Systemic Lupus Erythematosus
Thanks to Jill who asked me to write about lupus. Lupus is the common name for Systemic Lupus Erythematosus. It is an autoimmune disease first described by the physician Rogerius in the 12th Century. The origin of the name is uncertain, but one of the most popular is that many lupus sufferers have a rash on their faces resembling a wolf’s face. Lupus is Latin for wolf.
Autoimmune diseases are a group of illnesses caused by the immune system attacking a person’s own tissues. The clinical manifestations of lupus are caused by the immune system producing antibodies against proteins in the nuclei of cells, the part of the cell where DNA is located. Lupus sufferers likely have an underlying genetic predisposition to the disease. There is no single “lupus gene.” Like most genetic diseases, it appears to involve problems with multiple genes as well as environmental factors.
These environmental factors are felt to trigger damage to cells that exposes nuclear proteins to the immune system. These factors include ultraviolet light, stress, and some medications. Infections, likely by viruses, are also hypothesized to be instigators. Medication-induced lupus usually goes away when the offending drug is stopped.
It is estimated between 270,000 and 1.5 million people in the United States have lupus. It is ten times more likely to affect women than men, particularly young women. It is usually diagnosed between the ages of 16 and 55 and is also more common in African, Hispanic, Asian, and Native American populations. Other risk factors include being related to someone with it (5 to12 percent chance), smoking, sun sensitivity, and post-menopausal estrogen replacement therapy.
Lupus is known as the “great imitator” because it can present with signs and symptoms found in many other diseases. This is because the antibodies attack many different tissues of the body. This makes it difficult to diagnose, accounting for an average delay of five years between symptom onset and diagnosis. It is often characterized by flare-ups of disease activity followed by remissions.
The most common signs and symptoms of lupus include joint pain (especially the hands, wrists and knees), fever, rashes, muscle pain, fatigue, and weight loss. Some women report flares after ovulation and improvement with menstruation.
Since lupus involves an immune response, it can affect every organ system in the body. The most commonly affected include the heart, joints, skin, lungs, blood vessels, kidneys, and nervous system. Some people develop severe inflammation of the heart, kidneys or lungs. Joint involvement is present in about 90 percent of patients. The typical lupus rash is found on the cheeks and nose but can also present with scaling lesions elsewhere.
Diagnosing lupus can be very difficult. A patient has to have at least four of eleven symptom criteria either together, or over time. Each of the eleven criteria has varying specificity (if present the disease is likely) and sensitivity (if absent the disease is unlikely) for diagnosing lupus.
There are also laboratory tests that can help confirm the diagnosis. The most common is the ANA or Antinuclear Antibody test that looks for the antibodies that attack nuclear proteins. The likelihood of lupus is very low if the ANA is negative. If it is positive, additional confirmatory tests that look more specifically for antibodies to proteins in the nucleus are often done.
There is no cure for lupus, so the goal of treatment is to prevent flares and shorten the duration and severity of symptoms. There are many types of medications used to treat the disease. First line drugs are non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen and Aleve. If those fail, or more severe symptoms develop, stronger medications can be used to suppress the immune system.
There are also lifestyle changes that can reduce symptoms or limit flares. Patients should avoid direct sunlight and wear a high SPF sunscreen. Smokers should quit and those who are obese should lose weight to reduce stress on their joints.
The prognosis for lupus patients has improved dramatically. In the 1950s almost all patients died within five years of diagnosis. Patients can now expect to live five years 95 percent of the time. Infections from damaged organs and immune suppression from medications are the most common causes of death for lupus sufferers.
Dr. John Roberts is a retired member of the Franciscan Physician Network specializing in Family Medicine.