Faculty Bibliography

A 58-year-old man with a history of recurrent aphthous ulcers since childhood was admitted to the hospital with acute neurological decline characterised by loss of motor dexterity, dysarthria, dysphagia and unsteady gait. MRI brain was significant for symmetrical hyperintense T2 fluid attenuated inversion recovery (FLAIR) in the corticospinal tracts, including parts of the pons and the mesodiencephalic junction. Though initial concern was for neuro-Behçet's disease, brain biopsy ultimately revealed a diagnosis of astrocytoma. This report demonstrates a mimic of neuro-Behçet's disease and the importance of confirming the correct diagnosis prior to initiating therapy.

OBJECTIVE:The intestinal microbiota has been associated with the development of inflammatory arthritis. The aim of this study was to dissect intestinal mucosal immune responses in the preclinical phase of arthritis and determine the requirement of Th17 cells, beyond the cytokine interleukin-17 (IL-17), for arthritis development. We further examined whether the involvement of Th17 cells in arthritis depends on the host microbiota. METHODS:) mice, and assessed the impact of microbiota on the Th17-dependence of CIA. RESULTS: mice showed a specific reduction of mucosal Th17 and partially reduced IL-17-producing CD8 T cells. However, total levels of IL-17A, mostly produced by γδ T cells and neutrophils, were unaffected. Arthritis was significantly reduced in Th17-deficient mice, suggesting additional IL-17A-independent roles for Th17 cells. Accordingly, antigen-stimulated T cells from Th17-deficient mice produced less IL-17A, IL-17F and GM-CSF. Importantly, Th17-dependence of arthritis was lost upon substitution of intestinal microbiota. CONCLUSION/CONCLUSIONS:These data suggest that activation of mucosal immunity precedes arthritis development, and support a microbiota-dependent role for Th17 cells in arthritis. Therefore, a microbiome-guided stratification of patients might improve the efficacy of Th17-targeted therapies.

Background/Purpose: Psoriatic Arthritis (PsA) affects up to 30% patients with psoriasis and is characterized by wide spread synovio-entheseal inflammation. Physiologically, the human gut microbiota metabolizes dietary fiber into shortchain fatty acids (FA)- which exert anti-inflammatory effects by increasing activity of regulatory T cells (Tregs).Moreover, we have previously shown decreased abundance of Akkermansia and Ruminococcus and concomitant decrease in mediumchain FA (MCFA) levels in stool of PsA patients. We therefore hypothesized that FA supplementation may have favorable effects on gut microbiome and lead to increase in tolerance, potentially serving as therapeutic target in psoriatic disease.
Method(s): Wild type (WT)animals were fed SCFA-rich diet for 14 days followed by 16S rRNA sequencing and microbiota analysis of pellet specimens.We then evaluated effects ofMCFA-rich diet in healthy subjects. Peripheral blood and stool samples were collected at days 0, 7 and 14 for 16s rRNA sequencing and FACS. Finally, we conducted a small, prospective, proof-ofprinciple study in new-onset, drug-naive psoriatic disease patients (with or without PsA). Each participant received MCFA (1 gm 4 times a day for 6 weeks). Clinical history was obtained at baseline. Skin and joint exam were performed at baseline and follow up. Serum and stool samples were collected at baseline, weeks 3, and 6 for 16S rRNA sequencing and FACS, respectively. Wilcoxon signed-rank test was used to compare differences in Tregs before and after MCFA-rich administration.
Result(s): SCFA rich diet in WT mice led to statistically significant perturbations in gut bacterial composition 14 days into intervention, with a dramatic increase in commensals (Fig 1A; p<0.001), most notably in Akkermansia(Fig 1B). MCFA administration to healthy subjects (n=7) also led to significant changes in community structure (Fig 2A; p=0.03) and associated increases in circulating Treg cells (Fig 2B; p<0.001). These findings were also observed in psoriatic disease patients (n=4) showing a significant alteration in specific taxa, including Actinobacteria (Fig 2 C; p<0.05) and Mollicutes (p=0.09) and concomitant increase in circulatory Treg cells (Fig 2D)
Conclusion(s): In both health and psoriatic disease, MCFA supplementation is associated with distinct changes in human gut microbiota composition and peripheral Treg cells. These findings rationalize the need for a larger placebo controlled, prospective trial to study the effects of MCFA in patients with psoriasis and PsA as a potential therapy alone or in combination with DMARDs. (Figure Presented)

Background/Purpose: The microbiome serves a number of important functions, including modulation of the immune system and protection from pathogenic microorganisms1. Many autoimmune diseases have been associated with intestinal microbial dysbiosis1. Recent studies have also demonstrated that microbiota can affect the lifetime, bioavailability and efficacy of drugs2. Conversely, even drugs designed to specifically target human cells have been associated with changes in microbial composition3. To date, most research has focused on bacterial microorganisms and little is known about the role that fungal microorganisms (the mycobiome) play, including their interactions with bacteria. In this study, we characterized the ecological effects of biologic therapies on the intestinal mycobiome.
Method(s): Fecal samples were collected from SpA patients pre- and post-treatment with either tumor necrosis factor inhibitors (TNFi; n=15) or secukinumab (n=14), an anti-IL-17A monoclonal antibody (IL-17i). Subjects treated with TNFi were naive to biologic therapy, whereas those treated with secukinumab previously failed or had incomplete response to TNFi. Samples underwent DNA extraction, amplification, and gene sequencing of the ITS1 region conserved in fungi. In parallel, gene sequencing of the 16S rRNA gene region conserved in bacteria was also performed. Sequences were analyzed with R and Quantitative Insights into Microbial Ecology (QIIME).
Result(s): ITS fungal data reveled that, on average, subjects treated with TNFi and IL-17i did not have major differences in overall microbial alpha or beta diversity pre- and post-treatment. However, there were dramatic shifts in the relative abundance of specific taxa, such as Candida albicans, which were more prominent in the IL-17i cohort compared to the TNFi cohort (p=0.04). The IL-17i cohort also demonstrated similar changes in certain 16S bacterial taxa, including Clostridia (p=0.02) and Clostridiales (p=0.02).
Conclusion(s): We characterized, for the first time, the effects of two biologic therapies on human intestinal fungal and bacterial microbiota composition. Treatment with biologics, particularly IL-17i, leads to a gut microbial dysbiosis characterized by significant changes in abundance of C. albicans and Clostridia in a subgroup of SpA patients. This is in line with the known increased risk of candidiasis seen with IL-17i, and may at least partially explain the potential link between IL-17 blockade, intestinal dysbiosis, and the subclinical and clinical gut inflammation observed in some patients treated with these molecules. Further studies to understand the downstream effects of these perturbations may allow for the development of precision medicine approaches in PsA and SpA

At the 2017 annual meeting of the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) in Amsterdam, the Netherlands, a trainees symposium was held. Rheumatology and dermatology trainees engaged in psoriasis or psoriatic arthritis research presented their work. This report briefly reviews 6 oral presentations and 25 posters presented at the meeting.

Objective: To characterize the gut microbiota and host gene interactions in Reactive Arthritis (ReA) and postinfectious SpA. Methods: 32 patients with ReA and 32 controls with preceding Gastrointestinal (GI) and/or Genitourinary (GU) infections that did not develop arthritiswere prospectively recruited in Guatemala, a highly prevalent geographic region for this disease. Clinical variables, HLA status and 16S ribosomal RNA gene sequencing of intestinal microbiota were analysed. Results: Subjects with ReA showed no significant differences from controls in gut bacterial richness, alpha or beta diversity. However there was a higher abundance of Erwinia and Pseudomonas, and increased prevalence of typical enteropathogens associated with ReA. In Fact, at least one enteropathogen was present in 71.9% of ReA subjects vs 46.8% of controls (p<0.05). Subjects with ultrasound evidence of enthesitiswere enriched with Campylobacter,while subjects with Uveitis and radiographic sacroiliitis were enriched with Erwinia and unclassified Ruminococcaceae, respectively. Both were enriched in Dialister (log LDA>2). Host genetics, particularly HLA-A24 were associated with differences in gut microbiota diversity irrespective of disease status. We identified several co-occurring taxa that were also predictive of HLA-A24 status, including Ruminococcaceae-Rikenellaceae-Coriobacteriacea and Prevotellaceaeunclassified Sphingobacteriales-Elusimicrobiaceae. Conclusion: This is the first culture-independent study characterizing the gut microbial community of ReA. Although bacterial factors correlated with disease presence and clinical features of ReA, host genetics also appeared to be a major independent driver of intestinal community composition. Understanding of these gut microbiota host-genetic relationships may further clarify the pathogenesis of ReA and related Spondyloarthritis

Objective: To identify potential risk factors for the development of Reactive Arthritis (ReA) among Guatemalan patients with a known history of being infected with gastrointestinal (GI), genitourinary (GU), or sexually transmitted pathogens. A prospective study was performed to examine clinical, environmental, and genetic risk factors for the development of ReA. Methods: Patients were enrolled from July to October 2014. Cases and controls were recruited in the same time window. Cases were ascertained from 2 rheumatology clinics in Guatemala City: Asociacion Guatemalteca Anti Enfermedades Reumaticas (AGAR) and AGK: Private Clinic. ReAwas defined as inflammatory arthritis following a gastrointestinal (GI) or genitourinary infection (GU) and meeting the ASAS peripheral SpA criteria. Subjects had a preceding GI or GU infection 3-6 months before enrolment. A standardized questionnaire ascertained infection details, family history, medication, medical comorbidities, smoking status and literacy. Subjects completed a standardized joint and enthesis examination, radiographs of the Sacroiliac (SI) joints interpreted by a trained radiologist and ultrasound (USG) of the Achilles tendons. Results: 32 patients with ReA and 32 controls were enrolled.Mean age was 39 and 36 respectively. The majority of patients were female (81% and 63% (Figure presented) respectively). None of the controls had swollen or tender joints or entheses. History of Uveitis was present in 60%. The most frequent tender joint: right SI joint (81%). (see figure 1). The most common finding on SI joint Xray: bilateral sacroiliitis 45%. Enthesitis was noted on Achilles tendon ultrasound in 44% cases. All ReA patients had peripheral arthritis and 91% had back pain. Only 2 subjects from each group were found to carry an HLA-B27 allele. The most frequent HLA-A allele was HLA-A2 in both patients 44% and controls 63%. Serum Cathepsin K(ng/mL) levels were elevated in patients with ReA compared to controls (2.70 vs 2.17 p=0.028). All patients completed a follow up survey at 2 years (in person or by phone). 47% of patients had continued symptoms. Uveitis resolved in all but one of the patients. Conclusion: We report the results of a study examining the epidemiology of ReA in Guatemala. As expected, SpA characteristics were common: Achilles Enthesitis (67% on exam, 44% on USG). Strengths of this study: First, 81% were female, previous studies have reported ReA as a male-predominant disease, but as in Ankylosing Spondylitis (AS) women comprise a larger proportion of patients than previously recognized when newer definitions are used. This is the first study to examine potential risk factors for ReA, including serum biomarkers. Finally, this is one of the few studies to follow patients for persistence or resolution of symptoms at 2 years

OBJECTIVE: Reactive arthritis (ReA) is an inflammatory disorder occurring several weeks after gastrointestinal or genitourinary infections. HLA-B27 positivity is considered a risk factor, though not necessarily predictive of disease incidence. Among non-genetic factors, the intestinal microbiome may play a role in disease susceptibility. The objective of this study was to characterize the gut microbiota and host gene interactions in ReA and post-infectious spondyloarthritis. METHODS: Adult peripheral spondyloarthritis and control subjects with preceding infections that did not develop arthritis were prospectively recruited from a highly prevalent geographic region. Clinical variables, HLA status, and 16S rRNA gene sequencing of intestinal microbiota were analyzed. RESULTS: ReA subjects showed no significant differences from controls in gut bacterial richness or diversity. However, there was a significantly higher abundance of Erwinia and Pseudomonas, and increased prevalence of typical enteropathogens associated with ReA. Subjects with ultrasound evidence of enthesitis were enriched in Campylobacter, while subjects with uveitis and radiographic sacroiliitis were respectively enriched in Erwinia and unclassified Ruminococcaceae, and both enriched in Dialister. Host genetics, particularly HLA-A24, were associated with differences in gut microbiota diversity irrespective of disease status. We determined several co-occurring taxa that were also predictive of HLA-A24 status. CONCLUSION: This is the first culture-independent study characterizing the gut microbial community of post-infectious arthritis. Although bacterial factors correlated with disease presence and clinical features of ReA, host genetics also appeared to be a major independent driver of intestinal community composition. Understanding of these gut microbiota host-genetic relationships may further clarify the pathogenesis of post-infectious spondyloarthropathies.

The objective of the study is to determine the risk factors for the development of reactive arthritis (ReA) and examine the factors associated with the persistence of symptoms. Patients with a new diagnosis of ReA and controls with a gastrointestinal (GI), urogenital, or sexually transmitted infection in the 3-6 months prior to study entry were prospectively enrolled in Guatemala City. ReA patients fulfilled the Assessment in Spondyloarthritis International Society criteria for peripheral spondyloarthropathy (SpA). Patients underwent history, examination, Achilles tendon ultrasound, and blood draw. Human leukocyte antigen (HLA) type and serum biomarkers were measured. t tests and nonparametric equivalents were used to examine the association of clinical, laboratory, and imaging factors with ReA. Patients were contacted 2 years later to assess for persistence of symptoms. Study subjects included patients with ReA (N = 32) and controls (N = 32). ReA patients were most frequently infected in April whereas controls were most frequently infected in August. Two ReA patients and two controls were HLA-B27-positive. Serum cathepsin K and C-reactive protein were higher in ReA patients compared to controls (p = 0.03 for both), while total cholesterol and low-density lipoprotein were lower (p = 0.008 and 0.045, respectively). Among those with ReA, 15 (47%) patients had continued symptoms at 2 years. These patients had a lower matrix metalloproteinase-3 level at diagnosis than patients for whom ReA resolved (p = 0.004). HLA-B27 was not associated with development of ReA in Guatemala; however, the month of infection was associated with ReA. The most striking finding was the persistence of arthritis at 2 years in nearly half of the patients.

The role of the gut microbiome in models of inflammatory and autoimmune disease is now well characterized. Renewed interest in the human microbiome and its metabolites, as well as notable advances in host mucosal immunology, has opened multiple avenues of research to potentially modulate inflammatory responses. The complexity and interdependence of these diet-microbe-metabolite-host interactions are rapidly being unraveled. Importantly, most of the progress in the field comes from new knowledge about the functional properties of these microorganisms in physiology and their effect in mucosal immunity and distal inflammation. This review summarizes the preclinical and clinical evidence on how dietary, probiotic, prebiotic, and microbiome based therapeutics affect our understanding of wellness and disease, particularly in autoimmunity.