ABSTRACT
OBJECTIVE: To ascertain the clinical and serological associations of anti-Ku antibody. METHODS: Twenty-seven patients over a 7 year period (1987-1996) had anti-Ku antibody detected by counterimmunoelectrophoresis (CIEP). Nineteen patients were available for clinical review. Five patients were assessed by chart review. Serum was taken at review for repeat antibody analysis. Patients were assigned to diagnostic groups based on the American College of Rheumatology criteria. RESULTS: There were 22 women and 5 men. The duration of symptoms ranged from one year to 28 years. Nine patients fulfilled criteria for systemic lupus erythematosus (SLE), 4 scleroderma, 3 rheumatoid arthritis (RA), one discoid lupus, and 7 had an undifferentiated connective tissue disease. There was a low incidence of renal (2/24) and central nervous system involvement (1/24); 19/24 had Raynaud's phenomenon, 15/24 had inflammatory arthritis but only one had erosions on radiograph; 11/24 reported esophageal reflux symptoms. Three of 24 patients had myositis. All patients had anti-nuclear antibody using indirect immunofluorescence of > 640 titer with a speckled and nucleolar pattern. Anti-Ku antibody was detected on CIEP in 15/19 sera available for repeat testing. Three patients had anti-Ro antibody, 2 had anti-U1RNP antibody, one patient had anti-topoisomerase-1 and anti-Ro. CONCLUSION: Anti-Ku antibody is found in a wide variety of connective tissue syndromes. While several patients fulfilled diagnostic criteria for SLE, scleroderma, and RA, their clinical features were usually mild and did not form a distinctive clinical pattern. Common features associated with anti-Ku were Raynaud's phenomenon, arthralgia, skin thickening, and esophageal reflux. Few patients had associated autoantibody specificities found in SLE or scleroderma.
Subject(s)
Antigens, Nuclear , Autoantibodies/analysis , Autoantigens/immunology , Autoimmune Diseases/immunology , DNA Helicases , DNA-Binding Proteins/immunology , Nuclear Proteins/immunology , Adult , Aged , Aged, 80 and over , Autoimmune Diseases/diagnosis , Connective Tissue Diseases/diagnosis , Connective Tissue Diseases/immunology , Counterimmunoelectrophoresis , Female , Fluorescent Antibody Technique, Indirect , Humans , Ku Autoantigen , Male , Middle AgedABSTRACT
OBJECTIVE: Isolated congenital complete heart block (CCHB) occurs in 1/20,000 live births. More than 85% of mothers giving birth to affected infants are anti-Ro antibody positive, but only approximately 1% of babies with anti-Ro-positive mothers develop CCHB. We studied 2 sets of monozygotic twins discordant for CCHB. METHODS: Monozygosity was determined using placental examination and DNA microsatellite analysis. HLA typing was performed. Autoantibody studies were performed using counterimmunoelectrophoresis, immunoblotting, Ro 52 and Ro 60 enzyme-linked immunosorbent assay (ELISA), and indirect immunofluorescence (IIF) on Ro 60- and Ro 52-transfected HEp-2 cells. RESULTS: Both sets of twins were monozygotic. They had similar birth weights. Twin 2 in the second set required a pacemaker at age 2 months. Both mothers were positive for anti-Ro 52 and anti-Ro 60 antibody, and neither had anti-La antibody on immunoblot. One set of twins was studied at birth. Similar titers of anti-Ro 52 and anti-Ro 60 antibody were found by IIF and ELISA. CONCLUSION: There are no previous well-documented reports of monozygotic twins discordant for CCHB. These cases demonstrate that there is still discordance in the development of CCHB despite identical genetics and environmental exposure to anti-Ro antibody.
