Discovery and Validation of a Urinary Exosome mRNA Signature for the Diagnosis of Human Kidney Transplant Rejection

BackgroundDeveloping a noninvasive clinical test to accurately diagnose kidney allograft rejection is critical to improve allograft outcomes. Urinary exosomes, tiny vesicles released into the urine that carry parent cells’ proteins and nucleic acids, reflect the biologic function of the parent cells within the kidney, including immune cells. Their stability in urine makes them a potentially powerful tool for liquid biopsy and a noninvasive diagnostic biomarker for kidney-transplant rejection.MethodsUsing 192 of 220 urine samples with matched biopsy samples from 175 patients who underwent a clinically indicated kidney-transplant biopsy, we isolated urinary exosomal mRNAs and developed rejection signatures on the basis of differential gene expression. We used crossvalidation to assess the performance of the signatures on multiple data subsets.ResultsAn exosomal mRNA signature discriminated between biopsy samples from patients with all-cause rejection and those with no rejection, yielding an area under the curve (AUC) of 0.93 (95% CI, 0.87 to 0.98), which is significantly better than the current standard of care (increase in eGFR AUC of 0.57; 95% CI, 0.49 to 0.65). The exosome-based signature’s negative predictive value was 93.3% and its positive predictive value was 86.2%. Using the same approach, we identified an additional gene signature that discriminated patients with T cell–mediated rejection from those with antibody-mediated rejection (with an AUC of 0.87; 95% CI, 0.76 to 0.97). This signature’s negative predictive value was 90.6% and its positive predictive value was 77.8%.ConclusionsOur findings show that mRNA signatures derived from urinary exosomes represent a powerful and noninvasive tool to screen for kidney allograft rejection. This finding has the potential to assist clinicians in therapeutic decision making.     

Chronic ulcerative stomatitis: A comprehensive review and proposal for diagnostic criteria

Chronic ulcerative stomatitis (CUS) is an immune‐mediated disorder characterized by oral erosions and ulcers usually refractory to conventional treatments. The disease often involves middle‐aged and older women with painful lesions sometimes resembling those of erosive oral lichen planus (OLP). The most affected sites are the buccal mucosa, the gingiva and the tongue, but the skin is involved in 22.5% of cases. Histopathologic features in CUS are non‐specific and indistinguishable from those of OLP, with the exception of the presence of a mixed infiltrate composed of lymphocytes and plasma cells. Direct immunofluorescence (DIF) analysis reveals the presence of stratified epithelium‐specific antinuclear antibodies (SES‐ANA) in the lower third of the epithelium. The IgG antibodies detected on DIF are directed against the ?Np63α isoform of p63 expressed in the nuclei of the epithelial basal cells. A distinguishing feature of CUS is the low response to conventional corticosteroid therapy and the good outcome with hydroxychloroquine at the dosage of 200 mg/day or higher dosages. This paper presents a comprehensive review of CUS and is accompanied by a new case report (the 73rd case) and a proposal for updated diagnostic criteria.     

Characterization of human H1N1 influenza virus variants selected in vitro with zanamivir in the presence of sialic acid-containing molecules

Understanding the molecular mechanisms of influenza virus resistance to neuraminidase inhibitors is a main concern for their clinical use. In an attempt to reproduce in vivo selective conditions where influenza virus resistance to neuraminidase inhibitors can occur the zanamivir selection of an A/H1N1 influenza virus strain was carried out in Madin-Darby canine kidney cells performed in the presence or absence of sialic acid-containing inhibitor analogues that act as virus decoy receptors. The zanamivir-selected variants passaged in the presence of sialic acid-containing molecules resembling the human-like virus receptor lost the ability to bind red blood cells. Furthermore, whereas all zanamivir-selected variants exhibited a robust reduction in susceptibility to zanamivir in plaque assays only those obtained after extensive passages acquired a powerful neuraminidase enzyme resistance to zanamivir and oseltamivir. Evidence that balanced neuraminidase and hemagglutinin activities mediated by mutations induced during selection could play a role in the decrease of virus replication susceptibility to zanamivir is reported.     

Inter-laboratory comparison of qualitative and quantitative detection of hepatitis C (HCV) virus RNA in diagnostic virology: a multicentre study (MS) in Italy

BACKGROUND: The importance of the standardisation of nucleic acid amplification technology (NAT) assays for the detection of hepatitis C virus RNA is well known today, as many studies carried out in different European countries attest. The results of a previous study performed in Italy (J. Clin. Virol. 1 (2003) 83) by the Italian Society of Clinical Microbiology (AMCLI) showed that the use of external reference standards and of multicentre collaborative studies significantly improves laboratory performance for the qualitative evaluation of HCV RNA. OBJECTIVES: the AMCLI organised a new study on the standardisation of both the qualitative and the quantitative evaluation of HCV RNA with NAT in order to improve the implementation of the diagnostic methods for HCV RNA detection. STUDY DESIGN: seventeen diagnostic centres of major Italian Hospitals participated in this quality control study. The study consisted of testing three panels, each made up of 10 coded samples including negative and positive samples. Positive samples contained four levels of HCV RNA (genotype 1). RESULTS AND CONCLUSION: Seven out of 510 qualitative results obtained were incorrect (1.4%), two false negative and five false positive. The results gave a sensitivity of 99.5% and a specificity of 95.8%. Regarding quantitative tests, the geometric mean (GM) and standard deviation (S.D.) could be calculated only for the three highest HCV RNA levels. The percentage of results within the range of GM +/- 0.5 log(10) varied from 91% to 100%. Some laboratories had some difficulty in the exact quantification of the lowest (3.00 log IU/ml) as well as of the highest viral levels (6.35 log IU/ml) values, very near to the limits of the dynamic range of the assays. The comparison of the results of this study with that previously carried out one confirms that a regular participation in external quality assessment (EQA) assures the achievement of a high proficiency level in the diagnosis of HCV infection.     

Use of Standard Hypodermic Needles for Accessing Laparoscopic Adjustable Gastric Band Ports

Background  

Laparoscopic adjustable gastric banding is a common and successful method of surgically treating morbid obesity. A recipient will have to attend their surgeon’s rooms a number of times to optimally adjust the amount of fluid in the band and hence the amount of restriction. Manufacturers suggest that the ports should be accessed with special non-coring needles that may not always be available in regional or remote centers, and this could create a safety risk in cases where urgent band deflation is required.