The authors wish to make the following correction to this paper [...].
<p>Multiple studies have shown the microbiota to be abnormal in patients with spondyloarthritis (SpA). The purpose of this study was to explore the genetic contributions of these microbiota abnormalities. We analyzed the impact of HLA-B27 on the microbiota of children at risk for SpA and compared the microbiota of HLA-B27+ pediatric offspring of ankylosing spondylitis (AS) patients with that of HLA-B27+ children with SpA. Human DNA was obtained from the offspring for determination of HLA-B27 status and polygenic risk score (PRS). Fecal specimens were collected from both groups for sequencing of the V4 region of the 16S ribosomal RNA gene. Among the offspring of AS patients, there was slight clustering by HLA-B27 status. After adjusting for multiple comparisons, five operational taxonomic units (OTUs) representing three unique taxa distinguished the HLA-B27+ from negative children: and were lower in the HLA-B27+ offspring, while was higher. HLA-B27+ offspring without arthritis were compared to children with treatment-naïve HLA-B27+ SpA. After adjustments, clustering by diagnosis was present. A total of 21 OTUs were significantly associated with diagnosis state, including (higher in SpA patients) and (higher in controls). Thus, our data confirmed associations with and with juvenile SpA, and also suggest that the mechanism by which HLA-B27 is associated with SpA may not involve alterations of the microbiota.</p>
<p><strong>BACKGROUND: </strong>Prior studies have demonstrated abnormalities in the composition of the gastrointestinal microbiota in pediatric and adult patients with spondyloarthritis (SpA). In particular, diminished fecal abundance of Faecalibacterium prausnitzii and abnormalities in both directions in the abundance of the Bacteroides genus have been identified.</p>
<p><strong>METHODS: </strong>We obtained fecal specimens from 30 children with treatment-naïve enthesitis-related arthritis (ERA) and 19 healthy controls, as well as specimens from 11 adult patients with longstanding SpA and 10 adult healthy controls. All of the samples underwent sequencing of the 16S ribosomal DNA. A subset of the pediatric fecal samples was subjected to shotgun metagenomics sequencing.</p>
<p><strong>RESULTS: </strong>ERA patients had decreased abundance of the anti-inflammatory F. prausnitzii A2-165 strain (41 ± 28% versus 54 ± 20% of all sequences matching F. prausnitzii, p = 0.084) and an increased abundance of the control F. prausnitzii L2/6 strain (28 ± 28% versus 15 ± 15%, p = 0.038). Similar trends were observed in adults with longstanding SpA (n = 11) and controls (n = 10). In contrast, the fecal abundance of Bacteroides fragilis was increased in ERA subjects (2.0 ± 4.0% versus 0.45 ± 0.7% of all sequences, p = 0.045), yet was diminished in adult subjects (0.2 ± % versus 1.0 ± % of all sequences, p = 0.106). Shotgun metagenomics sequencing of the fecal DNA in the pediatric subjects revealed diminished coverage of the butanoate pathway (abundance normalized to controls of 1 ± 0.48 versus 0.72 ± 0.33 in ERA, p = 0.037).</p>
<p><strong>CONCLUSIONS: </strong>The anti-inflammatory F. prausnitzii A2-165 strain appears to be depleted in both pediatric and adult SpA. In contrast, B. fragilis may be depleted in adult disease yet abundant in pediatric SpA, suggesting developmental effects on the immune system.</p>
<p><strong>OBJECTIVE: </strong>There is wide variation in therapeutic approaches to systemic juvenile idiopathic arthritis (JIA) among North American rheumatologists. Understanding the comparative effectiveness of the diverse therapeutic options available for treatment of systemic JIA can result in better health outcomes. The Childhood Arthritis and Rheumatology Research Alliance (CARRA) developed consensus treatment plans and standardized assessment schedules for use in clinical practice to facilitate such studies.</p>
<p><strong>METHODS: </strong>Case-based surveys were administered to CARRA members to identify prevailing treatments for new-onset systemic JIA. A 2-day consensus conference in April 2010 employed modified nominal group technique to formulate preliminary treatment plans and determine important data elements for collection. Followup surveys were employed to refine the plans and assess clinical acceptability.</p>
<p><strong>RESULTS: </strong>The initial case-based survey identified significant variability among current treatment approaches for new-onset systemic JIA, underscoring the utility of standardized plans to evaluate comparative effectiveness. We developed 4 consensus treatment plans for the first 9 months of therapy, as well as case definitions and clinical and laboratory monitoring schedules. The 4 treatment regimens included glucocorticoids only, or therapy with methotrexate, anakinra, or tocilizumab, with or without glucocorticoids. This approach was approved by >78% of the CARRA membership.</p>
<p><strong>CONCLUSION: </strong>Four standardized treatment plans were developed for new-onset systemic JIA. Coupled with data collection at defined intervals, use of these treatment plans will create the opportunity to evaluate comparative effectiveness in an observational setting to optimize initial management of systemic JIA.</p>