Orally administrated iron is suspected to increase susceptibility to enteric infections among children in infection endemic regions. Here we investigated the effect of dietary iron on the pathology and local immune responses in intestinal infection models. Mice were held on iron-deficient, normal-iron, or high-iron diets and after two weeks they were orally challenged with the pathogen Citrobacter rodentium. Microbiome analysis by pyrosequencing revealed profound iron- and infection-induced shifts in microbiota composition. Fecal levels of the innate defensive molecules and markers of inflammation lipocalin-2 and calprotectin were not influenced by dietary iron intervention alone, but were markedly lower in mice on the iron-deficient diet after infection. Next, mice on the iron-deficient diet tended to gain more weight and to have a lower grade of colon pathology. Furthermore, survival of the nematode Caenorhabditis elegans infected with Salmonella enterica serovar Typhimurium was prolonged after iron-deprivation. Together, these data show that iron limitation restricts disease pathology upon bacterial infection. However, our data also showed decreased intestinal inflammatory responses of mice fed on high-iron diets. Thus additionally, our study indicates that the effects of iron on processes at the intestinal host-pathogen interface may highly depend on host iron status, immune status and gut microbiota composition.

Twenty to thirty percent of psoriasis (Pso) patients will develop psoriatic arthritis (PsA). Detection of Pso patients that are (at risk for) developing PsA is essential to prevent structural damage. We conducted a systematic search of five bibliographic databases, up to May 2020. We searched for studies assessing markers (clinical, laboratory, genetic) associated with the development or presence of PsA in Pso patients. Study selection and quality assessment of the included studies was performed, followed by a qualitative best evidence synthesis to determine the level of evidence for a marker and its association with concomitant/developing PsA in Pso. Overall, 259 possible markers were identified in 119 studies that met the inclusion criteria. Laboratory markers related to inflammation and bone metabolism reached a strong level of evidence for the association (not prediction) of PsA in Pso. Only CXCL10 showed strong evidence for a positive predictive value for PsA in Pso. The importance of timely detecting PsA in a Pso population, and finding more (bio)markers contributing to early detection, remains high.

No abstract

Objectives We aimed to investigate the disease activity and overall disease burden of (subgroups of) patients with PsA using the Psoriatic Arthritis Disease Activity Score (PASDAS) in an already tightly monitored cohort. Methods This is a cross-sectional study evaluating data from the first visit of 855 PsA patients after implementation of the PASDAS in our tightly monitored cohort [e.g. DAS 28 (DAS28) was provided as an anchor]. Differences in clinical outcomes between subgroups of patients using established cut-offs for disease activity status [i.e. very low (VLDA), low (LDA), moderate (MDA), and high disease activity (HDA)] were examined. Results Based on the PASDAS, 53.1% of patients were in VLDA/LDA. 29.5% of patients had ≥1 swollen joint, 20.6% had ≥1 enthesitis index point and 3.0% had active dactylitis. Based on DAS28, 77.5% of the patients were in VLDA/LDA. Patients reaching both DAS28 VLDA/LDA status and PASDAS VLDA/LDA status [N = 445 (52.0%)] were compared with patients reaching only DAS28 VLDA/LDA status [N = 218 (25.5%)]. For these latter patients, significantly worse scores on separate parameters were found in measures used for PASDAS/DAS28 calculation (e.g. swollen and tender joint count and patient’s visual analogue scale global disease activity) as well as other disease measures (e.g. function and inflammatory back pain). This result remained, even when the stricter VLDA cut-off was used for the DAS28. Conclusion PASDAS implementation uncovered relevant residual disease activity in a quarter of patients previously assessed as being in DAS28 VLDA/LDA, underscoring the potential value of PASDAS measurements in PsA clinical care.