Placenta-derived mesenchymal stromal cells as a treatment for refractory chronic gingivostomatitis in cats: eight cases (2018).

OBJECTIVES: The aim of this case series was to collect preliminary data on safety and efficacy of treating cats suffering from refractory feline chronic gingivostomatitis with a single intravenous therapy of cryopreserved placenta-derived mesenchymal stromal cells. MATERIALS AND METHODS: We planned the prospective inclusion of cats suffering from refractory chronic gingivostomatitis in three veterinary clinics. All cats received a single infusion of 10×106 cryopreserved cells. Follow-up evaluations were done at day 15 and at 2-, 3- and 6-months following infusion. Clinical disease severity was evaluated by dental specialists using a published stomatitis disease activity index scoring system coupled with an owners' assessment questionnaire. RESULTS: All eight cats attended all follow up visits. Cryopreserved ready-to-use placenta-derived cells administered systemically were safe and resulted in notable clinical improvement in all cats as reported by stomatitis disease activity index scoring and owner's survey. CLINICAL SIGNIFICANCE: Infusion of cryopreserved freshly thawed placenta-derived mesenchymal stromal cells appears to promote clinical and consequently behavioural benefits in cats with refractory chronic gingivostomatitis after having undergone full-mouth or premolar-molar tooth extraction. Future randomised studies are required to confirm safety and efficacy of this treatment.

Intra-articular administration of xenogeneic neonatal Mesenchymal Stromal Cells early after meniscal injury down-regulates metalloproteinase gene expression in synovium and prevents cartilage degradation in a rabbit model of osteoarthritis.

OBJECTIVE: The anti-inflammatory and anti-catabolic effects of neonatal Mesenchymal Stromal Cell (MSC) were investigated in a xenogeneic model of mild osteoarthritis (OA). The paracrine properties of MSC on synoviocytes were further investigated in vitro. STUDY DESIGN: OA was induced by medial meniscal release (MMR) in 30 rabbit knees. A single early (day 3) or delayed (day 15) intra-articular (IA) injection of MSC isolated from equine Umbilical Cord Wharton's jelly (UC-MSC) was performed. Rabbits were euthanized on days 15 or 56. OA grading was performed and gene expression of inflammatory cytokines and metalloproteinases was measured in synovial tissue. Paracrine effects of UC-MSC were investigated using UC-conditioned vs control medium on rabbit primary synoviocytes stimulated with interleukin 1 beta in vitro. RESULTS: No adverse local or systemic responses were observed clinically after xenogeneic UC-MSC injection. At study end point, cartilage fibrillation was lower in early treatment than in delayed treatment group. Cellular infiltrate was observed in the synovium of both UC-MSC groups. OA synovium exhibited a reduced expression of metalloproteinases-1, -3, -13 in the early cell-treated group at d56. In vitro, UC-conditioned medium exerted anti-inflammatory and anti-catabolic effects on synoviocytes exposed to pro-inflammatory stimulus. CONCLUSIONS: Early IA injection of equine UC-MSC was effective in preventing OA signs in rabbit knees following MMR. UC-MSC target the synovium and modulate the gene expression pattern of synoviocytes to promote an anti-catabolic environment. This confirms the synovium is a major target and mediator of MSC therapy, modulating the expression of matrix-degrading enzymes.

Integrated FDG-PET/CT does not make invasive staging of the intrathoracic lymph nodes in non-small cell lung cancer redundant: a prospective study.

BACKGROUND: Staging of non-small cell lung cancer (NSCLC) is important for determining choice of treatment and prognosis. The accuracy of FDG-PET scans for staging of lymph nodes is too low to replace invasive nodal staging. It is unknown whether the accuracy of integrated FDG-PET/CT scanning makes invasive staging redundant. METHODS: In a prospective study, the mediastinal and/or hilar lymph nodes in patients with proven NSCLC were investigated with integrated FDG-PET/CT scanning. Pathological confirmation of all suspect lymph nodes was obtained to calculate the accuracy of the fusion images. In addition, the use of the standardised uptake value (SUV) in the staging of intrathoracic lymph nodes was analysed. RESULTS: 105 intrathoracic lymph node stations from 52 patients with NSCLC were characterised. The prevalence of malignancy in the lymph nodes was 36%. The sensitivity of the integrated FDG-PET/CT scan to detect malignant lymph nodes was 84% and its specificity was 85% (positive likelihood ratio 5.64, negative likelihood ratio 0.19). SUV(max), SUV(mean) and the SUV(max)/SUV(liver) ratio were all significantly higher in malignant than in benign lymph nodes. The area under the receiver operating curve did not differ between these three quantitative variables, but the highest accuracy was found with the SUV(max)/SUV(liver) ratio. At a cut-off value of 1.5 for the SUV(max)/SUV(liver )ratio, the sensitivity and specificity to detect malignant lymph node invasion were 82% and 93%, respectively. CONCLUSION: The accuracy of integrated FDG-PET/CT scanning is too low to replace invasive intrathoracic lymph node staging in patients with NSCLC. The visual interpretation of the fusion images of the integrated FDG-PET/CT scan can be replaced by the quantitative variable SUV(max)/SUV(liver) without loss of accuracy for intrathoracic lymph node staging.

Cord blood volume reduction using an automated system (Sepax) vs. a semi-automated system (Optipress II) and a manual method (hydroxyethyl starch sedimentation) for routine cord blood banking: a comparative study.

Background With the development of cord blood banking, solutions have to be found to solve the storage space problem, by reducing the volume of cord blood units (CBU). Methods We compared total nucleated cell (TNC) and CD34(+) cell counts before and after processing with three different CBU volume reduction methods used consecutively in our bank: a manual method based on hydroxyethyl starch sedimentation (HES) (n=447), a top-and-bottom (TB) semi-automated method (n=181) using Optipress II, and the Sepax automated method (n=213). Statistical analysis was done using t-tests, linear regression and Spearman correlation coefficients. Adjusted variables included TNC, CD34(+) cell counts, CD34(+) cell percentage and CB volume before processing. Results TNC recovery was higher with Sepax (80.3+/-7.7%) than with HES (76.8+/-9.1%) and TB (60.7+/-13.5%) (P<0.0001, both). It was higher with HES than with TB (P<0.0001). CD34(+) cell recovery was higher with Sepax (86+/-11.6%) than with HES (81.5+/-12.5%) and TB (82.0+/-17.7%) (P<0.008 and <0.0001, respectively) and results with HES and TB were not significantly different (P=0.7). Interestingly, with Sepax, TNC and CD34(+) cell recoveries were not correlated with pre-processing values (P=0.8 and 0.4, respectively). Discussion In conclusion, the Sepax volume reduction method allows higher TNC and CD34(+) cell recoveries.

Development of a competitive PCR method for in vitro and in vivo quantification of herpes simplex virus thymidine kinase and neomycin resistance-expressing cells used in a clinical trial.

The aim of this study was to set up a sensitive and specific method to quantify the number of gene-modified cells in a gene therapy clinical trial currently underway at our institution. This trial involves the use of retrovirally transduced allogeneic T cells expressing the herpes simplex-1 thymidine kinase (HSV-TK) and neomycin-phosphotransferase (NeoR) resistance gene. Quantification by competitive PCR was performed, with two homologous internal standards (deltaTK, deltaNeoR), 30 bp shorter than the target sequences (TK, NeoR), coupled to fluorescent laser-based detection. Assessment of the amplification systems procedures was carried out for each sequence. The 30-bp deletion did not affect the amplification efficiency significantly. Determination of the plateau phase of both amplified sequences demonstrated that each sample must be quantified during the predetermined exponential phase. Finally, a blinded study of a transduced cell dilutions panel validated the overall methodology. The competitive PCR was applied to quantification of the retroviral transduction process by quantifying the NeoR gene in transduced PBMC samples (prior to G418 selection) from 18 donors in our clinical trial. A mean transduction efficiency of 9.78% +/- 1.37% was observed. We also quantified TK-expressing donor transgenic T cells in a murine GvHD model. Results demonstrated on initial expansion of donor HSV-TK- expression T cells as well as a significant ganciclovir (GCV)-induced decrease correlated with the number of circulating gene-modified T cells. Therefore, we have developed an efficient gene quantification tool that should be useful for in vivo monitoring of gene-modified cells.