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Candida auris a frequently multidrug-resistant yeast species that poses a global health threat due to its high potential for hospital outbreaks. While C. auris has become endemic in parts of Asia and Africa, transmissions have so far rarely been reported in Western Europe except for Great Britain and Spain. We describe the first documented patient-to-patient transmission of C. auris in Germany in a COVID-19 intensive care unit (ICU) and infection control measures implemented to prevent further spread of the pathogen.Identification of C. auris was performed by MALDI-TOF and confirmed by internal transcribed spacer (ITS) sequencing. Antifungal susceptibility testing was carried out. We conducted repeated cross-sectional examinations for the presence of C. auris in the patients of the affected ICU and investigated possible routes of transmission.The index patient had been transferred to Germany from a hospital in Northern Africa and was found to be colonised with C. auris. The contact patient developed C. auris sepsis. Infection prevention and control (IPC) measures included strict isolation of the two C. auris patients and regular screening of non-affected patients. No further case occurred during the subsequent weeks. Reusable blades used in video laryngoscope-guided intubation were considered as the most likely vehicle of transmission.In view of its high risk of transmission, vigilance regarding C. auris colonisation in patients referred from endemic countries is crucial. Strict and immediate IPC measures may have the potential to prevent C. auris outbreaks.

T lymphocytes accumulate in inflamed tissues of patients with chronic inflammatory diseases (CIDs) and express pro-inflammatory cytokines upon re-stimulation in vitro. Further, a significant genetic linkage to MHC genes suggests that T lymphocytes play an important role in the pathogenesis of CIDs including juvenile idiopathic arthritis (JIA). However, the functions of T lymphocytes in established disease remain elusive. Here we dissect the transcriptional and the clonal heterogeneity of synovial T lymphocytes in JIA patients by single-cell RNA sequencing combined with T cell receptor profiling on the same cells. We identify clonally expanded subpopulations of T lymphocytes expressing genes reflecting recent activation by antigen in situ. A PD-1+ TOX+ EOMES+ population of CD4+ T lymphocytes expressed immune regulatory genes and chemoattractant genes for myeloid cells. A PD-1+ TOX+ BHLHE40+ population of CD4+ , and a mirror population of CD8+ T lymphocytes expressed genes driving inflammation, and genes supporting B lymphocyte activation in situ. This analysis points out that multiple types of T lymphocytes have to be targeted for therapeutic regeneration of tolerance in arthritis.

Renal infiltration of inflammatory cells contributes to the pathogenesis of lupus nephritis (LN). Current knowledge on the recruitment mechanisms relies mainly on findings in rodent models. Here, we assess various chemokine pathways in human LN by comparing urinary chemokine concentrations (in 25 patients with acute LN and in 78 lupus patients without active LN) with the expression of corresponding chemokine receptors on urinary leukocytes (in ten acute LN patients). Nine urinary chemokines were significantly elevated in LN patients and correlated with renal disease activity and urinary cell counts; however, their concentrations displayed considerable interindividual heterogeneity. Analysis of the corresponding receptors revealed abundance of urinary CD8+ T cells for CCR5 and CXCR3, while CD4+ T cells were additionally enriched for CCR1, CCR6 and CXCR6. Urinary Treg showed similar CCR expression, and urinary CD14+ macrophages were enriched for CCR5 expressing cells. In conclusion, cell specific recruitment patterns seem to involve CCR5 and CXCR3 in all cells studied, while CD4+ T-cell subset recruitment is probably much more varied. However, urinary chemokine abundance in active LN is individually variable in our cohort and does not offer a singular chemokine usable as universal biomarker or potential future treatment target.

B1a B cells have been implicated in the pathogenesis of systemic lupus erythematosus; however, their precise contribution to the disease remains unclear. Here we analysed isotype expression, organ accumulation and autoreactivity of B1a cells in the NZB/W F1 murine model for systemic lupus erythematosus using flow cytometry, ELISPOT and adoptive cell transfer. In the course of lupus, the B1a compartment is expanded and B1a cells class switch to IgG. Class-switched B1a B cells were excluded from the peritoneal cavity but accumulated in the spleen and target organs such as kidneys and thymus. Autoreactive B1a B cells preferentially class switch, which leads to a subsequent loss of autoreactive B1a cells from the peritoneal cavity. We propose a model whereby autoreactive B1a B cells become activated early in the course of lupus and class switch to IgG. These autoreactive B1a B cells accumulate in the spleen and affected organs where they presumably secrete autoantibodies and contribute to the local and systemic pathogenesis.

Objective The high frequency of CD4+ T cells in interstitial infiltrates of patients with lupus nephritis suggests a contribution of these cells to local pathogenesis. The aim of this study was to examine the role of CXCR3 and the chemokine CXCL10 in recruiting these cells into the kidney and to determine whether the infiltrating T cells could be monitored in the urine to provide a reliable biomarker for acute lupus nephritis. Methods The frequencies of CD3+ T cells, CXCR3+ cells, and CXCL10+ cells were determined by immunohistochemical and immunofluorescence analyses of kidney sections from 18 patients with lupus nephritis. The frequency of CXCR3+CD4+ T cells was determined by flow cytometry of peripheral blood and urine from 38 patients with systemic lupus erythematosus (SLE), and the values were compared with disease activity as determined by the Systemic Lupus Erythematosus Disease Activity Index. Results In renal biopsy tissues from patients with lupus nephritis, a mean of 63% of the infiltrating cells expressed CXCR3, approximately 60% of them were T cells, and the CXCR3+ cells colocalized with CXCL10-producing cells. In biopsy tissues from SLE patients with acute nephritis, approximately 50% of the urinary CD4+ T cells were CXCR3+, as compared with 22% in the peripheral blood, and the frequency of urinary CXCR3+CD4+ T cells correlated with disease activity. Moreover, the number of urinary CD4+ T cells reflected nephritis activity, and elevation above 800 CD4+ T cells per 100 ml of urine sharply delineated active from inactive nephritis. Conclusion CXCR3+ T cells are recruited into the inflamed kidneys, are enriched in the urine, and are a valuable marker of nephritis activity in SLE. They also present a potential target for future therapies.