Deep learning automation of MEST-C classification in IgA nephropathy.

BACKGROUND: Although the MEST-C classification is among the best prognostic tools in immunoglobulin A nephropathy (IgAN), it has a wide interobserver variability between specialized pathologists and others. Therefore we trained and evaluated a tool using a neural network to automate the MEST-C grading. METHODS: Biopsies of patients with IgAN were divided into three independent groups: the Training cohort (n = 42) to train the network, the Test cohort (n = 66) to compare its pixel segmentation to that made by pathologists and the Application cohort (n = 88) to compare the MEST-C scores computed by the network or by pathologists. RESULTS: In the Test cohort, >73% of pixels were correctly identified by the network as M, E, S or C. In the Application cohort, the neural network area under the receiver operating characteristics curves were 0.88, 0.91, 0.88, 0.94, 0.96, 0.96 and 0.92 to predict M1, E1, S1, T1, T2, C1 and C2, respectively. The kappa coefficients between pathologists and the network assessments were substantial for E, S, T and C scores (kappa scores of 0.68, 0.79, 0.73 and 0.70, respectively) and moderate for M score (kappa score of 0.52). Network S and T scores were associated with the occurrence of the composite survival endpoint (death, dialysis, transplantation or doubling of serum creatinine) [hazard ratios 9.67 (P = .006) and 7.67 (P < .001), respectively]. CONCLUSIONS: This work highlights the possibility of automated recognition and quantification of each element of the MEST-C classification using deep learning methods.

Fusobacterium nucleatum bacteremia with pneumopathy in a patient receiving eculizumab: A case report.

Fusobacterium nucleatum is a common oral commensal bacterium capable of severe invasive infections. We report a case of a diffuse bilateral pneumopathy with F. nucleatum-positive blood culture successfully treated by common antibiotics in a patient receiving eculizumab for a drug-induced thrombotic microangiopathy (TMA). It is the first described case of a severe F. nucleatum-associated infection in a patient undergoing terminal complement inhibitor therapy. We suggest providing preventive dental care before eculizumab initiation.

Unusual Case of HIT With Cardiac Arrest During Hemodialysis.

OBJECTIVE: To report an unusual case of heparin-induced thrombocytopenia (HIT) with cardiac arrest during hemodialysis (HD). CASE SUMMARY: An 88-year-old man previously treated with HD under enoxaparin for 3 years presented with dizziness and cyanosis at the beginning of HD on 3 consecutive sessions. Even though the dialyzer membrane was changed, he presented with cardiac arrest, from which he recovered quickly. At the same time, the platelet count fell, and HIT was suspected. No thrombosis was found. Anti-PF4/H, IL8, and NAP2 antibodies were negative, but platelet aggregation tests and serotonin-release assay were positive. After implementing HD with danaparoid, the platelet count returned to normal, and the patient remained asymptomatic. DISCUSSION: Given the clinical context (low-molecular-weight heparin), complications (cardiac arrest and no thrombosis), and timing (3 years), this was an unusual case of HIT. According to the Naranjo probability scale, the causality of enoxaparin was evaluated as probable. In most reported cases, time to onset was short, clotting occurred in the extracorporeal system, and biological tests, including ELISA (enzyme-linked immunosorbent assay) anti-PF4/heparin, were positive. We found no triggering factor in this case, and given the biological results, a new antigenic target may be involved. CONCLUSIONS: HIT must be considered when acute systemic reactions occur at the beginning of HD sessions, even after several years of HD and with no change of anticoagulant, including low-molecular-weight heparin. The platelet count should be measured immediately after the reaction. The diagnosis is important because of possible cardiac arrest in this context.

Automatic Evaluation of Histological Prognostic Factors Using Two Consecutive Convolutional Neural Networks on Kidney Samples.

BACKGROUND AND OBJECTIVES: The prognosis of patients undergoing kidney tumor resection or kidney donation is linked to many histologic criteria. These criteria notably include glomerular density, glomerular volume, vascular luminal stenosis, and severity of interstitial fibrosis/tubular atrophy. Automated measurements through a deep-learning approach could save time and provide more precise data. This work aimed to develop a free tool to automatically obtain kidney histologic prognostic features. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: In total, 241 samples of healthy kidney tissue were split into three independent cohorts. The "Training" cohort (n=65) was used to train two convolutional neural networks: one to detect the cortex and a second to segment the kidney structures. The "Test" cohort (n=50) assessed their performance by comparing manually outlined regions of interest to predicted ones. The "Application" cohort (n=126) compared prognostic histologic data obtained manually or through the algorithm on the basis of the combination of the two convolutional neural networks. RESULTS: In the Test cohort, the networks isolated the cortex and segmented the elements of interest with good performances (>90% of the cortex, healthy tubules, glomeruli, and even globally sclerotic glomeruli were detected). In the Application cohort, the expected and predicted prognostic data were significantly correlated. The correlation coefficients r were 0.85 for glomerular volume, 0.51 for glomerular density, 0.75 for interstitial fibrosis, 0.71 for tubular atrophy, and 0.73 for vascular intimal thickness, respectively. The algorithm had a good ability to predict significant (>25%) tubular atrophy and interstitial fibrosis level (receiver operator characteristic curve with an area under the curve, 0.92 and 0.91, respectively) or a significant vascular luminal stenosis (>50%) (area under the curve, 0.85). CONCLUSION: This freely available tool enables the automated segmentation of kidney tissue to obtain prognostic histologic data in a fast, objective, reliable, and reproducible way.

Bacterial endocarditis complicating mitral annular calcification: a clinical and echocardiographic study.

BACKGROUND AND AIM OF THE STUDY: Although described in a number of necropsy studies, endocarditis on mitral annular calcification (MAC) has rarely been reported during life. The study aim was to assess the frequency and specific features of bacterial endocarditis complicating MAC. METHODS: Data relating to 62 cases of infective endocarditis of the native mitral valve diagnosed with multiplane transesophageal echocardiography (TEE) over a five-year period were collected prospectively. RESULTS: Among 62 patients, 15 (24%) had vegetations originating from a calcified mitral annulus (group 1), while 47 had classic leaflet endocarditis (group 2). Group 1 patients differed significantly from group 2 patients with regard to: (i) higher incidence of diabetes mellitus and cancers; (ii) initial clinical presentation, with febrile coma or meningoencephalitis in 53% of cases; (iii) echocardiographic features, with significantly greater vegetations, presence of calcium-dense echoes within the vegetation, high frequency of ring abscess, and high frequency of para-annular ventriculoatrial leakage; and (iv) poorer clinical outcome, with 53% in-hospital mortality. CONCLUSION: MAC appears to be an underestimated predisposing factor for a particularly severe type of bacterial endocarditis. The use of multiplane TEE should improve current knowledge of this disease.

A neutropenia suggesting an interaction between valacyclovir and mycophenolate mofetil.

Mycophenolate mofetil (MMF) is a drug which decreases the frequency of renal transplantation rejection. However, cytomegalovirus infections are a common feature of this treatment leading the physicians to prescribe antiviral prophylactic drugs like valacyclovir. During this association, neutropenia occur and the cause of this adverse effect is difficult to define. This report presents a case of neutropenia in a woman treated with MMF and valacyclovir. As the duration of the valacyclovir treatment exactly corresponds to the neutropenia duration, and the mycophenolate trough levels increased with the neutrophil count, the responsibility of this neutropenia was ascribed to valacyclovir. However, an examination of the literature for cases of neutropenia led to the suspicion of an interaction between MMF and valacyclovir. Mycophenolate may increase intracellular concentrations of valacyclovir up to haematotoxic levels. This mechanism may explain the interaction and further research is needed to confirm this interaction.