Clinical Performance of Two Methods for Detecting Anti SARS-CoV-2 Antibodies

Evaluating the clinical performance of available methods to detect antibodies against Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) has become a primordial issue in clinical laboratories. The aim of this study was to evaluate the clinical performance of two methods for SARS-CoV-2 antibodies detection, an automated Chemiluminescent Immunoassay (CLIA) and an immunochromatographic Lateral-Flow Assay (LFA) in patients with positive reverse transcription polymerase chain reaction (RT-PCR). Performance for CLIA method was Positive Agreement (PA) 56.6% and Negative Agreement (NA) 96,6% for IgM and PA 85.8%/NA 90,2% for IgG. Performance for LFA method was PA 56.2% and NA 100% for IgM and PA 95.5% and NA 100 % for IgG. LFA general agreement IgG was better than CLIA. In both methods, significant differences in Kappa index are observed when IgG and IgM are compared. When evaluating the data from a clinical perspective, we found that both method performance for IgM detection may not meet the expected requirements for their clinical utility and could lead to an inappropriate medical decision. The findings of this study show that both immunoassay methods might be reliable for assessing immunological response in COVID-19 patients. Our results also confirm that IgG measurement could be helpful, especially for epidemiological studies in our population. These results provide evidence to justify epidemiological studies in our population.

The Pivotal Role of Signal Regulatory Protein α in Exacerbating Pulmonary Fibrosis Complicated with Bacterial Infection

The pathogenesis of pulmonary fibrosis remains unknown. However, bacterial infections in patients with idiopathic pulmonary fibrosis are a serious complication that exacerbate the disease. Serum levels of Surfactant Protein D (SPD) are known to be elevated in patients with pulmonary fibrosis, but the role of SPD in pulmonary fibrosis complicated with bacterial infection is unknown. Lipopolysaccharide upregulates Interleukin (IL)-12p40 expression and IL-12p40 promotes Interferon Gamma (IFNγ) production to induce the T helper cell 1 (Th1) immune response via Signal Transducers and Activators of Transcription 4 (STAT4) signaling. A lack of IFNγ shifts the immune response from Th1 to Th2. IL-4 is a profibrotic Th2 cytokine that activates fibroblasts. Granulocyte-macrophage colony-stimulating factor induced by IL-1 and TNFα during the Th1 immune response upregulates Signal Regulatory Protein α (SIRPα) expression. Interferon Regulatory Factor 1 (IRF1) functions as the promoter activator of IL-12p40 after stimulation with LPS. SPD is a ligand for SIRPα, and SPD/SIRPα ligation activates the Mitogen-Activated Protein Kinase (MAPK)/Extracellular Signal-Related Kinase (ERK) signal cascade; ERK downregulates Interferon Regulatory Factor 1 (IRF1) expression. Consequently, the SPD/SIRPα signaling pathway decreases IL-12p40 production in human macrophages after exposure to LPS. IL-12p40 is a key immunoregulatory factor in bacterial infection that promotes production of IFNγ by T lymphocytes. Pulmonary fibroblasts are activated by IL-4/IL-4R ligation. IFNγ induces IRF1 via STAT1 signaling, and IRF1 acts as the promoter repressor of IL-4 to attenuate its production. IFNγ also inhibits IL-4R expression. A reduction in IFNγ induced by IL-12p40 deficiency via the SPD/SIRPα signaling pathway enhances IL-4 and IL-4R expression to augment the activity of fibroblasts. This finding indicates that pulmonary fibrosis is exacerbated by SPD/SIRPα signaling during bacterial infection.

Characterization of the Oral Microbiome in Canine Chronic Ulcerative Stomatitis

Canine chronic ulcerative stomatitis is a debilitating, oral mucosal disorder of dogs. A commonly held hypothesis for pathogenesis is that bacterial plaque on tooth surfaces is responsible for the ulcerative mucosal lesions. As such, therapy has focused on full-mouth, tooth extraction. Recent studies revealed a unique leukocyte profile in canine ulcerative stomatitis that is amenable to immune modulating therapy. What remains unknown is the role bacteria may play in dysbiosis and immune-inflammatory mechanisms. The microbiota of canine ulcerative stomatitis has not been characterized. Aims of the present study include determination of the microbiome of mucosal lesions in canine ulcerative stomatitis and that of the supragingival plaque of the opposing tooth. The microbiota of these surfaces was compared to healthy mucosa in the canine ulcerative stomatitis patient, and three non-stomatitis control patients. Our hypothesis was that specific microbial species or complexes are associated with ulcerative stomatitis. DNA from 100 clinical samples was evaluated using Next Generation Sequencing methods and was analyzed using LDA Effect Size and the non-parametric factorial Kruskal-Wallis sum-rank test. Statistically significant differences in species were determined from mucosal ulcers versus normal sites in ulcerative stomatitis patients. Species that were more prevalent on the ulcer lesions included putative periodontal pathogens, such as a Tannerella forsythia-like phylotype and Porphyromonas gingivicanis, a species related to the human pathogen Porphyromonas gingivalis. The microbial profile of the supragingival plaque of the abutting tooth to the ulcer revealed similar pathogens. This study showed that in dogs with stomatitis, the mucosal ulcer is inhabited by a unique, species-specific bacterial community and suggests significant differences between the oral mucosa of healthy dogs, dogs with severe periodontal disease, or dogs with oral mucosal tumors. Based on our results, full-mouth, tooth extraction may not be the optimal treatment of the disease.

A Prospective Review of Patients Receiving Intravitreal Anti-VEGF: How are we doing during the SARS-Cov-2 Pandemic?

Objective: During the SARS-CoV-2 pandemic, service provision of Anti- Vascular Endothelial Growth Factor (anti-VEGF) therapy is continued to prevent severe visual loss. As the majority of the patients requiring intravitreal anti- VEGF are elderly and vulnerable, we aim to assess the safety and efficacy of the delivery of anti-VEGF therapy. Method: A prospective data collection of 337 patients who attended the nurse led injection clinics in the UK during the lockdown period from 30 March 2020 to 1 June 2020. A follow up of all of the attended patients was conducted to assess for diagnosis of SARS-CoV-2. Results: 182 (54%) were female and 155 (46%) male. Majority (95%) were Caucasian and 5% were Asian ethnicity. The indication for anti-VEGF injection include wet age related macular degeneration (wet AMD) (70.9%), Diabetic Macular Oedema (DMO) (17.2%), and Retinal Vein Occlusion (RVO) (11.9%). Mean age was 78.84±9.76 for wet AMD, 67.63±3.26 for RVO and 59.28±14.54 for DMO. More wet AMD patients reported subjective deterioration of vision compared to RVO and DMO (40.2% vs. 37.5% vs. 22.4%) [P=0.04]. Chronic Obstructive Pulmonary Disease (COPD) is more common in the wet AMD group as compared to other groups (P=0.03). Five patients from the study group were tested for SARS-CoV-2, none were positive. Conclusion: Delivery of anti-VEGF therapy is safe with the current precautionary measures despite caring for a vulnerable group of patients. Majority of the wet AMD patients are continuing to attend intravitreal injection appointments.

Side Effects of In ovo Given Sunset Yellow FCF on the Embryonic Development of the Spleen by Means of Histological and Enzyme Histochemical Methods

Background: E110 is one of the food colorants which is widely used in dairy products, fast foods, jam and dry beverage powders, aqueous drug solutions, tablets, capsules, toothpastes mouthwashes, hair care products and cosmetics. Doubts have accumulated in recent years that food additives might cause allergic reactions in humans or increase these ailments. In this study, side effects of Sunset yellow FCF (E110) on the embryonic development of chicken spleen were evaluated by means of histological, histomorphometrical and enzyme histochemical methods. Methods: In the study, 250 fertilized broiler eggs obtained from a commercial broodstock were used. Eggs were divided into 5 groups each having 50 eggs. Control eggs were either nontreated or distilled water injected via air sac. The eggs in the experimental groups were injected with 100ng/egg, 500ng/egg and 1.000ng/egg E110 prior to incubation. Blood and spleen samples were taken from randomly selected 10 eggs of each group at 11th, 15th, 18th and 21st days of incubation. Leukocyte formula, alpha-naphtyl acetate esterase-positive and acid phosphatase-positive lymphocyte percentages were determined in the blood samples and embriyonic development of the spleen was assessed in the tissue sections. Results: In the 500ng/egg and 1.000ng/egg E110 injected experimental groups, embryonic development of the spleen retarded, alpha-naphtyl acetate esterase-positive and acid phosphatase-positive lymphocyte rates were significantly depressed. Conclusions: Significant disturbances in the immune system functions of the affected animals might occure at post-natal period of their life.