Serum and Salivary IgG and IgA Response After COVID-19 Messenger RNA Vaccination

Importance

There is still considerable controversy in the literature regarding the capacity of intramuscular messenger RNA (mRNA) vaccination to induce a mucosal immune response.

Objective

To compare serum and salivary IgG and IgA levels among mRNA-vaccinated individuals with or without previous SARS-CoV-2 infection.

Design, Setting, and Participants

In this cohort study, SARS-CoV-2-naive participants and those with previous infection were consecutively included in the CoviCompare P and CoviCompare M mRNA vaccination trials and followed up to day 180 after vaccination with either the BNT162b2 (Pfizer-BioNTech) vaccine or the mRNA-1273 (Moderna) vaccine at the beginning of the COVID-19 vaccination campaign (from February 19 to June 8, 2021) in France. Data were analyzed from October 25, 2022, to July 13, 2023.

Main Outcomes and Measures

An ultrasensitive digital enzyme-linked immunosorbent assay was used for the comparison of SARS-CoV-2 spike-specific serum and salivary IgG and IgA levels. Spike-specific secretory IgA level was also quantified at selected times.

Results

A total of 427 individuals were included in 3 groups: participants with SARS-CoV-2 prior to vaccination who received 1 single dose of BNT162b2 (Pfizer-BioNTech) (n = 120) and SARS-CoV-2-naive individuals who received 2 doses of mRNA-1273 (Moderna) (n = 172) or 2 doses of BNT162b2 (Pfizer-BioNTech) (n = 135). The median age was 68 (IQR, 39-75) years, and 228 (53.4%) were men. SARS-CoV-2 spike-specific IgG saliva levels increased after 1 or 2 vaccine injections in individuals with previous infection and SARS-CoV-2-naive individuals. After vaccination, SARS-CoV-2-specific saliva IgA levels, normalized with respect to total IgA levels, were significantly higher in participants with previous infection, as compared with the most responsive mRNA-1273 (Moderna) recipients (median normalized levels, 155 × 10-5 vs 37 × 10-5 at day 29; 107 × 10-5 vs 54 × 10-5 at day 57; and 104 × 10-5 vs 70 × 10-5 at day 180 [P < .001]). In contrast, compared with day 1, spike-specific IgA levels in the BNT162b2-vaccinated SARS-CoV-2-naive group increased only at day 57 (36 × 10-5 vs 49 × 10-5 [P = .01]). Bona fide multimeric secretory IgA levels were significantly higher in individuals with previous infection compared with SARS-CoV-2-naive individuals after 2 antigenic stimulations (median optical density, 0.36 [IQR, 0.16-0.63] vs 0.16 [IQR, 0.10-0.22]; P < .001).

Conclusions and Relevance

The findings of this cohort study suggest that mRNA vaccination was associated with mucosal immunity in individuals without prior SARS-CoV-2 infection, but at much lower levels than in previously infected individuals. Further studies are needed to determine the association between specific saliva IgA levels and prevention of infection or transmission.

[Vaccination of allogeneic haematopoietic stem cell transplant recipients: Guidelines from the Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC)]

During immune reconstitution following allogeneic haematopoietic stem cell transplantation (allo-HSCT), (re)vaccination of allo-HSCT recipients is recommended. Herein, we propose an update of practical recommendations regarding vaccination of allo-HSCT recipients. These recommendations, based on data from the literature, national and international guidelines and the consensus of the participants when no formally proven data are available, were elaborated during the workshop of practice harmonization organized by the Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC) in Lille in September 2022.

Diagnostic, clinical management, and outcome of bone flap-related osteomyelitis after cranioplasty

OBJECTIVES

We aimed to describe diagnostic, management, and outcome of bone flap-related osteomyelitis after cranioplasty.

METHODS

Patients followed up in our tertiary care hospital for bone flap-related osteomyelitis after cranioplasty were included in a retrospective cohort (2008-2021). Determinants of treatment failure were assessed using logistic regression and Kaplan-Meier curves analysis.

RESULTS

The 144 included patients (81 [56.3%] males; median age 53.4 [interquartile range [IQR], 42.6-62.5] years) mostly presented wound abnormalities (n = 115, 79.9%). All infections were documented, the main pathogens being Staphylococcus aureus (n = 64, 44.4%), Cutibacterium acnes (n = 57, 39.6%), gram-negative bacilli (n = 40, 27.8%) and/or non-aureus staphylococci (n = 34, 23.6%). Surgery was performed in 140 (97.2%) cases, for bone flap removal (n = 102, 72.9%) or debridement with flap retention (n = 31, 22.1%), along with 12.7 (IQR, 8.0-14.0) weeks of antimicrobial therapy. After a follow-up of 117.1 (IQR, 62.5-235.5) weeks, 37 (26.1%) failures were observed: 16 (43.2%) infection persistence, three (8.1%) relapses, 22 (59.5%) superinfections and/or two (1.7%) infection-related deaths. Excluding superinfections, determinants of the 19 (13.4%) specific failures were an index craniectomy for brain tumor (odds ratio = 4.038, P = 0.033) and curettage of bone edges (odds ratio = 0.342, P = 0.048).

CONCLUSION

Post-craniectomy bone flap osteomyelitis are difficult-to-treat infection, necessitating prolonged antimicrobial therapy with appropriate surgical debridement, and advocating for multidisciplinary management in dedicated reference centers.

Improving Diagnosis of Pulmonary Mucormycosis: Leads From a Contemporary National Study of 114 Cases

BACKGROUND

Pulmonary mucormycosis (PM) is a life-threatening invasive mold infection. Diagnosis of mucormycosis is challenging and often delayed, resulting in higher mortality.

RESEARCH QUESTION

Are the disease presentation of PM and contribution of diagnosis tools influenced by the patient's underlying condition?

STUDY DESIGN AND METHODS

All PM cases from six French teaching hospitals between 2008 and 2019 were retrospectively reviewed. Cases were defined according to updated European Organization for Research and Treatment of Cancer/Mycoses Study Group criteria with the addition of diabetes and trauma as host factors and positive serum or tissue PCR as mycologic evidence. Thoracic CT scans were reviewed centrally.

RESULTS

A total of 114 cases of PM were recorded, including 40% with disseminated forms. Main underlying conditions were hematologic malignancy (49%), allogeneic hematopoietic stem cell transplantation (21%), and solid organ transplantation (17%). When disseminated, main dissemination sites were the liver (48%), spleen (48%), brain (44%), and kidneys (37%). Radiologic presentation included consolidation (58%), pleural effusion (52%), reversed halo sign (26%), halo sign (24%), vascular abnormalities (26%), and cavity (23%). Serum quantitative polymerase chain reaction (qPCR) was positive in 42 (79%) of 53 patients and BAL in 46 (50%) of 96 patients. Results of transthoracic lung biopsy were diagnostic in 8 (73%) of 11 patients with noncontributive BAL. Overall 90-day mortality was 59%. Patients with neutropenia more frequently displayed an angioinvasive presentation, including reversed halo sign and disseminated disease (P < .05). Serum qPCR was more contributive in patients with neutropenia (91% vs 62%; P = .02), and BAL was more contributive in patients without neutropenia (69% vs 41%; P = .02). Serum qPCR was more frequently positive in patients with a > 3 cm main lesion (91% vs 62%; P = .02). Overall, positive qPCR was associated with an early diagnosis (P = .03) and treatment onset (P = .01).

INTERPRETATION

Neutropenia and radiologic findings influence disease presentation and contribution of diagnostic tools during PM. Serum qPCR is more contributive in patients with neutropenia and BAL examination in patients without neutropenia. Results of lung biopsies are highly contributive in cases of noncontributive BAL.

Case report: Continuous infusions of ceftazidime-avibactam and aztreonam in combination through elastomeric infusors for 12 weeks for the treatment of bone and joint infections due to metallo-β-lactamase producing Enterobacterales

Among carbapenem-resistant Enterobacterales, metallo-beta-lactamase producing strains represent a growing therapeutic challenge. While the association of aztreonam and ceftazidime-avibactam has been investigated in recent years for the treatment of infections involving these strains, little to no clinical data support the use of this association for the treatment of bone and joint infections. We report two cases of complex bone and joint infections involving metallo-beta-lactamase-producing Enterobacterales, successfully treated at our referral center with aztreonam and ceftazidime-avibactam for 12 weeks in continuous infusions through elastomeric infusors.

Burden of influenza in the elderly: a narrative review

PURPOSE OF REVIEW

This review provides an update on specificities of influenza in older adults (≥65-year-old), including epidemiology, burden in terms of hospitalization and mortality, extra-respiratory complications and specific challenges of prevention.

RECENT FINDINGS

In the past 2 years, influenza activity was drastically reduced by barrier measures implemented during the COVID-19 pandemic. A recent French epidemiological study covering 2010-2018 epidemic seasons estimated that 75% of costs induced by influenza-associated hospitalizations and complications were attributable to older adults, a population bearing more than 90% of influenza-associated excess mortality.In addition to their age, comorbidities and reduced vaccine response, long-term facility residents are at risk for nosocomial outbreaks. Beyond respiratory complications, influenza triggers acute myocardial infarction and ischemic stroke. Influenza might drive significant functional loss in frail older adults, which can lead to "catastrophic" or severe disability in up to 10% of patients. Vaccination remains the cornerstone of prevention, with enhanced immunization strategies (i.e., high-dose or adjuvanted formulations) to be largely implemented in older adults. Efforts to increase influenza vaccination uptake during the COVID-19 pandemic should be consolidated.

SUMMARY

Burden of influenza in the elderly is largely under-recognized, especially the cardiovascular complications and the impact on functional status, justifying more effective preventive strategies.

Distinct Immune Reconstitution Profiles Captured by Immune Functional Assays at 6 Months Post Allogeneic Hematopoietic Stem Cell Transplantation

Immune reconstitution after allogeneic-hematopoietic-stem-cell transplantation (allo-HSCT) is a complex and individual process. In this cross-sectional study, whole-blood (WB) immune functional assay (IFA) was used to characterize immune function by assessing immune-related gene/pathway alterations. The usefulness of this tool in the context of infection, 6 months after transplantation, was evaluated. Sixty allo-HSCT recipients at 6 months after transplantation and 10 healthy volunteers (HV) were included. WB was stimulated in standardized TruCulture tubes using lipopolysaccharides and Staphylococcal enterotoxin B. Gene expression was quantified using a custom 144-gene panel using NanoString nCounter technology and analyzed using Ingenuity Pathway Analysis. The relationships between immune function and clinical characteristics, immune cell counts, and post-transplantation infections were assessed. Allo-HSCT recipients were able to activate similar networks of the innate and adaptive immune response compared to HV, with, nevertheless, a lower intensity. A reduced number and a lower expression of genes associated with immunoregulatory and inflammatory processes were observed in allo-HSCT recipients. The use of immunosuppressive treatments was associated with a protracted immune reconstitution revealed by transcriptomic immunoprofiling. No difference in immune cell counts was observed among patients receiving or not receiving immunosuppressive treatments using a large immunophenotyping panel. Moreover, the expression of a set of genes, including CCL3/CCL4, was significantly lower in patients with Herpesviridae reactivation (32%, 19/60), which once again was not identified using classical immune cell counts. Transcriptional IFA revealed the heterogeneity among allo-HSCT recipients with a reduced immune function, a result that could not be captured by circulating immune cell counts. This highlights the potential added value of this tool for the personalized care of immunocompromised patients.

Cognition in People Aged 80 Years and Older: Determinants and Predictors of Change from a Population-Based Representative Study in Germany

BACKGROUND

The number of people aged 80 years and older (80+) will increase drastically in the upcoming decades. The preservation of cognitive functions will contribute to their quality of life and independence.

OBJECTIVES

To identify determinants of cognition and predictors of change in cognitive performance in the population 80+.

DESIGN

Cross-sectional and longitudinal population-based on the representative NRW80+ survey.

SETTING

Randomly drawn cases of people aged 80+ from the municipal registration offices, including people living in private homes and institutional settings.

PARTICIPANTS

The participants in the cross-sectional sample (N=1503, 65.5%female) were 84.7 years old (95%CI[84.5,85.0]) and had 12.3 years of education (95%CI[12.1,12.4]). The participants in the longitudinal sample (N=840, 62.5%female) were 84.9 years old (95%CI[84.6,85.2]) and had 12.3 years of education (95%CI[12.0,12.5]).

MEASUREMENTS

The cognitive screening DemTect, age, sex, education, and social, physical, and cognitive lifestyle activities, as well as subjective general health status and depressive symptoms, were assessed at baseline and 24-month follow-up.

RESULTS

Younger age, more years of education, and more cognitive lifestyle activities were identified as the most consistent determinants of both better cognitive performance and preservation of cognitive performance for both global cognition as well as the DemTect subtests on memory and executive functions.

CONCLUSIONS

Our findings reveal that commonly investigated determinants of, and change in, cognitive performance are valid for the people 80+ and highlight the importance of cognitive lifestyle activities for cognitive health. The maintenance of cognitive functions is a key aspect of healthy aging in terms of preserving independence in people 80+.

Outcomes of post-exposure vaccination by modified vaccinia Ankara to prevent mpox (formerly monkeypox): a retrospective observational study in Lyon, France, June to August 2022

Modified vaccinia virus Ankara vaccine (MVA-BN; Bavarian Nordic) is recommended to contacts of mpox cases up to 14 days post-exposure but the effectiveness of this strategy is unknown. Among 108 adults (≥ 18 years old) who received one dose of MVA-BN after exposure to mpox, 11 (10%) cases of breakthrough mpox were observed. Sexual exposure was associated with the risk of breakthrough mpox (p = 0.0179). Samples taken from vaccinated breakthrough mpox cases had similar rates of infectious virus isolation than unvaccinated mpox cases.

991. Single Center, Exploratory, Open-label Prospective Study Using the Minimally Invasive LysinDAIR Procedure (Lysin Administration During an Arthroscopic DAIR Procedure) in Patients with Suspected Relapsing Chronic Coagulase-Negative Staphylococci (CNS) Prosthetic Hip Infection (PHI)

Background

Exebacase, a recombinant staphylococcal lysin, has: (i) reported proof-of-concept data in Phase II in S. aureus bacteremia; (ii) demonstrated antibiofilm activity in vitro against S. epidermidis; and (iii) been used as salvage therapy in 4 patients with relapsing multidrug-resistant (MDR) S. epidermidis knee prosthetic joint infection (PJI) using the LysinDAIR (arthroscopic administration of exebacase [Lysin] with Debridement and Antibiotics Implant Retention) procedure. Surgical treatment of recurrent PHIs has high risk of morbidity and loss of function. We now report our experience with the LysinDAIR procedure for PHIs.

Methods

We performed a single center, exploratory, open-label prospective study using LysinDAIR and suppressive antimicrobial therapy (SAT) in patients with recurrent, chronic (inoculation >3 months prior to treatment) CNS PHI. In agreement with the French Health authority, exebacase (2 to 3.5 total mg in 30-50 ml [∼0.067 – 0.075 mg/ml]) was arthroscopically administered directly into the joint.

Results

Three consecutive patients were included (55 to 75 years). All had previous iterative hip prosthesis exchange with a high total number of surgeries (from 6 to 10) and recent persistent or intermittent fistula (Figure). All refused hip prosthesis explantation or surgeon considered explantation too high risk for loss of function and severe post-operative complications. Patients A and B had MDR S. epidermidis; Patient B had P. aeruginosa co-infection at the time of LysinDAIR. Patient C had a prior persistent S. lugdunensis PHI and relapse on arthrocentesis; K. pneumoniae was cultured at the time of LysinDAIR. No adverse events related to exebacase or the procedure were reported. At 2 years follow up, all patients had resolution of fistula and no clinical signs of infection on SAT (tedizolid (+/- ciprofloxacin [Patient B] or cotrimoxazole [Patient C]).

Description of the patients treated with the LysinDAIR procedure

Local signs of infection with discharge of the three patients (A, B and C) with complex relapsing prosthetic hip infection with X-ray before the LysinDAIR procedure and at 2 years of follow-up

Conclusion

The LysinDAIR procedure was easy-to-perform, safe and may have therapeutic potential to facilitate the success of SAT salvage therapy for chronic relapsing CNS PJIs, and potential cure of initial chronic PJI. Randomized clinical trials evaluating the LysinDAIR procedure in these clinical situations are clearly warranted.

Disclosures

Tristan Ferry, MD, PhD, Contrafect: Advisor/Consultant Camille Kolenda, n/a, Contrafect: Research grant frederic Laurent, n/a, Contrafect: Research grant cara cassino, n/a, Contrafect: Employee.

P397 Influence of underlying conditions on disease presentation and diagnostic strategy during pulmonary mucormycosis: Anational study of 114 cases

Poster session 3, September 23, 2022, 12:30 PM - 1:30 PM

 

Objectives

Pulmonary mucormycosis (PM) is a life-threatening invasive fungal infection mostly affecting immunocompromised patients. We aimed to study the influence of underlying conditions on disease presentation and diagnostic strategy during PM.

Methods

All PM cases from six French teaching hospitals between 2008 and 2019 were retrospectively reviewed. Cases were defined according to EORTC/MSG 2019 criteria with the addition of diabetes and traumatism as host factors and positive serum or tissue PCR as mycological evidence. Thoracic CT scans were reviewed centrally.

Results

Among 114 cases of PM, 52 (46%) were proven and 62 (54%) were probable, including 12 cases with a positive serum qPCR as the sole mycological criterion. Hematological malignancy was the most common risk factor (49%), followed by allogeneic hematopoietic stem-cell transplantation (21%), and solid organ transplantation (SOT, 17%). Fever was the first symptom for 66% patients and was more frequent in patients with neutropenia than in those without (97% vs 52%, P <.01). A total of 46 (40%) patients had a disseminated infection, which was more frequently reported in neutropenic patients (50% vs 25%, P <.01). Main dissemination sites were the liver (48%), spleen (48%), brain (44%), and kidneys (37%). Sinusitis was present in 13% of cases.

Chest radiological presentation included consolidation (58%), pleural effusion (52%), reversed halo sign (26%), halo sign (24%), vascular abnormalities (26%), and excavation (23%). The excavation was more frequently reported in SOT patients (64%, P <.01) compared with other groups. Vascular involvement was associated with reversed halo sign and Rhizomucor infection. Neutropenic patients presented more frequently than non-neutropenic patients with ground-glass opacities (75 vs 49%, P = .01), halo sign (32% vs 10%, P = .02), and reversed halo sign (35 vs 10%, P <.01).

A total of 83 (73%) patients had a positive fungal culture from any type of respiratory sample. Serum qPCR was positive for 42/53 patients (79%) and respiratory fluid qPCR for 16/21 (76%) patients. In neutropenic patients, BAL culture was less often positive (30% vs 66%, P <.01), and serum qPCR was more frequently positive (91% vs 62%, P = .02). A transthoracic lung biopsy was contributive in 8/11 (73%) patients with negative bronchoalveolar lavage (BAL). Serum qPCR was more frequently positive in patients with the main lesion of >3 cm in diameter (91% vs 62%, P = .02). Rhizomucor spp. Was identified in 31 patients (32%), Rhizopus spp. In 29 patients (30%), Lichtheimia spp. In 24 patients (25%), Mucor spp. In 10 patients (10%) and Cunninghamella spp. In 4 patients (4%). Neutropenic patients were more frequently infected with Rhizomucor (43% vs 13%, P <.01) and less frequently with Rhizopus (17% vs 50%, P <.01). Histopathological specimens were available for 48 patients (42%) and revealed Mucorales hyphae in 85% of cases. Patients with a disseminated infection and neutropenia presented more often with angioinvasion than patients with localized disease (50% vs 9%, P <.01 and 38% vs 13%, P = .10). Overall, 90-day mortality was 59%.

Conclusion

Underlying conditions significantly influenced clinical and radiological presentation and diagnostic tools’ contribution. Neutropenic patients present more frequently with dissemination, fever, reversed halo sign, pathological angioinvasion, the negativity of BAL culture, the positivity of serum qPCR, and Rhizomucor infection.

A Simple-to-Perform ifn-γ mRNA Gene Expression Assay on Whole Blood Accurately Appraises Varicella Zoster Virus-Specific Cell-Mediated Immunity After Allogeneic Hematopoietic Stem Cell Transplantation

Herpes zoster, which is due to the reactivation of Varicella zoster virus (VZV), is a leading cause of morbidity after allogeneic hematopoietic stem cell transplantation (allo-HSCT). While cell-mediated immunity (CMI) is critical to inhibiting VZV reactivation, CMI is not routinely assessed due to a lack of reliable tests. In this study, we aimed to evaluate VZV-specific CMI among allo-HSCT recipients (n = 60) and healthy individuals (HI, n = 17) through a panel of three immune functional assays after ex vivo stimulation by VZV antigen: quantification of (i) IFN-γ release in the supernatants, (ii) T-cell proliferation after a 7-day stimulation of peripheral blood mononuclear cells (PBMC), and (iii) measurement of the ifn-γ mRNA gene expression level after 24 h of stimulation of a whole-blood sample. VZV responsiveness was defined according to IFN-γ release from VZV-stimulated PBMC. Upon VZV stimulation, we found that allo-HSCT recipients at a median time of 6 [5-8] months post-transplant had lower IFN-γ release (median [IQR], 0.34 [0.12–8.56] vs. 409.5 [143.9–910.2] pg/ml, P <.0001) and fewer proliferating T cells (0.05 [0.01–0.57] % vs. 8.74 [3.12–15.05] %, P <.0001) than HI. A subset of allo-HSCT recipients (VZV-responders, n = 15/57, 26%) distinguished themselves from VZV-non-responders (n = 42/57, 74%; missing data, n = 3) by higher IFN-γ release (80.45 [54.3–312.8] vs. 0.22 [0.12–0.42] pg/ml, P <.0001) and T-cell proliferation (2.22 [1.18–7.56] % vs. 0.002 [0.001–0.11] %, P <.0001), suggesting recovery of VZV-specific CMI. Interestingly, VZV responders had a significant fold increase in ifn-γ gene expression, whereas ifn-γ mRNA was not detected in whole blood of VZV-non-responders (P <.0001). This study is the first to suggest that measurement of ifn-γ gene expression in 24-h-stimulated whole blood could be an accurate test of VZV-specific CMI. The routine use of this immune functional assay to guide antiviral prophylaxis at an individual level remains to be evaluated.

Prognosis and factors associated with disseminated nocardiosis: a ten-year retrospective multicenter study

OBJECTIVES

Nocardiosis is a rare opportunistic infection that is frequently associated with dissemination (i.e. involvement of several body sites). Identifying the factors associated with Nocardia spp. dissemination may help improving the management of patients with nocardiosis.

METHODS

This 10-year (2010-2020) retrospective multicenter cohort study included adult patients with Nocardia-confirmed infections. The first objective was to determine the factors associated with disseminated nocardiosis. The secondary endpoints were to determine and compare the management and the 12-month overall mortality in patients with localized and disseminated nocardiosis. Univariate and multivariate logistic regression analyses were used.

RESULTS

Nocardia spp. infection was confirmed in 110 patients, of whom 38 (34.5%) had disseminated nocardiosis. In univariate analysis, the factors associated with dissemination were immunosuppressive conditions: having an auto-immune disease and receiving high-dose corticosteroid (31.5% vs 8.3%, P=0.003 and 52.6% vs 26.3%, P=0.007, respectively). Absolute lymphocyte count <1G/L at diagnosis was the only biomarker associated with dissemination (57.2% vs 26.3%, P=0.007). Nocardia farcinica was not only the most frequent species identified in patient specimens (n=22, 20%) but was also associated with a higher rate of dissemination (36.8% vs 11.1%, P=0.002). Multivariate analysis confirmed the association between auto-immune diseases, lymphopenia, N. farcinica species and the higher rate of dissemination. Even though patients with disseminated nocardiosis were treated longer and more often with an antibiotic combination therapy, their 12-month overall mortality was significantly higher than that of patients with localized nocardiosis (36.8% vs 18%).

CONCLUSIONS

Dissemination of Nocardia spp. is favoured by auto-immune diseases, lymphopenia, and infection with N. farcinica.

Coxiella burnetti prosthetic joint infection in an immunocompromised woman: iterative surgeries, prolonged ofloxacin-rifampin treatment and complex reconstruction were needed for the cure

Background

Q fever is a zoonotic disease caused by the bacterium Coxiella burnetii, a strictly intracellular pathogen that can cause acute and chronic infection. Chronic Q fever can occur in immunocompetent as well as in immuno-compromised hosts, as a persistent localized infection. The main localizations are endocardial, vascular and, less frequently, osteoarticular. The most frequent osteoarticular form is spondyliscitis. Recommended treatment is combined doxycycline and hydroxychloroquine for 18 months, with cotrimoxazole as another option. Coxiella burnetti infection has been implicated in rare cases of prosthetic joint infection (PJI), and the medical and surgical management and outcome in such cases have been little reported.

Case presentation

We report an unusual case of chronic Q fever involving a hip arthroplasty in an immunocompromised woman treated with tumor necrosis factor (TNF)-α blockers for rheumatoid arthritis. Numerous surgical procedures (explantation, “second look”, femoral resection and revision by megaprosthesis), modification of the immunosuppressant therapy and switch from doxycycline-hydroxychloroquine to prolonged ofloxacin-rifampin combination therapy were needed to achieve reconstruction and treat the PJI, with a follow-up of 7 years.

Conclusions

Coxiella burnetti PJI is a complex infection that requires dedicated management in an experienced reference center. Combined use of ofloxacin-rifampin can be effective.

Safety of Tedizolid as Suppressive Antimicrobial Therapy for Patients With Complex Implant-Associated Bone and Joint Infection due to Multidrug-Resistant Gram-Positive Pathogens: Results From the TediSAT Cohort Study

A prospective cohort study was conducted to evaluate long-term safety of tedizolid as suppressive antimicrobial treatment in patients with implant-associated bone and joint infection caused by multidrug-resistant gram-positive pathogens. Seventeen patients received tedizolid with a median duration of treatment of 6 months. No patients developed a serious adverse event.

Population pharmacokinetics of daptomycin in patients with bone and joint infection: minimal effect of rifampicin co-administration and confirmation of a sex difference

BACKGROUND

Daptomycin is increasingly used in the treatment of bone and joint infection (BJI), but its pharmacokinetics (PK) and dosage requirements have not been thoroughly investigated in this indication. Daptomycin may be co-administered with rifampicin, which raises questions about a potential drug interaction.

OBJECTIVES

To investigate the population PK and dosage requirements of daptomycin in patients with BJI, and examine the influence of rifampicin co-administration.

METHODS

A population approach was used to analyse PK data from patients who received daptomycin in our regional reference for BJI. We examined the influence of available covariates, including rifampicin co-administration on daptomycin PK. Simulations performed with the final model investigated the influence of dosages and covariates on PTA for both efficacy and safety.

RESULTS

A total of 1303 daptomycin concentrations from 183 patients were analysed. A two-compartment model best described the data. Significant intra-individual variability was observed. Daptomycin clearance was influenced by renal function and sex, with females having a 26% lower typical clearance than males. Central volume of distribution (V1) was influenced by body weight, age, sex and rifampicin co-administration. Typical V1 was 11% lower in patients who were co-administered rifampicin. In PK/PD simulations, sex influenced the probability of AUC24/MIC target attainment, while rifampicin had a marginal effect.

CONCLUSIONS

A daptomycin dosage of 8 mg/kg/24 h in women and 10 mg/kg/24 h in men should optimize efficacy but may lead to excessive trough concentrations in many patients, especially in women. Therapeutic drug monitoring appears necessary for precision dosing of daptomycin.

Pharmacokinetic/Pharmacodynamic Dosage Individualization of Suppressive Beta-Lactam Therapy Administered by Subcutaneous Route in Patients With Prosthetic Joint Infection

Suppressive parenteral antibiotic therapy with beta-lactams may be necessary in patients with Gram-negative bone and joint infection (BJI). Subcutaneous drug administration can facilitate this therapy in outpatient setting, but there is limited information about this practice. We have developed an original approach for drug dosing in this context, based on therapeutic drug monitoring (TDM) and pharmacokinetic/pharmacodynamic (PK/PD) principles. The objective of this study was to describe our approach and its first results in a case series. We analyzed data from patients who received suppressive antibiotic therapy by subcutaneous (SC) route with beta-lactams as salvage therapy for prosthetic joint infection (PJI) and had TDM with PK/PD-based dose adjustment. Ten patients (six women and four men with a mean age of 77 years) were included from January 2017 to May 2020. The drugs administered by SC route were ceftazidime (n = 4), ertapenem (n = 4), and ceftriaxone (n = 2). In each patient, PK/PD-guided dosage individualization was performed based on TDM and minimum inhibitory concentration (MIC) measurements. The dose interval could be prolonged from twice daily to thrice weekly in some patients, while preserving the achievement of PK/PD targets. The infection was totally controlled by the strategy in nine out the 10 patients during a median follow-up of 1,035 days (~3 years). No patient acquired carbapenem-resistant Gram-negative bacteria during the follow-up. One patient presented treatment failure with acquired drug resistance under therapy, which could be explained by late MIC determination and insufficient exposure, retrospectively. To conclude, our innovative approach, based on model-based TDM, MIC determination, and individualized PK/PD goals, facilitates, and optimizes suppressive outpatient beta-lactam therapy administered by SC route for PJI. These encouraging results advocate for larger clinical evaluation.

Recrudescence of a high parasitaemia, severe Plasmodium falciparum malaria episode, treated by artesunate monotherapy

A patient presenting with severe malaria, with hyperparasitaemia, received 7-day artesunate monotherapy. A severe recrudescence was detected and attributed to hyperparasitaemia, monotherapy and a polyclonal infection without Kelch 13 gene mutation. A second treatment with artesunate, then quinine, followed by artemether-lumefantrine, was successful.

Bone and Joint Infection Involving Corynebacterium spp.: From Clinical Features to Pathophysiological Pathways

Introduction: Corynebacteria represent often-neglected etiological agents of post-traumatic and/or post-operative bone and joint infection (BJI). We describe here clinical characteristics and bacteriological determinants of this condition. Methods: A retrospective cohort study described characteristics, outcome and determinants of treatment failure of all patients with proven Corynebacterium spp. BJI (i.e., ≥2 culture-positive gold-standard samples). Available strains were further characterized regarding their antibiotic susceptibilies, abilities to form early (BioFilm Ring Test®) and mature (crystal violet staining method) biofilms and to invade osteoblasts (gentamicin protection assay). Results: The 51 included BJI were mostly chronic (88.2%), orthopedic device-related (74.5%) and polymicrobial (78.4%). After a follow-up of 60.7 weeks (IQR, 30.1-115.1), 20 (39.2%) treatment failures were observed, including 4 Corynebacterium-documented relapses, mostly associated with non-optimal surgical management (OR 7.291; p = 0.039). Internalization rate within MG63 human osteoblasts was higher for strains isolated from delayed (>3 months) BJI (p < 0.001). Infection of murine osteoblasts deleted for the β1-integrin resulted in a drastic reduction in the internalization rate. No difference was observed regarding biofilm formation. Conclusions: Surgical management plays a crucial role in outcome of BJI involving corynebacteria, as often chronic and device-associated infections. Sanctuarisation within osteoblasts, implicating the β1 cellular integrin, may represent a pivotal virulence factor associated with BJI chronicity.

Slowly or Nonresolving Legionnaires' Disease: Case Series and Literature Review

BACKGROUND

Rarely, Legionnaires' disease (LD) can progress into a slowly or nonresolving form.

METHODS

A nationwide retrospective study was conducted by the French National Reference Center for Legionella (2013-2017) including cases of slowly or nonresolving LD defined as persistent clinical symptoms, computed tomography (CT) scan abnormalities, and Legionella detection in lower respiratory tract specimens by culture and/or real-time (RT) polymerase chain reaction (PCR) >30 days after symptom onset.

RESULTS

Twelve cases of community-acquired slowly or nonresolving LD were identified among 1686 cases of culture-positive LD. Median (interquartile range [IQR]) age was 63 (29-82) years. Ten (83.3%) patients had ≥1 immunosuppressive factor. Clinically, 9 patients transiently recovered before further deterioration (median [IQR] symptom-free interval, 30 [18-55] days), 3 patients had uniformly persistent symptoms (median [IQR] time, 48 [41.5-54] days). Two patients had >2 recurrences. CT scan imagery found lung abscess in 5 (41.6%) cases. Slowly or nonresolving LD was diagnosed on positive Legionella cultures (n = 10, 83.3%) at 49.5 (IQR, 33.7-79) days. Two cases were documented through positive Legionella RT PCR at 52 and 53 days (cycle threshold detection of 21.5 and 33.7, respectively). No genomic microevolution and no Legionella resistance to antibiotics were detected. The median (IQR) duration of treatment was 46.5 (21-92.5) days. Two empyema cases required thoracic surgery. At a median (IQR) follow-up of 26 (14-41.5) months, LD-attributable mortality was 16.6% (n = 2).

CONCLUSIONS

Slowly or nonresolving LD may occur in immunocompromised patients, possibly leading to lung abscess and empyema.

Pseudomonas aeruginosa Implant-Associated Bone and Joint Infections: Experience in a Regional Reference Center in France

Background:P. aeruginosa implant-associated bone and joint infections (BJI) is considered to be one of the most difficult to treat BJI. The data focusing specifically on this pathogen are sparse, and it seems difficult to extrapolate the results obtained with Enterobacteriaceae.

Methods: We performed a retrospective observation study of all P. aeruginosa implant-associated BJI diagnosed at our institution from 2011 to 2018. We defined failure as any type of relapse, including persistence of the same P. aeruginosa, superinfection by another organism(s) or any other cause of relapse such as the need for a subsequent surgery. Nonparametric statistical methods were used to compare the study groups and Kaplan-Meier curves and multivariate Cox analysis and were used to detect determinants associated with treatment failure.

Results: A total of 90 patients (62% men, median age 60 years IQR 47–72) including 30 (33%) prosthetic-joint infections and 60 (66%) other implant-associated BJIs were studied. Most of them were acute (62%). During the prolonged follow-up, (median 20 months; IQR 9–37), 23 patients (26%) experienced treatment failure. Optimal surgical treatment (DAIR for acute forms, explantation, 1-stage or 2-stage exchange for others) was significantly associated with a higher success rate in the univariate analysis (p = 0.003). Sixty-four (71%) patients received effective initial treatment against P. aeruginosa administered and 81 of them (90%) did for at least 3 weeks: both these parameters correlated with a higher success rate. In the multivariate Cox-analysis optimal surgical treatment, IV effective treatment of at least 3 weeks and treatment with ciprofloxacin for at least 3 months proved to be independently associated to a better outcome in patients with P. aeruginosa implant-associated BJI.

Conclusion:P. aeruginosa implant-associated BJI is one of the most difficult-to-treat BJI, with a strong impact on the prognosis of the surgical strategy. An effective initial IV antibiotic treatment for at least 3 weeks seems to be required, followed by oral ciprofloxacin for a total duration of 3 months.

Récurrences symptomatiques de COVID-19 confirmées après guérison clinique d’un premier épisode : rechute, réinfection ou rebond inflammatoire ?

Introduction

Bien que, par analogie aux autres coronavirus, la maladie COVID-19 induite par SARS-CoV-2 ait été initialement supposée monophasique et transitoirement immunisante, de rares publications rapportent des patients avec 2^e épisode. L’objectif de cette étude est de décrire les caractéristiques cliniques, la séquence moléculaire de détection virale, et le devenir de patients présentant 2 épisodes distincts de COVID-19.

Matériels et méthodes

Une étude nationale multicentrique rétrospective observationnelle a recensé les patients présentant un 2^e épisode aigu symptomatique de COVID-19, défini par au moins un signe clinique majeur typique, et une PCR SARS-CoV-2 positive dans les voies aériennes, après :

– au moins 21 jours du début du 1^er épisode ;

– une phase de guérison clinique (retour à l’état antérieur, ou sortie de soins aigus sans oxygène), sans diagnostic différentiel infectieux, thromboembolique ou inflammatoire.

Résultats

Onze patients présentant un 2^e épisode de COVID-19 après une guérison clinique médiane [étendue] de 10 [3–27] jours ont été recensés, et 2 groupes ont été individualisés.

Dans le 1^er, 4 soignants sans comorbidités, d’âge médian 32,5 [19–43] ans, potentiellement re-exposés au SARS-CoV- (3 dans des unités de soins COVID, 1 au domicile), ont présenté aux 2 épisodes une maladie modérée suivie en ambulatoire.

Dans le 2^e groupe, 7 patients comorbides (dont 2 sous chimiothérapie), d’âges médian 73 [54–91] ans, ont été hospitalisés en soins aigus à chaque épisode. Au 1^er, 3 patients ont reçu des corticoïdes. Aucune réexposition au SARS-CoV-2 n’a été documentée, et 3 patients sont décédés, dont 2 de syndrome de détresse respiratoire aiguë sans autre cause que le SARS-CoV-2.

Au 2^e épisode, tous les scanners montraient des signes aigus de COVID-19, 4/9 PCR avaient des « cycle threshold » (CT) < 30, et 1 sur 2 cultures virales pratiquées était positive. La sérologie SARS-CoV-2 après j21 était positive pour 6 patients, et négative pour 3 (du 2^e groupe).

Conclusion

Cette étude exploratoire confirme la possibilité de récurrences de symptômes après guérison clinique d’un premier épisode de COVID-19. La positivité des PCR aux 2^e épisodes (de plusieurs gènes ou avec CT bas) et au moins une culture virale positive, sans diagnostic différentiel identifié, sont en faveur d’une origine virale à ces récurrences. Les caractéristiques des 2 groupes de patients suggèrent soit des réinfections, soit des réactivations virales. Un déficit immunitaire relatif cellulaire ou humoral (par épuisement professionnel ou immuno-senescence, ou traitements immunosuppresseurs), pourraient entraver la clairance virale ou l’efficacité immunitaire antivirale contre les réinfections à SARS-CoV-2. De plus larges études épidémiologiques, et immuno-virologiques sont nécessaires pour comprendre la fréquence et le(s) mécanisme(s) de ces récurrences.

Plasma Cell Infiltration on Histopathological Samples of Chronic Bone and Joint Infections due to Cutibacterium acnes: A series of 21 Cases

Introduction: Histopathological definition of bone and joint infection (BJI) is based on Mirra's criterion (≥ 5 polymorphonuclears (PMNs) per field in 5 high power fields (HPFs)). However, this definition does not seem appropriate for chronic BJIs caused by slow-growing germs such as Cutibacterium acnes (C. acnes). The aim of this study was to confirm that Mirra's criterion is not adequate for diagnosis of BJIs due to C. acnes. The second objective was to determine if plasma cell infiltration could be useful for the diagnosis of chronic BJIs due to C. acnes. Methods: We retrospectively selected 25 consecutive patients from 2009 to 2013 with chronic BJIs due to C. acnes. Histological analysis was performed on the 21 cases with at least two C. acnes positive cultures. In addition of Mirra's criterion, the number of plasma cells (≥5 plasma cells/5 HPFs, defined as "CRIOAc Lyon's criterion") was implemented in the histopathological analysis. Patients were defined as infected, if at least one of the two criteria were present. Results: According to Mirra's and CRIOAc Lyon's criteria, positive histopathology was observed in 12 (57.1%) and 15 (71.4%) cases respectively. Considering the 9 cases with negative Mirra's criterion, high plasma cell infiltration (≥5 plasma cells per field/5 HPFs) was observed in 5 cases (55.6%), and low plasma cells infiltration (2-5 plasma cells per field/5 HPFs) was observed in 4 other cases (44.4%). Conclusions: Adding CRIOAc Lyon's criterion to Mirra's criterion might restore some histopathological diagnosis of chronic BJIs due to C. acnes when a chronic BJI is clinically suspected.

Clinical recurrences of COVID-19 symptoms after recovery: Viral relapse, reinfection or inflammatory rebound?

For the first 3 months of COVID-19 pandemic, COVID-19 was expected to be an immunizing non-relapsing disease. We report a national case series of 11 virologically-confirmed COVID-19 patients having experienced a second clinically- and virologically-confirmed acute COVID-19 episode. According to the clinical history, we discuss either re-infection or reactivation hypothesis. Larger studies including further virological, immunological and epidemiologic data are needed to understand the mechanisms of these recurrences.

Genetic polymorphisms of ABCB1 (P-glycoprotein) as a covariate influencing daptomycin pharmacokinetics: a population analysis in patients with bone and joint infection

BACKGROUND

Daptomycin has been recognized as a therapeutic option for the treatment of bone and joint infection (BJI). Gene polymorphism of ABCB1, the gene encoding P-glycoprotein (P-gp), may influence daptomycin pharmacokinetics (PK).

OBJECTIVES

We aimed to examine population PK of daptomycin and its determinants, including genetic factors, in patients with BJI.

PATIENTS AND METHODS

We analysed data from patients who received daptomycin for BJI between 2012 and 2016 in our regional reference centre and who had measured daptomycin concentrations and P-gp genotyping. A population approach was used to analyse PK data. In covariate analysis, we examined the influence of three single nucleotide variations (SNVs) of ABCB1 (3435C > T, 2677G > T/A and 1236C > T) and that of the corresponding haplotype on daptomycin PK parameters. Simulations performed with the final model examined the influence of covariates on the probability to achieve pharmacodynamic (PD) targets.

RESULTS

Data from 81 patients were analysed. Daptomycin body CL (CLDAP) correlated with CLCR and was 23% greater in males than in females. Daptomycin central V (V1) was allometrically scaled to body weight and was 25% lower in patients with homozygous CGC ABCB1 haplotype than in patients with any other genotype. Simulations performed with the model showed that sex and P-gp haplotype may influence the PTA for high MIC values and that a dosage of 10 mg/kg/24 h would optimize efficacy.

CONCLUSIONS

Daptomycin dosages higher than currently recommended should be evaluated in patients with BJI. Gender and P-gp gene polymorphism should be further examined as determinants of dosage requirements.

Efficacy and Safety of Revaccination against Tetanus, Diphtheria, Haemophilus influenzae Type b and Hepatitis B Virus in a Prospective Cohort of Adult Recipients of Allogeneic Hematopoietic Stem Cell Transplantation

Data on immunogenicity and safety of the recommended revaccination schedule against diphtheria, tetanus, poliomyelitis, pertussis, Haemophilus influenzae type b (Hib), and hepatitis B in adult allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients are limited. This prospective single-center cohort study (April 2014 to March 2018) included adult allo-HSCT recipients referred to a dedicated vaccinology consultation and vaccinated with the pediatric combined diphtheria, tetanus, acellular pertussis, hepatitis B virus, inactivated poliovirus, and Haemophilus influenzae type b (DTaP(±HB)-IPV-Hib) vaccine (3 doses 1 month apart, booster dose 1 year later). The proportion of responders to tetanus, diphtheria, Hib, and hepatitis B vaccine and geometric mean concentrations (GMCs) of antibodies were assessed before and up to 24 months after vaccination. A total of 106 patients were vaccinated at a median (interquartile range) time of 12.4 (10 to 18.4) months post-transplant. At 5.3 (4.8 to 6.6) and 23.1 (21.1 to 25.1) months after vaccine initiation, high and sustained rates of protective antibody titers were achieved for tetanus (97.8% [95% confidence interval (95% CI), 92.4% to 99.7%], n = 91/93 and 100% [95% CI, 92% to 100%], n = 44/44), diphtheria (94.6% [95% CI, 87.9% to 98.2%], n = 88/93 and 90.9% [95% CI, 78.3% to 97.5%], n = 40/44), Hib (96.6% [95% CI, 90.4% to 99.3%], n = 85/88 and 93% [95% CI, 80.9% to 98.5%], n = 40/43), and hepatitis B (83.5% [95% CI, 73.5% to 90.9%], n = 66/79 and 81.1% [95% CI, 64.8% to 92%], n = 30/37). Underlying disease, stem cell source, chronic graft-versus-host-disease, and extracorporeal photopheresis differentially influenced GMCs of tetanus, diphtheria, and hepatitis B antibodies after 3 doses but not in the long term (24 months). Six (5.7%) patients experienced mild side effects. The pediatric DTaP(±HB)-IPV-Hib vaccine was safe and effective in eliciting a sustained protective humoral response in adult allo-HSCT recipients. Hepatitis B revaccination might be optimized by using higher antigen doses.

Vaccination in adult liver transplantation candidates and recipients

In patients with chronic liver disease and liver transplant recipients, cirrhosis-associated immune dysfunction syndrome and immunosuppressant drug regimens required to prevent graft rejection lead to a high risk of severe infections, associated with acute liver decompensation, graft loss and increased mortality. In addition to maintain their global health status, vaccination represents a major preventive measure against specific infectious risks of particular concern in this population, such as invasive pneumococcal diseases, influenza or viral hepatitis A and B. However, immunization in this setting raises several issues: i) recommended vaccination schedules rely on sparse immunogenicity data without clinical efficacy and effectiveness trials designed for this specific population; ii) dynamics of immunosuppression makes timing of immunization challenging; iii) live attenuated vaccines are contraindicated after transplantation; and iv) vaccines tolerance is poorly known in cirrhotic patients. This review outlines the rational for vaccination in adult liver transplant candidates and recipients and available data regarding immunization in this specific population.

Cerebral empyema and abscesses due to Cutibacterium acnes

INTRODUCTION

Cutibacterium acnes is a commensal bacterium of the skin, frequently reported in prosthetic shoulder or spinal implant infections, but rarely in cranial and intracranial infections.

METHODS

We retrospectively reviewed patients with intracranial samples positive to Cutibacterium acnes managed in the neurosurgical units of our hospital of Lyon, France, between 2008-2016.

RESULTS

We included 29 patients, of whom 23 had empyema (with or without abscess), 17 had cranial osteomyelitis, and six only had abscess. Prior neurosurgery was reported in 28 patients, and the remaining patient had four spontaneous abscesses. Twelve patients had polymicrobial infections, including methicillin-susceptible Staphylococcus in 11 cases. The clinical diagnosis was difficult because of indolent and delayed symptoms: a CT scan or MRI was required. Thirteen patients (52%) had material at the infection site. All patients with bone flap implant or bones from biological banks had a bone flap-associated infection. Drainage was surgically performed in 25 cases or by CT scan-guided aspiration in four cases. All patients received an adapted antibiotic therapy (from three weeks to six months). The outcome was favorable in 28 patients. Three patients relapsed during the antibiotic therapy, requiring further surgery.

CONCLUSION

Cutibacterium acnes can be responsible for postoperative empyema and cerebral abscesses, with particular indolent forms, which make their diagnosis difficult. They are often polymicrobial and associated with bone flap osteomyelitis. Their outcome is favorable after drainage and adapted antibiotic therapy.

Clinical utility of leflunomide for BK polyomavirus associated nephropathy in kidney transplant recipients: A multicenter retrospective study

BACKGROUND

BK polyomavirus associated nephropathy (BKPyVAN) is a significant clinical issue in kidney transplant (KT) recipients. No specific therapy is currently available, although treatment with leflunomide may be part of the therapeutic strategy. Here, we sought to examine the impact of leflunomide on the evolution of BKPyVAN.

METHODS

This was an observational retrospective study conducted in 3 French transplant centers. KT recipients who developed BKPyVAN and received leflunomide after failure of other treatment approaches were deemed eligible. Graft function, viral clearance, patient survival, rejection rates, treatment tolerability, and immunosuppression levels served as the main outcome measures.

RESULTS

A total of 55 patients were included. Treatment with leflunomide was started after a mean of 1.4 ± 4.1months  after BKPyVAN diagnosis. Between the introduction of leflunomide and the end of follow-up, creatinine levels increased by 31 ± 118% (P = 0.04), whereas viremia decreased by 79 ± 37% (P < 0.001). Blood viral clearance was observed in 76% of the study patients. Rejection episodes occurred in 33% of the participants. Eleven patients lost their graft (9 of which because of BKPyVAN). Ten patients developed adverse effects and 3 discontinued leflunomide.

CONCLUSION

We cannot conclude about the exact place of leflunomide in the therapeutic strategy of BKPyVAN. It may be a part of the therapy to promote BK polyomavirus clearance in cases of BKPyVAN who fail to improve after immunosuppression lowering alone. Unfortunately, a significant decline in renal function and high rejection rates remain major clinical challenges.

VaccHemInf project: protocol for a prospective cohort study of efficacy, safety and characterisation of immune functional response to vaccinations in haematopoietic stem cell transplant recipients

INTRODUCTION

Immune reconstitution after haematopoietic stem cell transplantation (HSCT) is a complex and dynamic process, varying from a state of nearly complete immunosuppression to an expected full immune recovery. Specific vaccination guidelines recommend reimmunisation after HSCT but data regarding vaccine efficacy in this unique population are scarce. New immune functional assays could enable prediction of vaccine response in the setting of HSCT.

METHODS AND ANALYSIS

A prospective, longitudinal single-centre cohort study of autologous and allogeneic HSCT recipients was designed in order to determine the vaccine response to five vaccine targets (pneumococcus, hepatitis B virus, Haemophilus Influenzae type b, tetanus and diphtheria) and to correlate it to immune function parameters. A workflow was set up to study serological response to vaccines and to describe the functional immune status of 100 HSCT recipients (50 autologous and 50 allogeneic) before and 3, 12 and 24 months after primary immunisation. At each time point, 'basic' immune status recording (serology, immunophenotyping of lymphocyte subsets by flow cytometry) will be assessed. The immune response will furthermore be evaluated before and 3 months after primary vaccination by two ex vivo immune functional assays assessing: (1) tumour necrosis factor alpha, interferon gamma production and host messenger RNA expression on whole-blood stimulation by lipopolysaccharide or Staphylococcus aureus enterotoxin B and (2) T-lymphocyte proliferation in response to a standard mitogen (phytohaemagglutinin) or to selected recall antigens. Reference intervals will be determined from a cohort of 30 healthy volunteers. This translational study will provide data describing vaccine response, immune functionality of HSCT recipients over time and will allow mapping HSCT recipients with regard to their immune function.

ETHICS AND DISSEMINATION

Ethical approval has been obtained from the institutional review board (no 69HCL17_0769). Results will be communicated at scientific meetings and submitted for publication in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT03659773; Pre-results.

Infections after upper extremity allotransplantation: a worldwide population cohort study, 1998-2017

Risk-to-benefit analysis of upper extremity allotransplantation (UEA) warrants a careful assessment of immunosuppression-related complications. This first systematic report of infectious complications after UEA aimed to compare incidence and pattern of infections to that observed after kidney transplantation (KT). We conducted a matched cohort study among UEA and KT recipients from the International Registry on Hand and Composite Tissue Transplantation and the French transplant database DIVAT. All UEA recipients between 1998 and 2016 were matched with KT recipients (1:5) regarding age, sex, cytomegalovirus (CMV) serostatus and induction treatment. Infections were analyzed at three posttransplant periods (early: 0-6 months, intermediate: 7-12 months, late: >12 months). Sixty-one UEA recipients and 305 KT recipients were included. Incidence of infection was higher after UEA than after KT during the early period (3.27 vs. 1.95 per 1000 transplant-days, P = 0.01), but not statistically different during the intermediate (0.61 vs. 0.45/1000, P = 0.5) nor the late period (0.15 vs. 0.21/1000, P = 0.11). The distribution of infectious syndromes was significantly different, with mucocutaneous infections predominating after UEA, urinary tract infections and pneumonia predominating after KT. Incidence of infection is high during the first 6 months after UEA. After 1 year, the burden of infections is low, with favorable patterns.

A practical approach to tuberculosis diagnosis and treatment in liver transplant recipients in a low-prevalence area

Solid organ transplant candidates/recipients are at risk of mycobacterial infections. Although guidelines on the management of latent tuberculosis infection and active tuberculosis are available for solid organ transplant recipients, limited guidance focuses on end-stage liver disease or liver transplant recipients who require management in a referral center. Therapeutic challenges arise from direct antituberculosis drug-related hepatotoxicity, and substantial metabolic interactions between immunosuppressive and antituberculosis drugs. Another issue is the optimal timing of therapy with regards to the time of transplantation. This review focuses on the importance of tuberculosis screening with immunological tests, challenges in the diagnosis, management, and treatment of latent tuberculosis infection and active tuberculosis, as well as risk assessment for active tuberculosis in the critical peri-liver transplantation period. We detail therapeutic adjustments required for the management of antituberculosis drugs in latent tuberculosis infection and active tuberculosis, particularly when concomitantly using rifampicin and immunosuppressive drugs.

Salvage Debridement, Antibiotics and Implant Retention ("DAIR") With Local Injection of a Selected Cocktail of Bacteriophages: Is It an Option for an Elderly Patient With Relapsing Staphylococcus aureus Prosthetic-Joint Infection?

Local injection of a bacteriophages mix during debridement, antibiotics and implant retention ("DAIR") was performed to treat a relapsing Staphylococcus aureus chronic prosthetic joint infection (PJI). This salvage treatment was safe and associated with a clinical success. Scientific evaluation of the potential clinical benefit of bacteriophages as antibiofilm treatment in PJI is now feasible and required.

Prolonged Cefoxitin Infusion Using Mobile Elastomeric Infusors In Outpatients With Bone And Joint Infection

We reviewed all outpatients with bone and joint infection treated with cefoxitin in continuous intravenous infusion using mobile elastomeric infusors in our regional reference center between 2014 and 2017. The stability of cefoxitin provides an interesting and well-tolerated alternative for continuous infusion in outpatients with polymicrobial bone and joint infection.

Microbiologic epidemiology depending on time to occurrence of prosthetic joint infection: a prospective cohort study

OBJECTIVES

The high microbiologic diversity encountered in prosthetic joint infection (PJI) makes the choice of empirical antimicrobial therapies challenging, especially in cases of implant retention or one-stage exchange. Despite the risk of dysbiosis and toxicity, the combination of vancomycin with a broad-spectrum β-lactam is currently recommended in all cases, even if Gram-negative bacilli (GNB) might be less represented in late PJI. In this context, this study aimed to describe the microbiologic epidemiology of PJI according to the chronology of infection.

METHODS

This prospective cohort study (2011-2016) evaluated the microbiologic aetiology of 567 PJI according to time of occurrence from prosthesis implantation-early (<3 months), delayed (3-12 months) and late (>12 months)-as well as mechanism of acquisition.

RESULTS

Initial microbiologic documentation (n = 511; 90.1%) disclosed 164 (28.9%) Staphylococcus aureus (including 26 (16.1%) methicillin-resistant S. aureus), 162 (28.6%) coagulase-negative staphylococci (including 81 (59.1%) methicillin-resistant coagulase-negative staphylococci), 80 (14.1%) Enterobacteriaceae, 74 (13.1%) streptococci and 60 (10.6%) Cutibacterium acnes. Considering nonhaematogenous late PJI (n = 182), Enterobacteriaceae (n = 7; 3.8%) were less represented than in the first year after implantation (n = 56; 17.2%; p <0.001), without difference regarding nonfermenting GNB (4.6% and 2.7%, respectively). The prevalence of anaerobes (n = 40; 21.9%; including 32 (80.0%) C. acnes) was higher in late PJI (p <0.001). Consequently, a broad-spectrum β-lactam might be useful in 12 patients (6.6%) with late PJI only compared to 66 patients (20.3%) with early/delayed PJI (p <0.001).

CONCLUSIONS

Considering the minority amount of GNB in late postoperative PJI, the empirical use of a broad-spectrum β-lactam should be reconsidered, especially when a two-stage exchange is planned.