Dataset Information

Polymorphisms within the adenosine receptor 2a gene are associated with adverse events in RA patients treated with MTX.

ABSTRACT:

Objective

To examine the role of adenosine receptor 2a gene (ADORA2a) polymorphisms on outcome of MTX treatment in RA.

Methods

Subjects included 309 RA patients with a defined response to MTX. Patients were included if they were (i) good responders (n = 147) (ESR <20 for >6/12 on stable dose of MTX) (ii) inefficacy failures (n = 101) (physician statement and failure to reduce ESR/CRP by 20%) or (iii) adverse event (AE) failures (n = 61) (verified by medical record review). AEs were sub-divided into gastrointestinal (GI) (n = 24), abnormal LFTs (n = 20) or other (n = 17). 8 single nucleotide polymorphisms (SNPs) within ADORA2a were genotyped using the Sequenom MALDI-TOF platform.

Results

Five SNPs within ADORA2a were associated with stopping MTX for AEs (OR 2.1-3.07, P < 0.05 for all). Analysis by AE type showed that the association was specific for GI toxicity. No association was observed between ADORA2a and inefficacy outcomes.

Conclusion

Genetic variation within ADORA2a is significantly associated with AEs on MTX, specifically GI AEs. Knowledge of the ADORA2a genotype may help to improve identification of patients at high risk of GI toxicity with MTX.

SUBMITTER: Hider SL

PROVIDER: S-EPMC2468887 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:Adenosine is generated in increased concentrations at sites of injury/hypoxia and mediates a variety of physiological and pharmacological effects via G protein-coupled receptors (A(1), A(2A), A(2B), and A(3)). Because all adenosine receptors are expressed on osteoclasts, we determined the role of A(2A) receptor in the regulation of osteoclast differentiation. Differentiation and bone resorption were studied as the macrophage colony-stimulating factor-1-receptor activator of NF-κB ligand formation of multinucleated tartrate-resistant acid phosphatase (TRAP)-positive cells from primary murine bone marrow-derived precursors. A(2A) receptor and osteoclast marker expression levels were studied by RT-PCR. Cytokine secretion was assayed by enzyme-linked immunosorbent assay. In vivo examination of A(2A) knockout (KO)/control bones was determined by TRAP staining, micro-computed tomography, and electron microscopy. The A(2A) receptor agonist, CGS21680, inhibited osteoclast differentiation and function (half maximal inhibitory concentration, 50 nmol/L), increased the percentage of immature osteoclast precursors, and decreased IL-1β and tumor necrosis factor-α secretion, an effect that was reversed by the A(2A) antagonist, ZM241385. Cathepsin K and osteopontin mRNA expression increased in control and ZM241385-pretreated osteoclasts, and this was blocked by CGS21680. Micro-computed tomography of A(2A)KO mouse femurs showed a significantly decreased bone volume/trabecular bone volume ratio, decreased trabecular number, and increased trabecular space. A(2A)KO femurs showed an increased TRAP-positive osteoclast. Electron microscopy in A(2A)KO femurs showed marked osteoclast membrane folding and increased bone resorption. Thus, adenosine, acting via the A(2A) receptor, inhibits macrophage colony-stimulating factor-1-receptor activator of NF-κB ligand-stimulated osteoclast differentiation and may regulate bone turnover under conditions in which adenosine levels are elevated.