The Expert Series: Lupus Lab Tests and Blood Work
In this episode of The Expert Series, Christine Lee, MD, MPH describes lupus lab tests and blood work, touching on the following areas:
- Difficulty of diagnosis
- Other diagnostic tools
Read the transcript
The following transcript is automatically generated and may contain typos or misspellings. Please listen to the episode for the most accurate language.
Welcome to The Expert Series brought to you by the Lupus Foundation of America. Our speaker today is Dr. Christine Lee, who's a member of the clinical teaching faculty and an attending physician at Cedar Sinai Medical Center. Today, Dr. Lee will be speaking about lupus lab tests and blood work. I'd like to turn it over to Dr. Lee, and thank you for joining us.
Dr. Lee 0:22
Great, thank you. So today we'll be discussing lab tests and lupus. Topics of discussion will include difficulty of diagnosis, antibodies, and their significance or lack thereof, testing prognosis and other useful diagnostic tools.
Patients report waiting nearly six years from onset of symptoms before receiving an accurate diagnosis of lupus. There seems to be a diagnosis disconnect in which patients report nearly six years to obtain a correct lupus diagnosis and seeing four different physicians, whereas rheumatologists report being able to diagnose a patient with lupus in two to three visits. 60% of patients report being initially misdiagnosed.
So what makes diagnosing lupus so challenging? 52% of patients report that they minimize their symptoms when talking to physicians, while 72% of physicians are unaware that patients tend to under report their symptoms. In addition, symptoms and antibodies evolve over time. No single biomarker has adequate performance. And anti dsDNA is only about 33% positive in many studies. There's also many unreliable or inconsistent lab results using different forms of testing, including the Eliza and multiplex.
So timely and accurate diagnosis affects costs and clinical outcomes. Reviewing the American College of Rheumatology criteria for classification of lupus, this includes not only clinical criteria, but the lab criteria as well. I'll run over the clinical really quickly, which includes skin criteria including butterfly or discoid, rashes, Sun sensitivity and oral or ulcers, as well as systemic criteria, which includes arthritis, serositus, kidney disorders and neurological disorders. Lab findings include blood abnormalities such as immunologic disorders, including the presence of anti phospholipid, antibodies, lupus anticoagulant, anti dsDNA, anti Smith, and false positive syphilis tests. A positive ANA is also listed as one of the criteria and one needs four out of 11 of this combined clinical and laboratory criteria for lupus.
So no single test can determine whether a person has lupus but like the tests that I mentioned before they can help make a diagnosis. Not only do we look at antibodies, sometimes we do skin biopsies or kidney biopsies as well. An ANA test which is an anti nuclear antibody is the umbrella antibody for auto immune disease. Typically, we check this by looking at human epithelial cells, a Lupus patients blood is added and if antibodies are present in the blood, they're identified by tagging with an immuno fluorescent material and detected by a fluorescent microscope. So the sensitivity of the ANA is quite high for lupus over 95% of lupus patients are positive. So if you have a negative ANA a lupus diagnosis is unlikely. There are many false positives so an ANA is not specific, and you can see it turn positive and other diseases such as rheumatoid arthritis or chronic infections. Again, a positive ANA doesn't confirm diagnosis of lupus, you need other criteria as well. Looking into more specific antibodies to anti dsDNA, which is positive about 60% of lupus patients, this is highly specific. And we see that it does tend to fluctuate with disease activity and it's also found in active lupus nephritis patients therefore, we often use this as a disease activity monitoring marker. The anti Smith antibody is also very specific for lupus as well, and it's present in 10 to 30% of lupus patients. Anti phospholipid antibodies which include the lupus anticoagulant, anti cardio life and antibody and anti-beta-2 glycoprotein antibody are also very helpful for helping us figure out if a patient has lupus or not. These are associated with clotting disorders, such as blood clots in the arteries or veins as well as frequent miscarriages. Other blood abnormalities we look at include the blood count as inpatients may have anemia, or decreased platelets or decreased white cells.
Other labs that we look at include in a general screening for patients a complete blood count urine analysis, blood chemistries, inflammation markers, including an ESR, which is a sedimentation rate as well as CRP, which is a C reactive protein. We look at complement levels as well. And often times, X rays or imaging tests of affected organs are helpful. We also look at echocardiograms to see if there's any involvement in the heart depending on the patient. And often times, electrical studies such as EEGs, or EMGs, which are neurological studies to look at whether a person has neuropathy or seizures can be helpful in determining the diagnosis of lupus.
Now, in conclusion, Lupus is a heterogeneous disease that's not defined by a concrete set of laboratory markers. Rather, it takes a combination of antibody testing symptoms and exam findings to make a swift and accurate diagnosis. Now, while auto antibodies can predate the onset of disease, it's generally not recommended to conduct ANA screenings in the general population. Therefore, with the right clinical suspicion, one should check an ANA. But it's important to remember that the diagnosis of lupus includes much more than simply an ANA or just laboratory findings. It's important to look at each individual loan and also clinical findings. Thank you.
Thank you, Dr. Lee for joining us today. We appreciate all of the great information that you shared about lupus lab tests and bloodwork.
For those listening in we invite you to check out additional segments of The Expert Series at lupus.org. If you'd like to learn more about living well with lupus, you can find additional resources on the National Resource Center on Lupus, or you can call one of our health educators at 1-800-558-0121. If you would like to connect with others who are impacted by lupus, check out our online community, LupusConnect, where you can talk with others find emotional support, and discuss practical insights for coping with the daily challenges of lupus. Thank you and have a wonderful day.
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- Episode 1: Managing and Preventing Flares
- Episode 2: Financing Your Medical Care
- Episode 3: Tips for Managing Medication Side Effects
- Episode 4: Diet and Lupus: Separating Fact and Fiction
- Episode 5: Lupus and Brain Fog
- Episode 6: Lupus and Men
- Episode 7: Complementary and Alternative Medicine
- Episode 8: Clinical Trials and Lupus
- Episode 9: Lupus 101
- Episode 10: Exercise and Lupus
- Episode 11: Lupus Lab Work and Blood Tests
- Episode 1: Skin Lupus - Beyond the Butterfly Rash
- Episode 2: Becoming a Self-Advocate
- Episode 3: Lupus and Heart Health
- Episode 4: Lupus and the Kidneys
- Episode 5: Preparing for a Doctor's Appointment
- Episode 6: Childhood Lupus and Mental Health
- Episode 7: Vaccine Safety and Lupus
- Episode 8: 5 Common Questions About Diagnosing Lupus
- Episode 9: Planning for Pregnancy with Lupus
- Episode 10: Lupus and Eye Health
- Episode 1: Lupus Foundation of America Health Educators and Resources
- Episode 2: Fatty Acids and Lupus
- Episode 3: Mental Health and Wellness During a Time of Uncertainty
- Episode 4: Telehealth and Lupus
- Episode 5: Reproductive Health and Lupus
- Episode 6: The Impact of Racial Trauma on Mental Health
- Episode 7: Kidney Health and Lupus
- Episode 8: The Importance of Support
- Episode 9: Trust and Participation in Research
- Episode 10: Advice from the Community
- Episode 1: Lupus and Physical Activity
- Episode 2: Top Questions about Skin and Hair
- Episode 3: Managing Your Journey with Lupus Nephritis
- Episode 4: Improving Health Visits for People with Lupus
- Episode 5: Could It Be Lupus?
- Episode 6: Men’s Health and Special Considerations with Lupus
- Episode 7: Making it Work with Lupus
- Episode 8: 2021 Lupus Treatment Research Updates
- Episode 9: Lupus Myths and Realities (podcast in Spanish)
- Episode 10: Diet, Nutrition, and Kidney Health
- Episode 11: Caring for Caregivers
- Episode 12: Winter Wellness
- Episode 1: Medication Management
- Episode 2: The heart and lupus
- Episode 3: Recursos Financieros Para Personas Hispanas/Latinas con Lupus (Financial Resources for Hispanics/Latinos with lupus)
- Episode 4: Lupus and Antiphospholipid Syndrome (APS)
- Episode 5: Self-care & self-management for people with lupus
- Episode 6: Fertility and reproductive health
- Episode 7: Participating in Clinical Trials
- Episode 8: Lupus and the Eyes
- Episode 9: Respuestas de nuestra educadora de la salud
- Episode 10: Health Disparities and Social Determinants of Health
- Episode 11: Lupus and bone health
- Episode 12: Step therapy and access to medications
- Episode 13: Remission: Can my lupus go away?
Christine Lee, MD, MPH
Rheumatologist, NICU, Cedars-Sinai Medical Center
Christine Lee, MD, MPH is a member of the clinical teaching faculty and attending physician at the Cedars-Sinai Medical Center in Los Angeles. Read Bio