Imaging Features of the Juvenile Inflammatory Arthropathies

We discuss the imaging of several juvenile inflammatory arthropathies including juvenile idiopathic arthritis, juvenile systemic lupus erythematosus, juvenile scleroderma, juvenile dermatomyositis, and chronic recurrent multifocal osteomyelitis. Juvenile idiopathic arthritis is the most common autoimmune chronic systemic disease of connective tissue in children. The remaining systemic juvenile connective tissue diseases are rare. However, they require early diagnosis and initiation of treatment to prevent injury, not only to the musculoskeletal system but also to the internal organs, and even death. Imaging of juvenile inflammatory arthropathies has relied for years on radiography. Recent advances in disease-modifying drugs have led to a greater emphasis on the detection of early inflammation not evident on plain radiography. Ultrasound examination allows for the early recognition of the disease process in the soft tissues. Magnetic resonance imaging detects early inflammatory changes involving the soft tissues, the subcortical bone of peripheral joints, the spine, and entheses.

Cross-disorder risk gene CACNA1C differentially modulates susceptibility to psychiatric disorders during development and adulthood

Single-nucleotide polymorphisms (SNPs) in CACNA1C, the α1C subunit of the voltage-gated L-type calcium channel Cav1.2, rank among the most consistent and replicable genetics findings in psychiatry and have been associated with schizophrenia, bipolar disorder and major depression. However, genetic variants of complex diseases often only confer a marginal increase in disease risk, which is additionally influenced by the environment. Here we show that embryonic deletion of Cacna1c in forebrain glutamatergic neurons promotes the manifestation of endophenotypes related to psychiatric disorders including cognitive decline, impaired synaptic plasticity, reduced sociability, hyperactivity and increased anxiety. Additional analyses revealed that depletion of Cacna1c during embryonic development also increases the susceptibility to chronic stress, which suggest that Cav1.2 interacts with the environment to shape disease vulnerability. Remarkably, this was not observed when Cacna1c was deleted in glutamatergic neurons during adulthood, where the later deletion even improved cognitive flexibility, strengthened synaptic plasticity and induced stress resilience. In a parallel gene × environment design in humans, we additionally demonstrate that SNPs in CACNA1C significantly interact with adverse life events to alter the risk to develop symptoms of psychiatric disorders. Overall, our results further validate Cacna1c as a cross-disorder risk gene in mice and humans, and additionally suggest a differential role for Cav1.2 during development and adulthood in shaping cognition, sociability, emotional behavior and stress susceptibility. This may prompt the consideration for pharmacological manipulation of Cav1.2 in neuropsychiatric disorders with developmental and/or stress-related origins.

Inadequate CD18 shedding and increased depletion of soluble CD18 contributes to inflammatory activity in spondyloarthritis (P5090)

Spondyloarthritis (SpA) is characterized by inflammation in the axial skeleton and entheses. Integrin adhesion molecules containing the CD18 chain are pivotal regulators of leukocyte extravasation from the blood into zones of inflammation. Recently, we showed that CD18 is shed from leukocytes forming a soluble form of CD18 (sCD18) in the blood. Here we show that plasma sCD18 is a marker of inflammatory activity in SpA. The plasma levels of sCD18 were decreased in SpA patients compared with healthy controls and showed inverse correlations with disease activity scores including the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) score. Remarkably, this situation could be simulated in vitro. Thus, the degree of CD18 shedding from SpA patient-derived PBMC correlated inversely with the BASDAI score. According to flow cytometric analyses, CD18 was primarily shed from intermediate (CD14++ CD16+) monocytes. In agreement with earlier reports identifying CD18 as a substrate for MMP-9, the concentration of this enzyme in the culture supernatants correlated with the sCD18 concentration. Also, sCD18 complexes adhered to TNFα-stimulated endothelial cells expressing high levels of ICAM-1 but not to unstimulated cells. Taken together, our data links alterations in plasma sCD18 and inflammatory activity in SpA. The low plasma level of sCD18 in SpA seems to be a combination of inadequate CD18 shedding and increased depletion of sCD18 potentially affecting leukocyte migration.

Repair of erosions in rheumatoid arthritis does occur. Results from 2 studies by the OMERACT Subcommittee on Healing of Erosions

The committee was charged with determining whether healing of erosions in rheumatoid arthritis (RA) occurs. Two exercises were performed: The first asked the committee members, as a panel of experts, to express agreement or disagreement with the presence of improvement and features of bone reaction to injury in images submitted by members as examples of healing. The second presented panel members with 28 pairs of serial images, 14 chosen to illustrate progression and 14 chosen to illustrate repair. Agreement was tested on 8 items: global judgment on which image in the pair was better, relative size of the erosion in the 2 images, judgment on which image was first, presence and extent of sclerosis, cortication, filling-in, remodeling, and reconstituting normal structure. Our results showed good agreement, among the 15 respondents, on global assessment of which image was better and which image showed the smaller erosion. Correct assignment of sequence was only slightly better than expected by chance (in 65% of the cases). Agreement was poor regarding the presence of morphologic features of bone repair. A majority of a panel of experts agreed on which 2nd images in a set of paired, serial images represented improvement and which showed progression based on global assessment of which was better and on size of erosion. Features of bone repair were not distinctive and did not enable the panel to deduce the correct sequence of the serial images. This study provides evidence that repair of bone damage in RA does occur, resulting in some degree of improvement, which was recognized by a majority of a panel of experts.