Cilloniz, C. | Search bioRxiv

bioRxiv2018

MagicplexTM Sepsis real-time test for the rapid diagnosis of bloodstream infections in adults

Sepsis is a serious health condition worldwide, affecting more than 30 million people globally each year. In 2017, the World Health Organization (WHO) adopted a resolution on sepsis: \"improving the prevention, diagnosis and clinical management of sepsis\", with the aim of improving early diagnosis, management and prevention to save lives. Blood culture (BC) is generally used to diagnose sepsis because of the low quantity of microbes occurring in the blood during such infections. However, approximately 50% of bloodstream infections (BSI) give negative BC, this figure being higher for sepsis, which delays the start of appropriate antimicrobial therapy. This prospective study evaluated a multiplex real-time polymerase chain reaction, the MagicplexTM Sepsis test (MP), for the detection of pathogens from whole blood, comparing it to routine BC. We analysed 809 blood samples from 636 adult patients, with 132/809 (16.3%) of the samples positive for one or more relevant microorganism according to BC and/or MP. The sensitivity and specificity of MP were 29% and 95%, respectively, while the level of agreement between BC and MP was 87%. The rate of contaminated samples was higher for BC (10%) than MP (4.8%) (P < 0.001). Patients with only MP-positive samples were more likely to be on antimicrobial treatment (47%) than those with only BC-positive samples (18%) (P = 0.002). In summary, the MP test reduces the time taken to identify the microbial pathogen, improving the diagnosis of BSI in patients on antibiotic treatment.

microbiology↗

bioRxiv2017

Lymphopenic community acquired pneumonia, an unnoticed phenotype associated to mortality in non immuno-suppressed patients: a retrospective cohort study

BackgroundThe role of neutrophil and lymphocyte counts as predictors of prognosis in Community Acquired Pneumonia (CAP) has not been appropriately studied.\n\nMethodsThis was a retrospective study to evaluate by multivariate regression analysis, the association between neutrophil and lymphocyte counts with mortality at 30-days post discharge in two large cohorts of hospitalized patients with CAP and no prior immunosupression: a multicentric with 1550 patients recruited at 14 hospitals in Spain and a unicentric with 2840 patients recruited at the Hospital Clinic-Barcelona.\n\nFindingsThe unicentric cohort accounted with a higher proportion of critically ill patients: 586 (20{middle dot}6%) vs 131 (8{middle dot}5%) and non survivors 245 (8{middle dot}6%) vs 74 (4{middle dot}8%). Lymphopenia (< 1000 lymphocytes/mm3) was present in the 52{middle dot}8% of the patients in both cohorts. A sub-group of lymphopenic patients, those with lymphocyte counts below decil 3 (677 lymphocytes/mm3 in the multicentric cohort and 651 lymphocytes/mm3 in the unicentric one), showed > 2-fold increase in the risk of mortality, independently of the CURB-65 score, critical illness and receiving an appropriated antibiotic treatment: (OR [CI95%], p) (2{middle dot}18 [1{middle dot}21- 3{middle dot}92], 0{middle dot}009) and (2{middle dot}33 [1{middle dot}61-3{middle dot}33], <0{middle dot}001) respectively. Neutrophil counts were not associated with mortality risk.\n\nInterpretationLymphopenia is present in a half of the patients with CAP needing of hospitalization, in absence of antecendents of immunosupression. Lymphopenic CAP with lymphocyte counts < 664 lymphocytes/mm3 constitutes a particular immunological phenotype of the disease which is associated to an increased risk of mortality.\n\nFundingCibeRes, 2009 Support to Research Groups of Catalonia 911, IDIBAPS, SEPAR, SVN

immunology↗