Pitfalls of Potential Lupus Diagnosis

In fact, rheumatologists cited the testing of ANA subserologies without a positive ANA and clinical suspicion of immune-mediated disease as one of their top five concerns in the 2013 Choosing Wisely survey conducted by the American College of Rheumatology as part of a wider American Board of Internal Medicine campaign.⁵

Dr. Ugarte-Gil

“If we ask for a test in a patient without a clinical suspicion of an immune-mediated disorder, we may end up with over-diagnosis of SLE,” say Drs. Alarcón and Ugarte-Gil. “In addition to the risk of overtreatment and the psychological impact of this over-diagnosis, these tests would lead to an increase in the cost of care for both the health system and the patient without any tangible benefit.”

There is an unmet need to identify patients who are either at high risk of developing SLE or just early in the process due to the presence of genetic or environmental factors, they say. Rheumatologists should use terms like “potential lupus” with extreme caution until we have a better understanding of SLE pathogenesis.

Complement tests may one day help identify at-risk patients, say Drs. Alarcón and Ugarte-Gil. While these tests seem to be more useful for SLE diagnosis than previous approaches, they are not widely available and used right now.

A two-tier methodology for SLE diagnosis comparing cell-bound complement (Cd4) activation products on erythrocytes, B cells, and other specific autoantibodies proposed by a group of lupus researchers in a 2014 paper in the online journal Lupus Science & Medicine may help identify patients who are at higher risk of SLE, but it’s too soon to say for sure.⁶

“Two-tier methodology has a higher sensitivity and specificity than previous strategies for SLE diagnosis, but it has been tested only in U.S. patients, mainly Caucasians,” they say. “Its specificity and sensitivity could vary among patients from other ethnic groups. Additionally, only 304 patients were included in this study, and probably, patients with less frequent manifestations were not included.”

At this time, rheumatologists’ understanding of lupus still lags behind that of RA, which has extensive literature to identify at-risk patients, say Drs. Alarcón and Ugarte-Gil. As clues to SLE pathophysiology emerge, clinicians will be better equipped to identify which individuals need series of laboratory tests to confirm disease and which ones merit a wait-and-see approach.

Susan Bernstein is a freelance medical journalist based in Atlanta.

References

1. Alarcón GS, Ugarte-Gil MF. Incomplete systemic lupus erythematosus: Early diagnosis or overdiagnosis? Arthritis Care Res. 2016 Mar;68(3):285–287.
2. Costenbader KH, Schur PH. We need better classification and terminology for ‘people at high risk of or in the process of developing lupus.’ Arthritis Care Res. 2015 May;67(5):593–596.
3. Narain S, Richards HB, Satoh M, et al. Diagnostic accuracy for lupus and other systemic autoimmune diseases in the community setting. Arch Intern Med. 2004 Dec 13–27;164(22):2435–2441.
4. Ugarte-Gil MF, Pons-Estel GJ, Molineros J, et al. Disease features and outcomes in United States lupus patients of Hispanic origin and their Mestizo counterparts in Latin America: A commentary. Rheumatology (Oxford). 2016 Mar;55(3):436–440.
5. Yazdany J, Schmajuk G, Robbins M, et al. Choosing Wisely: The American College of Rheumatology’s top 5 list of things physicians and patients should question. Arthritis Care Res. 2013 Mar;65(3):329–339.
6. Putterman C, Furie R, Ramsey-Goldman R, et al. Cell-bound complement activation products in systemic lupus erythematosus: Comparison with anti-double-stranded DNA and standard complement. Lupus Sci Med. Published online 2014;1(1):e000056.