Metagenomics for the microbiological diagnosis of hospital-acquired pneumonia and ventilator-associated pneumonia (HAP/VAP) in intensive care unit (ICU): a proof-of-concept study.

BACKGROUND: Hospital-acquired and ventilator-associated-pneumonia (HAP/VAP) are one of the most prevalent health-care associated infections in the intensive care unit (ICU). Culture-independent methods were therefore developed to provide faster route to diagnosis and treatment. Among these, metagenomic next-generation sequencing (mNGS) has shown considerable promise. METHODS: This proof-of-concept study describes the technical feasibility and evaluates the clinical validity of the mNGS for the detection and characterization of the etiologic agents causing hospital-acquired and ventilator-associated pneumonia. We performed a prospective study of all patients with HAP/VAP hospitalized in our intensive care unit for whom a bronchoalveolar lavage (BAL) was performed between July 2017 and November 2018. We compared BAL fluid culture and mNGS results of these patients. RESULTS: A total of 32 BAL fluids were fully analyzed. Of these, 22 (69%) were positive by culture and all pathogens identified were also reported by mNGS. Among the culture-positive BAL samples, additional bacterial species were revealed by mNGS for 12 patients, raising the issue of their pathogenic role (colonization versus coinfection). Among BALF with culture-negative test, 5 were positive in mNGS test. CONCLUSIONS: This study revealed concordant results for pneumonia panel pathogens between mNGS and culture-positive tests and identified additional pathogens potentially implicated in pneumonia without etiologic diagnosis by culture. mNGS has emerged as a promising methodology for infectious disease diagnoses to support conventional methods. Prospective studies with real-time mNGS are warranted to examine the impact on antimicrobial decision-making and clinical outcome.

Prognostic value of complement serum C3 level and glomerular C3 deposits in anti-glomerular basement membrane disease.

Background and objectives: Activation of the complement system is involved in the pathogenesis of anti-glomerular basement membrane (anti-GBM) disease. Glomerular deposits of complement 3 (C3) are often detected on kidney biopsies. The primary objective of this study was to analyze the prognostic value of the serum C3 level and the presence of C3 glomerular deposits in patients with anti-GBM disease. Methods: We conducted a retrospective cohort study of 150 single-positive patients with anti-GBM disease diagnosed between 1997 and 2017. Patients were categorized according to the serum C3 level (forming a low C3 (C3<1.23 g/L) and a high C3 (C3≥1.23 g/L) groups) and positivity for C3 glomerular staining (forming the C3+ and C3- groups). The main outcomes were kidney survival and patient survival. Results: Of the 150 patients included, 89 (65%) were men. The median [interquartile range (IQR)] age was 45 [26-64]. At diagnosis, kidney involvement was characterized by a median [IQR] peak serum creatinine (SCr) level of 578 [298-977] µmol/L, and 106 (71%) patients required dialysis. Patients in the low C3 group (72 patients) had more severe kidney disease at presentation, as characterized by higher prevalences of oligoanuria, peak SCr ≥500 µmol/L (69%, vs. 53% in the high C3 group; p=0.03), nephrotic syndrome (42%, vs. 24%, respectively; p=0.02) and fibrous forms on the kidney biopsy (21%, vs. 8%, respectively; p=0.04). Similarly, we observed a negative association between the presence of C3 glomerular deposits (in 52 (41%) patients) and the prevalence of cellular forms (83%, vs. 58% in the C3- group; p=0.003) and acute tubulo-interstitial lesions (60%, vs. 36% in the C3- group; p=0.007). When considering patients not on dialysis at diagnosis, the kidney survival rate at 12 months was poorer in the C3+ group (50% [25-76], vs. 91% [78-100] in the C3- group; p=0.01), with a hazard ratio [95% confidence interval] of 5.71 [1.13-28.85] (p=0.04, after adjusting for SCr). Conclusion: In patients with anti-GBM disease, a low serum C3 level and the presence of C3 glomerular deposits were associated with more severe disease and histological kidney involvement at diagnosis. In patients not on dialysis at diagnosis, the presence of C3 deposits was associated with worse kidney survival.

Severe Infection in Anti-Glomerular Basement Membrane Disease: A Retrospective Multicenter French Study.

In patients presenting with anti-glomerular basement membrane (GBM) disease with advanced isolated kidney involvement, the benefit of intensive therapy remains controversial due to adverse events, particularly infection. We aim to describe the burden of severe infections (SI) (requiring hospitalization or intravenous antibiotics) and identify predictive factors of SI in a large cohort of patients with anti-GBM disease. Among the 201 patients (median [IQR] age, 53 [30-71] years) included, 74 had pulmonary involvement and 127 isolated glomerulonephritis. A total of 161 SI occurred in 116 patients during the first year after diagnosis. These infections occurred during the early stage of care (median [IQR] time, 13 [8-19] days after diagnosis) with mainly pulmonary (45%), catheter-associated bacteremia (22%) and urinary tract (21%) infections. In multivariable analysis, positive ANCA (HR [95\% CI] 1.62 [1.07--2.44]; p = 0.02) and age at diagnosis (HR [95% CI] 1.10 [1.00-1.21]; p = 0.047) remained independently associated with SI. Age-adjusted severe infection during the first three months was associated with an increased three-year mortality rate (HR [95% CI] 3.13 [1.24-7.88]; p = 0.01). Thus, SI is a common early complication in anti-GBM disease, particularly in the elderly and those with positive anti-neutrophil cytoplasmic antibodies (ANCA). No significant association was observed between immunosuppressive strategy and occurrence of SI.

Predonation Single Kidney Glomerular Filtration Rate in Living Kidney Transplantation to Predict Graft Function and Donor Functional Gain.

BACKGROUND: The 2 main objectives regarding living kidney transplant are to provide optimal graft function and to ensure the safety of donation. Our study hypothesized that the glomerular filtration rate of a single kidney (skGFR), when transplanted, might predict graft function and that the skGFR of the remaining kidney could predict donor functional gain. METHODS: A prospective monocentric study was conducted at Grenoble-Alpes University Hospital. Twenty couples of donors and recipients were included. Dimercaptosuccinic acid renal scintigraphy and 51Cr-ethylene-diamine tetra-acetic acid clearance were evaluated predonation to calculate skGFR. All patients had renal function according to 51Cr-ethylene-diamine tetra-acetic acid clearance at 1 year post transplant to assess graft function and donor functional gain. All donors had normal renal function predonation. RESULTS: At 1 year post transplant, median glomerular filtration rate of the graft was 50 mL/min/1.73 m2 (range, 46-56 mL/min/1.73 m2) and donor median glomerular filtration rate was 59 mL/min/1.73 m2 (range, 55-74 mL/min/1.73 m2). Median functional gain was 20 mL/min/1.73 m2 (range, 12-22 mL/min/1.73 m2). No statistical correlation was found between skGFR of the transplanted kidney and graft function at 1 year (R2 = 0.096, P = .7). For the donor, functional gain was not associated with predonation skGFR of the remaining kidney (R2 = 0.17, P = .5). A statistical difference was found between donor functional gain (18 [SD, 10] mL/min) and recipient gain (delta between skGFR before and after transplant, 7 [SD, 16] mL/min; P = .02). CONCLUSION: Predonation skGFR of the transplanted kidney had no influence on renal allograft function at 1 year post transplant. Similarly, there was no association between measured skGFR of the remaining kidney and donor functional gain at 1 year.

Delayed renal dysfunction and flash pulmonary edema post endovascular abdominal aneurysm repair.

After endovascular aortic repair (EVAR), the deterioration in long-term renal function is probably multifactorial. Preoperative renal failure is an independent risk factor. Postoperative renal dysfunction can be associated with inadvertent renal artery occlusion, renal artery complications as stenosis, plaque dislodgement, or dissection. Ischemic nephropathy can accelerate hypertension and circulatory congestion. We report a case of coverage of the renal arteries symptomatic with flash pulmonary edema and renal failure 15 months after EVAR, suggesting a delayed endograft migration. The patient had complete resolution of symptoms and renal function after renal artery stenting with placement between endograft and aneurysm to the left renal artery.