Clinical implications of ANCA positivity in a hospital setting: a tertiary center experience.

ANCA testing plays an established critical role in the diagnosis of ANCA Associated vasculitis (AAV). The spectrum of diseases associated with positive ANCA has recently broadened, thus calling into question the diagnostic implications of ANCA positivity in a hospital setting. We retrospectively studied all adult patients who had a positive ANCA test (by Indirect Immunofluorescence (IIF), ELISA or both) performed over the span of 19 years. Subjects were then divided into discordant (positive on one assay) and concordant ANCA (positive on both assays) groups based on their ANCA positivity status. The two groups were then compared with regards to their demographic, clinical and laboratory characteristics, the indication for ANCA testing in both groups and their final diagnoses. Of the 9189 ANCA tests ordered during the 19-year span of the study, 389 (4.2%) were positive. Two hundred and forty subjects met the exclusion criteria (patients aged less than 18 years or the lack of clinical and laboratory data in the medical file) thus resulting in a final cohort of 149 subjects. Of them, 122 subjects had discrepant ANCA results and 27 had matching ANCA results. Most cases in the discrepancy group were IIF positive and ELISA negative (86.8%). The diagnosis of AAV was highly unlikely in cases with discrepant IIF and ELISA serologies compared to cases with matching IIF and ELISA serologies (4.1% versus 44.4%, p value < 0.001). The diagnosis of AAV in unlikely in subjects with discrepancies between IIF and ELISA, particularly with only positive IIF.

Trends in antimicrobial resistance among bacteria causing septic arthritis in adults in a single center: A 15-years retrospective analysis.

Septic arthritis (SA) is commonly associated with Staphylococcal or Streptococcal infections. Overtime, there has been a global increase in the distribution of antimicrobial resistance within both Gram-positive bacteria such as methicillin-resistant Staphylococcus aureus (MRSA) and Gram-negative bacteria such as extended-spectrum beta-lactamase (ESBL) positive Enterobacteriacea. The aim of this study was to determine whether this change in epidemiology similarly affected the distribution of resistant pathogens causing SA. The study was conducted at the Shaare Zedek Medical Center in Jerusalem, Israel. All adult patients diagnosed with SA during 2002-2016 were included in the cohort. Antimicrobial resistance trends were examined over three periods: 2002-2009, 2010-2013, and 2014-2016. Of 85 patients with SA, mean age of patients was 66.8 (± 20.3) years, with male predominance (n = 62, 66%). Most SA cases involved native knee joints and more than 85% (n = 80) were acquired in the community. The most common isolates were S. aureus (n = 38, 45%) and beta-hemolytic streptococci (n = 13, 15%). MRSA SA was diagnosed in 8% of all SA cases (n = 7). An increasing, although non-significant trend in MRSA SA was observed during the study period (p = 0.3). Gram-negative infections were uncommon (n = 14). No ESBL-positive or carbapenem-resistant Enterobacteriacea were detected. Over a 15-year study period, no significant increase in resistant pathogens causing SA was observed. In the era of antibiotic stewardship, these results strengthen our practice of administering narrow-spectrum antimicrobials empirically for SA. However, our findings cannot be generalized to regions with higher rates of MRSA in the community.