Immunological characteristics and possible pathogenic role of urinary CD11c+ macrophages in lupus nephritis.

OBJECTIVES: Kidney-infiltrating immune cells can contribute to the pathogenesis of lupus nephritis (LN). We investigated the immunological characteristics of CD11c+ macrophages and their functions associated with the pathogenesis of LN. METHODS: CD11c+ macrophages were examined in the urine samples of patients with LN. Phenotypic markers and pro-inflammatory cytokine expression levels were analysed by flow cytometry. To determine the origin of urinary macrophages, peripheral monocytes were treated with sera from patients with systemic lupus erythematosus (SLE). The pathogenic role of CD11c+ macrophages in tubulointerstitial damage was investigated using SLE sera-treated monocytes and HK-2 cells. RESULTS: Urinary CD11c+ macrophages expressed pro-inflammatory cytokines, such as IL-6 and IL-1ß, and resembled infiltrated monocytes rather than tissue-resident macrophages with respect to surface marker expression. CD11c+ macrophages had high expression levels of the chemokine receptor CXCR3, which were correlated with cognate chemokine IP-10 expression in urinary tubular epithelial cells. When treated with sera from SLE patients, peripheral monocytes acquired the morphological and functional characteristics of urinary CD11c+ macrophages, which was blocked by DNase treatment. Finally, SLE sera-treated monocytes induced fibronectin expression, apoptosis and cell detachment in HK-2 cells via production of IL-6. CONCLUSION: CD11c+ macrophages may be involved in the pathogenesis of tubulointerstitial injury in LN.

Dynamic changes in circulating PD-1+CD8+ T lymphocytes for predicting treatment response to PD-1 blockade in patients with non-small-cell lung cancer.

BACKGROUND: The predictive value of immune monitoring with circulating CD8+ T lymphocytes for treatment response to programmed cell death protein 1 (PD-1) inhibitors has not been explored in non-small-cell lung cancer (NSCLC), prompting us to investigate whether dynamic changes in PD-1+CD8+ T lymphocytes have predictive value for durable clinical benefit (DCB) and survival after PD-1 blockade. METHODS: Patients with recurrent and/or metastatic NSCLC treated with PD-1 inhibitors were enrolled (discovery cohort; n = 94). Peripheral blood was obtained immediately before and after one cycle of treatment with PD-1 blockade. Phenotyping of circulating CD8+ T lymphocytes was conducted using multi-colour flow cytometry. Predictive values of dynamic changes in circulating PD-1+CD8+ T lymphocytes during the first cycle were validated in an independent cohort (validation cohort; n = 54) of a prospective trial with a PD-1 inhibitor (NCT03486119). RESULTS: Circulating PD-1+CD8+ T lymphocytes were enriched with effector/memory populations with elevated expression of activation- and exhaustion-related markers. Reduction in the frequency of PD-1+ cells among CD8+ T lymphocytes after one cycle of treatment was associated with a higher probability of DCB and superior survival outcomes in the discovery cohort. Similar results were obtained in the analysis of tumour antigen NY-ESO-1-specific CD8+ T lymphocytes and the validation cohort. Mechanistically, PD-1 molecule expression on CD8+ T lymphocytes suppresses the effector functions of tumour antigen-specific CD8+ T lymphocytes. CONCLUSIONS: Dynamic changes in circulating PD-1+CD8+ T lymphocytes predict clinical, and survival benefit from PD-1 blockade treatment in NSCLC, providing a useful tool to identify patient subgroups who will optimally benefit from PD-1 inhibitors.

Synovial fluid CD69+CD8+ T cells with tissue-resident phenotype mediate perforin-dependent citrullination in rheumatoid arthritis.

OBJECTIVES: Although the importance of tissue-resident memory T (TRM) cells in organ-specific chronic inflammation has been recognised, little is known about their role in rheumatoid arthritis (RA). Here, we examined the characteristics of synovial fluid CD8+ T cells that express canonical TRM markers CD69 and CD103, and their role in the pathogenesis of RA. METHODS: Synovial fluid mononuclear cells (SFMCs) were obtained from patients with RA. Flow cytometric analysis of surface markers and cytotoxic molecules of CD8+ T cells was performed. TCR repertoire of CD8+ T cells was analysed by TCRVß CDR3 sequencing. Citrullination with the formation of neutrophil extracellular trap (NET) was evaluated by immunofluorescence staining. RESULTS: The frequency of CD8+ T cells was increased in SFMCs, and these CD8+ T cells were primarily comprised of CD45RA- memory T cells expressing CD69 and/or CD103. CD69+CD8+ T cells exhibited TRM phenotypes, including upregulation of CXCR6, CD49a and CD101, and downregulation of S1PR1 and KLF2. TCR repertoire analysis showed that these cells were an oligoclonally expanded population with increased expression of cytotoxic molecules. The treatment of neutrophils with supernatant from IL-15-stimulated CD69+CD8+ T cells induced perforin-mediated histone citrullination and NET formation irrespective of their CD103 expression. The frequency of perforin-expressing cells among CD69+CD8+ T cells in SFMCs was significantly higher in patients with anti-citrullinated protein antibody (ACPA) than in those without ACPA. CONCLUSION: CD69+CD8+ T cells in the SFMCs of RA patients exhibit TRM-like features. These cells may participate in the pathogenesis of RA via perforin-mediated citrullination.

Platelet-enriched fibrin glue and platelet-rich plasma in the repair of bone defects adjacent to titanium dental implants.

PURPOSE: The aim of this study was to compare the effects of platelet-enriched fibrin glue and platelet-rich plasma (PRP) on the repair of bone defects adjacent to titanium dental implants. MATERIALS AND METHODS: In 6 mongrel dogs, 3 screw-shaped titanium dental implants per dog were placed into the osteotomy sites in the tibia. Before implantation, a standardized gap (2.0 mm) was created between the implant surface and the surrounding bone walls. Six gaps were left empty (control group), 6 gaps were filled with autogenous particulate bone mixed with PRP (PRP group), and 6 gaps were filled with autogenous particulate bone mixed with platelet-enriched fibrin glue (fibrin glue group). RESULTS: After 6 weeks, the bone-implant contact was 59.7% in the fibrin glue group, 29.2% in the PRP group, and 10.2% in the control defects; this difference was statistically significant (P < .05). DISCUSSION AND CONCLUSION: Greater bone-implant contact was achieved with platelet-enriched fibrin glue than with PRP. The results indicate that platelet-enriched fibrin glue can induce a stronger peri-implant bone reaction than PRP in the treatment of bone defects adjacent to titanium dental implants.

Nerve regeneration with the use of a poly(l-lactide-co-glycolic acid)-coated collagen tube filled with collagen gel.

AIM: The aim of this study was to develop a novel artificial nerve conduit and to evaluate its efficiency based on the promotion of peripheral nerve regeneration in rabbits. MATERIAL AND METHODS: The nerve conduit was made of a poly (l-lactide-co-glycolic acid)-coated collagen tube filled with collagen gel. The conduits were implanted into a 15 mm gap in the peroneal nerves of five rabbits. On the contralateral side, the defects were bridged with collagen-filled vein grafts. RESULTS: Twelve weeks postoperatively nerve regeneration was superior to the vein graft in the PLGA-coated collagen tube, both morphologically and electrophysiologically. CONCLUSION: The results indicate the superiority of the PLGA-coated collagen tube over vein grafts. Furthermore, they show that entubulation repair with this type of tube can support nerve regeneration over a nerve gap distance of at least 15 mm.

Cyanoacrylate adhesive for closing sinus membrane perforations during sinus lifts.

INTRODUCTION: Sinus lift procedures depend greatly on fragile structures and anatomical variations. The procedure may cause sinus membrane perforations, which can lead to graft infection and early failure. AIM: To assess the efficacy of cyanoacrylate adhesive in the management of large perforations of the maxillary sinus membrane during sinus lifts. MATERIAL AND METHODS: Six rabbits were used in the study. Sinus membrane perforations (about 1.5 cm in length) were repaired with cyanoacrylate adhesive on one side of the maxillary sinus. On the contralateral side, an identical laceration was not repaired. Histological evaluation was performed 2 weeks after the operation. RESULTS: Wounds repaired with cyanoacrylate adhesive showed newly formed continuous epithelium across the previous perforation site and there was sinusitis on the contralateral side. CONCLUSION: These results support the clinical use of cyanoacrylate adhesive for repairing sinus membrane perforations.

Vertical alveolar ridge augmentation using autogenous bone grafts and platelet-enriched fibrin glue with simultaneous implant placement.

OBJECTIVE: The aim of this study was to evaluate the combined use of autogenous bone and platelet-enriched fibrin glue as grafting material for vertical alveolar ridge augmentation with simultaneous implant placement in a canine alveolar ridge defect model. STUDY DESIGN: In 6 mongrel dogs, bilateral vertical alveolar ridge defects were created in the mandible. After 3 months of healing, 2 dental implants were placed in each defect of the mandible, creating 6-mm supra-alveolar peri-implant defects. The 2 implants per defect were subjected to surgical treatments involving either a combination of autogenous bone grafts and platelet-enriched fibrin glue, or a conventional flap procedure only (control). After a healing period of 6 months, the dogs were humanely killed for histological and histometric analyses. RESULTS: Implant placement alone produced limited vertical alveolar height (0.6 +/- 0.4 mm). However, alveolar augmentation including a combination of autogenous bone grafts and platelet-enriched fibrin glue with simultaneous implant placement resulted in alveolar ridge augmentation amounting to 4.2 +/- 1.0 mm, comprising 63% of the defect height. New bone-implant contact was 40.5% in the defects treated with combined autogenous bone grafts and platelet-enriched fibrin glue, and was 48.4% in the resident bone; this difference was not statistically significant. CONCLUSION: The present study demonstrates that vertical alveolar ridge augmentation using autogenous bone grafts and platelet-enriched fibrin glue with simultaneous implant placement might effectively increase vertical alveolar ridge height and allow for an acceptable level of osseointegration.

A retrospective study of the effects on sinus complications of exposing dental implants to the maxillary sinus cavity.

OBJECTIVE: The aim of this study was to investigate whether dental implant exposure to the maxillary sinus cavity increased the risk of maxillary sinus complications. STUDY DESIGN: Nine patients with 23 implants that had been inserted into the maxillary sinus more than 4 mm without lifting the sinus mucous membranes were evaluated for sinus complications 6 to 10 months after implant insertion, using a questionnaire and computerized tomography (CT). RESULTS: There were no clinical signs of sinusitis in any patient. However, CT scans showed postoperative sinus mucous thickening around 14 of the 23 implants. CONCLUSION: This study showed that implant exposure to the maxillary sinus cavity can cause sinus mucous thickening around the implants.

The effect of platelet-rich plasma on bone healing around implants placed in bone defects treated with Bio-Oss: a pilot study in the dog tibia.

OBJECTIVE: The aim of this study was to examine the influence of platelet-rich plasma (PRP) used as an adjunct to Bio-Oss for the repair of bone defects adjacent to titanium dental implants. STUDY DESIGN: In 6 mongrel dogs, 12 screw-shaped titanium dental implants were inserted into the osteotomy sites in the dogs' tibias. Before implantation, a standardized gap (2.0 mm) was created between the implant surface and the surrounding bony walls. The gaps were filled with either Bio-Oss cancellous granules alone or Bio-Oss cancellous granules mixed with PRP. RESULTS: After 4 months, the Bio-Oss-treated defects revealed a significantly higher percentage of bone-implant contact than the defects treated with Bio-Oss and PRP (60.1% vs. 30.8%; P < .05). CONCLUSION: The results indicate that when PRP is used as an adjunct to Bio-Oss in the repair of bone defects adjacent to titanium dental implants, PRP may decrease periimplant bone healing.

Maxillary sinus floor augmentation using autogenous bone grafts and platelet-enriched fibrin glue with simultaneous implant placement.

OBJECTIVE: The aim of this study was to evaluate the use of autogenous bone in combination with platelet-enriched fibrin glue as a grafting material for maxillary sinus augmentation with simultaneous implant placement in dogs. STUDY DESIGN: The mucous membranes of 12 sinuses in 6 dogs were elevated bilaterally. In the right sinus, autogenous bone mixed with platelet-enriched fibrin glue was grafted into the space between the membrane and the sinus wall. In the left sinus, autogenous bone alone was grafted as a control. At the same time, 2 dental implants were inserted into the grafting material through the maxillary sinus floor. The animals were killed 6 months after surgery. RESULTS: The mean bone-implant contact was 40.5% on the fibrin glue side and 32.3% on the control side (P < .05). The mean height of newly formed bone in the augmented area was 12.2 mm on the fibrin glue side and 10.7 mm on the control side (P < .05). CONCLUSION: The results indicate that the use of autogenous bone mixed with platelet-enriched fibrin glue can achieve results superior to those for grafts of autogenous bone alone. The specific improvements of this technique include enhanced osseointegration of dental implants and increased height of new bone.

Flapless implant surgery: an experimental study.

OBJECTIVE: The purpose of this study was to examine the effect of flapless implant surgery on crestal bone loss and osseointegration in a canine mandible model. STUDY DESIGN: In 6 mongrel dogs, bilateral, edentulated, flat alveolar ridges were created in the mandible. After 3 months of healing, 2 implants in each side were placed by either flap or flapless procedures. After a healing period of 8 weeks, microcomputerized tomography at the implantation site was performed. Osseointegration was calculated as percentage of implant surface in contact with bone. Additionally, bone height was measured in the peri-implant bone. RESULTS: The mean osseointegration was greater at flapless sites (70.4%) than at sites with flaps (59.5%) (P < .05). The mean peri-implant bone height was greater at flapless sites (10.1 mm) than at sites with flaps (9.0 mm) (P < .05). CONCLUSION: Flapless surgery can achieve results superior to surgery with reflected flaps. The specific improvements of this technique include enhanced osseointegration of dental implants and increased bone height.

Treatment of experimental peri-implantitis using autogenous bone grafts and platelet-enriched fibrin glue in dogs.

OBJECTIVE: The purpose of this study was to evaluate the effects of autogenous bone grafts and platelet-enriched fibrin glue in the treatment of peri-implantitis. STUDY DESIGN: Thirty-six screw-type commercially pure titanium implants with rough acid-etched surfaces were inserted into 6 mongrel dogs 3 months after extraction of mandibular premolars. After 3 months of healing, peri-implantitis was induced by placing gauze and wire around the implants. Once peri-implantitis was created, surgical treatments involving a combination of autogenous bone grafts and platelet-enriched fibrin glue, autogenous bone grafts alone, or a conventional flap procedure only (control) were carried out. Six months later, biopsies of the implant sites were taken and prepared for ground sectioning and analysis. RESULTS: The amount of reosseointegration was significantly higher in peri-implantitis defects treated with combined autogenous bone grafts and platelet-enriched fibrin glue as compared with the other 2 treatment procedures. A mean bone-to-implant contact of 50.1% was obtained in the peri-implantitis lesions treated with combined autogenous bone grafts and platelet-enriched fibrin glue. The corresponding values for the autogenous bone grafts and control groups were 19.3% and 6.5%, respectively. CONCLUSION: The present study demonstrates that surgical treatment involving the combined use of autogenous bone grafts and platelet-enriched fibrin glue might effectively promote reosseointegration in lesions resulting from peri-implantitis.

The use of autologous fibrin glue for closing sinus membrane perforations during sinus lifts.

Sinus lift procedures depend greatly on fragile structures and anatomical variations. These procedures may cause sinus membrane perforations, which can lead to graft infection and early failure. The aim of this study was to assess the efficacy of autologous fibrin glue in the management of large perforations of the maxillary sinus membrane occurring during sinus lifts. After elevating the sinus membrane in the bilateral maxillary sinuses of 6 adult female mongrel dogs, a laceration (about 2.0 cm in length) was made in the membrane and either repaired with autologous fibrin glue or covered with a bioabsorbable collagen membrane as a control. Wounded areas were biopsied 2 weeks after the operation. Wounds repaired with autologous fibrin glue showed newly formed continuous epithelium across the previous perforation site. However, extensive fibrosis, inflammatory infiltration, and absent epithelium were observed in wounds treated with the collagen membrane control. Our results support the clinical use of autologous fibrin glue for repairing sinus membrane perforations.

The effect of platelet-enriched fibrin glue on bone regeneration in autogenous bone grafts.

OBJECTIVE: The aim of this study was to examine the ability of platelet-enriched fibrin glue to enhance bone formation in critically sized defects in the dog mandible. STUDY DESIGN: Seven adult female mongrel dogs underwent continuity resections on both sides of the mandible; 1 defect was reconstructed with the original particulate bone mixed with platelet-enriched fibrin glue, and as a control the contralateral defect was reconstructed with the original particulate bone alone. RESULTS: Biopsies after 6 weeks showed that the addition of platelet-enriched fibrin glue enhanced new bone formation in the autogenous bone grafts. CONCLUSION: Our data suggest that fibrin nets formed by fibrinogen, in combination with growth factors present in platelet-enriched fibrin glue, might effectively promote bone healing at bone graft sites.

A comparative qualitative histological analysis of tissue-engineered bone using bone marrow mesenchymal stem cells, alveolar bone cells, and periosteal cells.

For tissue-engineered bone formation, autogenous osteogenic cells are of paramount importance for successful bone formation. In order to investigate the donor cell-related differences in tissue-engineered bone, cultured bone marrow mesenchymal stem cells, cultured alveolar bone cells, and cultured periosteal cells were examined for their in vivo potential to form bone. These cells were isolated from dogs, expanded in vitro, mixed with autologous fibrin glue and BMP-2, and then injected into the subcutaneous space on the dorsum of nude mice. Bone formation was evaluated at 12 weeks. Histomorphometric analysis demonstrated that the subcutaneous nodules formed in nude mice contained 26.9% newly formed bone when using the bone marrow mesenchymal stem cells, 41.1% newly formed bone when using the alveolar bone cells, and 58.2% newly formed bone when using the periosteal cells. The results suggest that periosteal cells are the best choice for enhancing bone formation in tissue engineering of bone regeneration.

A comparative histologic analysis of tissue-engineered bone using platelet-rich plasma and platelet-enriched fibrin glue.

OBJECTIVE: The aim of this study was to compare the effects of platelet-rich plasma (PRP) and platelet-enriched fibrin glue on bone formation in bone tissue engineering. STUDY DESIGN: PRP was mixed with bone marrow mesenchymal stem cells and bone morphogenetic protein-2 (BMP-2), and the composites were injected into the subcutaneous space on the dorsum of nude mice. On the contralateral side of the dorsum, platelet-enriched fibrin glue/bone marrow mesenchymal stem cells/BMP-2 composites were injected. Bone formation was evaluated after 12 weeks. RESULTS: The volumes of subcutaneous nodules formed in nude mice were 55 +/- 18 microL at the PRP/bone marrow mesenchymal stem cells/BMP-2 sites and 135 +/- 27 microL at the platelet-enriched fibrin glue/bone marrow mesenchymal stem cells/BMP-2 sites. Histomorphometric analysis demonstrated that the nodules contained 14.9 +/- 4.1% newly formed bone when using PRP and 19.8 +/- 3.6% newly formed bone when using platelet-enriched fibrin glue. CONCLUSION: The results indicated that the osteogenic characteristics of platelet-enriched fibrin glue are superior to PRP in bone tissue engineering.

Bridging mandibular continuity defects with miniplates: an experimental study.

Various miniplate fixation techniques were studied in dogs to determine whether the use of miniplate fixation provides sufficient stability in mandibular continuity defects. Continuity resections measuring 15 mm were made on the mandibles of 16 dogs and were bridged using 4 miniplate fixation techniques, each replicated 4 times. All dogs were placed on a normal diet throughout the postoperative period. Clinical and radiological examinations were carried out 6 weeks later. We found that the group with both double miniplates and bicortical screws was stable, whereas the groups utilizing either a single miniplate or monocortical screws were not. The results of this study indicate that using a combination of double miniplates and bicortical screws to bridge defects after mandibular resection produces stable and predictable results.

The effects of exposing dental implants to the maxillary sinus cavity on sinus complications.

OBJECTIVE: The aim of this study was to investigate whether dental implant exposure to the maxillary sinus cavity increases the risk of maxillary sinus complications. STUDY DESIGN: An implant was placed bilaterally in the maxillary sinus of 8 adult female mongrel dogs in a way that it penetrated the bone and mucous membrane of the maxillary sinus floor to the extent of 2 mm, 4 mm, or 8 mm. The implants were left in place for 6 months. RESULTS: Radiographic and histologic examinations did not show any signs of pathologic findings in the maxillary sinus of the 8 dogs. CONCLUSION: This study indicates that implant protrusion into the maxillary sinus cavity is not related to the development of sinus complications in canines.

The need for intermaxillary fixation in sagittal split osteotomy setbacks with bicortical screw fixation.

OBJECTIVE: The aim of this study was to decide whether use of bicortical screw fixation provides sufficient stability to dispense with intermaxillary fixation (IMF). STUDY DESIGN: Eighty-six patients who had undergone surgical setback of the mandible using bilateral sagittal split ramus osteotomies were examined. Group 1 (15 patients) received miniplate fixation with IMF for 6 weeks, and group 2 (71 patients) received bicortical screw fixation and immediate postoperative function. The 2 groups were evaluated radiographically for postsurgical changes of the pogonion 24 months postoperatively. RESULTS: There was no significant difference in the magnitude of the relapse between the 2 groups over the 24-month postoperative period. CONCLUSION: The use of bicortical screw fixation after sagittal split setback of the mandible provides sufficient stability to dispense with IMF.

Critical size defect in the canine mandible.

OBJECTIVE: The purpose of this study was to determine the minimum size defect in a canine mandible that would not spontaneously heal during the dog's natural life (the critical size defect). STUDY DESIGN: Sixteen adult female mongrel dogs underwent continuity resection on both sides of the mandible to create bilateral defects. In 8 dogs, mandibular defects ranging from 5 to 20 mm were created with periosteal resection. In the other 8 dogs, mandibular defects ranging from 30 to 60 mm were created preserving the periosteum. The dogs were then killed at 6 months and the defects examined using radiographs and histologic analysis. RESULTS: When the periosteum was removed, mandibular defects greater than 15 mm failed to heal across the entire defect. However, when the periosteum was preserved, mandibular defects needed to be greater than 50 mm in order to fail to heal. CONCLUSION: The critical size defect in a canine mandible model is 15 mm when the periosteum is removed and 50 mm when the periosteum is preserved.