The famous musician Seal is known for his numerous international hits, and for living with an autoimmune disease: the scars on his face are the result of discoid lupus erythematosus. Picture: C. Grube for Access2music.de, wikimedia
Systemic lupus erythematosus (SLE) is a chronic inflammatory disease with manifold manifestations. SLE belongs to the family of autoimmune disorders, diseases that occur, when a mislead immune system attacks the body’s own structures. SLE can affect almost any organ system, thus its presentation and course are highly variable, and diagnosis and therapy may be challenging.
With the intention to classify SLE patients for research and surveillance studies and to support clinicians in confirming a diagnosis, a set of clinical and laboratory classification criteria has been developed and released by the American College of Rheumatology (ACR). The first classification criteria for SLE were originally published in 1971 [1,2]. They have been updated 1982  and 1997  to incorporate new immunologic knowledge and improve patient classification. In contrast to the 1987 criteria, the 1997 criteria have not been validated.
The most recent addendum to the classification criteria for SLE dates from 2012, when the Systemic Lupus International Collaborating Clinics (SLICC) group published a revision and validation of the ACR criteria .
Anti-Centromere B on HEp2 cells
HEp2 cells are held dear in autoimmune diagnostics. They are invaluable for people engaged in analysing autoantibodies, as E. coli is for molecular biologists or mice for toxicologists.
In spite of a wide range of other suitable methods and technologies, determination of autoantibodies with indirect immuno-fluorescence assays (IFA) on human epithelioma (HEp2) cells still contributes significantly to the diagnosis of autoimmune diseases. The widely recognised advantages of this method are high sensitivity and a broad spectrum of antibodies that can be analysed simultaneously. In addition to mere detection of antibodies a characteristic fluorescence pattern and staining of metaphase and cytoplasmic cells offer supplementary information.
When an autoimmune disease is suspected, the HEp-2 test usually is the first line test. Any positive result is then followed up by a step-wise diagnostic approach, including other immunological tests like ELISA (enzyme-linked immunosorbent assay) for single antibody specificities or immunoblot tests.
Antibodies to various autoantigens may be present in sera of patients who will develop Lupus erythematosus up to seven years before onset of disease symptoms
Autoantibodies against dsDNA are diagnostic markers for Systemic Lupus Erythematosus.
Autoantibodies are specific and sensitive biomarkers for autoimmune diseases and indispensible diagnostic tools. They may also be involved in pathogenic processes underlying the disease and will potentially occur in sera of apparently healthy people long before onset of the first symptoms.
C. Eriksson, S. Raantapaa-Dalquist and their colleagues from Umeå University in Sweden have focused on this preclinical phase in the development of Systemic Lupus Erythematosus (SLE). (more…)
Blood Tests for the Diagnosis of Lupus
Welcome to our Autoimmunity Blog! The subject of this post is blood tests for the diagnosis of lupus.
Lupus facial rash in a typical wolf-like distribution.
The emphasis of this article is on the detection of autoantibodies relevant to the diagnosis of SLE. Specifically, this includes detection of ANA (antinuclear antibodies) by immunofluorescence and individual tests for various ANA, including anti-dsDNA, anti-Sm, anti-U1RNP (also anti-U1-RNP or anti-RNP), and anti-histone, as well as anti-SS-A/Ro and anti-SS-B/La.
Tests for ANA are also highly useful in differential diagnostics, especially when diseases with symptoms resembling SLE must be distinguished from lupus itself, for example fibromyalgia, infections like tuberculosis and HIV/AIDS, or certain malignant tumours, particularly lymphoma and leukaemia. (more…)