Lupus Tests & Diagnosis
Systemic Lupus Erythematosis (SLE) is a treatable systemic autoimmune disease in which the body’s immune system attacks the cells and tissue of any part of its own body. As a result of the damage that the immune system does to its own body, the body suffers tissue damage and inflammation, fatigue, malaise, butterfly rash across the nose and cheeks, photosensitivity and other symptoms. Patients with SLE experience alternating periods of flares (illness) and remissions. Lupus may cause damage to the organs, most commonly the heart, liver, kidneys, skin, blood vessels, lungs and nervous system. If you have already been diagnosed, you may want to look into some of the Lupus Clinical Trials being performed at Achieve Clinical Research in Birmingham, Alabama.
90% of lupus patients are women. Most women with lupus are in their childbearing years (ages 15 to 35) and of non-European descent. Lupus presents many risks for pregnant women and their fetuses; there is an increased risk of flare-ups during pregnancy as well as in-utero fetal death caused by lupus-inflicted spontaneous abortions. It is highly recommended that women with SLE have various medical check-ups until birth, as well as post birth doctor visits to watch out for flare-ups.
Standard routine clinical tests that suggest that the person has an active systemic disease (multiple organ involvement) include:
- Serum protein electrophoresis, which may reveal increased gammaglobulin and decreased albumin
- Elevated sedimentation rate (ESR) and CRP (C-reactive protein) binding, which are both commonly elevated in inflammation
- Abnormalities of liver function tests
- Standard blood counts, which may reveal anemia and low platelet and white cell counts
- Standard chemistry tests that may reveal kidney involvement
- Increased muscle enzymes if there is muscle involvement
There is no single test available for diagnosing lupus. Rather, there is a variety of testing done to make the diagnosis in combination with information about family history of SLE, other coexisting diseases or medical conditions and symptoms of the disease. Often, symptoms appear gradually over time, and therefore it may take years to make the appropriate diagnosis.
The following is a list of blood tests used to diagnose lupus:
- Anti-DNA antibody test to determine if there are antibodies to the genetic material in the cell
- Anti-nuclear antibody test (ANA), used to determine if auto-antibodies to cell nuclei are present in the blood
- Serum (blood) complement test, to study the level of proteins that can be taken over in immune reactions
- Testing to examine specific levels of complement proteins C3 and C4
- Anti-Sm antibody test, to verify if there are antibodies to Sm (a ribonucleoprotein located in the nucleus of cells) present
It can be quite difficult to properly interpret and connect the results of tests and symptoms. It is easier for doctors to diagnose lupus when signs and symptoms are accompanied with positive test results indicating the presence of this disease. However, a complicating factor is that different laboratories may come up with different results of clinical tests, making it difficult for physicians to determine a lupus diagnosis. Also, positive test results indicating lupus could be due to other diseases, and sometimes they are present in healthy people. Another complicating factor is that test results indicating lupus may be positive at some times and negative at others.
The following is a basic outline of clinical test results indicating lupus.
Active Lupus activity parallels with:
A rise in:
- CRP (C-reactive protein) binding
- Sedimentation rate (ESR)
- tests of liver and kidney function (AST, ALT, BUN, creatinine)
- CPK (muscle enzyme)
- Urine protein or cellular casts
A decrease in:
- CBC or complete blood count (white blood cell count, hemoglobin, platelets)
- Complement components
- Serum albumin
Lupus is usually diagnosed upon patients’ complaints of ostensibly unconnected symptoms. Family practitioners, pediatricians and internists can diagnose SLE using clinical testing and correlating them with their patients’ symptoms. Lupus patients can keep lupus in check by having check ups with their rheumatologists and sticking to their prescribed drug regimen to subside and protect against flare-ups. Check out some of the many Lupus Organizations working towards helping people who have this disease like the Lupus Foundation of America and others.