US is a feasible imaging modality for measurement of the response of RA small-joint synovitis to therapy.

Proteoglycans are among the most abundant and structurally complex biomacromolecules and play critical roles in connective tissues. They are composed of a core protein onto which glycosaminoglycan (GAG) side chains are attached via a linker region. Biallelic mutations in B3GALT6, encoding one of the linker region glycosyltransferases, are known to cause either spondyloepimetaphyseal dysplasia (SEMD) or a severe pleiotropic form of Ehlers-Danlos syndromes (EDS). This study provides clinical, molecular and biochemical data on 12 patients with biallelic B3GALT6 mutations. Notably, all patients have features of both EDS and SEMD. In addition, some patients have severe and potential life-threatening complications such as aortic dilatation and aneurysm, cervical spine instability and respiratory insufficiency. Whole-exome sequencing, next generation panel sequencing and direct sequencing identified biallelic B3GALT6 mutations in all patients. We show that these mutations reduce the amount of β3GalT6 protein and lead to a complete loss of galactosyltransferase activity. In turn, this leads to deficient GAG synthesis, and ultrastructural abnormalities in collagen fibril organization. In conclusion, this study redefines the phenotype associated with B3GALT6 mutations on the basis of clinical, molecular and biochemical data in 12 patients, and provides an in-depth assessment of β3GalT6 activity and GAG synthesis to better understand this rare condition.

Increased MMP-3 levels in SF are found in inflammatory arthropathies and are not specific for erosive joint diseases. MMP-3 in SF is therefore a potential candidate for the assessment of the inflammatory process in joints. However, the exclusive determination of the active form could indicate the degree of joint destruction.

Extrapulmonary sarcoidosis, and particularly the presence of musculoskeletal complications of the disease, may require chronic corticosteroid therapy. In five patients with biopsy-proven sarcoidosis and presenting recalcitrant forms of the disease, we introduced low-dose oral methotrexate (MTX) [10 mg/week (7.5-15)] for 30 months (16-34) to control the clinical and biological symptoms as well as to try to reduce the intolerated steroid posology. Beneficial effects were observed within 8-12 weeks in all patients, which allowed a reduction of 59% (35-75) of the corticosteroid posology, and maintained with a follow-up of 3 yr in 4/5 patients. No significant toxicity was observed. MTX appears to be an efficient, safe and corticosteroid-sparing therapeutic agent for the treatment of recalcitrant musculoskeletal manifestations of sarcoidosis.

Summary.A patient with Jo-1 antibody-associated polymyositis (Jo-1 PM) had a Karnofsky score of 40% and severe muscle, liver and lung damage that was refractory to standard therapy. The female patient received an autologous T-cell-depleted haematopoietic stem cell transplant (HSCT) after myeloablative conditioning. The transplant procedure was complicated by severe adult respiratory distress syndrome (ARDS) and adenovirus-associated haemorrhagic cystitis as well as cytomegalovirus (CMV) reactivation. The patient's creatinine phosphokinase (CPK) and alanine transaminase (ALT) values were normal on day 21. The patient's strength has improved remarkably and her dyspnoea is subjectively improved. At 15 months after the transplant, the patient was well with a Karnofsky score of 80% and had been off any therapy, including steroids, for 14 months.