lactoferrin and Connective-Tissue-Diseases

To study the prevalence of antineutrophil cytoplasmic antibodies against lactoferrin in patients with connective tissue diseases and to characterize the antibody response to lactoferrin in these patients.. Sera from 60 patients with systemic lupus erythematosus, 98 with rheumatoid arthritis, 11 with systemic sclerosis, and 6 with mixed connective tissue disease were studied. The presence of anti-lactoferrin antibodies was detected by enzyme-linked immunosorbent assay. The IgG subclass reactivity of antibodies to lactoferrin was analyzed by biotin-extravidin amplified enzyme-linked immunosorbent assay and monoclonal antibodies to human IgG subclasses.. Anti-lactoferrin antibodies were found in 15 patients (5 patients with rheumatoid arthritis and 10 with systemic lupus erythematosus). IgG1 was the predominant subclass for antibodies to lactoferrin.. Patients with connective tissue diseases are known to develop multiple auto-antibodies; anti-lactoferrin antibodies mainly of IgG1 isotype can also be found in patients with rheumatoid arthritis and more often in patients with systemic lupus erythematosus.

Topics: Adolescent; Adult; Aged; Antibodies, Anti-Idiotypic; Biomarkers; Case-Control Studies; Connective Tissue Diseases; Enzyme-Linked Immunosorbent Assay; Female; Humans; Immunoglobulin G; Lactoferrin; Male; Middle Aged; Probability; Prognosis; Reference Values; Retrospective Studies; Sensitivity and Specificity; Severity of Illness Index

Sjögren's syndrome is an autoimmune condition affecting the lacrimal and salivary glands and can be associated with rheumatoid arthritis and primary biliary cirrhosis. Parotid salivas collected from patients and normal controls were analysed for lactoferrin, IgA and beta2-microglobulin (measured by ELISA), and cystatin (measured by a enzyme inhibition assay). Output data provided less variable means, whilst expressing results as a proportion of the total protein provided greater specificity as markers for Sjögren's syndrome. Levels of specificity for IgA, lactoferrin and beta2-microglobulin were all high (100, 95 and 100%, respectively). Sensitivity levels of these markers (but not cystatin) tended to be similar for Sjögren's syndrome secondary to primary biliary cirrhosis (IgA, 25%; lactoferrin, 63%; and beta2-microglobulin, 50%), compared to Sjögren's syndrome secondary to connective tissue diseases such as rheumatoid arthritis (IgA, 50%; lactoferrin, 86%; and beta2-microglobulin; 38%).

Topics: Arthritis, Rheumatoid; beta 2-Microglobulin; Case-Control Studies; Connective Tissue Diseases; Cystatins; Humans; Immunoglobulin A, Secretory; Lactoferrin; Liver Cirrhosis, Biliary; Parotid Gland; Saliva; Salivary Proteins and Peptides; Secretory Rate; Sjogren's Syndrome

To compare the protein composition of tear fluid obtained from patients with primary Sjögren's syndrome, patients with other connective tissue diseases and control individuals.. SDS polyacrylamide gel electrophoresis followed by staining with Coomassie blue and Western blotting.. Comparison revealed the presence of a characteristic difference in the ratio of intensity between the albumin and lactoferrin bands. An albumin:lactoferrin ratio above 2:1 was significantly more common in patients with primary Sjögren's syndrome than in patients with other connective tissue diseases or the controls.. An albumin:lactoferrin ratio above 2:1 may therefore prove of use when diagnosing 1(0)SS. Used as a test, its sensitivity was 67% and its specificity 100%.

Topics: Adult; Aged; Aged, 80 and over; Albumins; Blotting, Western; Connective Tissue Diseases; Electrophoresis, Polyacrylamide Gel; Eye Proteins; Female; Humans; Lactoferrin; Male; Middle Aged; Sensitivity and Specificity; Sjogren's Syndrome; Tears

Antibodies to lactoferrin were detected in about 20% of patients with SLE, irrespective of the presence of renal involvement and in 10% of patients with rheumatoid arthritis and in 19% of patients with scleroderma. We conclude that anti-lactoferrin antibodies may be found in different types of connective tissue disease. Their clinical significance in these diseases however remains to be elucidated.

Topics: Antibodies, Antineutrophil Cytoplasmic; Antibody Specificity; Arthritis, Rheumatoid; Autoantibodies; Autoantigens; Connective Tissue Diseases; Humans; Immunoglobulin G; Lactoferrin; Lupus Erythematosus, Systemic