Biomaterial Database

Predominance of IgM anti-U1RNP antibodies in patients with systemic lupus erythematosus. 1996

P G Vlachoyiannopoulos, and A Guialis, and G Tzioufas, and H M Moutsopoulos

Department of Pathophysiology, University of Athens, Medical School, Greece.

Anti-U1RNP antibodies occur in patients with mixed connective tissue disease (MCTD), systemic sclerosis (SSc), systemic lupus erythematosus (SLE) and other ill-defined connective tissue diseases. To associate the isotypes of anti-U1RNP antibodies with the diagnosis of the disease, namely SLE or MCTD, sequential sera of patients positive for anti-U1RNP antibodies by counterimmunoelectrophoresis (CIE) (32 with SLE, 35 with MCTD) were tested for IgG and IgM anti-U1RNP antibodies by enzyme-linked immunosorbent assay (ELISA) using affinity-purified U1snRNP complexes. Results from ELISA were confirmed by RNA precipitation. IgG RNA precipitation of HeLa cellular extracts was performed using the bulk of the IgG fraction removed from each serum after binding to protein A-Sepharose beads. IgM RNA precipitation was carried out on the IgM fraction of the serum bound to protein A-Sepharose-rabbit anti-human IgM immune complexes. RNAs were electrophoresed in 10.5% acrylamide-7 M urea gels and detected with the silver stain. ELISA showed that all sera were positive to IgG anti-U1RNP, while 12 of the 35 MCTD and 21 of the 32 SLE patients possessed IgM anti-U1RNP (P < 0.025). IgM anti-U1RNP reactivity was found during the follow-up in 20% of 44 sera from 17 MCTD patients and 68% of 112 sera from 23 SLE patients (P < 0.0001). IgG from all the sera precipitated U1RNPs. Eight of the MCTD sera also precipitated U2RNPs and 14 of the SLE sera U2 and/or U4/U6, U5 RNPs. IgM from MCTD sera did not precipitate URNPs, while IgM from SLE sera precipitated predominantly U1RNPs. These data suggest that IgM anti-U1RNP antibodies occur predominantly in patients with SLE. The occurrence of IgG anti-U1RNP without IgM is more frequent in MCTD.

UI	MeSH Term	Description	Entries
D007074	Immunoglobulin G	The major immunoglobulin isotype class in normal human serum. There are several isotype subclasses of IgG, for example, IgG1, IgG2A, and IgG2B.	Gamma Globulin, 7S,IgG,IgG Antibody,Allerglobuline,IgG(T),IgG1,IgG2,IgG2A,IgG2B,IgG3,IgG4,Immunoglobulin GT,Polyglobin,7S Gamma Globulin,Antibody, IgG,GT, Immunoglobulin
D007075	Immunoglobulin M	A class of immunoglobulin bearing mu chains (IMMUNOGLOBULIN MU-CHAINS). IgM can fix COMPLEMENT. The name comes from its high molecular weight and originally was called a macroglobulin.	Gamma Globulin, 19S,IgM,IgM Antibody,IgM1,IgM2,19S Gamma Globulin,Antibody, IgM
D008180	Lupus Erythematosus, Systemic	A chronic, relapsing, inflammatory, and often febrile multisystemic disorder of connective tissue, characterized principally by involvement of the skin, joints, kidneys, and serosal membranes. It is of unknown etiology, but is thought to represent a failure of the regulatory mechanisms of the autoimmune system. The disease is marked by a wide range of system dysfunctions, an elevated erythrocyte sedimentation rate, and the formation of LE cells in the blood or bone marrow.	Libman-Sacks Disease,Lupus Erythematosus Disseminatus,Systemic Lupus Erythematosus,Disease, Libman-Sacks,Libman Sacks Disease
D008947	Mixed Connective Tissue Disease	A syndrome with overlapping clinical features of systemic lupus erythematosus, scleroderma, polymyositis, and Raynaud's phenomenon. The disease is differentially characterized by high serum titers of antibodies to ribonuclease-sensitive extractable (saline soluble) nuclear antigen and a "speckled" epidermal nuclear staining pattern on direct immunofluorescence.	Connective Tissue Disease, Mixed,Sharp Syndrome,MCTD,Syndrome, Sharp
D004797	Enzyme-Linked Immunosorbent Assay	An immunoassay utilizing an antibody labeled with an enzyme marker such as horseradish peroxidase. While either the enzyme or the antibody is bound to an immunosorbent substrate, they both retain their biologic activity; the change in enzyme activity as a result of the enzyme-antibody-antigen reaction is proportional to the concentration of the antigen and can be measured spectrophotometrically or with the naked eye. Many variations of the method have been developed.	ELISA,Assay, Enzyme-Linked Immunosorbent,Assays, Enzyme-Linked Immunosorbent,Enzyme Linked Immunosorbent Assay,Enzyme-Linked Immunosorbent Assays,Immunosorbent Assay, Enzyme-Linked,Immunosorbent Assays, Enzyme-Linked
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000974	Antibodies, Antinuclear	Autoantibodies directed against various nuclear antigens including DNA, RNA, histones, acidic nuclear proteins, or complexes of these molecular elements. Antinuclear antibodies are found in systemic autoimmune diseases including systemic lupus erythematosus, Sjogren's syndrome, scleroderma, polymyositis, and mixed connective tissue disease.	Anti-DNA Antibodies,Antibodies, Anti-DNA,Antinuclear Antibodies,Antinuclear Autoantibodies,Antinuclear Autoantibody,Antinuclear Factors,Antinuclear Antibody,Antinuclear Factor,Anti DNA Antibodies,Antibody, Antinuclear,Autoantibody, Antinuclear,Factor, Antinuclear
D012313	RNA	A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. (Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)	RNA, Non-Polyadenylated,Ribonucleic Acid,Gene Products, RNA,Non-Polyadenylated RNA,Acid, Ribonucleic,Non Polyadenylated RNA,RNA Gene Products,RNA, Non Polyadenylated
D015151	Immunoblotting	Immunologic method used for detecting or quantifying immunoreactive substances. The substance is identified by first immobilizing it by blotting onto a membrane and then tagging it with labeled antibodies.	Dot Immunoblotting,Electroimmunoblotting,Immunoelectroblotting,Reverse Immunoblotting,Immunoblotting, Dot,Immunoblotting, Reverse,Dot Immunoblottings,Electroimmunoblottings,Immunoblottings,Immunoblottings, Dot,Immunoblottings, Reverse,Immunoelectroblottings,Reverse Immunoblottings
D017412	Ribonucleoprotein, U1 Small Nuclear	A nuclear RNA-protein complex that plays a role in RNA processing. In the nucleoplasm, the U1 snRNP along with other small nuclear ribonucleoproteins (U2, U4-U6, and U5) assemble into SPLICEOSOMES that remove introns from pre-mRNA by splicing. The U1 snRNA forms base pairs with conserved sequence motifs at the 5'-splice site and recognizes both the 5'- and 3'-splice sites and may have a fundamental role in aligning the two sites for the splicing reaction.	Small Nuclear Ribonucleoproteins, U1,U1 Small Nuclear Ribonucleoproteins,U1 snRNP,Ribonucleoproteins, Small, U1