashes of discoid lupus (round, red, raised rashes, sometimes progressing to loss of the epidermis resulting in scarring);
ulcers inside the mouth or nose;
arthritis involving at least two joints and having tenderness, swelling, or effusion;
photosensitivity;
haematological disorders (haemolytic anemia, leukopenia, lymphocytopenia, or thrombocytopenia not caused by drugs);
renal involvement, in the presence of a proteinuria greater than 0.5 g per day;
presence of antinuclear antibodies (ANA);
presence of anti-ds DNA or anti-Sm or antiphospholipid antibodies, or false positive serological test for syphilis;
nervous system involvement (convulsions and/or psychosis).

If at least four of these criteria are met, follow-up blood tests will be required

First, the presence of antinuclear antibodies (ANA) will be investigated: although these can also be detected in the presence of other diseases, most people with SLE have them.

Once identified, the specialist will usually order a test for antibodies to double-stranded DNA (anti-ds-DNA) and other autoantibodies (e.g. ENA panel).

With the results, and with further serological investigations (blood count, ESR, renal function, urinalysis), it will therefore be possible to make a diagnosis with certainty.

People with lupus typically have several of these conditions:

drop in red blood cells
drop in white blood cells
drop in platelets
Elevated ESR (indicating inflammation)
elevated serum levels of antinuclear antibodies (ANA)
positivity of some of the subtypes of antinuclear antibodies (ENA panel), in particular Anti-Sm, sometimes combined with Anti-RNP, Anti-SSA and/or Anti-SSB
hyperazotemia
blood in urine
protein in urine

Once the diagnosis has been made, the specialist will eventually prescribe further investigations with the aim of assessing the extent and severity of the disease:

electrocardiogram, to check that the heart is not affected
Chest x-ray, to check the status of the lungs
kidney biopsy, to evaluate the state of the kidneys
skin biopsy

Systemic lupus erythematosus: the cure

Systemic lupus erythematosus is a disease that cannot be cured, but that can be controlled pharmacologically.

The therapy varies from patient to patient, and is aimed at controlling symptoms and preventing further complications.

If the patient suffers from a mild form of SLE, the use of non-steroidal anti-inflammatory drugs (NSAIDs) is often sufficient, in order to control the pain (especially in the joints and muscles) and the temperature rise, and of antimalarial drugs, at the same time to relieve skin and joint symptoms and to reduce the frequency of exacerbations.

Phototherapy is also a useful treatment to control rashes, as are corticosteroid creams or ointments.

It is also always recommended to use a sunscreen with an SPF of at least 30.

In the most serious forms, lupus is instead treated with corticosteroid drugs, in doses and methods of administration (topical, oral, intravenous) that vary according to the severity of the disease.

Corticosteroid drugs reduce myalgias (muscle pains), joint disorders, control skin symptoms, and prevent the onset of complications such as pleurisy, pericarditis, and vasculitis.

In the most severe forms, immunosuppressant drugs also play an important role which, by suppressing the immune system, control its excessive reactivity in this disease and consequently reduce inflammation; alongside these, especially in recent years, the importance of monoclonal antibodies has emerged.

In patients with lupus suffering from vascular problems, there may also be an indication for taking anticoagulant therapy to prevent thromboembolic phenomena.

Usually, initially, the therapy consists in controlling the acute inflammatory state and, once obtained, in the use of drugs that can prevent the onset of symptoms and complications; in some cases the drugs, depending on the progress of the disease, can be reduced in their dosage or suspended.

Then there are rules of behavior that the patient must follow to prevent the symptoms of systemic lupus erythematosus from getting worse; between these:

protect yourself during exposure to the sun, using creams with a high SPF
do not smoke (smoking makes cardiovascular problems worse)
follow a healthy and balanced diet to control high blood pressure and not damage the kidneys
get enough vitamin D
follow up regularly

Systemic lupus erythematosus: the prognosis

Unlike the Fifties, in which the life expectancy of patients affected by systemic lupus erythematosus was five years, today the disease can be treated successfully, with a life expectancy almost comparable to that of the unaffected population – provided take medications appropriately.

The prognosis is more favorable in women than in men and children.

When SLE occurs after age 60, the course is usually benign.

It is also essential to monitor patients’ comorbidities (e.g. hypertension, hypercholesterolemia).

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