Faculty Bibliography

OBJECTIVE: To characterize the diversity and taxonomic relative abundance of the gut microbiota in patients with never-treated, recent-onset psoriatic arthritis (PsA). METHODS: High-throughput 16S ribosomal RNA pyrosequencing was utilized to compare the community composition of gut microbiota in patients with PsA (n = 16), patients with psoriasis of the skin (n = 15), and healthy, matched control subjects (n = 17). Samples were further assessed for the presence and levels of fecal and serum secretory IgA (sIgA), proinflammatory proteins, and fatty acids. RESULTS: The gut microbiota observed in patients with PsA and patients with skin psoriasis was less diverse when compared to that in healthy controls. This could be attributed to the reduced presence of several taxa. Samples from both patient groups showed a relative decrease in abundance of Coprococcus species, while samples from PsA patients were also characterized by a significant reduction in Akkermansia, Ruminococcus, and Pseudobutyrivibrio. Supernatants of fecal samples from PsA patients revealed an increase in sIgA levels and decrease in RANKL levels. Analysis of fatty acids revealed low fecal quantities of hexanoate and heptanoate in both patients with PsA and patients with psoriasis. CONCLUSION: Patients with PsA and patients with skin psoriasis had a lower relative abundance of multiple intestinal bacteria. Although some genera were concomitantly decreased in both conditions, PsA samples had a lower abundance of reportedly beneficial taxa. This gut microbiota profile in PsA was similar to that previously described in patients with inflammatory bowel disease and was associated with changes in specific inflammatory proteins unique to this group, and distinct from that in patients with skin psoriasis and healthy controls. Thus, the role of the gut microbiome in the continuum of psoriasis-PsA pathogenesis and the associated immune response merits further study.

Psoriatic arthritis (PsA) is an inflammatory arthritis associated with psoriasis that can lead to decreased health-related quality of life and permanent joint damage leading to functional decline. In addition to joint and skin manifestations, both psoriasis and PsA are associated with numerous comorbidities and extraarticular/cutaneous manifestations, which may influence the physician's choice of therapy. The objectives of this review are (1) to identify comorbidities in patients with PsA based on the available evidence; (2) to examine the effects of these comorbidities or extraarticular/cutaneous manifestation on the management of patients with PsA as well as the selection of therapy; and (3) to highlight research needs around comorbidities and treatment paradigms. This review is part of a treatment recommendations update initiated by the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA).

Psoriasis is a chronic inflammatory skin condition, characterized by T-helper (Th) 1 and Th17 cell activation. Ustekinumab is a fully human immunoglobulin G1kappa monoclonal antibody that targets the common p40 subunit that is shared by both interleukin (IL)-12 and IL-23, consequently inhibiting T-cell differentiation along both Th1 and Th17 pathways. This is a report of two patients who developed psoriatic arthritis during ustekinumab treatment for psoriasis. Neither patient had a personal or family history of arthritis.

OBJECTIVE: To compare disease activity, radiographic features, and bone density in psoriatic arthritis (PsA) and rheumatoid arthritis (RA) matched cohorts. METHODS: Disease activity and radiographic data in the Consortium of Rheumatology Researchers of North America database from 2001 to 2008 were compared for 2481 patients with PsA and 17,107 patients with RA subsequently matched for age, gender, and disease duration. Radiographic outcomes included presence of erosions, and joint deformity. In addition, bone mineral density (BMD) scores for lumbar spine (L-spine) and femoral neck were compared using the same matching criteria plus weight and smoking status. RESULTS: Tender (4.5 vs 3.4, p < 0.001) and swollen (4.4 vs 2.9, p < 0.012) joint counts, and modified Health Assessment Questionnaire scores were significantly higher (0.4 vs 0.3, p < 0.001) in patients with RA compared with patients with PsA. Patient general health and pain scores were also higher in patients with RA vs patients with PsA. Joint erosions (47.4% vs 37.6%, p = 0.020) and deformity (25.2% vs 21.6%, p = 0.021) were more prevalent in RA than PsA. In multivariate analysis, a reduced prevalence of erosions in PsA vs RA was noted (OR 0.609, p < 0.001). After matching, T-scores for L-spine (-0.54 vs -0.36, p = 0.077) and femoral neck (-0.88 vs -0.93, p = 0.643) were similar in patients with RA and patients with PsA, although body weight was a major confounder. CONCLUSION: The level of disease activity and radiographic damage was significantly higher for RA vs PsA subjects, although the magnitude of differences was relatively small. BMD levels were comparable between cohorts. Outcomes in patients with PsA and patients with RA may be more similar than previously reported

Purpose: The etiology of RA remains unknown, but genetic and environmental factors have been implicated. An infectious trigger has been sought but conventional microbiologic techniques have been uninformative. The human intestine contains a dense, diverse and poorly characterized (>=80% uncultured) bacterial population whose collective genome (microbiome) is >=100 times larger than its human host. We (DRL) have recently shown in mice that gut-residing bacteria drive autoimmune arthritis via Th17 cell activation (Immunity 2010). Multiple lines of investigation also suggest a link between RA and oral microbes. Methods: As part of an NIH ARRA grant, the NYU Microbiome Center for Rheumatology and Autoimmunity was established to study gut and oral microbiota in RA and related conditions. A cross-sectional study and prospective proof-of-concept antibiotic intervention trial are ongoing. Fecal samples are collected, periodontal status assessed and oral samples obtained by subgingival biofilm collection. To date, oral/intestinal microbiomes have been analyzed in 8 RA patients, 3 psoriatic arthritis (PsA) patients and 9 healthy controls. Periodontal status was characterized in 30 RA, 4 PsA and 8 controls. DNA was purified and variable 16s rRNA gene regions amplified. PCR products were pyrosequenced (454 Life Sciences), and DNA sequences compared to the RDP and BLAST catalogs. rDNA-based phylogenetic trees were created, and the UNIFRAC metric used to compare bacterial communities across individuals. Sera from all subjects were evaluated for anti-citrullinated peptide antibodies (ACPA). Results: Prevotellaceae family was significantly overrepresented in fecal microbiota from ACPA+ RA patients (range 13%-85%; mean=38%) vs ACPA-individuals (mean=4.3%); p=0.003. One ACPA+ healthy individual and 1 ACPA+ PsA patient shared similar microbiomes with ACPA+ RA. Subgingival microbiomes in patients with new-onset drug-naive RA exhibited overabundance of the Spirochetaceae/Prevotellaceae/Porphyromonaceae families (mean=53%) compared to chronic-active RA and healthy controls (mean=18.5%). Periodontal assessment revealed 78% of examined sites bled upon probing in RA patients (mean age 39; 73% female), significantly more than controls (38% PsA, 12% healthy; p<0.001 vs RA); 66% of RA patients also presented with moderate periodontitis compared to PsA (25%) and controls (12%). Conclusions: This is the first study using high-throughput technologies to assess oral and intestinal microbiota in RA. Our data corroborate prior reports demonstrating an underappreciated high prevalence of periodontal disease at a young age in patients with RA. Moreover, our preliminary data suggest that ACPA generation may be associated with larger populations of Prevotellaceae in both oral and intestinal microbiomes. In response to such altered microbial flora, certain predisposed individuals may develop auto-inflammatory disease, through mechanisms that may include the generation of cyclic citrullinated peptides or Th17 cell activation in the intestinal mucosa. Thus, the oral and intestinal microbiota merit further investigation as potential triggers for autoimmunity and clinical RA