A short History of Indirect Immunofluorescence Technology


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. Continue reading

Why Are Autoimmune Diseases More Common in Women than Men?


No matter if it’s rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), or multiple sclerosis (MS): most autoimmune diseases affect women significantly more often than men. It is possible that this could be at least partially explained by the occurrence of age-associated B cells (ABCs), as described in an article recently published in Blood, the journal of the American Society of Hematology. Continue reading

Rheumatology Diagnostics: Indirect Immunofluorescence Tests (IIF assays) on HEp-2 Cells


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).

This pictures shows anti-RNP pattern on HEp-2 cells after ANA-HEp-2 indirect immunofluorescence assay

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. Continue reading

Autoantibodies precede manifestation of Lupus by years


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

 

Immunoflurescence image of anti-dsDNA-antibodies for the diagnosis of SLE

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). Continue reading

Blood Tests for the Diagnosis of Lupus


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.

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.  Continue reading