Comparative Analysis of Antimicrobial Antibodies between Mild and Severe COVID-19.

Patients with 2019 coronavirus disease (COVID-19) exhibit a broad spectrum of clinical presentations. A person's antimicrobial antibody profile, as partially shaped by past infection or vaccination, can reflect the immune system health that is critical to control and resolve the infection. We performed an explorative immunoproteomics study using microbial protein arrays displaying 318 full-length antigens from 77 viruses and 3 bacteria. We compared antimicrobial antibody profiles between 135 patients with mild COVID-19 disease and 215 patients with severe disease in 3 independent cohorts from Mexico and Italy. Severe disease patients were older with higher prevalence of comorbidities. We confirmed that severe disease patients elicited a stronger anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) response. We showed that antibodies against HCoV-229E and HcoV-NL63 but not against HcoV-HKU1 and HcoV-OC43 were also higher in those who had severe disease. We revealed that for a set of IgG and IgA antibodies targeting coronaviruses, herpesviruses, and other respiratory viruses, a subgroup of patients with the highest reactivity levels had a greater incidence of severe disease compared to those with mild disease across all three cohorts. On the contrary, fewer antibodies showed consistent greater prevalence in mild disease in all 3 cohorts. IMPORTANCE The clinical presentations of COVID-19 range from asymptomatic to critical illness that may lead to intensive care or even death. The health of the immune system, as partially shaped by past infections or vaccinations, is critical to control and resolve the infection. Using an innovative protein array platform, we surveyed antibodies against hundreds of full-length microbial antigens from 80 different viruses and bacteria in COVID-19 patients from different geographic regions with mild or severe disease. We not only confirmed the association of severe COVID-19 disease with higher reactivity of antibody responses to SARS-CoV-2 but also uncovered known and novel associations with antibody responses against herpesviruses and other respiratory viruses. Our study represents a significant step forward in understanding the factors contributing to COVID-19 disease severity. We also demonstrate the power of comprehensive antimicrobial antibody profiling in deciphering risk factors for severe COVID-19. We anticipate that our approach will have broad applications in infectious diseases.

Sinonasal Biomarkers Defining Type 2-High and Type 2-Low Inflammation in Chronic Rhinosinusitis with Nasal Polyps.

The complex pathophysiology of chronic rhinosinusitis with nasal polyps (CRSwNP) generates a spectrum of phenotypes with a wide variety of inflammatory states. We enrolled 44 very-likely-to-be type 2 CRSwNP patients in order to evaluate the load of inflammation and to analyze human interleukins in nasal secretion. Clinical data were collected to evaluate the severity of the disease. High levels of IL-5, IL-4, IL-6, and IL-33 were detected in all type 2 CRSwNP patients. By analyzing type 2 cytokine profiles and local eosinophil count, we identified two coherent clusters: the first was characterized by high levels of IL-4, IL-5, IL-6, and a high-grade eosinophil count (type 2-high); the second had lower levels of cytokines and poor or absent eosinophilic inflammation (type-2 low). IL-5 levels were significantly higher within the type 2 cytokine and it was the most reliable biomarker for differentiating the two clusters. In type 2-high inflammatory profile clinical scores, the mean number of previous surgeries and need for systemic corticosteroids were significantly higher compared to type 2-low. Our research demonstrated the potential role of type 2 biomarkers, and in particular, of IL-5 in identifying patients with a more severe phenotype based on a high inflammatory load.

Calprotectin in nasal secretion: a new biomarker of non-type 2 inflammation in CRSwNP.

Objective: We analysed calprotectin in sinonasal secretions of different chronic rhinosinusitis with nasal polyps (CRSwNP) endotypes to assess its role as a biomarker of non-type 2 inflammation. Methods: We included primary diffuse CRSwNP patients (n = 41) and three different control groups [non-allergic rhinitis (NAR) (n = 13), non-allergic eosinophilic syndrome (NARES) (n = 10) and healthy subjects (n = 12)]. Calprotectin levels were detected in nasal secretions using a chemiluminescent immunoassay (CLIA). Results: Calprotectin levels in nasal secretions were significantly higher in all non-type 2 endotypes of CRSwNP compared to healthy controls (p < 0.05). In contrast, in type-2 CRSwNP calprotectin was significantly lower compared to controls (p < 0.05). A significant correlation between calprotectin levels and neutrophilic count/HPF was found in CRSwNP (p < 0.01). Clinically, mean levels of calprotectin and neutrophilia were significantly higher in patients who previously underwent 3 or more endoscopic sinus surgeries (p < 0.05). Conclusions: Calprotectin in nasal secretions may be a biomarker of non-type 2 inflammation. Low levels of calprotectin are indicative of a type-2 immune response in both CRSwNP and non-allergic rhinitis. We observed that calprotectin levels significantly increased based on the number of previous surgeries.

Analytical Performance Evaluation of a New Calcitonin Assay.

BACKGROUND: The use of efficient laboratory calcitonin (CT) testing is required for optimal management of medullary thyroid carcinoma. Several pitfalls are related to the calcitonin laboratory assays and a careful evaluation is needed. We report the analytical performances of the new Siemens ADVIA-Centaur-CALCT (CT-XPT) assay and its comparison with our standard method DiaSorin-Calcitonin-II-Gen (CT-LIA) assay. METHODS: Analytical performance of the CT-XPT-assay, limit of blank (LOB), limit of detection (LOD), and limit of quantification (LOQ), were determined. We also evaluated the in vitro stability of the sample, together with the linearity and percentage recovery. RESULTS: The CT-XPT-assay showed a better detection limit than the CT-LIA assay, with lower values of LOB (0.86 pg/mL vs 1.00 pg/mL) and LOQ (1.65 pg/mL vs 3.00 pg/mL). Both values were in agreement with those reported by the manufacturer. Within- and between-run precision demonstrated a good concordance of results. Regarding the in vitro stability of CT, the low CT concentration sera showed a much greater decrease in CT levels compared to the high concentration sera. Correlation studies showed a good correlation between the two methods (Kappa Cohen coefficent, KC: 0.68, agreement % for male: 89.58%; KC: 0.63; agreement % for female: 88.33%). CONCLUSIONS: Our findings showed a good correlation between the CT-LIA and CT-XPT methods. Moreover, we demonstrated that the analytical performance of the CT-XPT assay, together with its technical specifications, could represent major features of the CT-XPT method. Collectively, the technical evaluation and the analytical results described in the presented paper highlight that the novel CT-XPT is a valid method for CT testing in a clinical diagnostic setting.

Cortisol circadian rhythm and jet-lag syndrome: evaluation of salivary cortisol rhythm in a group of eastward travelers.

PURPOSE: The activity of the hypothalamus-pituitary-adrenal axis plays a crucial role as an endogenous stress-reactive system. Lifestyle and work often interfere with the endogenous circadian rhythms and can modify the physiological patterns of stress-hormones secretion, including cortisol. We evaluated the cortisol circadian rhythm in the "jet-lag syndrome" that is the most known condition associated with the desynchronization of the circadian rhythm. METHODS: To assess the modifications of cortisol secretion after a long-haul flight, we compared baseline and post-travel salivary cortisol rhythm in a group of 28 healthy eastward travelers (from the U.S.A. or Canada to Italy). The salivary samples were collected about 1 week before the departure at 11 p.m. on day 0 and at 8 a.m., 12 a.m. (midday) and 11 p.m. on day 1 (R0). The same samples were obtained after the landing, the day they flew back home (R1). RESULTS: Statistical analysis showed a significant difference between R0 and R1 for each sample considered (p < 0.005). In particular, the post-travel salivary cortisol levels detected at 11 p.m. both on day 0 and on day 1, were significantly higher than at baseline. Post-travel morning salivary cortisol levels were lower compared with basal rhythm and increased during the morning, reaching the acrophase at 12 a.m. CONCLUSIONS: In eastward travelers, crossing more than five time zones, the cortisol circadian rhythm after the return to the East "remained behind," being synchronized with the West time. This impaired cortisol secretion can contribute to the pathogenesis of the jet-lag syndrome.

Effects of Thyroid Hormone Treatment on Diaphragmatic Efficiency in Mechanically Ventilated Subjects With Nonthyroidal Illness Syndrome.

BACKGROUND: Several respiratory abnormalities can be present in primary hypothyroidism and can be reversed with adequate hormone treatment. However, the role of thyroid hormone replacement therapy on the respiratory system in patients with nonthyroidal illness syndrome is still unclear. This physiologic study evaluated the effect of thyroid hormone treatment on respiratory muscle function in subjects with nonthyroidal illness syndrome and while on mechanical ventilation. The primary end point was neuromechanical efficiency, which provides an estimate of the efficiency of diaphragmatic contraction. Secondary end points were the transdiaphragmatic pressure-time product and the swing of the electrical activity of the diaphragm, which reflect the work of breathing and inspiratory effort, respectively. METHODS: Fifteen subjects on mechanical ventilation for ≥48 h and with a diagnosis of nonthyroidal illness syndrome who had a failed spontaneous breathing trial, received intravenous triiodothyronine. The hormone was administered as an intravenous bolus of 0.4 µg/kg triiodothyronine, followed by continuous perfusion at 0.6 µg/kg for 24 h. Neuromechanical efficiency was calculated as the ratio between the drop in airway pressure during an expiratory occlusion and the corresponding electrical activity of the diaphragm peak. Recordings were taken at baseline and after 3, 6, and 24 h. RESULTS: After study completion, free triiodothyronine serum concentrations increased in all the subjects (mean ± SD increase, 0.84 ± 0.34 pg/mL). Neuromechanical efficiency showed no significant changes throughout the study (mean ± SD baseline, 1.40 ± 0.87 cm H2O/µV; 3 h, 1.28 ± 0.64 cm H2O/µV; 6 h, 1.33 ± 0.87 cm H2O/µV; 24 h, 1.41 ± 0.96 cm H2O/µV). Similarly, no variations in transdiaphragmatic pressure-time product per min (mean ± SD baseline, 238.1 ± 124 cm H2O × s/min; 3 h, 242.5 ± 140.3 cm H2O × s /min; 6 h, 247.5 ± 161.7 cm H2O × s/min; 24 h, 281.2 ± 201.2 cm H2O × s/min) or swing of electrical activity of the diaphragm (mean ± baseline, 20.9 ± 13.1 µV; 3 h, 17.2 ± 8.3 µV; 6 h, 17.4 ± 11.3 µV; 24 h, 20.3 ± 13.7 µV) were observed during hormone administration. CONCLUSIONS: In the subjects on mechanical ventilation who were admitted to the ICU with nonthyroidal illness syndrome, thyroid hormone replacement treatment did not yield any benefit on respiratory muscle function when assessed by neuromechanical efficiency, which indicated that, in these subjects restoring normal levels of serum thyroid hormones is debatable. (ClinicalTrials.gov registration NCT03157466.).