Neutrophil Activity and Extracellular Matrix Degradation: Drivers of Lung Tissue Destruction in Fatal COVID-19 Cases and Implications for Long COVID

Pulmonary fibrosis, severe alveolitis, and the inability to restore alveolar epithelial architecture are primary causes of respiratory failure in fatal COVID-19 cases. However, the factors contributing to abnormal fibrosis in critically ill COVID-19 patients remain unclear. This study analyzed the histopathology of lung specimens from eight COVID-19 and six non-COVID-19 postmortems. We assessed the distribution and changes in extracellular matrix (ECM) proteins, including elastin and collagen, in lung alveoli through morphometric analyses. Our findings reveal the significant degradation of elastin fibers along the thin alveolar walls of the lung parenchyma, a process that precedes the onset of interstitial collagen deposition and widespread intra-alveolar fibrosis. Lungs with collapsed alveoli and organized fibrotic regions showed extensive fragmentation of elastin fibers, accompanied by alveolar epithelial cell death. Immunoblotting of lung autopsy tissue extracts confirmed elastin degradation. Importantly, we found that the loss of elastin was strongly correlated with the induction of neutrophil elastase (NE), a potent protease that degrades ECM. This study affirms the critical role of neutrophils and neutrophil enzymes in the pathogenesis of COVID-19. Consistently, we observed increased staining for peptidyl arginine deiminase, a marker for neutrophil extracellular trap release, and myeloperoxidase, an enzyme-generating reactive oxygen radical, indicating active neutrophil involvement in lung pathology. These findings place neutrophils and elastin degradation at the center of impaired alveolar function and argue that elastolysis and alveolitis trigger abnormal ECM repair and fibrosis in fatal COVID-19 cases. Importantly, this study has implications for severe COVID-19 complications, including long COVID and other chronic inflammatory and fibrotic disorders.

Safety and efficacy of the anti-PD1 immunotherapy with nivolumab in trichoblastic carcinomas

Trichoblastic carcinoma is a rare malignant cutaneous adnexal tumor with a risk of local invasion and distant metastasis. As of today, there is no consensus for the treatment of locally advanced or metastatic trichoblastic carcinoma. "AcSé Nivolumab" is a multi-center Phase II basket clinical trial (NCT03012581) evaluating the safety and efficacy of nivolumab in several cohorts of rare, advanced cancers. Here we report the results of nivolumab in patients with trichoblastic carcinoma. Of the eleven patients enrolled in the study, five patients had been previously treated by sonic hedgehog inhibitors. The primary endpoint 12-week objective response rate was 9.1% (N = 1/11) with 1 partial response. Six patients who progressed under previous lines of treatment showed stable disease at 12 weeks, reflecting a good control of the disease with nivolumab. Furthermore, 54.5% of the patients (N = 6/11) had their disease under control at 6 months. The 1-year overall survival was 80%, and the median progression-free survival was 8.4 months (95%CI, 5.7 to NA). With 2 responders (2 complete responses), the best response rate to nivolumab at any time was 18.2% (95%CI, 2.3-51.8%). No new safety signals were identified, and adverse events observed herein were previously described and well known with nivolumab monotherapy. These results are promising, suggesting that nivolumab might be an option for patients with advanced trichoblastic carcinomas. Further studies on larger cohorts are necessary to confirm these results and define the role of nivolumab in the treatment of trichoblastic carcinomas.

P10.12.A CDK12/CDK13 inhibition disrupts a transcriptional program critical for glioblastoma survival

Background

Glioblastoma multiforme (GBM) is the most prevalent and aggressive malignant tumor of the central nervous system. With a median survival of only one year, GBM patients have a particularly poor prognosis, highlighting a clear need for novel therapeutic strategies to target this disease. Transcriptional cyclin-dependent kinases (CDK), which phosphorylate key residues of RNA polymerase II (RNAPII) C-terminal domain (CTD), play a major role in sustaining aberrant transcriptional programs that are key to development and maintenance of cancer cells.

Material and Methods

We used pharmacological inhibition and genetic ablation to study effects of CDK12/CDK13 depletion on the proliferatory and migratory capacity of GBM cells and mouse xenografts. SLAM-seq, CUT&RUN and cell cycle assays were used to study the mechanistic effects of CDK12/CDK13 depletion in GBM cells.

Results

CDK12/CDK13 depletion markedly reduced the proliferatory and migratory capacity of GBM cells, as well as in vivo growth. CDK12/CDK13 inhibition potentiated existing chemotherapeutic treatments. Mechanistically, inhibition of CDK12/CDK13 leads to a genome-wide abrogation of RNAPII CTD phosphorylation, which in turn disrupts transcription and cell cycle progression in GBM cells.

Conclusion

These results provide proof-of-concept for the potential of CDK12 and CDK13 as therapeutic targets for GBM.

New Insights into Clinical and Mechanistic Heterogeneity of the Acute Respiratory Distress Syndrome: Summary of the Aspen Lung Conference 2021

Clinical and molecular heterogeneity are common features of human disease. Understanding the basis for heterogeneity has led to major advances in therapy for many cancers and pulmonary diseases such as cystic fibrosis and asthma. Although heterogeneity of risk factors, disease severity, and outcomes in survivors are common features of the acute respiratory distress syndrome (ARDS), many challenges exist in understanding the clinical and molecular basis for disease heterogeneity and using heterogeneity to tailor therapy for individual patients. This report summarizes the proceedings of the 2021 Aspen Lung Conference, which was organized to review key issues related to understanding clinical and molecular heterogeneity in ARDS. The goals were to review new information about ARDS phenotypes, to explore multicellular and multisystem mechanisms responsible for heterogeneity, and to review how best to account for clinical and molecular heterogeneity in clinical trial design and assessment of outcomes. The report concludes with recommendations for future research to understand the clinical and basic mechanisms underlying heterogeneity in ARDS to advance the development of new treatments for this life-threatening critical illness.

POS0533 REPURPOSING FIB-4 SCORE IN RHEUMATOID ARTHRITIS: DATA FROM THE ESPOIR COHORT

Background

The Fibrosis-4 (FIB4) score, including age, transaminases and platelets, can detect severe fibrosis (F3-F4) in patients with Non Alcoolic Steato Hepatitis (NASH) and could be of interest in the follow-up of patients with RA. Indeed, platelets contribute to the pathophysiology of RA, transaminases are used in the liver monitoring of our treatments. In addition, retrospective data suggested the association between FIB4 and mortality in RA (1).

Objectives

We aimed to evaluate the value of the FIB4 score as a prognostic factor in RA in the prospective ESPOIR cohort.

Methods

Patients of the ESPOIR cohort diagnosed with RA according to ACR-EULAR criteria were included in our analysis. The formula for the FIB-4 score is as follows: [Age (years) × ASAT (U/L)] / [Platelet count (10^9/L) × ALT (U/L)1/2]. The analyses were based on linear mixed-effects models with a random effect on the subject to account for repeated measures throughout time.

Results

633 of the 813 patients included met the ACR/EULAR criteria for RA and had a calculable FIB4 score. Median FIB4 was 0.75 IQR (0.53-0.99) and 61 patients (9.6%) had a high FIB4 score at baseline. Baseline FIB4 was significantly higher in patients with a chronic alcohol consumption (p=0.021) or viral hepatitis (p<0.001). In multivariate analysis, including the main baseline prognostic factors for progression of RA (swollen Joint Count, CRP, Presence of ACPA, Rheumatoid Factor and modified Sharp score), FIB4 was not independently associated with progression of DAS28 during 10 years of follow-up, unlike baseline CRP and SJC. Baseline FIB4 was not associated with the modified Sharp score at 10-year follow-up unlike age and the presence of ACPA (Table 1). FIB4 was not associated with mortality (p=0.77) or major adverse cardiovascular events (p=0.22) during the 10-year follow-up. No significant change in FIB4 score over time was related to the use of NSAIDs, methotrexate, tocilizumab or other DMARDs.

Table 1.

Associations of FIB4 score with DAS28 and modified Sharp score evolutions in multivariate analyses

VariableVariables included in modelp-valueDAS28Time<0.0001Age0.97Baseline number of swollen joints<0.0001Baseline Rheumatoid Factor0.51evolution over timeBaseline ACPA (presence)0.97Baseline CRP<0.0001Baseline modified Sharp score > 00.15Baseline FIB40.26Modified Sharp scoreTime0.052Age0.0005Baseline number of swollen joints0.38Baseline Rheumatoid Factor0.61evolution over timeBaseline ACPA (presence)0.012Baseline CRP0.84Baseline FIB40.25

Conclusion

Our study was the first to evaluate the value of FIB4 in a prospective cohort of RA patients. The present prospective cohort study with a 10-year follow-up did not find a prognostic role of FIB4 in RA, in contrast to previous retrospective studies. Reassuringly, FIB4 score was not increased by DMARD treatment after 10 years of follow-up, confirming the absence of long-term DMARD-related hepatotoxicity.

References

[1]Seung Up Kim, Beom Kyung Kim, Jun Yong Park, Do Young Kim, Sang Hoon Ahn, Yong-Beom Park, Kwang-Hyub Han & Sang-Won Lee (2018): Fibrosis-4 index at diagnosis can predict all-cause mortality in patients with rheumatoid arthritis: A retrospective monocentric study, Modern Rheumatology, DOI: 10.1080/14397595.2018.1558760

Figure 1.

Impact of baseline FIB4 score on DAS28, HAQ and total modified-Sharp score over time.

Acknowledgements

An unrestricted grant from Merck Sharp and Dohme (MSD) was allocated for the first 5 years. Two additional grants from INSERM were obtained to support part of the biological database. The French Society of Rheumatology, Pfizer, Abbvie, Lilly, Sanofi also supported the ESPOIR cohort study.

We also wish to thank Nathalie Rincheval (CHU Montpellier and EA 2415) who did expert monitoring and data management and all the investigators who recruited and followed the patients (F. Berenbaum, Paris-Saint Antoine, MC. Boissier, Paris-Bobigny, A. Cantagrel, Toulouse, B. Combe, Montpellier, M. Dougados, Paris-Cochin, P. Fardellone et P. Boumier Amiens, B. Fautrel, Paris-La Pitié, RM. Flipo, Lille, Ph. Goupille, Tours, F. Liote, Paris- Lariboisière, O. Vittecoq, Rouen, X. Mariette, Paris Bicetre, P. Dieude, Paris Bichat, A. Saraux, Brest, T. Schaeverbeke, Bordeaux, J. Sibilia, Strasbourg) V. Devauchelle and C Lukas for expert X-ray reading.

Disclosure of Interests

None declared.

Reduction in ionizing radiation exposure during minimally invasive anterior plate osteosynthesis of distal radius fracture: Naive versus deliberate practice

This study aimed to decrease surgeon exposure to ionizing radiation through a new learning technique, "deliberate practice", which consists in improving performance by setting goals with feedback. The hypothesis was that exposure to ionizing radiation during distal radius fracture surgery using the minimally invasive plate osteosynthesis (MIPO) technique decreased faster with "deliberate" practice than with "naïve" practice. Radiographic dosimetry was measured in the first 30 fractures operated on by MIPO by 6 surgeons. The first 3 surgeons operated "naively" (Group 1) and the next 3 according to the "deliberate" procedure (Group 2). Group 2 received weekly feedback (number of exposed hands, number of fluoroscopic views, exposure duration, and X-ray dose). An expert, using fluoroscopic images and surgical videos, provided suggestions for improvement. Mean number of exposed hands was 23.66 in Group 1 and 1.9 in Group 2. Mean number of fluoroscopic views was 78.31 and 35.0, respectively. Mean X-ray exposure time was 74.34 and 32.89 s, respectively. Mean dosimetry was 1.40 mGy (and 0.59 mGy, respectively. The hypothesis was thus confirmed: dosimetry decreased faster in Group 2 than in Group 1. Teaching this deliberate practice should be generalized, to decrease the growth phase and increase the plateau phase of the learning curve.

APOL1 risk variants in individuals of African genetic ancestry drive endothelial cell defects that exacerbate sepsis

The incidence and severity of sepsis is higher among individuals of African versus European ancestry. We found that genetic risk variants (RVs) in the trypanolytic factor apolipoprotein L1 (APOL1), present only in individuals of African ancestry, were associated with increased sepsis incidence and severity. Serum APOL1 levels correlated with sepsis and COVID-19 severity, and single-cell sequencing in human kidneys revealed high expression of APOL1 in endothelial cells. Analysis of mice with endothelial-specific expression of RV APOL1 and in vitro studies demonstrated that RV APOL1 interfered with mitophagy, leading to cytosolic release of mitochondrial DNA and activation of the inflammasome (NLRP3) and the cytosolic nucleotide sensing pathways (STING). Genetic deletion or pharmacological inhibition of NLRP3 and STING protected mice from RV APOL1-induced permeability defects and proinflammatory endothelial changes in sepsis. Our studies identify the inflammasome and STING pathways as potential targets to reduce APOL1-associated health disparities in sepsis and COVID-19.

Efficacy of sonic hedgehog inhibitors rechallenge, after initial complete response in recurrent advanced basal cell carcinoma: a retrospective study from the CARADERM database

BACKGROUND

Smoothened (SMO) inhibitors, blocking the sonic hedgehog pathway, have been approved for advanced basal cell carcinoma (aBCC). Safety analyses reveal a high rate of adverse events (AEs) and, most of the time, vismodegib is most commonly stopped when the best overall response is reached. The long-term evolution of aBCC after vismodegib discontinuation is poorly described. The aim of this study is to evaluate the efficacy and safety of the SMO inhibitors (SMOis) available (vismodegib and sonidegib) following rechallenge after complete response (CR) following an initial treatment by vismodegib.

MATERIALS AND METHODS

This real-life, retrospective, multicenter and descriptive study is based on an extraction from the CARADERM accredited database, including 40 French regional hospitals, of patients requiring BCC systemic treatment.

RESULTS

Of 303 patients treated with vismodegib, 110 achieved an initial CR. The vast majority of these patients (98.2%) stopped vismodegib, notably due to poorly tolerated AEs. The CARADERM database provided a median follow-up of 21 months (13.5-36.0 months) after CR. Of the 110 patients, 48.1% relapsed after a median relapse-free survival of 24 months (13.0-38.0 months). Among them, 35 patients were retreated by an SMOi and the overall response rate was 65.7% (34.3% of CR and 31.4% of partial response). The median duration of retreatment was 6.0 months (4.0-9.5 months).

CONCLUSION

Our real-life study, carried out on patients with complex clinical pictures, shows that after treatment discontinuation, 48.1% of patients achieved CR relapse within an average of 24 months (13.0-38.0 months). It emphasized that even though rechallenge can be considered as a therapeutic option, efficacy seems to decrease, suggesting the development of resistance mechanisms.

Immunogenicity and safety of two monovalent rotavirus vaccines, ROTAVAC® and ROTAVAC 5D® in Zambian infants

BACKGROUND AND AIMS

ROTAVAC® (frozen formulation stored at -20 °C) and ROTAVAC 5D® (liquid formulation stable at 2-8 °C) are rotavirus vaccines derived from the 116E human neonatal rotavirus strain, developed and licensed in India. This study evaluated and compared the safety and immunogenicity of these vaccines in an infant population in Zambia.

METHODS

We conducted a phase 2b, open-label, randomized, controlled trial wherein 450 infants 6 to 8 weeks of age were randomized equally to receive three doses of ROTAVAC or ROTAVAC 5D, or two doses of ROTARIX®. Study vaccines were administered concomitantly with routine immunizations. Blood samples were collected pre-vaccination and 28 days after the last dose. Serum anti-rotavirus IgA antibodies were measured by ELISA, with WC3 and 89-12 rotavirus strains as viral lysates in the assays. The primary analysis was to assess non-inferiority of ROTAVAC 5D to ROTAVAC in terms of the geometric mean concentration (GMC) of serum IgA (WC3) antibodies. Seroresponse and seropositivity were also determined. Safety was evaluated as occurrence of immediate, solicited, unsolicited, and serious adverse events after each dose.

RESULTS

The study evaluated 388 infants in the per-protocol population. All three vaccines were well tolerated and immunogenic. The post-vaccination GMCs were 14.0 U/mL (95% CI: 10.4, 18.8) and 18.1 U/mL (95% CI: 13.7, 24.0) for the ROTAVAC and ROTAVAC 5D groups, respectively, yielding a ratio of 1.3 (95% CI: 0.9, 1.9), thus meeting the pre-set non-inferiority criteria. Solicited and unsolicited adverse events were similar across all study arms. No death or intussusception case was reported during study period.

CONCLUSIONS

Among Zambian infants, both ROTAVAC and ROTAVAC 5D were well tolerated and the immunogenicity of ROTAVAC 5D was non-inferior to that of ROTAVAC. These results are consistent with those observed in licensure trials in India and support use of these vaccines across wider geographical areas.

Which adjuvant treatment for patients with BRAFV600-mutant cutaneous melanoma?

Treatment of patients with melanoma has considerably improved over the past decade and more recently with adjuvant therapies for patients with American Joint Committee on Cancer (AJCC) stage III (loco-regional metastases) or IV (distant metastases) totally resected melanoma, in order to prevent recurrence. In the adjuvant setting, two options are available to patients with BRAF^V600-mutant AJCC stage III totally resected melanoma: anti-PD-1 blockers (nivolumab or pembrolizumab) or BRAF plus MEK inhibitors (dabrafenib plus trametinib). In the absence of comparative studies, it is difficult to determine which of these options is best. Our aim was to review published studies focusing on the management of patients with BRAF^V600-mutant melanoma in the adjuvant setting. We also reviewed the main clinical trials of BRAF plus MEK inhibitors and immunotherapy in advanced (i.e. unresectable metastatic) BRAF-mutant melanoma in an attempt to identify results potentially affecting the management of patients on adjuvants. More adverse events are observed with targeted therapy, but all resolve rapidly upon drug discontinuation, whereas with immune checkpoint blockers some adverse events may persist. New therapeutic strategies are emerging, notably neoadjuvant therapies for stage III patients and adjuvant therapies for stage II patients; the place of the adjuvant strategy amidst all these options will soon be re-evaluated. The choice of adjuvant treatment could influence the choice of subsequent treatments in neo-adjuvant or metastatic settings. This review will lead clinicians to a better understanding of the different adjuvant treatments available for patients with totally resected AJCC stage III and IV BRAF^V600-mutant melanoma before considering subsequent treatment strategies.

CD8 T cells compensate for impaired humoral immunity in COVID-19 patients with hematologic cancer

Cancer patients have increased morbidity and mortality from Coronavirus Disease 2019 (COVID-19), but the underlying immune mechanisms are unknown. In a cohort of 100 cancer patients hospitalized for COVID-19 at the University of Pennsylvania Health System, we found that patients with hematologic cancers had a significantly higher mortality relative to patients with solid cancers after accounting for confounders including ECOG performance status and active cancer status. We performed flow cytometric and serologic analyses of 106 cancer patients and 113 non-cancer controls from two additional cohorts at Penn and Memorial Sloan Kettering Cancer Center. Patients with solid cancers exhibited an immune phenotype similar to non-cancer patients during acute COVID-19 whereas patients with hematologic cancers had significant impairment of B cells and SARS-CoV-2-specific antibody responses. High dimensional analysis of flow cytometric data revealed 5 distinct immune phenotypes. An immune phenotype characterized by CD8 T cell depletion was associated with a high viral load and the highest mortality of 71%, among all cancer patients. In contrast, despite impaired B cell responses, patients with hematologic cancers and preserved CD8 T cells had a lower viral load and mortality. These data highlight the importance of CD8 T cells in acute COVID-19, particularly in the setting of impaired humoral immunity. Further, depletion of B cells with anti-CD20 therapy resulted in almost complete abrogation of SARS-CoV-2-specific IgG and IgM antibodies, but was not associated with increased mortality compared to other hematologic cancers, when adequate CD8 T cells were present. Finally, higher CD8 T cell counts were associated with improved overall survival in patients with hematologic cancers. Thus, CD8 T cells likely compensate for deficient humoral immunity and influence clinical recovery of COVID-19. These observations have important implications for cancer and COVID-19-directed treatments, immunosuppressive therapies, and for understanding the role of B and T cells in acute COVID-19.

Precision medicine in acute respiratory distress syndrome: workshop report and recommendations for future research

Acute respiratory distress syndrome (ARDS) is a devastating critical illness that can be triggered by a wide range of insults and remains associated with a high mortality of around 40%. The search for targeted treatment for ARDS has been disappointing, possibly due to the enormous heterogeneity within the syndrome. In this perspective from the European Respiratory Society research seminar on "Precision medicine in ARDS", we will summarise the current evidence for heterogeneity, explore the evidence in favour of precision medicine and provide a roadmap for further research in ARDS. There is evident variation in the presentation of ARDS on three distinct levels: 1) aetiological; 2) physiological and 3) biological, which leads us to the conclusion that there is no typical ARDS. The lack of a common presentation implies that intervention studies in patients with ARDS need to be phenotype aware and apply a precision medicine approach in order to avoid the lack of success in therapeutic trials that we faced in recent decades. Deeper phenotyping and integrative analysis of the sources of variation might result in identification of additional treatable traits that represent specific pathobiological mechanisms, or so-called endotypes.

[Medical biostatistics with GMRC Shiny Stats - learning by doing]

Biostatistics are omnipresent in the scientific and medical literature and are an essential skill for any health student. We have developed a practical training tool - GMRC Shiny stats - an interactive application specifically dedicated to medical data statistical analysis. The application has been designed to provide an analysis workflow corresponding to the usual progression of an experienced statistician during data analysis. The most common statistical analyses can be performed (descriptive statistics, inferences according to frequentist methods, survival analyses, correlation, agreement measurements, etc.). GMRC Shiny stats is intuitive and user-friendly and assists students in choosing the most appropriate statistical tests. With all these functionalities, students can learn statistical analysis by doing. Getting involved in the statistical analysis and processing of their own data is likely to improve their biostatistics skills.

[The role of new molecular tests in the diagnosis of melanoma in a setting of congenital nævus in an infant]

INTRODUCTION

Congenital and infantile melanomas are extremely rare. We report a case of a child presenting at birth with a giant congenital nevus complicated by melanoma and on long-term follow-up with exploration using new immunohistochemistry and molecular biology tools.

OBSERVATION

A new-born girl presented at birth with a large congenital cervico-mandibular tumour with para-pharyngeal extension and underlying osteolysis. At 7 months, histology and immunohistochemistry of the operative specimen revealed nodules with atypical features (mitotic figures, necrosis and positive expression of KI67 and P53 in approximatively 50 % of the melanocytic nuclei). A diagnosis was made of infantile melanoma associated with congenital nevi. Repeated surgery and monitoring (clinical and imaging) were performed. At the age of 7 years, as there was no evidence of metastatic lesions, further analyses were performed on the initial operative specimen. Investigation of transcription factor expression using immunohistochemistry, comparative genomic hybridization and histology-guided mass spectrometry, although suspect, did not in itself support a diagnosis of melanoma. Finally, at the age of 7 years, hepatic and pulmonary metastases were reported. Despite combined immunotherapy with ipilimumab and nivolumab, the child died 5 months later.

CONCLUSION

This case illustrates the complexity of diagnosis of infantile melanoma and the risk of metastatic involvement long after the initial diagnosis. Diagnosis may be difficult and necessitates expert advice and the application of several recent methods to reach a conclusion and initiate appropriate treatment.

Viscosity of liquid Na-K alloys from molecular dynamics simulations

The shear viscosity of liquid Na-K alloys is computed from molecular dynamics simulations using the Green-Kubo formalism. Interatomic interactions are described using effective pair potentials obtained from Fiolhais pseudo-potential and self-consistent screening. The composition dependence of the viscosity is first investigated at 373 K, then its temperature dependence at three different compositions, namely Na₁₀-K₉₀, Na₅₀-K₅₀, and Na₉₀-K₁₀. Simulation results are first compared with available experimental data. The evolution of the viscosity of the alloys versus temperature is similar to that of a pure one component fluid. This is discussed in connection with the chemical order of the mixtures.

Dialkylcarbamoyl chloride-coated versus alginate dressings after pilonidal sinus excision: a randomized clinical trial (SORKYSA study)

Background

Disease of the pilonidal sinus is a common condition that affects mainly young adults. Options for management include excision of the sinus tracts, leaving the wound open to heal by secondary intention. The aim of this study was to compare wound healing with dialkylcarbamoyl chloride (DACC)‐coated dressings versus alginate dressings.

Methods

This multicentre trial randomized consecutive patients undergoing surgery for pilonidal disease to postoperative wound care with either DACC‐coated or alginate dressings. The primary outcome was the proportion of wounds healed after 75 days. Secondary outcomes were the local status of wounds during the healing process, the quality assessment of the dressings by the patient, and the time needed to return to usual activities.

Results

A total of 246 patients were included: 120 in the DACC‐coated group and 126 in the alginate group. In per‐protocol analysis, there were significantly more patients with completely healed wounds after 75 days in the DACC group than in the alginate group: 78 of 103 (75·7 per cent) versus 58 of 97 (60 per cent) respectively (odds ratio 2·55, 95 per cent c.i. 1·12 to 5·92; P = 0·023). During follow‐up, wounds with alginate dressings had more fibrin than those with DACC‐coated dressings, but the difference was not significant (P = 0·079). There was no difference between the two arms in patients' assessment of the dressings.

Conclusion

The number of wounds completely healed at 75 days was significantly higher for DACC‐coated compared with alginate dressings. However, the preplanned, clinically significant improvement in healing of 20 per cent was not reached. Registration number: NCT02011802 ( https://clinicaltrials.gov/).