A neural network for glomerulus classification based on histological images of kidney biopsy

Abstract Background Computer-aided diagnosis (CAD) systems based on medical images could support physicians in the decision-making process. During the last decades, researchers have proposed CAD systems in several medical domains achieving promising results. CAD systems play an important role in digital pathology supporting pathologists in analyzing biopsy slides by means of standardized and objective workflows. In the proposed work, we designed and tested a novel CAD system module based on image processing techniques and machine learning, whose objective was to classify the condition affecting renal corpuscles (glomeruli) between sclerotic and non-sclerotic. Such discrimination is useful for the biopsy slides evaluation performed by pathologists. Results We collected 26 digital slides taken from the kidneys of 19 donors with Periodic Acid-Schiff staining. Expert pathologists have conducted the slides preparation, digital acquisition and glomeruli annotations. Before setting the classifiers, we evaluated several feature extraction techniques from the annotated regions. Then, a feature reduction procedure followed by a shallow artificial neural network allowed discriminating between the glomeruli classes. We evaluated the workflow considering an independent dataset (i.e., processing images not used in the training procedure). Ten independent runs of the training algorithm, and evaluation, allowed achieving MCC and Accuracy of 0.95 (± 0.01) and 0.99 (standard deviation < 0.00), respectively. We also obtained good precision (0.9844 ± 0.0111) and recall (0.9310 ± 0.0153). Conclusions Results on the test set confirm that the proposed workflow is consistent and reliable for the investigated domain, and it can support the clinical practice of discriminating the two classes of glomeruli. Analyses on misclassifications show that the involved images are usually affected by staining artefacts or present partial sections due to slice preparation and staining processes. In clinical practice, however, pathologists discard images showing such artefacts

Polymyxin-B hemoperfusion in septic patients: analysis of a multicenter registry

Background: In 2010, the EUPHAS 2 collaborative group created a registry with the purpose of recording data from critically ill patients suffering from severe sepsis and septic shock treated with polymyxin-B hemoperfusion (PMX-HP) for endotoxin removal. The aim of the registry was to verify the application of PMX-HP in the daily clinical practice. Methods: The EUPHAS 2 registry involved 57 centers between January 2010 and December 2014, collecting retrospective data of 357 patients (297 in Europe and 60 in Asia) suffering from severe sepsis and septic shock caused by proved or suspected infection related to Gram negative bacteria. All patients received atleast one cycle of extracorporeal endotoxin removal by PMX-HP. Results: Septic shock was diagnosed in 305 (85.4&nbsp;%) patients. The most common source of infection was abdominal (44.0&nbsp;%) followed by pulmonary (17.6&nbsp;%). Gram negative bacteria represented 60.6&nbsp;% of the pathogens responsible of infection. After 72&nbsp;h from the first cycle of PMX-HP, some of the SOFA score components significantly improved with respect to baseline: cardiovascular (2.16&nbsp;\ub1&nbsp;1.77 from 3.32&nbsp;\ub1&nbsp;1.29, p&nbsp;&lt;&nbsp;0.0001), respiratory (1.95&nbsp;\ub1&nbsp;0.95 from 2.40&nbsp;\ub1&nbsp;1.06, p&nbsp;&lt;&nbsp;0.001) and renal (1.84&nbsp;\ub1&nbsp;1.77 from 2.23&nbsp;\ub1&nbsp;1.62, p&nbsp;=&nbsp;0.013). Overall 28-day survival rate was 54.5&nbsp;% (60.4&nbsp;% in abdominal and 47.5&nbsp;% in pulmonary infection). Patients with abdominal infection treated with PMX-HP within 24&nbsp;h from the diagnosis of septic shock had a 28-day survival rate of 64.5&nbsp;%. Patients showing a significantly cardiovascular improvement after PMX-HP had a 28-survival rate of 75&nbsp;% in comparison to the 39&nbsp;% of patients who did not (p&nbsp;&lt;&nbsp;0.001). Cox regression analysis found the variation of cardiovascular, respiratory and coagulation SOFA to be independent covariates for 28-day survival. In European patients were observed a higher 28-day (58.8 vs. 34.5&nbsp;%, p&nbsp;=&nbsp;0.003), ICU (59 vs. 36.7&nbsp;%, p&nbsp;=&nbsp;0.006) and hospital survival rate (53.2 vs. 35&nbsp;%, p&nbsp;=&nbsp;0.02) than in Asian patients. However, the two populations were highly heterogeneous in terms of source of infection and severity scores at admission. Conclusion: The EUPHAS 2 is the largest registry conducted outside Japan on the clinical use of PMX-HP in septic patients. Data analysis confirmed the feasibility of PMX-HP to treat septic patients in daily clinical practice, showing clinical benefits associated with endotoxin removal without significant adverse events related to the extracorporeal technique