Low-dose mycophenolate mofetil improves survival in a murine model of Staphylococcus aureus sepsis by increasing bacterial clearance and phagocyte function.

Regulators of TLRs signaling pathways play an important role in the control of the pro-inflammatory response that contributes to sepsis-induced tissue injury. Mycophenolate mofetil, an immunosuppressive drug inhibiting lymphocyte proliferation, has been reported to be a regulator of TLRs signaling pathways. Whether MMF used at infra-immunosuppressive doses has an impact on survival and on innate immune response in sepsis is unknown. C57BL/6J mice were infected intraperitoneally with 10 <sup>8</sup> CFU Staphylococcus aureus, and treated or not with low-dose of MMF (20mg/kg/day during 4 days). Survival rate and bacterial clearance were compared. Cytokine levels, quantitative and qualitative cellular responses were assessed. S. aureus - infected mice treated with MMF exhibited improved survival compared to non-treated ones (48% vs 10%, p<0.001). With the dose used for all experiments, MMF did not show any effect on lymphocyte proliferation. MMF treatment also improved local and systemic bacterial clearance, improved phagocytosis activity of peritoneal macrophages resulting in decreased inflammatory cytokines secretion. MMF-treated mice showed enhanced activation of NF-κB seemed with a suspected TLR4-dependent mechanism. These results suggest that infra-immunosuppressive doses of MMF improve host defense during S. aureus sepsis and protects infected mice from fatal outcome by regulating innate immune responses. The signaling pathways involved could be TLR4-dependent. This work brings new perspectives in pathogenesis and therapeutic approaches of severe infections

Association of combined PD- L1 expression and tumour- infiltrating lymphocyte features with survival and treatment outcomes in patients with metastatic melanoma

BackgroundRecent advances obtained with immune checkpoint inhibitors (ICIs) targeting the programmed cell death- 1 (PD- 1) protein have significantly improved the outcome of patients with metastatic melanoma. The PD- L1 expression in tumour cells as detected by immunohistochemistry is a predictive biomarker in some solid tumours, but appears insufficient as prognostic or predictive factor of response to ICIs in metastatic melanomas.ObjectivesWe investigated whether the presence and the features of pretreatment CD8+tumour- infiltrating T lymphocytes (TILs) could be a complementary prognostic or predictive biomarker in patients with metastatic melanoma.MethodsIn this retrospective study, we evaluated the association of PD- L1 expression - ¥5% of tumour cells combined with TIL features (CD8, CD28, Ki67) with the overall survival (OS) among 51 patients treated with ICIs and 54 patients treated with other treatment options (non- ICIs).ResultsPD- L1 positivity was observed in 33% and 39% of primary melanomas and matched metastases, respectively, with, however, poor concordance between the primary and the matched metastatic site (κ = 0.283). No significant association was noted between PD- L1 expression and CD8+TIL profile analysed as single markers and OS or response to immunotherapy. Instead, their combined analysis in primary melanoma samples showed that the PD- L1- /CD8+status was significantly associated with prolonged OS in the whole population (P = 0.04) and in the subgroup treated with non- ICIs (P = 0.009). Conversely, the PD- L1+/CD8+ status was a good prognostic factor in patients treated with ICIs (P = 0.022), whereas was significantly associated with poor prognosis in patients treated with non- ICIs (P = 0.014). While the expression of CD28 was not related to outcome, the Ki67 expression was significantly associated with poor OS in the subgroup CD8+TIL+/PD- L1- (P = 0.02).ConclusionsThe pretreatment combination of PD- L1 expression with the level of CD8+TILs could better assess OS and predict therapeutic response of patients with metastatic melanoma treated by either immunotherapy or other treatment regimens.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/155478/1/jdv16016_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/155478/2/jdv16016.pd

Splenectomy and/or cyclophosphamide as salvage therapies in thrombotic thrombocytopenic purpura: the French TMA Reference Center experience: SALVAGE THERAPIES IN SEVERE TTP

BACKGROUND: The objective was to assess the efficacy and safety of splenectomy and cyclophosphamide as salvage therapies in severe thrombotic thrombocytopenic purpura (TTP).STUDY DESIGN AND METHODS: During a 10-year period, patients who did not improve with plasma exchanges, steroids, vincristine, and/or rituximab were considered for splenectomy or cyclophosphamide. Patients with a documented severe (<10% of normal value) acquired ADAMTS13 deficiency are reported here. RESULTS: Eighteen patients with a severe acquired ADAMTS13 deficiency required a salvage therapy. Thirteen patients had a splenectomy 19 (interquartile range [IQR], 10-51) days after TTP diagnosis. One patient died the day after splenectomy. The remaining patients improved platelets (PLTs) until Day 6, along with a rapid and major lactate dehydrogenase improvement. Six patients, however, subsequently experienced a transient worsening. Durable PLT count recovery in survivors was observed within 13 (IQR, 11.5-25.5) days. Postoperative complications included thromboembolic events (two cases) and infections (five cases). Five patients received pulses of cyclophosphamide 12 (IQR, 12-15) days after TTP diagnosis. All patients recovered PLTs 10 (IQR, 9-24) days after the first pulse and two experienced a transient worsening. Three patients experienced infections. Three relapses occurred 5 months, 2.5 years, and 4.5 years after splenectomy and one relapse occurred 3.5 years after cyclophosphamide. After a 2.5 (IQR, 0.75-6.2)-year follow-up, the overall survival was 94%. CONCLUSION: Cyclophosphamide and splenectomy provide comparable high remission rates in severe TTP with acceptable side effects and should be considered in the more severe patients who do not improve with other therapies

Enteral versus parenteral early nutrition in ventilated adults with shock: a randomised, controlled, multicentre, open-label, parallel-group study (NUTRIREA-2)

BACKGROUND: Whether the route of early feeding affects outcomes of patients with severe critical illnesses is controversial. We hypothesised that outcomes were better with early first-line enteral nutrition than with early first-line parenteral nutrition. METHODS: In this randomised, controlled, multicentre, open-label, parallel-group study (NUTRIREA-2 trial) done at 44 French intensive-care units (ICUs), adults (18 years or older) receiving invasive mechanical ventilation and vasopressor support for shock were randomly assigned (1:1) to either parenteral nutrition or enteral nutrition, both targeting normocaloric goals (20-25 kcal/kg per day), within 24 h after intubation. Randomisation was stratified by centre using permutation blocks of variable sizes. Given that route of nutrition cannot be masked, blinding of the physicians and nurses was not feasible. Patients receiving parenteral nutrition could be switched to enteral nutrition after at least 72 h in the event of shock resolution (no vasopressor support for 24 consecutive hours and arterial lactate <2 mmol/L). The primary endpoint was mortality on day 28 after randomisation in the intention-to-treat-population. This study is registered with ClinicalTrials.gov, number NCT01802099. FINDINGS: After the second interim analysis, the independent Data Safety and Monitoring Board deemed that completing patient enrolment was unlikely to significantly change the results of the trial and recommended stopping patient recruitment. Between March 22, 2013, and June 30, 2015, 2410 patients were enrolled and randomly assigned; 1202 to the enteral group and 1208 to the parenteral group. By day 28, 443 (37%) of 1202 patients in the enteral group and 422 (35%) of 1208 patients in the parenteral group had died (absolute difference estimate 2·0%; [95% CI -1·9 to 5·8]; p=0·33). Cumulative incidence of patients with ICU-acquired infections did not differ between the enteral group (173 [14%]) and the parenteral group (194 [16%]; hazard ratio [HR] 0·89 [95% CI 0·72-1·09]; p=0·25). Compared with the parenteral group, the enteral group had higher cumulative incidences of patients with vomiting (406 [34%] vs 246 [20%]; HR 1·89 [1·62-2·20]; p<0·0001), diarrhoea (432 [36%] vs 393 [33%]; 1·20 [1·05-1·37]; p=0·009), bowel ischaemia (19 [2%] vs five [<1%]; 3·84 [1·43-10·3]; p=0·007), and acute colonic pseudo-obstruction (11 [1%] vs three [<1%]; 3·7 [1·03-13·2; p=0·04). INTERPRETATION: In critically ill adults with shock, early isocaloric enteral nutrition did not reduce mortality or the risk of secondary infections but was associated with a greater risk of digestive complications compared with early isocaloric parenteral nutrition. FUNDING: La Roche-sur-Yon Departmental Hospital and French Ministry of Health

Clinical and molecular practice of European thoracic pathology laboratories during the COVID-19 pandemic. The past and the near future.

This study evaluated the consequences in Europe of the COVID-19 outbreak on pathology laboratories orientated toward the diagnosis of thoracic diseases. A survey was sent to 71 pathology laboratories from 21 European countries. The questionnaire requested information concerning the organization of biosafety, the clinical and molecular pathology, the biobanking, the workload, the associated research into COVID-19, and the organization of education and training during the COVID-19 crisis, from 15 March to 31 May 2020, compared with the same period in 2019. Questionnaires were returned from 53/71 (75%) laboratories from 18 European countries. The biosafety procedures were heterogeneous. The workload in clinical and molecular pathology decreased dramatically by 31% (range, 3%-55%) and 26% (range, 7%-62%), respectively. According to the professional category, between 28% and 41% of the staff members were not present in the laboratories but did teleworking. A total of 70% of the laboratories developed virtual meetings for the training of residents and junior pathologists. During the period of study, none of the staff members with confirmed COVID-19 became infected as a result of handling samples. The COVID-19 pandemic has had a strong impact on most of the European pathology laboratories included in this study. Urgent implementation of several changes to the organization of most of these laboratories, notably to better harmonize biosafety procedures, was noted at the onset of the pandemic and maintained in the event of a new wave of infection occurring in Europe

Assessment of plasma chitotriosidase activity, CCL18/PARC concentration and NP-C suspicion index in the diagnosis of Niemann-Pick disease type C: A prospective observational study

Background: Niemann-Pick disease type C (NP-C) is a rare, autosomal recessive neurodegenerative disease caused by mutations in either the NPC1 or NPC2 genes. The diagnosis of NP-C remains challenging due to the non-specific, heterogeneous nature of signs/symptoms. This study assessed the utility of plasma chitotriosidase (ChT) and Chemokine (C-C motif) ligand 18 (CCL18)/pulmonary and activation-regulated chemokine (PARC) in conjunction with the NP-C suspicion index (NP-C SI) for guiding confirmatory laboratory testing in patients with suspected NP-C. Methods: In a prospective observational cohort study, incorporating a retrospective determination of NP-C SI scores, two different diagnostic approaches were applied in two separate groups of unrelated patients from 51 Spanish medical centers (n = 118 in both groups). From Jan 2010 to Apr 2012 (Period 1), patients with =2 clinical signs/symptoms of NP-C were considered ''suspected NP-C'' cases, and NPC1/NPC2 sequencing, plasma chitotriosidase (ChT), CCL18/PARC and sphingomyelinase levels were assessed. Based on findings in Period 1, plasma ChT and CCL18/PARC, and NP-C SI prediction scores were determined in a second group of patients between May 2012 and Apr 2014 (Period 2), and NPC1 and NPC2 were sequenced only in those with elevated ChT and/or elevated CCL18/PARC and/or NP-C SI =70. Filipin staining and 7-ketocholesterol (7-KC) measurements were performed in all patients with NP-C gene mutations, where possible. Results: In total across Periods 1 and 2, 10/236 (4%) patients had a confirmed diagnosis o NP-C based on gene sequencing (5/118 4.2%] in each Period): all of these patients had two causal NPC1 mutations. Single mutant NPC1 alleles were detected in 8/236 (3%) patients, overall. Positive filipin staining results comprised three classical and five variant biochemical phenotypes. No NPC2 mutations were detected. All patients with NPC1 mutations had high ChT activity, high CCL18/PARC concentrations and/or NP-C SI scores =70. Plasma 7-KC was higher than control cut-off values in all patients with two NPC1 mutations, and in the majority of patients with single mutations. Family studies identified three further NP-C patients. Conclusion: This approach may be very useful for laboratories that do not have mass spectrometry facilities and therefore, they cannot use other NP-C biomarkers for diagnosis

From weak Allee effect to no Allee effect in Richards’ growth models

Population dynamics have been attracting interest since many years. Among the considered models, the Richards’ equations remain one of the most popular to describe biological growth processes. On the other hand, Allee effect is currently a major focus of ecological research, which occurs when positive density dependence dominates at low densities. In this chapter, we propose the dynamical study of classes of functions based on Richards’ models describing the existence or not of Allee effect. We investigate bifurcation structures in generalized Richards’ functions and we look for the conditions in the (β, r) parameter plane for the existence of a weak Allee effect region. We show that the existence of this region is related with the existence of a dovetail structure. When the Allee limit varies, the weak Allee effect region disappears when the dovetail structure also disappears. Consequently, we deduce the transition from the weak Allee effect to no Allee effect to this family of functions. To support our analysis, we present fold and flip bifurcation curves and numerical simulations of several bifurcation diagrams