(1) Background: A growing body of evidence highlights that intestinal dysbiosis is associated with the development of psoriasis. The gut–skin axis is the novel concept of the interaction between skin diseases and microbiome through inflammatory mediators, metabolites and the intestinal barrier. The objective of this study was to synthesize current data on the gut microbial composition in psoriasis. (2) Methods: We conducted a systematic review of studies investigating intestinal microbiome in psoriasis, using the PRISMA checklist. We searched MEDLINE, EMBASE, and Web of Science databases for relevant published articles (2000–2020). (3) Results: All of the 10 retrieved studies reported alterations in the gut microbiome in patients with psoriasis. Eight studies assessed alpha- and beta-diversity. Four of them reported a lack of change in alpha-diversity, but all confirmed significant changes in beta-diversity. At the phylum-level, at least two or more studies reported a lower relative abundance of Bacteroidetes, and higher Firmicutes in psoriasis patients versus healthy controls. (4) Conclusions: There is a significant association between alterations in gut microbial composition and psoriasis; however, there is high heterogeneity between studies. More unified methodological standards in large-scale studies are needed to understand microbiota’s contribution to psoriasis pathogenesis and its modulation as a potential therapeutic strategy.

Background: Systemic sclerosis is an immune-mediated rheumatic disease characterized by vascular abnormalities, tissue fibrosis and autoimmune phenomena. Summary: Renal disease occurring in patients with systemic sclerosis may have a variable clinicopathological picture. The most specific renal condition associated with systemic sclerosis is scleroderma renal crisis, characterized by acute onset of renal failure and severe hypertension. Although the management of scleroderma renal crisis was revolutionized by the introduction of angiotensin-converting enzyme inhibitors, there is still a significant proportion of patients with poor outcomes. Therefore, research on establishing disease markers (clinical, ultrasonographical and serological) and clear diagnostic criteria, which could limit the risk of developing scleroderma renal crisis and facilitate diagnosis of this complication, is ongoing. Other forms of renal involvement in systemic sclerosis include vasculitis, an isolated reduced glomerular filtration rate in systemic sclerosis, antiphospholipid-associated nephropathy, high intrarenal arterial stiffness and proteinuria. Key Messages: Scleroderma renal crisis is the most specific and lifethreatening renal presentation of systemic sclerosis, albeit with declining prevalence. In patients with scleroderma renal crisis, it is mandatory to control blood pressure early with increasing doses of angiotensin-converting enzyme inhibitors, along with other antihypertensive drugs if necessary. There is a strong association between renal involvement and patients' outcomes in systemic sclerosis; consequently, it becomes mandatory to find markers that may be used to identify patients with an especially high risk of scleroderma renal crisis.

Psoriasis is a chronic inflammatory systemic disease. Growing evidence suggests that human homeostasis depends on a mutualistic relationship with gut bacteria that produce a number of biologically active compounds. Therefore, enteric microbiota dysbiosis with gut barrier disruption may be an important factor in the development of chronic inflammatory diseases. The aim of our study was to assess non-invasive markers of intestinal barrier integrity in patients with moderate to severe psoriasis. Concentrations of claudin-3 (intestinal epithelial tight junction structure) and intestinal fatty acid binding protein (I-FABP; marker of enterocyte damage) were determined in the blood of patients with chronic plaque psoriasis (n = 20) and healthy individuals (n = 20) using commercially available enzyme-linked immunoassay test kits. Claudin-3 concentration was higher in patients with psoriasis compared with healthy control (median, 54.07 vs 42.36 ng/mL; P < 0.001). Patients with psoriasis also had elevated concentration of plasma I-FABP (median, 708.8 vs 147.1 pg/mL; P < 0.05). Our results support the hypothesis that dysfunction of the intestinal barrier in psoriasis disturbs the homeostatic equilibrium between the microbiota and immune system. Further studies are needed in order to develop new therapeutic interventions based on modulation of intestinal permeability.

Alterations of intestinal microbiota play a significant role in the pathogenesis of psoriasis. Dysbiosis may cause disruption of the intestinal barrier, which contributes to immune activation by translocation of microbial antigens and metabolites. Intestinal fatty acid binding protein (I-FABP) serves as a biomarker of enterocyte damage. The aim of this study was to investigate clinical and metabolic factors affecting plasma concentration of I-FABP in patients with psoriasis. Eighty patients with psoriasis and 40 control subjects were enrolled in the study. Serum I-FABP (243.00 (108.88–787.10) vs. 114.38 (51.60–241.60) pg/ml, p < 0.001) and neutrophil to lymphocyte ratio (NLR; 2.59 (1.96–3.09) vs. 1.72 (1.36–47 2.11), p < 0.01) were significantly increased in patients with psoriasis compared to controls. A significant positive correlation was found between I-FABP and body mass index (BMI) (r = 0.82, p < 0.001), Psoriasis Area Severity Index (PASI) (r = 0.78, p < 0.001) and neutrophil to lymphocyte ratio (NLR) (r = 0.24, p < 0.001). Rising quartiles of I-FABP were associated with increasing values of BMI, PASI and NLR. The results of the logistic regression model confirmed an increased risk of higher disease severity with I-FABP concentration – odds ratio 3.34 per 100 pg/mL I-FABP increase. In conclusion, intestinal integrity in patients with psoriasis is affected by obesity, severity of the disease and systemic inflammation. The modulation of gut barrier may represent a new therapeutic approach for psoriasis.

Systemic sclerosis (SSc) is an autoimmune disease characterized by vasculopathy and uncontrolled cutaneous and internal organs fibrosis. Diagnosis of SSc in an early phase can be difficult because of a lack of typical symptoms. The delay in diagnosis and treatment of SSc may lead to uncontrolled progression of the disease, thus identification of possible early indicators of skin and organ involvement to prevent their further damage is necessary. The aim of this study is to review the latest biomarkers of organ involvement in SSc. In patients with lung fibrosis lung-epithelial-derived surfactant protein (SP-D), the glycoprotein Krebs von den Lungen-6 (KL-6), and chemokine ligands 2, 4 and 18 (CCL2, CXCL4, CCL18) are elevated, while in patients with skin fibrosis serum levels of heat shock protein 27 (Hsp27), interleukin 16 (IL-16), and IgG–galactosylation ratio are increased. Adiponectin concentration is inversely correlated with the intensity of cutaneous fibrosis. Skin gene profiling also seems very promising. In patients with heart involvement increased serum levels of brain natriuretic peptide (BNP) are present, as well as raised Midkine and Follistatin-like 3 (FSTL3) proteins, ratios of Cu/Se and ceruloplasmin(CP) /Circulating selenoprotein P(SELENOP) and higher whole blood viscosity level. Elevated calprotectin levels are found in individuals with gastrointestinal involvement. Increased levels of chemerin and ARA autoantibodies are associated with renal involvement, whereas high levels of adhesion molecules are found in patients with scleroderma renal crisis (SRC). Currently there are no biomarkers in use that can specifically identify the early involvement of organs.