Complement C3d is not associated with axial spondyloarthritis and magnetic resonance imaging changes at the sacroiliac joint.

OBJECTIVE: To investigate the associations between complement C3d and inflammatory and structural changes by magnetic resonance imaging (MRI) at the sacroiliac joints (SIJ) suggestive of axial spondyloarthritis, according to the Assessment of SpondyloArthritis international Society (ASAS) criteria, in patients with low back pain. METHOD: This was a cross-sectional study of patients referred to the Spine Centre of Southern Denmark owing to unspecified low back pain (Spines of Southern Denmark cohort). The patients were divided into three groups: group 1: patients fulfilling the ASAS criteria for axial spondyloarthritis (axSpA, n = 96); group 2: patients with either a positive MRI of the SIJ and no spondyloarthritis features, or a negative MRI of the SIJ but positive human leucocyte antigen-B27 and one spondyloarthritis feature (non-axSpA, n = 38); group 3: patients with unspecified low back pain for > 3 months (control group, n = 82). Complement C3d was measured with double-decker rocket immunoelectrophoresis and evaluated in relation to the group division and baseline findings by SIJ MRI. RESULTS: In total, 184 C3d analyses were performed. The mean ± sd level of C3d was 33.8 ± 8.1 AU/mL. There were no differences in C3d levels between the three patient groups, mean values being: axSpA = 34.3 ± 7.9 AU/mL, non-axSpA = 33.5 ± 6.9 AU/mL, and controls = 33.4 ± 9.2 AU/mL. The level of C3d was not related to MRI findings. CONCLUSIONS: In these patients, complement C3d was not associated with active or structural SIJ changes on MRI suggestive of axial spondyloarthritis.

Incidence of ankylosing spondylitis and spondyloarthritis in 2000-2013: a nationwide Danish cohort study.

Objective: To describe the incidence of ankylosing spondylitis (AS) and spondyloarthritis (SpA) in the Danish population in 2000-2013, at national and regional level, and to investigate any trends in incidence over time.Methods: From the Danish National Patient Registry (NPR), we identified patients diagnosed with AS (International Classification of Diseases, 10th revision: M45) or SpA (M46) from 1 January 2000 to 31 December 2013. Patients without a relevant contact in NPR at 12-24 months after initial diagnosis were excluded. Incidence rate ratios (IRRs) were calculated using the background population of men and women aged 18-45 years in 2000-2013 as a comparator. Variations in incidence between periods and the five Danish regions were evaluated.Results: In total, 3042 incident cases were identified (AS: 1849; SpA: 1193). AS incidence increased from 476 in 2000-2004 to 660 in 2010-2013; the IRR (95% confidence interval) increased from 1.49 (1.33-1.67) in 2005-2009 to 1.74 (1.53-1.97) in 2010-2013. SpA incidence increased from 156 in 2000-2004 to 707 in 2010-2013; the IRR increased from 2.45 (2.03-2.94) in 2005-2009 to 6.31 (5.27-7.55) in 2010-2013. The incidence of both AS and SpA increased in all five regions.Conclusion: The incidence of both AS and SpA in Denmark increased from 2000 to 2013. However, the proportion of patients diagnosed with SpA rather than AS was significantly higher in 2010-2013. This may be due to increased awareness of SpA and new treatment options, but possibly also misclassification of patients with SpA.

The incidence of bone marrow oedema at the sacroiliac joints in a non-rheumatological population - a retrospective cohort study.

BACKGROUND: The purpose of this study is to determine the incidence of bone marrow oedema (BME) at magnetic resonance imaging (MRI) of the sacroiliac joints (SIJ) in a non- rheumatological population, and to explore whether patient-reported outcome measures are suitable for predicting BME at the SIJ at referral. Furthermore, to investigate the final clinical diagnoses three months after initial SIJ MRI. METHODS: This study was a retrospective cohort study consisting of patients 18-45 years of age that were referred for a SIJ MRI between 1 July 2016 to 30 June 2017 at the Department of Radiology in Lillebaelt Hospital, Denmark. The SIJ MRI radiological reports were evaluated for signs of BME. Principal and secondary diagnoses according to the 10th version of International Classification of Diseases (ICD-10)-three months after the initial MRI-were identified in the electronic patient record system. For a subgroup of patients, patient- reported outcome measures, such as the 23-item Roland Morris Disability Questionnaire, quality of life and pain intensity in the back and leg were included from the local SpineData database. RESULTS: In total, 333 patients were included, and 187 (56.2%) of those patients received a final diagnosis within three months after the SIJ MRI. BME was detected in 63 (18.9%) patients; 17 (9.1%) patients had both BME at SIJ MRI and were diagnosed with spondyloarthritis (M45/M46). There was no statistically significant difference between patients with and without BME regarding demographics, quality of life, pain descriptions or function. CONCLUSIONS: The incidence of BME in the cohort correlates well to previous studies regarding the incidence of SIJ MRI changes in non-rheumatological populations in Denmark. Patient-reported outcome measures do not seem to contribute to identifying patients with early-phase BME in a non-rheumatological population.

The correlation between cell-free DNA and tumour burden was estimated by PET/CT in patients with advanced NSCLC.

BACKGROUND: Cell-free DNA (cfDNA) circulating in the blood holds a possible prognostic value in malignant diseases. Under malignant conditions, the level of cfDNA increases but the biological mechanism remains to be fully understood. We aimed to examine the correlation between cfDNA and total tumour burden defined by positron emission tomography (PET) parameters. METHODS: Patients with advanced non-small cell lung cancer (NSCLC) were enrolled into a prospective biomarker trial. Before treatment, plasma was extracted and the level of cfDNA was determined by qPCR. An (18)F-fluorodeoxyglucose ((18)F-FDG) PET/computed tomography (CT) scan was performed and evaluated in terms of metabolic tumour volume (MTV) and total lesion glycolysis (TLG). Tumour contours were delineated semi-automatically by a threshold standardised uptake value (SUV) of 2.5. The primary end point was correlation among cfDNA, MTV and TLG. The secondary end point was overall survival (OS) according to cfDNA, MTV and TLG. RESULTS: Fifty-three patients were included. There were no correlations between cfDNA and MTV (r=0.1) or TLG (r=0.1). cfDNA >75th percentile was correlated with shorter OS (P=0.02), confirmed in a multivariate analysis. MTV>the median was associated with a significantly shorter OS (P=0.02). There was no significant difference in OS according to TLG (P=0.08). CONCLUSION: Cell-free DNA may not be a simple measure of tumour burden, but seems to reflect more complex mechanisms of tumour biology, making it attractive as an independent prognostic marker.

DNA-RNA polymerase complexes associated with the membrane from bacteriophage T2- or T4-infected Escherichia coli. I. General properties.

Properties of DNA-RNA polymerase complexes, apparently bound to a fraction of the cell membrane of bacteriophage T2- or T4-infected Escherichia coli, are described. Evidence is presented to show that the complexes initiate the asymmetric synthesis of RNA, and release the finished product. The transcription capacity per unit of beta' + beta was 10 times higher at 6 min than at 30 min after infection.

DNA-RNA polymerase complexes associated with the membrane from bacteriophage T2- or T4-infected Escherichia coli. II. A comparison of in vitro RNA with the in vivo RNA products.

Membrane preparations, containing DNA-RNA polymerase from bacteriophage T2- or T4-infected Escherichia coli, caused the asymmetric synthesis of RNA classes similar to those produced sequentially in vivo: 1, Pre-early RNA was formed when a membrane preparation was isolated 1 min after infection. 2, Pre-early and delayed early RNA, in roughly the same proportion as that obtained in vivo, was synthesized by a preparation obtained 6 min after infection. 3, Pre-early, delayed early and late genes were transcribed by preparations isolated from cells during the late period of infection. In late preparations, however, less late and more pre-early RNA was usually synthesized in vitro than that obtained in vivo. Late RNA was not synthesized when a phage T4 mutant defective in either gene 33 or gene 55 was used. Evidence is presented to show that late RNA synthesis cannot solely be accounted for from the completion of already initiated chains.

Conversion of Escherichia coli RNA polymerase to a template independent enzyme.

Preparations of RNA polymerase (E.C.2.7.7.6) from uninfected Escherichia coli, T4 infected Escherichia coli, and Acinetobacter calcoaceticus when centrifuged in sucrose gradients in the absence of magnesium ions gave rise to five peaks, all of which were able to form polymers from ribonucleoside 5'-triphosphates in the absence of template or primer. All of the peaks obtained from the Escherichia coli enzyme appeared to contain the subunit alpha and beta and, in addition, polypeptides which appeared to be derived from the subunit beta.