Inflammatory Type 2 cDCs Acquire Features of cDC1s and Macrophages to Orchestrate Immunity to Respiratory Virus Infection.

The phenotypic and functional dichotomy between IRF8+ type 1 and IRF4+ type 2 conventional dendritic cells (cDC1s and cDC2s, respectively) is well accepted; it is unknown how robust this dichotomy is under inflammatory conditions, when additionally monocyte-derived cells (MCs) become competent antigen-presenting cells (APCs). Using single-cell technologies in models of respiratory viral infection, we found that lung cDC2s acquired expression of the Fc receptor CD64 shared with MCs and of IRF8 shared with cDC1s. These inflammatory cDC2s (inf-cDC2s) were superior in inducing CD4+ T helper (Th) cell polarization while simultaneously presenting antigen to CD8+ T cells. When carefully separated from inf-cDC2s, MCs lacked APC function. Inf-cDC2s matured in response to cell-intrinsic Toll-like receptor and type 1 interferon receptor signaling, upregulated an IRF8-dependent maturation module, and acquired antigens via convalescent serum and Fc receptors. Because hybrid inf-cDC2s are easily confused with monocyte-derived cells, their existence could explain why APC functions have been attributed to MCs.

P75NTR+CD64+ neutrophils promote sepsis-induced acute lung injury.

Patients suffering from sepsis-induced acute lung injury (ALI) exhibit a high mortality rate, and their prognosis is closely associated with infiltration of neutrophils into the lungs. In this study, we found a significant elevation of CD64+ neutrophils, which highly expressed p75 neurotrophin receptor (p75NTR) in peripheral blood of mice and patients with sepsis-induced ALI. p75NTR+CD64+ neutrophils were also abundantly expressed in the lung of ALI mice induced by lipopolysaccharide. Conditional knock-out of the myeloid lineage's p75NTR gene improved the survival rates, attenuated lung tissue inflammation, reduced neutrophil infiltration and enhanced the phagocytic functions of CD64+ neutrophils. In vitro, p75NTR+CD64+ neutrophils exhibited an upregulation and compromised phagocytic activity in blood samples of ALI patients. Blocking p75NTR activity by soluble p75NTR extracellular domain peptide (p75ECD-Fc) boosted CD64+ neutrophils phagocytic activity and reduced inflammatory cytokine production via regulation of the NF-κB activity. The findings strongly indicate that p75NTR+CD64+ neutrophils are a novel pathogenic neutrophil subpopulation promoting sepsis-induced ALI.

Neutrophil CD64 index as a new early predictive biomarker for infected pancreatic necrosis in acute pancreatitis.

OBJECTIVE: Infectious pancreatic necrosis (IPN) is a serious complication of acute pancreatitis, and early recognition and timely intervention are the keys to improving clinical outcomes. The purpose of this study was to investigate the predictive capacity of the neutrophil CD64 index (nCD64 index) on IPN in patients with acute pancreatitis METHODS: This study comprises two independent cohorts: the training cohort consisted of 202 patients from Hunan Provincial People's Hospital, and the validation cohort consisted of 100 patients from Changsha Central Hospital. Peripheral blood samples were collected on the day of admission and on the 3rd, 5th, 7th, and 10th days of hospitalization, and the nCD64 index was detected by flow cytometry. Additionally, relevant clinical characteristics and laboratory biomarkers were collected and analyzed. RESULTS: We observed that nCD64 index on admission was significantly higher in the IPN group than Non-IPN group (p < 0.001). In the training cohort, a higher occurrence rate of IPN was observed in the high nCD64 index group compared to the moderate and low nCD64 index group (p < 0.001). Further analysis showed that nCD64 index was significant positive correlated with the incidence rate of IPN (p < 0.001, correlation coefficient = 0.972). Furthermore, logistic regression analysis showed that high expression of the nCD64 index on admission was a risk factor for the occurrence of IPN (OR = 2.971, p = 0.038). We further found that the nCD64 index of IPN patients was significantly higher than the Non-IPN patients on the days 1, 3, and 5 after admission, and the nCD64 index of IPN patients before and after the onset (p < 0.05). At the same time, this study revealed that the nCD64 index on admission showed good predictive efficacy for IPN (AUC = 0.859, sensitivity = 80.8%, specificity = 87.5%), which was comparable to APACHE II score. And this finding was further validated in an independent cohort of 100 participants (AUC = 0.919, Sensitivity = 100.0%, Specificity = 76.6%). CONCLUSION: This study demonstrated the clinical value of nCD64 index in patients with IPN patients for the first time through two independent cohort studies. The nCD64 index can be used as an early prediction and risk assessment tool for the occurrence of IPN, contributing to the improvement of patient outcomes and efficiency of medical resource allocation.

Prognostic performance of neutrophil CD64 expression in patients with complicated intra-abdominal infections - a prospective study.

No study yet analyzed the prognostic abilities of neutrophil CD64 expression (nCD64) in complicated intra-abdominal infections (cIAIs), therefore our aim was to evaluate the possible association between this biomarker and outcome in such patients. This single-center prospective study was conducted in the Department of Surgical Diseases at a University Hospital 'Prof. Dr. Stoyan Kirkovich' Stara Zagora for the period November 2018 - August 2021. We used flow cytometry to measure the percentage of nCD64 preoperatively and on the 3rd postoperative day (POD) in 62 patients with cIAIs and 31 healthy controls. Of the 62 enrolled patients, nine (14.5%) died during hospitalization. The perioperative expression of nCD64 was significantly higher in non-survivors compared to survivors (p = 0.02 before surgery and p = 0.024 after surgery). ROC Curve analysis revealed the good prognostic value of pre- and postoperative nCD64 levels as mortality predictors (AUROC = 0.744 and 0.765, respectively). Preoperatively, the identified sensitivity and specificity for nCD64 cut-off = 94.8% were 66.7% and 84.6%, respectively and on the 3rd POD for nCD64 cut-off = 84.85% we observed a sensitivity of 71.4% and a specificity of 78.8%. Neutrophil CD64 shows good prognostic value in patients with cIAIs both preoperatively and on the 3rd POD.

The role of proadrenomedullin, interleukin 6 and CD64 in the diagnosis and prognosis of septic shock.

INTRODUCTION: Sepsis and septic shock are disorders of tissue perfusion and microcirculation associated with increased mortality. The role of biomarkers such as proadrenomedullin (PRO-ADM), interleukin 6 (IL-6) and neutrophil CD64 (CD64) in the diagnosis and prognosis of septic shock has been studied. METHODS: GCS, SOFA score, APACHE 2 score, lactate, CRP, procalcitonin, PRO-ADM, IL-6, CD64 level and 28-day mortality were evaluated in patients with septic shock followed-up in the intensive care unit of Marmara University Hospital between July 2021 and December 2021. The study was planned as prospective, non-drug clinical research Committee. RESULTS: There were no statistically significant differences between patient groups in gender, BMI, and presence of comorbidities (p > 0.05). The alive patient group had significantly higher GCS values and lower SOFA, APACHE 2, lactate and CD64 values than the dead patient group (p < 0.01). The cut-off values of laboratory parameters were determined using ROC analysis to predict mortality, SOFA and CD64 had high AUC. This is also a good indicator for mortality.The multivariate logistic regression model was estimated using the backward selection method. The mortality of ICU patients was predicted by a SOFA-value ≥ 12 (OR (95%CI) = 56.13 (5.44-578.64)), CD64 value ≥ 28.54 (OR (95% CI) = 23.78 (2.61-216.85)), and ADM-value ≥ 86.79 (OR (95% CI) = 15.86 (1.02-246.49)) (p < 0.05) . CONCLUSION: In conclusion, serum CD64 level, PRO-ADM level, and SOFA score proved to be effective parameters for predicting prognosis and mortality in septic shock. However, IL-6 proved to be a weak biomarker and failed to predict mortality. CD64, which is easier and more practical to use, can be used instead of the SOFA score.

IgG antispike persistence and immunophenotype in children infected by SARS-CoV-2.

AIM: The immune status of children recovering from SARS-CoV-2 infection is not completely understood. We describe IgG antispike persistence in children infected during the first two pandemic waves. In addition, we compared with healthy controls their leukocyte populations and CD64 expression. METHODS: Cross-sectional study. Carried out from October 2021 to February 2022 in nonreinfected and nonvaccinated children with SARS-CoV-2 in 2020. The presence of antispike IgG was studied using chemiluminescent immunoassay. Leukocyte populations were analysed using flow cytometry and marked for CD45, CD4, CD8 and CD64. Statistical minor than 0.05 was considered significant. RESULTS: One hundred and eighty-three control and 77 patients were included. IgG antispike determinations were performed after a median of 501 days (262-464); 52 of 77 children were positive. Cases showed significantly higher percentages of monocytes, lymphocytes, CD8+ and CD4+ . In addition, CD64 expression was higher in monocytes and neutrophils. The presence of IgG antispike was accompanied by a higher percentage of CD64+ neutrophils. CONCLUSION: In our series, the SARS-CoV-2 IgG antispike protein was usually positive beyond 1 year after infection. Furthermore, leukocyte populations from cases differ from controls, with higher CD64 expression on neutrophils and monocytes. Prospective clinical observations are required to confirm the implications of these findings.

Monocyte HLADR and Immune Dysregulation Index as Biomarkers for COVID-19 Severity and Mortality.

Immune dysregulation in COVID-19 is the major causal factor associated with disease progression and mortality. Role of monocyte HLA-DR (mHLA-DR), neutrophil CD64 (nCD64) and Immune dysregulation index (IDI) were studied in COVID-19 patients for assessing severity and outcome. Results were compared with other laboratory parameters. Antibody bound per cell for mHLA-DR, nCD64 and IDI were measured in 100 COVID-19 patients by flow cytometry within 12 h of hospital admission. Thirty healthy controls (HC) were included. Clinical and laboratory parameters like C - reactive protein (CRP), Procalcitonin (PCT), Absolute Lymphocyte count (ALC), Absolute Neutrophil count (ANC) and Neutrophil to Lymphocyte ratio (NLR) were recorded. Patients were followed up until recovery with discharge or death. Parameters from 54 mild (MCOV-19), 46 severe (SCOV-19) and 30 HC were analysed. mHLA-DR revealed significant and graded down regulation in MCOV-19 and SCOV-19 as compared to HC whereas IDI was lowest in HC with increasing values in MCOV-19 and SCOV-19. For diagnostic discrimination of MCOV-19 and SCOV-19, IDI revealed highest AUC (0.99). All three immune parameters revealed significant difference between survivors (n = 78) and non-survivors (n = 22). mHLA-DR < 7010 and IDI > 12 had significant association with mortality. Four best performing parameters to identify patients with SCOV-19 at higher risk of mortality were IDI, NLR, ALC and PCT. mHLA-DR and IDI, in addition to NLR and ALC at admission and during hospital stay can be utilized for patient triaging, monitoring, early intervention, and mortality prediction. IDI reported for the first time in this study, appears most promising. Immune monitoring of 'in hospital' cases may provide optimized treatment options. Supplementary Information: The online version contains supplementary material available at 10.1007/s12291-022-01087-z.

Luminal bacteria coated with IgA and IgG during intestinal inflammation as a new and abundant stimulus for colonic macrophages.

In the gut, secretory immunoglobulin A is the predominant humoral response against commensals, although healthy hosts also produce microbiota-specific IgG antibodies. During intestinal inflammation, the content of IgG in the lumen increases along with the proportion of commensal bacteria coated with this antibody, suggesting signalling through the IgG-CD64 axis in the pathogenesis of inflammatory bowel diseases. In this work, we evaluated day by day the frequency of faecal bacteria coated with IgA and IgG during the development of DSS colitis. We studied the phenotype and phagocytic activity of F4/80+ CD64+ colonic macrophages, as well as the production of cytokines and nitric oxide by lamina propria or bone marrow-derived macrophages after stimulation with IgA+ , IgG+ and IgA+ IgG+ bacteria. We found that the percentage of faecal IgA+ IgG+ double-coated bacteria increased rapidly during DSS colitis. Also, analysis of the luminal content of mice with colitis showed a markedly superior ability to coat fresh bacteria. IgA+ IgG+ bacteria were the most potent stimulus for phagocytic activity involving CD64 and Dectin-1 receptors. IgA+ IgG+ bacteria observed during the development of DSS colitis could represent a new marker to monitor permeability and inflammatory progression. The interaction of IgA+ IgG+ bacteria with CD64+ F4/80+ macrophages could be part of the complex cascade of events in colitis. Interestingly, after stimulation, CD64+ colonic macrophages showed features similar to those of restorative macrophages that are relevant for tissue repair and healing.

Neutrophil CD64 index as a superior indicator for diagnosing, monitoring bacterial infection, and evaluating antibiotic therapy: a case control study.

BACKGROUND: Neutrophil CD64 (nCD64) index has been widely studied as an indication of bacteria-infected diseases, but the exact usage of nCD64 index in monitoring infections remains debated. So this study aims to investigate the functionality of nCD64 index in tracking infections' progression and evaluating antibiotic therapy. METHODS: 160 participants (36 healthy controls, 34 culture-negative patients, 56 respiratory tract infected patients, and 34 bloodstream infected patients) were recruited and divided into groups. Data on nCD64 index, T lymphocyte subsets, and conventional indicators, including white blood cell count, neutrophil to lymphocyte ratio, procalcitonin, and C-reactive protein, were tested and compared. RESULTS: Bacteria-infected patients had significantly higher nCD64 indexes (p < 0.05), especially patients with both bloodstream and respiratory tract infections. The nCD64 index could identify infected patients from culture-negative patients or controls, which conventional indicators cannot achieve. We followed up with 24 infected patients and found that their nCD64 indexes were promptly down-regulated after effective antibiotic therapy (3.16 ± 3.01 vs. 1.20 ± 1.47, p < 0.001). CONCLUSION: The nCD64 index is a sensitive indicator for clinical diagnosis of bacterial infection, especially in monitoring infection and evaluating antibiotics' efficacy. Therefore, nCD64 has the potential to improve diagnostic accuracy and provide rapid feedback on monitoring disease progression in infected patients.

Multi-marker approach using C-reactive protein, procalcitonin, neutrophil CD64 index for the prognosis of sepsis in intensive care unit: a retrospective cohort study.

BACKGROUND: We aimed to explore the prognostic utilities of C-reactive protein (CRP), procalcitonin (PCT), neutrophil CD64 (nCD64) index, in combination or alone, in septic patients. METHODS: We retrospectively included 349 septic patients (based on Sepsis 3.0 definition). The primary outcome was 28-day all-cause mortality. Cox regression model, receiver-operating characteristic (ROC) curve, reclassification analysis, Kaplan-Meier survival curves were performed to evaluate the predictive efficacy of the above parameters. RESULTS: CRP, nCD64 index were independent predictors of 28-day mortality for sepsis in the Cox regression model [CRP, HR 1.004 (95% CI 1.002-1.006), P < 0.001; nCD64 index, HR 1.263 (95% CI 1.187-1.345, P < 0.001]. Area under the ROC curve (AUC) of CRP, PCT, nCD64 index, nCD64 index plus PCT, nCD64 index plus CRP, were 0.798 (95% CI 0.752-0.839), 0.833 (95% CI 0.790-0.871), 0.906 (95% CI 0.870-0.935), 0.910 (95% CI 0.875-0.938), 0.916 (95% CI 0.881-0.943), respectively. nCD64 plus CRP performed best in prediction, discrimination, and reclassification of the 28-day mortality risk in sepsis. The risk of 28-day mortality increased stepwise as the number of data exceeding optimal cut-off values increased. CONCLUSIONS: nCD64 index combined with CRP was superior to CRP, PCT, nCD64 index and nCD64 index plus PCT in predicting 28-day mortality in sepsis. Multi-marker approach could improve the predictive accuracy and be beneficial for septic patients.

Neutrophil CD64 index for diagnosis of infectious disease in the pediatric ICU: a single-center prospective study.

BACKGROUND: Infection is a major cause of death in children, and it is particularly important to identify biological indicators of early infection. Previous studies showed that the neutrophil CD64 (nCD64) index may be a useful biomarker for infection. The purpose of this study was to investigate use of the nCD64 index to identify infection in children from a pediatric ICU (PICU) in China. METHODS: This prospective observational study enrolled 201 children who were admitted to our PICU and were divided into an infection group and a non-infection group. In each patient, C-reactive protein (CRP), nCD64 index, procalcitonin (PCT), and white blood cell count were measured during the first 24 h after admission. Receiver operating characteristic (ROC) analyses were used to determine the sensitivity, specificity, and diagnostic value of the nCD64 index for infection. RESULTS: Among all 201 children, the infection group had greater levels of CRP, nCD64 index, and PCT (all p < 0.05). ROC analysis indicated the nCD64 index had a sensitivity of 68.8%, specificity of 90.7%, accuracy of 80.5%, and an optimal cut-off value of 0.14, which had better diagnostic value than CRP or PCT. For children with postoperative fever, the nCD64 index also distinguished systemic inflammatory response syndrome (SIRS) from infection with accuracy of 79%. CONCLUSIONS: The nCD64 index is a useful biomarker for the diagnosis of early infection in children admitted to the PICU.

Serum and Synovial Biomarkers for Distinguishing Between Chronic Periprosthetic Joint Infections and Rheumatoid Arthritis: A Prospective Cohort Study.

BACKGROUND: Inflammatory responses in patients with active rheumatoid arthritis (RA) may lead to the current serum and synovial fluid biomarkers that misidentify chronic periprosthetic joint infection (PJI). We sought to investigate the expression of serum and synovial biomarkers in patients with active RA and to calculate thresholds for valuable biomarkers that distinguish between chronic PJI and active RA. METHODS: This prospective study was initiated to enroll 70 patients undergoing revision arthroplasty from January 2019 to January 2021, and 30 patients with active RA cumulative knee from August 2020 to March 2021. The Musculoskeletal Infection Society definition of PJI was utilized for the classification of cases as aseptic or infected. Serum d-dimer, erythrocyte sedimentation rate, C-reactive protein, and interleukin-6 (IL-6), as well as synovial IL-6, percentage of polymorphonuclear neutrophils, and CD64 index level were measured preoperatively. RESULTS: An increase in biomarker concentrations were observed in group C (active RA). Synovial fluid CD64 index exhibited good discriminatory power between group B (chronic PJI) and group C with an area under curve of 0.930. For the diagnosis of chronic PJI in the presence of active RA, the optimal threshold value of synovial CD64 index was 0.87, with a sensitivity of 82.86% and a specificity of 93.33%. CONCLUSION: Current serum biomarkers (erythrocyte sedimentation rate, C-reactive protein, IL-6, and d-dimer) did not apply to the diagnosis of suspected PJI with active RA. Fortunately, satisfactory results can be achieved by adjusting the threshold of synovial fluid biomarkers.

Diagnostic value of neutrophil CD64, procalcitonin, and interleukin-6 in sepsis: a meta-analysis.

BACKGROUND: The aim of the study was to conduct a meta-analysis to evaluate the accuracy of neutrophil CD64, procalcitonin (PCT), and interleukin-6 (IL-6) as markers for the diagnosis of sepsis in adult patients. METHODS: Various databases were searched to collect published studies on the diagnosis of sepsis in adult patients using neutrophil CD64, PCT, and IL-6 levels. Utilizing the Stata SE 15.0 software, forest plots and the area under the summary receiver operating characteristic curves were drawn. The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio, and area under the curve (AUC) were calculated. RESULTS: Fifty-four articles were included in the study. The pooled sensitivity, specificity, and AUC of neutrophil CD64 for the diagnosis of sepsis were 0.88 (95% confidence interval [CI], 0.81-0.92), 0.88 (95% CI, 0.83-0.91), and 0.94 (95% CI, 0.91-0.96), respectively. The pooled sensitivity, specificity, and AUC of PCT for the diagnosis of sepsis were 0.82 (95% CI, 0.78-0.85), 0.78 (95% CI, 0.74-0.82), and 0.87 (95% CI, 0.83-0.89), respectively. Subgroup analysis showed that the AUC for PCT diagnosis of intensive care unit (ICU) sepsis was 0.86 (95% CI, 0.83-0.89) and the AUC for PCT diagnosis of non-ICU sepsis was 0.82 (95% CI, 0.78-0.85). The pooled sensitivity, specificity, and AUC of IL-6 for the diagnosis of sepsis were 0.72 (95% CI, 0.65-0.78), 0.70 (95% CI, 0.62-0.76), and 0.77 (95% CI, 0.73-0.80), respectively. CONCLUSIONS: Of the three biomarkers studied, neutrophil CD64 showed the highest diagnostic value for sepsis, followed by PCT, and IL-6. On the other hand, PCT showed a better diagnostic potential for the diagnosis of sepsis in patients with severe conditions compared with that in patients with non-severe conditions.

Cell-Surface Biomarkers, C-Reactive Protein and Haematological Parameters for Diagnosing Late Onset Sepsis in Pre-term Neonates.

OBJECTIVE: To compare the diagnostic accuracy of white blood cell-surface biomarkers (CD64, CD11b and HLA-DR), C-reactive protein (CRP) and hematological parameters to diagnose definite sepsis among pre-term neonates presenting with suspected late-onset neonatal sepsis (LONS). DESIGN: This was a prospective, single-gate, diagnostic study in a Level III neonatal unit. Fifty-three neonates (gestation, <34 weeks) with LONS (onset, >72 age), were enrolled. Cell-surface biomarkers, CRP and haematological parameters were assayed at 0 and 48 h after onset. The reference standard was definite sepsis, defined as a positive blood culture with a non-contaminant organism. The index tests (cell-surface biomarkers, CRP and haematological parameters) were compared between subjects with or without 'definite sepsis'. The area under the receiver operator characteristics curves (AUC) generated for each index test at 0 and 48 h was compared. SETTING: Level III neonatal unit in a tertiary care institute. RESULTS: Of 53 enrolled pre-term infants, 24 had definite sepsis. Among all the index tests evaluated, CRP at 48 h had the highest AUC [0.82 (95% confidence interval, 0.69, 0.92)]. The expression of CD11b and HLA-DR was significantly reduced among the septic neonates. Among the cell-surface biomarkers, the maximum AUC was recorded for HLA-DR at 48 [0.68 (95% CI, 0.54, 0.81)]. Comparisons between index tests were not statistically significant. CONCLUSION: C-reactive protein is superior to other sepsis screen biomarkers and white blood cell-surface biomarkers in diagnosing culture-positive LONS among pre-term infants. CD64, CD11b and HLA DR as diagnostic tests in this group have limited discriminatory value. LAY SUMMARY: The diagnosis of neonatal blood stream infections is a challenge. In response to bacterial blood stream infections, white blood cells are known to produce an excess of certain types of specialized proteins on their surface, including CD64, CD11b and HLA-DR. In this study we evaluated the concentration of these cell-surface proteins for diagnosing blood stream infections in pre-mature newborn babies, whose onset of infection was beyond 72 h of life. We compared these tests against standard tests that are currently in clinical use, such as C-reactive protein and blood white cell counts. All tests were performed at the time of initially suspecting the infection and 48 h later. The gold standard against which all these tests were evaluated was blood culture, in which the offending bacteria are grown in specialized laboratory media. Of 53 pre-mature babies with suspected infection, 24 had blood culture-proven infection. Among all tests, C-reactive protein at 48 h had the best ability to distinguish definite infection from no infection. The expression of CD11b and HLA-DR was significantly reduced among infected neonates. We conclude that C-reactive protein is superior to white blood cell-surface proteins and white cell count in diagnosing definite late-onset infections among pre-term infants.

Celiac Disease Defined by Over-Sensitivity to Gliadin Activation and Superior Antigen Presentation of Dendritic Cells.

The autoimmune condition, Celiac Disease (CeD), displays broad clinical symptoms due to gluten exposure. Its genetic association with DQ variants in the human leukocyte antigen (HLA) system has been recognised. Monocyte-derived mature dendritic cells (MoDCs) present gluten peptides through HLA-DQ and co-stimulatory molecules to T lymphocytes, eliciting a cytokine-rich microenvironment. Having access to CeD associated families prevalent in the Czech Republic, this study utilised an in vitro model to investigate their differential monocyte profile. The higher monocyte yields isolated from PBMCs of CeD patients versus control individuals also reflected the greater proportion of dendritic cells derived from these sources following lipopolysaccharide (LPS)/ peptic-tryptic-gliadin (PTG) fragment stimulation. Cell surface markers of CeD monocytes and MoDCs were subsequently profiled. This foremost study identified a novel bio-profile characterised by elevated CD64 and reduced CD33 levels, unique to CD14++ monocytes of CeD patients. Normalisation to LPS stimulation revealed the increased sensitivity of CeD-MoDCs to PTG, as shown by CD86 and HLA-DQ flow cytometric readouts. Enhanced CD86 and HLA-DQ expression in CeD-MoDCs were revealed by confocal microscopy. Analysis highlighted their dominance at the CeD-MoDC membrane in comparison to controls, reflective of superior antigen presentation ability. In conclusion, this investigative study deciphered the monocytes and MoDCs of CeD patients with the identification of a novel bio-profile marker of potential diagnostic value for clinical interpretation. Herein, the characterisation of CD86 and HLA-DQ as activators to stimulants, along with robust membrane assembly reflective of efficient antigen presentation, offers CeD targeted therapeutic avenues worth further exploration.

Differential expression of CD64 in patients with Mycobacterium tuberculosis infection: A potential biomarker for clinical diagnosis and prognosis.

To evaluate the clinical utility of neutrophil (n)CD64 index to diagnose pulmonary tuberculosis (PTB) and extrapulmonary TB (ePTB) and to predict the outcome of Mycobacterium tuberculosis infection. We recruited 189 patients with active TB and 140 controls and measured the differential expression of nCD64 index using flow cytometry. The receiver operating characteristics (ROC) curve analysis was performed to estimate the diagnostic performance of the nCD64 index and T-SPOT.TB assay for the diagnosis of TB. Furthermore, we analysed whether the nCD64 index in patients with TB was correlated with inflammatory indicators. Finally, we assessed the prognosis of patients by following the dynamic changes of the nCD64 index once a week. The nCD64 index was significantly higher in active TB group (PTB and ePTB), than in the anti-TB and healthy controls (HC) groups. The sensitivity and specificity of nCD64 index for the differential diagnosis of PTB and pneumonia (PN) patients were 68.33% and 77.55%, respectively. The sensitivity and specificity of nCD64 index for the diagnosis of tuberculous meningitis (TBM) were 53.85% and 100%, respectively. Furthermore, there was a weak correlation between the nCD64 index and inflammatory indicators. More importantly, with the improvement in patient condition, the nCD64 index started to decline in the first week of anti-TB therapy and significantly decreased at 4 weeks after treatment. Our study demonstrated that the CD64 assay is a rapid, non-invasive and stable method for clinical application, and the nCD64 index can serve as a potential biomarker for the diagnosis and prognosis of TB.

Engineering the interactions between a plant-produced HIV antibody and human Fc receptors.

Plants can provide a cost-effective and scalable technology for production of therapeutic monoclonal antibodies, with the potential for precise engineering of glycosylation. Glycan structures in the antibody Fc region influence binding properties to Fc receptors, which opens opportunities for modulation of antibody effector functions. To test the impact of glycosylation in detail, on binding to human Fc receptors, different glycovariants of VRC01, a broadly neutralizing HIV monoclonal antibody, were generated in Nicotiana benthamiana and characterized. These include glycovariants lacking plant characteristic α1,3-fucose and ß1,2-xylose residues and glycans extended with terminal ß1,4-galactose. Surface plasmon resonance-based assays were established for kinetic/affinity evaluation of antibody-FcγR interactions, and revealed that antibodies with typical plant glycosylation have a limited capacity to engage FcγRI, FcγRIIa, FcγRIIb and FcγRIIIa; however, the binding characteristics can be restored and even improved with targeted glycoengineering. All plant-made glycovariants had a slightly reduced affinity to the neonatal Fc receptor (FcRn) compared with HEK cell-derived antibody. However, this was independent of plant glycosylation, but related to the oxidation status of two methionine residues in the Fc region. This points towards a need for process optimization to control oxidation levels and improve the quality of plant-produced antibodies.

Report of a new six-panel flow cytometry marker for early differential diagnosis of APL from HLA-DR negative Non-APL leukemia.

Although AML-M3 (APL) and HLA-DR negative non-APL are characterized by negative HLA-DR antigen, they are different entities with similar morphology in some cases. The aim of this study is the precise, differential diagnosis of APL from HLA-DR negative non-APL by flow cytometry to narrow the diagnosis window. Bone marrow or blood samples of 580 AML patients were analyzed, and flow cytometry and molecular analysis were performed for the diagnosis of blood disorders. In 105 HLA-DR negative AML patients, expression of HLA-DR, CD33, CD117, CD11b, CD64, CD34, CD9 and myeloperoxidase staining pattern were evaluated. Fifty-six patients were diagnosed with APL, and 49 patients were diagnosed with HLA-DR negative non-APL. The APL blasts expressed CD33, CD117, CD64, and CD9 in 100%, 80.3%, 94.6%, and 100% of the cases, respectively. HLA-DR negative non-APL blasts expressed CD33, CD117, CD64 and CD9 in 75.5%, 59.1%, 32.6%, and 73.4% of the cases, respectively. APL cells were negative for HLA-DR, CD11b, and CD34 in 96.4%, 94.6%, and 91.0%, respectively. Blasts in HLA-DR negative non M3-AML were negative for CD11b, CD117, and CD34 in 77.5%, 40.9%, and 22.4%, respectively. We also investigated myeloperoxidase (MPO) staining pattern and found strong diffuse reaction in APL cells while HLA-DR negative non-APL cells showed focal positive reaction. In all of the APL patients, except for one, PML/RARA translocation was positive, and in another case with HLA-DR negative non-APL, PML/RARA and other translocations were not detected. The six-panel combination profile rapidly and specifically identifies APL from other HLA-DR negative AML.

Autoantibody-induced internalization of CNS AQP4 water channel and EAAT2 glutamate transporter requires astrocytic Fc receptor.

Aquaporin-4 (AQP4) water channel-specific IgG distinguishes neuromyelitis optica (NMO) from multiple sclerosis and causes characteristic immunopathology in which central nervous system (CNS) demyelination is secondary. Early events initiating the pathophysiological outcomes of IgG binding to astrocytic AQP4 are poorly understood. CNS lesions reflect events documented in vitro following IgG interaction with AQP4: AQP4 internalization, attenuated glutamate uptake, intramyelinic edema, interleukin-6 release, complement activation, inflammatory cell recruitment, and demyelination. Here, we demonstrate that AQP4 internalization requires AQP4-bound IgG to engage an astrocytic Fcγ receptor (FcγR). IgG-lacking Fc redistributes AQP4 within the plasma membrane and induces interleukin-6 release. However, AQP4 endocytosis requires an activating FcγR's gamma subunit and involves astrocytic membrane loss of an inhibitory FcγR, CD32B. Interaction of the IgG-AQP4 complex with FcγRs triggers coendocytosis of the excitatory amino acid transporter 2 (EAAT2). Requirement of FcγR engagement for internalization of two astrocytic membrane proteins critical to CNS homeostasis identifies a complement-independent, upstream target for potential early therapeutic intervention in NMO.

[AN ADULT CASE OF PERIODIC FEVER, APHTHOUS STOMATITIS, PHARYNGITIS, AND ADENITIS (PFAPA) SYNDROME DEVELOPED IN CHILDHOOD AND DIAGNOSED AFTER PROGRESS MORE THAN 30 YEARS].

We report an adult case of periodic fever, aphthous stomatitis, pharyngitis, and adenitis (PFAPA) syndrome, who had a tonsillectomy at 10 years old and relapsed later. An early 40's-year-old man had been suffering from recurrent fever attack once in 1-2 months during childhood. He was accompanied by fever which was persist for several days, aphthous stomatitis, tongued tonsillitis with moss, pharyngitis, and submandibular lymphadenitis with tenderness. He was not doing well during fare-up. At the time of admission, CRP level was 12.5mg/dl and the remarkably increased expression of CD64 on neutrophils was found. Bacterial infections and collagen diseases were excluded by the several examinations. We suspected PFAPA syndrome, and treated with cimetidine, but cimetidine was not effective. At the time of flare up, administration of prednisolone was remarkably effective. We diagnosed PFAPA syndrome on the basis of clinical courses. Genetic analysis of responsible gene of familial Mediterranean fever, MEFV showed E148Q heterozygous mutation in exon 2.Since an adult case of PFAPA syndrome is likely to be made misunderstanding for infectious recurrent pharyngitis, it is important to note that we should consider PFAPA syndrome as a differential diagnosis when we meet with the adult patient of recurrent fever.