Analysis of 15 cases from a monocentric cohort of 307 liver abscesses.

BACKGROUND: Out of the context of haematological patients, Candida sp. is rarely retrieved from pyogenic liver abscesses (PLA). OBJECTIVES: Our objective was to assess the risk factors for occurrence, and clinical, microbiological characteristics, management and outcome of Candida pyogenic liver abscesses (C-PLA). PATIENTS/METHODS: We retrospectively analysed C-PLA cases and compared them to pyogenic liver abscesses exclusively due to bacteria (B-PLA) included in our monocentric database on liver abscesses. Unfavourable course was defined as the occurrence of a primary treatment failure (PTF), recurrence after an initial cure, or death within 3 months after diagnosis. RESULTS: Between 2010 and 2018, 15 C-PLA and 292 B-PLA were included. All C-PLA had a biliary origin and were polymicrobial. All patients with C-PLA had at least one comorbidity at risk for Candida infection and 7 (53.3%) presented with sepsis requiring an admission in intensive care unit. Median duration of antifungal treatment was 42 days [24-55]. In multivariate analysis, compared with B-PLA, a medical history of malignancy (OR 4.16; 95%CI 1.15-18.72) or liver abscess (OR 7.39; 95%CI 2.10-26.62), and sepsis with severity criteria (OR 3.52; 95%CI 1.07-11.90) were independently associated with the occurrence of C-PLA. In multivariate analysis, C-PLA was associated with a higher risk of recurrence (HR 3.08; 95%CI 1.38-11.22). CONCLUSION: Candida liver abscesses in non-neutropenic is a rare and severe disease. The high rate of recurrence should lead to discuss a more intensive treatment.

Control of acute myeloid leukemia by a trifunctional NKp46-CD16a-NK cell engager targeting CD123.

CD123, the alpha chain of the IL-3 receptor, is an attractive target for acute myeloid leukemia (AML) treatment. However, cytotoxic antibodies or T cell engagers targeting CD123 had insufficient efficacy or safety in clinical trials. We show that expression of CD64, the high-affinity receptor for human IgG, on AML blasts confers resistance to anti-CD123 antibody-dependent cell cytotoxicity (ADCC) in vitro. We engineer a trifunctional natural killer cell engager (NKCE) that targets CD123 on AML blasts and NKp46 and CD16a on NK cells (CD123-NKCE). CD123-NKCE has potent antitumor activity against primary AML blasts regardless of CD64 expression and induces NK cell activation and cytokine secretion only in the presence of AML cells. Its antitumor activity in a mouse CD123+ tumor model exceeds that of the benchmark ADCC-enhanced antibody. In nonhuman primates, it had prolonged pharmacodynamic effects, depleting CD123+ cells for more than 10 days with no signs of toxicity and very low inflammatory cytokine induction over a large dose range. These results support clinical development of CD123-NKCE.

Hypervirulent Klebsiella Pneumoniae, an Emerging Cause of Endogenous Endophthalmitis in A French Center: A Comparative Cohort Study.

INTRODUCTION: Klebsiella pneumoniae (KP) is the most common cause of endogenous endophthalmitis (EE) in Asia, but data in Europe are scarce. We describe eight cases of KP EE compared to a cohort of EE in a French center. METHODS: EE cases were retrospectively studied between January 2014 and January 2021. KP EE cases were analyzed to assess clinical, microbiological features, and outcome. RESULTS: Among the 33 EE cases identified, the first causative agent (24%, n = 8) was KP, mainly (7/8) with hypervirulent phenotype (hvKP). All but one of these cases occurred from December 2019 to January 2021. Contrary to non-KP patients, KP patients had multiple extraocular infective foci (p = .006), all presented with liver abscesses (p < .001), 50% had cerebral involvement (p = .13). Visual outcome was poor in both groups. CONCLUSION: KP is an emerging cause of EE in a French center, consistently associated with liver abscesses, frequent cerebral involvement, and predominance of hvKP strains.

Antitumor immunity induced by antibody-based natural killer cell engager therapeutics armed with not-alpha IL-2 variant.

Harnessing innate immunity is emerging as a promising therapeutic approach in cancer. We report here the design of tetraspecific molecules engaging natural killer (NK) cell-activating receptors NKp46 and CD16a, the ß-chain of the interleukin-2 receptor (IL-2R), and a tumor-associated antigen (TAA). In vitro, these tetraspecific antibody-based natural killer cell engager therapeutics (ANKETs) induce a preferential activation and proliferation of NK cells, and the binding to the targeted TAA triggers NK cell cytotoxicity and cytokine and chemokine production. In vivo, tetraspecific ANKETs induce NK cell proliferation and their accumulation at the tumor bed, as well as the control of local and disseminated tumors. Treatment of non-human primates with CD20-directed tetraspecific ANKET leads to CD20+ circulating B cell depletion, with minimal systemic cytokine release and no sign of toxicity. Tetraspecific ANKETs, thus, constitute a technological platform for harnessing NK cells as next-generation cancer immunotherapies.

Large retrospective study analysing predictive factors of primary treatment failure, recurrence and death in pyogenic liver abscesses.

PURPOSE: Pyogenic liver abscess (PLA) is a severe disease, which unfavourable evolution remains frequent. Our objective was to assess predictive factors of unfavourable outcome in patients with PLA. METHODS: We conducted a retrospective study in a French tertiary care centre. All patients admitted for PLA between 2010 and 2018 were included. Unfavourable course was defined as the occurrence of a primary treatment failure (PTF), recurrence of PLA after an initial cure, or death within 3 months after diagnosis. Hazard ratios (95% CI) were calculated with multivariable Cox proportional hazard models. RESULTS: 302 patients were included among which 91 (30.1%) patients had an unfavourable outcome because of PTF, recurrence or death in 55 (18.2%), 28 (9.2%) and 32 (10.6%) patients, respectively. Hepatic metastases (HR 2.08; 95% CI 1.04-4.15), a nosocomial infection (2.25; 1.14-4.42), portal thrombosis (2.12; 1.14-3.93), and the isolation of Enterococcus spp. (2.18; 1.22- 3.90) were independently associated with PTF. Ischemic cholangitis (6.30; 2.70-14.70) and the isolation of Streptococcus spp. (3.72; 1.36-10.16) were associated with the risk of recurrence. Charlson comorbidity index (HR 1.30 per one point; 95% CI 1.15-1.46; p < 0.001), portal thrombosis (3.53; 1.65-7.56) and the presence of multi-drug-resistant organisms (3.81; 1.73-8.40) were associated with mortality within 3 months following PLA diagnosis. PLA drainage was the only factor associated with a lower mortality (0.14; 0.06-0.34). CONCLUSION: Identification of specific risk factors may help to improve the management of PLA and to elaborate targeted recommendations according to patient's and disease's characteristics.

Exploiting Natural Killer Cell Engagers to Control Pediatric B-cell Precursor Acute Lymphoblastic Leukemia.

Natural killer (NK) cells represent a promising cell type in antitumor immunotherapy for efficacy and safety, particularly in the treatment of hematologic malignancies. NK cells have been shown to exert antileukemia activity in the context of haploidentical hematopoietic stem cell transplantation (haplo-HSCT). Products have been developed to boost the activation of NK cells only when cross-linked by tumor cells, avoiding any off-target effect. Here, we tested the in vitro effect of different NK-cell engagers (NKCE), which trigger either NKp46 or NKp30 together with CD16A, and target either CD19 or CD20 to induce killing of pediatric B-cell precursor acute lymphoblastic leukemia (BCP-ALL). Target cells were NALM-16 and MHH-CALL-4 cell lines and four primary leukemias, while effector cells were resting NK cells derived from healthy donors and pediatric patients with leukemia after αßT/B-depleted haplo-HSCT. The NK cell-resistant MHH-CALL-4 was efficiently killed using all NKCEs. Boosting of NK activity against MHH-CALL-4 was also evident by degranulation and IFNγ production. Because of the lack of CD20 and high expression of CD19 on primary BCP-ALL, we focused on NKCEs targeting CD19. NKp46- and NKp30-based NKCEs displayed similar potency at inducing NK-cell activity, even when challenged with primary BCP-ALL blasts. Their efficacy was shown also using NK cells derived from transplanted patients. NKCE-induced activation against BCP-ALL can override HLA-specific inhibitory interactions, although the strongest response was observed by the alloreactive NK-cell subset. These data support the therapeutic use of NKp46/CD16A/CD19-NKCE to fight refractory/relapsed leukemia in pretransplantation or posttransplantation settings.

Autoantibodies Neutralizing Type I Interferons in 20% of COVID-19 Deaths in a French Hospital.

Recent studies reported the presence of pre-existing autoantibodies (auto-Abs) neutralizing type I interferons (IFNs) in at least 15% of patients with critical COVID-19 pneumonia. In one study, these auto-Abs were found in almost 20% of deceased patients across all ages. We aimed to assess the prevalence and clinical impact of the auto-Abs to type I IFNs in the Seine-Saint-Denis district, which was one of the most affected areas by COVID-19 in France during the first wave. We tested for the presence of auto-Abs neutralizing type I IFNs in a cohort of patients admitted for critical COVID-19 pneumonia during the first wave in the spring of 2020 in the medicine departments at Robert Ballanger Hospital, Aulnay sous Bois. We found circulating auto-Abs that neutralized 100 pg/mL IFN-α2 and/or IFN-ω in the plasma (diluted 1/10) of 7.9% (11 of 139) of the patients hospitalized for critical COVID-19. The presence of neutralizing auto-Abs was associated with an increased risk of mortality, as these auto-Abs were detected in 21% of patients who died from COVID-19 pneumonia. Deceased patients with and without auto-Abs did not present overt clinical differences. These results confirm both the importance of type I IFN immunity in host defense against SARS-CoV-2 infection and the usefulness of detection of auto-Abs neutralizing type I IFNs in the management of patients.

Spontaneous and postsurgical/traumatic Klebsiella pneumoniae meningitis: two distinct clinico-microbiological entities.

OBJECTIVES: To analyze and compare the characteristics and outcomes of spontaneous meningitis (SM) versus postsurgical/traumatic meningitis (PSTM) due to Klebsiella pneumoniae. METHODS: A retrospective multicentric cohort study of all K. pneumoniae meningitis cases managed between January 2007 and May 2018 was carried out in seven university hospitals in the Paris area. The microbiological characteristics of 16 available K. pneumoniae isolates were further analyzed, and the genomes of seven of those isolated from SM were sequenced. RESULTS: Among 35 cases, 10 were SM and 25 were PSTM. SM cases more severe than PSTM cases, with higher septic shock (p = 0.004) and in-hospital mortality rates (p = 0.004). In contrast, relapse occurred in five patients from the PSTM group versus no patients from the SM group. All K. pneumoniae strains recovered from SM but none of those recovered from PSTM displayed hypervirulent phenotypic (positive string test) and genotypic (genes corresponding to capsular serotypes K1 or K2; virulence genes rmpA and iutA) characteristics (p < 0.0001). PSTM tended to be more frequently polymicrobial (p = 0.08) and caused by an extended-spectrum ß-lactamase producing strain (p = 0.08) than SM. CONCLUSIONS: SM and PSTM are two entities differing both from a clinical and a microbiological standpoint. SM appears to be a more serious infection, induced by hypervirulent K. pneumoniae strains.

Autoantibodies neutralizing type I interferons in 20% of COVID-19 deaths in a French hospital.

Recent studies reported the presence of pre-existing autoantibodies (auto-Abs) neutralizing type I interferons (IFNs) in at least 15% of patients with critical or severe COVID-19 pneumonia. In one study, these auto-Abs were found in almost 20% of deceased patients across all ages. We aimed to assess the prevalence and clinical impact of the auto-Abs to type I IFNs in Seine-Saint-Denis district, which was one of the most affected areas by COVID-19 in France during the first wave. We tested for the presence of auto-Abs neutralizing type I IFNs in a cohort of patients admitted for critical COVID-19 pneumonia during the first wave in the spring of 2020 in medicine departments at Robert Ballanger Hospital, Aulnay sous Bois. We found circulating auto-Abs that neutralized 100 pg/mL IFN-α2 and/or IFN-ω in plasma 1/10 in 7.9% (11 of 139) of patients hospitalized for critical COVID-19. The presence of neutralizing auto-Abs was associated with an increased risk of mortality as these auto-Abs were detected in 21% of patients who died from COVID-19 pneumonia. Deceased patients with and without auto-Abs did not present overt clinical differences. These results confirm both the importance of IFN-I immunity in host defense against SARS-CoV-2 infection and the usefulness of detection of auto-Abs neutralizing type I IFNs in the management of patients.

Combination blockade of KLRG1 and PD-1 promotes immune control of local and disseminated cancers.

Checkpoint blockade therapy is effective against many cancers; however, new targets need to be identified to treat patients who do not respond to current treatment or demonstrate immune escape. Here, we showed that blocking the inhibitory receptor Killer cell lectin-like receptor G1 (KLRG1) enhances anti-tumor immunity mediated by NK cells and CD8+ T cells. We found that loss of KLRG1 signaling alone significantly decreased melanoma and breast cancer tumor growth in the lungs of mice. In addition, we demonstrated that KLRG1 blockade can synergize with PD-1 checkpoint therapy to increase the therapeutic efficacy compared to either treatment alone. This effect was even observed with tumors that do not respond to PD-1 checkpoint therapy. Double blockade therapy led to significantly decreased tumor size, increased frequency and activation of CD8+ T cells, and increased NK cell frequency and maturation in the tumor microenvironment. These findings demonstrate that KLRG1 is a novel checkpoint inhibitor target that affects NK and T cell anti-tumor immunity, both alone and in conjunction with established immunotherapies.

Targeting MICA/B with cytotoxic therapeutic antibodies leads to tumor control.

Background: MICA and MICB are tightly regulated stress-induced proteins that trigger the immune system by binding to the activating receptor NKG2D on cytotoxic lymphocytes. MICA and MICB are highly polymorphic molecules with prevalent expression on several types of solid tumors and limited expression in normal/healthy tissues, making them attractive targets for therapeutic intervention. Methods: We have generated a series of anti-MICA and MICB cross-reactive antibodies with the unique feature of binding to the most prevalent isoforms of both these molecules. Results: The anti-MICA and MICB antibody MICAB1, a human IgG1 Fc-engineered monoclonal antibody (mAb), displayed potent antibody-dependent cellular cytotoxicity (ADCC) and antibody-dependent cellular phagocytosis (ADCP) of MICA/B-expressing tumor cells in vitro. However, it showed insufficient efficiency against solid tumors in vivo, which prompted the development of antibody-drug conjugates (ADC). Indeed, optimal tumor control was achieved with MICAB1-ADC format in several solid tumor models, including patient-derived xenografts (PDX) and carcinogen-induced tumors in immunocompetent MICAgen transgenic mice. Conclusions: These data indicate that MICA and MICB are promising targets for cytotoxic immunotherapy.

Effect of Tocilizumab in Hospitalized Patients with Severe COVID-19 Pneumonia: A Case-Control Cohort Study.

Tocilizumab, an anti-interleukin-6 receptor, administrated during the right timeframe may be beneficial against coronavirus-disease-2019 (COVID-19) pneumonia. All patients admitted for severe COVID-19 pneumonia (SpO2 ≤ 96% despite O2-support ≥ 6 L/min) without invasive mechanical ventilation were included in a retrospective cohort study in a primary care hospital. The treatment effect of a single-dose, 400 mg, of tocilizumab was assessed by comparing those who received tocilizumab to those who did not. Selection bias was mitigated using three statistical methods. Primary outcome measure was a composite of mortality and ventilation at day 28. A total of 246 patients were included (106 were treated with tocilizumab). Overall, 105 (42.7%) patients presented the primary outcome, with 71 (28.9%) deaths during the 28-day follow-up. Propensity-score-matched 84 pairs of comparable patients. In the matched cohort (n = 168), tocilizumab was associated with fewer primary outcomes than the control group (hazard ratio (HR) = 0.49 (95% confidence interval (95%CI) = 0.3-0.81), p-value = 0.005). These results were similar in the overall cohort (n = 246), with Cox multivariable analysis yielding a protective association between tocilizumab and primary outcome (adjusted HR = 0.26 (95%CI = 0.135-0.51, p = 0.0001), confirmed by inverse probability score weighting (IPSW) analysis (p < 0.0001). Analyses on mortality only, with 28 days of follow-up, yielded similar results. In this study, tocilizumab 400 mg in a single-dose was associated with improved survival without mechanical ventilation in patients with severe COVID-19.

Ocular Examinations and Investigation of Intraocular Pressure, Tear Production, Central Corneal Thickness, and Corneal Touch Threshold in a Captive Flock of Atlantic Puffins (Fratercula arctica).

Ocular examinations were completed on a group of 10 Atlantic puffins (Fratercula arctica), 5 males and 5 females that ranged in age from 8 months to older than 30 years. The exams consisted of intraocular pressure/rebound tonometry, tear production/phenol red thread test, central corneal thickness/ultrasound pachymetry, and corneal sensitivity/esthesiometry. On ocular examination, there were no corneal abnormalities observed. Bilateral cataracts were diagnosed in 8 puffins, 6 of which were considered incipient, focal subcapsular opacities. One bird had hypermature cataracts and was removed from the study and excluded from data analysis; the other birds had no evidence of ophthalmic pathology that would interfere with diagnostic results (n = 9). All results for 9 birds were included in the study, with the exception of 1 puffin's tear production, which was too low for accurate assessment and was excluded from data analysis. There were no significant differences between right and left eye measurements for intraocular pressure, corneal thickness, and corneal sensitivity. The median intraocular pressure for both eyes (OU) was 13 mm Hg with an interquartile range [IQR] of 12-15 mm Hg. The median corneal thickness OU was 241 µm, IQR 233-248 µm. The median corneal sensitivity OU was 1.13 cm, IQR 0.81-1.50 cm. There was a significant difference between right and left eye measurements for tear production (right eye median, 7.5 mm/15 s, IQR 6.5-9.3 mm/15 s; and left eye median, 5.0 mm/15 s, IQR 4.0-7.3 mm/15 s) (P= .03), with the right eye producing more tears than the left. However, 1 puffin was determined to be an outlier, and when removed, there was no longer a significant difference (OU median, 7.0 mm/15 s, IQR 4.6-8.0 mm/15 s) (P = .38). There was no significant difference between sex and intraocular pressure, tear production, and corneal sensitivity. However, there was a significant difference between sex and corneal thickness (P = .02), with males (left eye median, 249 µm, IQR 241-249 µm) having thicker corneas than females (left eye median, 236 µm, 234-238 µm). Although sample size precluded statistical testing, there appeared to be an association between opacities and increasing age. There were no associations between age and intraocular pressure, tear production, or corneal thickness. There was a moderate correlation between age and corneal sensitivity, with older birds showing decreased corneal sensitivity (r = -0.57). Although the sample size of 9 birds was small, these findings provide preliminary ranges for ocular parameters of Atlantic puffins.

Long-term results after elective laparoscopic surgery for colorectal cancer in octogenarians.

BACKGROUND: The aim of this study was to investigate the short- and long-term outcomes after elective laparoscopic surgery (LPS) for colorectal cancer patients over 80 years of age. METHODS: This was a retrospective study of all patients of 80 and above, who underwent elective colorectal resection, between January 2007 and January 2016. Data were analysed from a prospectively collected cancer database and cross checked with patient records. Determinants of survival were analysed using log-rank test and Kaplan-Meier curves. RESULTS: We identified 293 patients; 110 underwent LPS. LPS had significantly better overall survival (p = 0.0065) and disease-free survival (DFS) (p = 0.006). The LPS group also had a shorter length of stay (LOS)-9 vs 11 days (p < 0.00001), 90-day mortality-5.5 vs 13.7% (p = 0.03) and required fewer blood transfusions 22.7 vs 40.4% (p = 0.002), when compared to open surgery (OPS). There was no difference in 30-day mortality 1.8 vs 4.9% (p = 0.22), anastomotic leakage 2.3 vs 6% (p = 0.20) or post-operative complication rates 44.5 vs 50.8% (p = 0.30). CONCLUSIONS: LPS for patients in their 80s is characterised by better overall and DFS compared to open procedures and is associated with shorter post-operative LOS, and significantly lower 90-day mortality. Patients operated on laparoscopically also required fewer post-operative blood transfusions.

Severe toxoplasmosis imported from tropical Africa in immunocompetent patients: A case series.

BACKGROUND: Toxoplasmosis is a zoonosis caused by the protozoan Toxoplasma gondii. In immunocompetent patients the infection is usually benign. However, cases of severe and even lethal primo-infections are regularly reported in South America. In contrast, data from tropical Africa are fragmentary. METHODS: Data for French cases of severe toxoplasmosis acquired between 2013 and 2018, in tropical Africa and among immunocompetent patients were collected retrospectively in 2018. RESULTS: Four male patients with a mean age of 34-years were identified. All infections originated in West or Central Africa. The clinical presentations were heterogeneous: two patients had severe disseminated toxoplasmosis, of which one presented with chorioretinitis associated with myositis and the other with febrile pneumopathy; one patient presented with post-infectious acute cerebellar ataxia and the final case had general symptoms and skin manifestations. The diagnosis of acute toxoplasmosis was confirmed by serology in four patients. Molecular diagnosis confirmed T. gondii infection in three patients with Africa 1 as the dominant genotype. The infection was cured with anti-infective treatment in all four patients. Ocular sequelae were reported in the two patients with chorioretinitis. CONCLUSIONS: Imported cases of severe toxoplasmosis in immunocompetent patients are rare in France. However, this aetiology should be evoked rapidly in a patient with a severe infectious syndrome who has recently visited or originated from tropical Africa.

Multifunctional Natural Killer Cell Engagers Targeting NKp46 Trigger Protective Tumor Immunity.

Over the last decade, various new therapies have been developed to promote anti-tumor immunity. Despite interesting clinical results in hematological malignancies, the development of bispecific killer-cell-engager antibody formats directed against tumor cells and stimulating anti-tumor T cell immunity has proved challenging, mostly due to toxicity problems. We report here the generation of trifunctional natural killer (NK) cell engagers (NKCEs), targeting two activating receptors, NKp46 and CD16, on NK cells and a tumor antigen on cancer cells. Trifunctional NKCEs were more potent in vitro than clinical therapeutic antibodies targeting the same tumor antigen. They had similar in vivo pharmacokinetics to full IgG antibodies and no off-target effects and efficiently controlled tumor growth in mouse models of solid and invasive tumors. Trifunctional NKCEs thus constitute a new generation of molecules for fighting cancer. VIDEO ABSTRACT.

Blocking Antibodies Targeting the CD39/CD73 Immunosuppressive Pathway Unleash Immune Responses in Combination Cancer Therapies.

Immune checkpoint inhibitors have revolutionized cancer treatment. However, many cancers are resistant to ICIs, and the targeting of additional inhibitory signals is crucial for limiting tumor evasion. The production of adenosine via the sequential activity of CD39 and CD73 ectoenzymes participates to the generation of an immunosuppressive tumor microenvironment. In order to disrupt the adenosine pathway, we generated two antibodies, IPH5201 and IPH5301, targeting human membrane-associated and soluble forms of CD39 and CD73, respectively, and efficiently blocking the hydrolysis of immunogenic ATP into immunosuppressive adenosine. These antibodies promoted antitumor immunity by stimulating dendritic cells and macrophages and by restoring the activation of T cells isolated from cancer patients. In a human CD39 knockin mouse preclinical model, IPH5201 increased the anti-tumor activity of the ATP-inducing chemotherapeutic drug oxaliplatin. These results support the use of anti-CD39 and anti-CD73 monoclonal antibodies and their combination with immune checkpoint inhibitors and chemotherapies in cancer.

Anti-NKG2A mAb Is a Checkpoint Inhibitor that Promotes Anti-tumor Immunity by Unleashing Both T and NK Cells.

Checkpoint inhibitors have revolutionized cancer treatment. However, only a minority of patients respond to these immunotherapies. Here, we report that blocking the inhibitory NKG2A receptor enhances tumor immunity by promoting both natural killer (NK) and CD8+ T cell effector functions in mice and humans. Monalizumab, a humanized anti-NKG2A antibody, enhanced NK cell activity against various tumor cells and rescued CD8+ T cell function in combination with PD-x axis blockade. Monalizumab also stimulated NK cell activity against antibody-coated target cells. Interim results of a phase II trial of monalizumab plus cetuximab in previously treated squamous cell carcinoma of the head and neck showed a 31% objective response rate. Most common adverse events were fatigue (17%), pyrexia (13%), and headache (10%). NKG2A targeting with monalizumab is thus a novel checkpoint inhibitory mechanism promoting anti-tumor immunity by enhancing the activity of both T and NK cells, which may complement first-generation immunotherapies against cancer.