The anti-dsDNA (double-stranded DNA) ELISA is a blood test used to detect antibodies that mistakenly target the body's own DNA. Elevated levels of these antibodies are strongly associated with systemic lupus erythematosus (SLE), an autoimmune disease. The test involves coating a plate with dsDNA, adding the patient's blood sample, and detecting any bound antibodies using an enzyme-linked reaction. A positive result can aid in the diagnosis of SLE and help monitor disease activity.

THE CENTROMERE ANTIBODY (ACA) TEST DETECTS AND MEASURES THE AMOUNT OF ANTICENTROMERE ANTIBODY IN THE BLOOD TO HELP DIAGNOSE A FORM OF SYSTEMIC SCLEROSIS (SCLERODERMA). SYSTEMIC SCLEROSIS IS A GROUP OF RARE CONNECTIVE TISSUE DISORDERS. THE TEST MAY BE USED TO DISTINGUISH BETWEEN THIS AND OTHER CONDITIONS WITH SIMILAR SYMPTOMS. TESTING MAY BE USED TO PROVIDE THE DOCTOR WITH ADDITIONAL INFORMATION IF AN ANA (ANTINUCLEAR ANTIBODY) TEST IS POSITIVE.

U1RNP ANTIBODY IN COMBINATION WITH SMITH ANTIBODY PROVIDES ADDITIONAL SUPPORT FOR THE DIAGNOSIS OF SLE. A POSITIVE U1RNP ANTIBODY ALONE WITH THE CORRESPONDING CLINICAL HISTORY SUPPORTS THE DIAGNOSIS OF MIXED CONNECTIVE TISSUE DISEASE.

SS-A/RO IS AN EXTRACTABLE NUCLEAR ANTIGEN WITH ANTIBODIES OCCURING IN PATIENTS WITH SJOGREN S SYNDROME (90%), LUPUS ERYTHEMATOSUS (40-60%) & RHEUMATOID ARTHRITIS. THIS ASSAY IS USEFUL FOR EVALUATING PATIENTS WITH SIGNS AND SYMPTOMS OF CONNECTIVE TISSUE DISORDER IN WHOM ANA IS POSITIVE.

SS-B/LA IS AN EXTRACTABLE NUCLEAR ANTIGEN WITH ANTIBODIES OCCURING IN PATIENTS WITH SJOGREN S SYNDROME (60%) & LUPUS ERYTHEMATOSUS (15%). THIS ASSAY IS USEFUL FOR EVALUATING PATIENTS WITH SIGNS AND SYMPTOMS OF CONNECTIVE TISSUE DISORDER IN WHOM ANA IS POSITIVE.

THE RHEUMATOID FACTOR (RF) TEST DETECTS THE PRESENCE OF AN AUTOANTIBODY (AN ANTIBODY THAT ATTACKS THE BODYS OWN TISSUES) IN THE BLOOD. RF IS AN ANTIBODY AGAINST THE FC REGION OF IGG, ANOTHER TYPE OF ANTIBODY.

C4 IS CRITICAL TO ACTIVATION OF CLASSICAL PATHWAY. DECREASED LEVELS ARE SEEN IN PATIENTS WITH SLE, IMMUNE COMPLEX DISEASE AND HEREDITARY ANGIOEDEMA. CONGENITAL DEFICIENCY OF C4 INCREASES THE RISK OF RECURRENT BACTEREMIA ESPECIALLY S.PNEUMONIAE. THIS ASSAY IS USEFUL IN THE DIAGNOSIS OF C4 DEFICIENCY AND FOR INVESTIGATION OF A PATIENT WITH AN UNDETECTABLE TOTAL COMPLEMENT (CH50) LEVEL.

C3 IS AN ACUTE PHASE REACTANT. DECREASED LEVELS ARE SEEN IN PATIENTS WITH SLE, ENDOCARDITIS AND DIC. CONGENITAL DEFICIENCY OF C3 INCREASES THE RISK OF RECURRENT BACTEREMIA. THIS ASSAY IS USEFUL FOR THE DIAGNOSIS OF C3 DEFICIENCY AND FOR INVESTIGATION OF A PATIENT WITH AN UNDETECTABLE TOTAL COMPLEMENT (CH50) LEVEL.