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 rRNA pyrosequencing was utilized to compare community composition of gut microbiota in PsA patients (n=16), subjects with psoriasis of the skin (Ps) (n=15) and healthy, matched-controls (n=17). Samples were further assessed for the presence and levels of fecal and serum secretory immunoglobulin A (sIgA), pro-inflammatory proteins and fatty-acids. Results The gut microbiota observed in PsA and Ps patients was less diverse when compared to healthy controls. These could be attributed to the reduced presence of several taxa. While both groups showed a relative decrease in Coprococcus spp., PsA samples were characterized by a significant reduction in Akkermansia, Ruminococcus, and Pseudobutyrivibrio. Supernatants of fecal samples from PsA patients revealed an increase in sIgA and a decrease in receptor activator of nuclear factor kappa-B ligand (RANKL) levels. Fatty acid analysis revealed low levels of hexanoate and heptanoate in PsA and Ps patients. Conclusion PsA and Ps patients had a lower relative abundance of multiple intestinal bacteria. Although some genera were concomitantly decreased in both conditions, PsA samples had lower abundance of reportedly beneficial taxa. This gut microbiota profile in PsA was similar to that published for patients with IBD and was associated with changes in specific inflammatory proteins unique to this group, and distinct from Ps and controls. Thus, the role of gut microbiota in the continuum of Ps-PsA pathogenesis and the associated immune response merits further study.

Purpose of Review Despite progress towards understanding the molecular pathogenesis of Rheumatoid Arthritis (RA), its etiology remains elusive. Genes are important but rather insufficient to explain the majority of RA cases. This review describes novel data supporting the microbiome and its interactions with the human host as potential en(‘in’)vironmental factors in RA pathogenesis. Recent Findings Animal models of inflammatory arthritis have shown that the presence of bacteria in mucosal surfaces is sufficient to alter local and systemic host immune responses and elicit joint inflammation. Human RA studies have focused on three mucosal sites: the gut, the gingival, and the respiratory tree. The oral microbiome, and specifically Porphyromonas gingivalis (P. gingivalis), has long been implicated. Novel sequencing technologies have allowed investigations into the role of the gut microbiome in the development of autoimmune arthritis. Most recently, the pulmonary parenchyma has also been described as yet another possible mucosal site of initiation of autoimmunity in RA. Summary Emerging data implicates the microbiome in RA pathogenesis. Mucosal sites exposed to a high load of bacterial antigens - such as the periodontium, lung, and gut - may represent the initial site of autoimmune generation. If validated, these findings could lead to the discovery of potential biomarkers and therapeutic approaches in the pre-clinical and clinical phases of RA.

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The COVID-19 pandemic has presented a major unanticipated stress on the workforce, organizational structure, systems of care, and critical resource supplies. To ensure provider safety, to maximize efficiency, and to optimize patient outcomes, health systems need to be agile. Critical care cardiologists may be uniquely positioned to treat the numerous respiratory and cardiovascular complications of the SARS-CoV-2 and support clinicians without critical care training who may be suddenly asked to care for critically ill patients. This review draws upon the experiences of colleagues from heavily impacted regions of the United States and Europe, as well as lessons learned from military mass casualty medicine. This review offers pragmatic suggestions on how to implement scalable models for critical care delivery, cultivate educational tools for team training, and embrace technologies (e.g., telemedicine) to enable effective collaboration despite social distancing imperatives.