The OMRF Clinical Immunology Laboratory, under the direction of Dr. Judith James, performs a variety of tests to identify these autoantibodies for diagnostic and treatment purposes. The Reichlin Profile, also known as the Lupus Profile, is the definitive diagnostic test for these autoimmune diseases.
The following three tests comprise the Reichlin Profile:
- ANA – Antinuclear antibodies are present in many rheumatic diseases, and often are not specific for any single disease. They are present in over 95% of SLE patients, 86% of scleroderma patients, and in lower frequencies in rheumatoid arthritis (RA), Sjogren’s syndrome, and polymyositis.
- dsDNA – Anti-double strand DNA at a titer of 1:10 or more strongly suggests SLE.
- ENA – Extractable nuclear antibodies (precipitating antibodies) have definitive diagnostic information. Precipitating antibodies to soluble tissue antigens are present in diverse rheumatic diseases: anti-Sm is highly specific for SLE; anti-nRNP (nuclear ribonucleo- protein) is present in SLE and overlap syndromes with scleroderma and polymyositis; anti-Scl-70 is highly specific for scleroderma; anti-Ro and anti-La are associated with SLE and Sjogren’s syndrome; Anti-P (Ribosomal P) is a new specificity related to psychosis in SLE patients and may be enriched in patients with nephritis and unexplained hepatitis; anti-Jo-1, anti-PM-Scl and anti-Mi-2 may be seen in polymyositis patients. Precipitating antibodies are detected by the formation of precipitin lines in agar gel against calf thymus extract (CTE); or rabbit thymus extract (RTE) for anti-Scl70. When a line does not show identity with known antibodies against tissue extracts, the precipitin is called UIL (unidentified line), which is associated with “rheumatic disease,” but their specificities are unknown. When polymyositis is suspected a more sensitive and definitive method, immunoprecipitation, is indicated for the detection of myositis-specific antibodies that may be present at levels to low to be detected by ENA.
- ANCA (anti-neutrophil cytoplasm antibody) detects autoantibodies against neutrophil specific antigens. cANCA (cytoplasmic) is highly specific for necrotizing vasculitis and is present in more than 90% of biopsy proven Wegener’s granulomatosis but also in classical polyarteritis nodosa and Churg-Strauss’ syndrome. pANCA (perinuclear) is less specific than C-ANCA but is present in a high proportion of cases of crescentic glomerulonephritis and microscopic polyarteritis nodosa. There are numerous antigens associated with both cANCA and pANCA. PR3 (serine protease3) and MPO (myeloperoxidase) are available to help further define autoimmune vasculitis disorders.
- aPL (antibodies to phospholipid) – are associated with recurrent fetal loss and recurrent thromboses and strokes. aPL can be found in SLE as well as non-SLE patients and conditions with positivity include migraines, peripheral vascular disease, and some autoimmune cases of myocardial infarction and post-bypass graft thromboses.
- CCP (cyclic citrullinated peptides) – is a new test for the early detection of RA. These antibodies predict erosive disease, and are present in 30-40% of seronegative RA.
- CH-50 and CRYOGLOBULINS – these results must be interpreted in the context of the individual clinical case, but they may indicate or be used to monitor disease activity.
For more information regarding the OMRF Clinical Laboratory please call Jill Black at (405) 271-7395, or the laboratory staff at (405) 271-7771.