Objective: To investigate synovial fluid (SF) for the presence of CR1 and to study its relationship to SF leukocytes and to serum levels of soluble CR1 (sCR1) in patients with rheumatic diseases.
Methods: Synovial fluids were collected from 35 patients with rheumatoid arthritis (RA) and 26 patients with other inflammatory joint diseases. Total CR1 in the SF and serum were measured with a sandwich enzyme-linked immunosorbent assay (ELISA) that recognized both soluble and transmembrane forms of CR1. The characteristics of CR1 in SF were analyzed by ultracentrifugation and by a second ELISA specific for transmembrane CR1.
Results: CR1 was found in all SF samples tested (range 5-281 ng/ml). SF CR1 was higher in patients with RA (mean +/- SD 81 +/- 66 ng/ml) than in those with other inflammatory joint diseases (31.8 +/- 23.8 ng/ml) (P < 0.001). Serum sCR1 was not significantly increased in the patients compared with the normal subjects. There was no correlation between serum sCR1 and SF CR1. In 44% of the patients, the SF CR1 level was higher than the serum sCR1 level. A fraction (30-80%) of SF CR1 was pelleted by ultracentrifugation and, unlike serum sCR1, it reacted in an ELISA specific for transmembrane CR1. Thus, SF contained 2 forms of CR1: a membrane-associated and a soluble form, which was confirmed by sucrose density-gradient ultracentrifugation. SF CR1 levels correlated directly with the number of SF total leukocytes and polymorphonuclear leukocytes (PMN). These 2 forms of CR1 were also found in the supernatant of in vitro-activated PMN from normal subjects. SF CR1 exhibited the capacity to act as a cofactor for the factor I degradation of C3b.
Conclusion: CR1 is found in the SF of patients with joint inflammation. The data suggest that SF CR1 originates from the infiltrating leukocytes, which shed both a soluble and a membrane-associated form. Whether SF CR1 participates in the local regulation of complement activation remains to be examined.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1002/art.1780400318 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Functions of the Bloom Syndrome Helicase N-terminal Intrinsically Disordered Region.
Genetics
January 2025
Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
Bloom Syndrome helicase (Blm) is a RecQ family helicase involved in DNA repair, cell-cycle progression, and development. Pathogenic variants in human BLM cause the autosomal recessive disorder Bloom Syndrome, characterized by predisposition to numerous types of cancer. Prior studies of Drosophila Blm mutants lacking helicase activity or protein have shown sensitivity to DNA damaging agents, defects in repairing DNA double-strand breaks (DSBs), female sterility, and improper segregation of chromosomes in meiosis.
View Article and Find Full Text PDFTranscriptome of capsular contracture around breast implants mimics allograft rejection: a matched case-control study.
Plast Reconstr Surg
December 2024
Copenhagen University Hospital, Department of Plastic Surgery and Burns Treatment, Rigshospitalet, Copenhagen, Denmark.
Background: Capsular contracture is a frequent and severe complication following breast implant surgery. Although several theories on the pathophysiology exist, the exact molecular mechanisms remain unclear. This study aimed to identify the specific genes, signaling pathways, and immune cells associated with capsular contracture.
View Article and Find Full Text PDFIdentification and Validation of Potential Biomarkers and Therapeutic Targets of COVID-19-related Depression.
Comb Chem High Throughput Screen
January 2025
Department of Emergency, First Medical Center of Chinese PLA General Hospital, 28 Fuxing Road, Beijing, 100853, China.
Background: The prevalence of depression in COVID-19 patients is notably high, disrupting daily life routines and compounding the burden of other chronic health conditions. In addition, to elucidate the connection between COVID-19 and depression, we conducted an analysis of commonly differentially expressed genes [co-DEGs], uncovering potential biomarkers and therapeutic avenues specific to COVID-19-related depression.
Methods: We obtained gene expression profiles from the Gene Expression Omnibus [GEO] database with strategic keyword searches ["COVID-19", "depression," and "SARS"].
Untangling the Genetic Threads of Alzheimer's: Insights into Risk Factors and Biomarkers.
Curr Gene Ther
January 2025
Department of Animal Biology, Faculty of Natural Sciences, University of Tabriz, Tabriz, Iran.
Dementia is a comprehensive term that refers to illnesses characterized by a decline in cognitive memory and other cognitive functions, affecting a person's overall ability to operate. The exact causes of dementia are unknown to this day. The heterogeneity of Alzheimer's indicates the contribution of genetic polymorphism to this disease.
View Article and Find Full Text PDFThe Differential Complement, Fc and Chemokine Receptor Expression of B Cells in IgG4-Related Pancreatobiliary Disease and Primary Sclerosing Cholangitis and Its Relevance for Targeting B Cell Pathways in Disease.
Biomedicines
December 2024
Peter Medawar Building for Pathogen Research, Nuffield Department of Medicine, University of Oxford, South Parks Road, Oxford OX1 3SY, UK.
Immune-mediated liver and biliary conditions, such as IgG4-related pancreatobiliary disease (IgG4-PB) and a subset of primary sclerosing cholangitis (PSC- high(h)IgG4), exhibit increased IgG4 levels in the blood. The relative expression of IgG4+ and IgG1+ B cells in the blood and the expression of complement and Fc receptors on these IgG1+ and IgG4+ B cells in IgG4-PB and PSC have not been previously described. We hypothesised that the patterns of expression of these cells and their receptors would differ, are relevant to disease pathogenesis and may represent therapeutic targets.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!