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.
Liver Disease Diagnostics: Antibody-Based Diagnosis of Autoimmune Liver Disease
For the launch of our Liver-9-Line immunoblot test (to our press release “Liver Disease Diagnostics by Immunoblot” of May 16, 2011), I dug through a pile of literature on the topic of autoantibody-based diagnosis of autoimmune diseases of the liver. In the last week I picked it all up again and worked through it systematically.
The interior surface of the liver. A reproduction of a lithograph plate from Gray’s Anatomy.
The reason for my renewed interest is that we brought four more ELISA tests for liver diagnostics to the market two weeks ago. They are the Anti-LKM-1, Anti-SLA, Anti-gp210, and Anti-Sp100 tests, all designed for fully automated autoimmune diagnosis with our Alegria system. All four test systems assist the formulation of a diagnosis when autoimmune hepatitis (AIH) and primary biliary cirrhosis (PBC) are suspected, or for differential diagnosis when another disorder of the liver is assumed. (more…)
The GRÜNER CLUB AUTOIMMUN blog featured a fine post about the history of indirect immunofluorescence. In that article my Austrian colleague Barbara Fabian, community manager of GRÜNER CLUB AUTOIMMUN, described in great detail how indirect immunofluorescence technology, or: IFT, and also referred to as IIF assay, has become an indispensible tool of autoimmune disease diagnostics over the last two decades, and how IFT has become a standard laboratory technique used in serological autoimmune diagnostics.
Without further ado I have translated Barbara’s post in order to make you this text, and especially the interesting images, available. – Here it is:
The Development of Indirect Immunofluorescence Technology (IFT)
by Barbara Fabian, MSc, Community Manager of GRÜNER CLUB AUTOIMMUN
Over the last 20 years, the detection of autoantibodies has developed into an indispensible component of autoimmune diagnostics. Along with serological and clinical data, autoimmune status has become an important building block in the formation of diagnoses. (more…)
Immunofluorescence patterns help eliminate “false positives” in diagnosing autoimmune rheumatic diseases
The detection of anti-nuclear antibodies, the ANA test, is a clear (laboratory-) diagnostic indicator of rheumatic autoimmune disease. One of the standard laboratory tests for the detection of these antinuclear antibodies is IIF, the indirect immunofluorescence assay, on human HEp-2 cells (ANA-HEp-2 test).
ANA-HEp-2 indirect immunofluorescence test (IIF): antibodies against RNP (ribonucleoproteins) – interphase nucleoli: coarse granular positive, nucleoli neglected; mitotic cells: negative (400x) – © ORGENTEC Diagnostika, Mainz
However, for up to 13% of healthy individuals, indirect immunofluorescence may detect anti-nuclear antibodies. Most of these healthy people will not develop an autoimmune disease – despite the positive ANA test. It is thus a challenge for the physician to differentiate these healthy, false-positive patients from those ANA-positive patients who already have an inflammatory rheumatic disease or who truly have an increased risk of developing such an autoimmune disease.
Several very specific IIF patterns
In a large study, Brazilian IIF experts have now worked out the fundamental differences between the ANA-HEp-2 test results on serum samples from healthy individuals and the immunofluorescence patterns from serum samples of patients with rheumatic disease; they have described various IIF patterns that can be used to differentiate between the two patient groups (Mariz et al. 2011). This study was published a few weeks ago in the January issue of Arthritis & Rheumatism, the journal of the American College of Rheumatology (ACR). In their article, the scientists from the Universidade Federal de São Paulo, Brazil, explain in detail that there are several very specific immunofluorescence patterns in the ANA-HEp-2 assay with which the autoimmune rheumatic diseases (ARD) are truly associated. (more…)
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…)