View Full Version : Laser technology to diagnose Lupus

04-22-2006, 03:24 PM
To All Members: Our Beloved Administrator sent me the following article:

A University of Calgary researcher is about to make a huge step forward in the diagnosis of lupus.

It used to take five to seven years to diagnose the disease.

Dr. Marvin Fritzler's new laser technology offers a diagnosis within a minute and half.

Getting answers that quickly will speed treatment.

Without early treatment, lupus can leave lasting damage.

Here is what my research found, it is an abstract from the 9th international workshop on autoantibodies and autoimmunity:

Autoantibodies to the Sm antigens are specifically found in 5 to 30% of patients with systemic lupus erythematosus (SLE) depending on the detection system and the patient group. Several immunoassays designed for research and diagnostic laboratory use have been developed. The autoantigens employed in these tests include purified native proteins, recombinant polypeptides, and synthetic peptides. In the present study, we compared the clinical accuracy of anti-Sm autoantibody assays from commercial suppliers including different conventional enzyme-linked immunosorbent assay (ELISA) systems based on purified Sm antigens, an addressable laser bead assay and a newly developed anti-Sm peptide assay. Although the clinical sensitivity of all assays under investigation was comparable, relatively poor correlations and significant differences in specificity were found with a patient cohort of 150 patients. The sensitivity and specificity were 10 and 94%, respectively, for the anti-Sm ELISA from Euroimmun, 10 and 90%, respectively, for the QuantaLite Sm (INOVA), 12 and 88%, respectively, for the Sm assay in the Varelisa ReCombi ANA profile (Pharmacia Diagnostics), 10 and 94%, respectively, for the QuantaPlex Sm (INOVA), and 12 and 100%, respectively, for the new SmD3 peptide-based ELISA (Varelisa Sm Antibodies). The majority of positive test results within the control groups were found in patients with mixed connective tissue disease. Based on the results, we conclude that the detection of anti-Sm antibodies strongly depends both on the nature of the antigen and on the detection system. Finally, we conclude that the recently identified SmD peptide containing a symmetrical dimethylarginine at position 112 of D3 represents a promising tool for the detection of a highly specific subpopulation of anti-Sm antibodies. In the present study, we showed that the detection of anti-PM/Scl antibodies using an ELISA system based on a major PM/Scl-100 epitope is remarkably improved compared with conventional detection methods. It could be shown that a subpopulation of PM/Scl antibodies directed against the PM1-α peptide is present in 55% of PM/Scl patients, in 13.2% of Scl patients and in 7.5% of PM patients. In rare cases anti-PM1-α reactivity was also found in patients suffering from HCV, SLE or melanoma. Within our patient cohorts we found no statistical evidence of a positive association between anti-PM1-α and antibodies other than to PM/Scl components. Based on the results of the present study we conclude that anti-PM1-α antibodies are exclusively present in sera from patients suffering from Scl or PM and most frequently in patients with the PM/Scl overlap syndrome. We therefore conclude that the new anti-PM1-α ELISA test offers a new serological test that will improve the diagnosis of complex connective tissue disorders."

Basically, this issue of commercially supplied autoassays in anti-SM lab tests being less effective than the laser technology (anti-PM1-a ELISA) testing is still being studied.
I will continue to monitor the studies and keep you advised.