Objective To assess sensitivity/specificity of CT vs RT-PCR for the diagnosis of COVID-19 pneumonia in a prospective Italian cohort of symptomatic patients during the outbreak peak. Methods In this cross-sectional study, we included all consecutive patients who presented to the ER between March 13 and 23 for suspected COVID-19 and underwent CT and RT-PCR within 3 days. Using a structured report, radiologists prospectively classified CTs in highly suggestive, suggestive, and non-suggestive of COVID-19 pneumonia. Ground-glass, consolidation, and visual extension of parenchymal changes were collected. Three different RT-PCR-based reference standard definitions were used. Oxygen saturation level, CRP, LDH, and blood cell counts were collected and compared between CT/RT-PCR classes. Results The study included 696 patients (41.4% women; age 59 ± 15.8 years): 423/454 (93%) patients with highly suggestive CT, 97/ 127 (76%) with suggestive CT, and 31/115 (27%) with non-suggestive CT had positive RT-PCR. CT sensitivity ranged from 73 to 77% and from 90 to 94% for high and low positivity threshold, respectively. Specificity ranged from 79 to 84% for high positivity threshold and was about 58% for low positivity threshold. PPV remained ≥ 90% in all cases. Ground-glass was more frequent in patients with positive RT-PCR in all CT classes. Blood tests were significantly associated with RT-PCR and CT classes. Leukocytes, lymphocytes, neutrophils, and platelets decreased, CRP and LDH increased from non-suggestive to suggestive CT classes. Conclusions During the outbreak peak (in a high-prevalence setting), CT presented high PPV and may be considered a good reference to recognize COVID-19 patients while waiting for RT-PCR confirmation. Key Points • During the epidemic peak, CT showed high positive predictive value and sensitivity for COVID-19 pneumonia when compared with RT-PCR. • Blood tests were significantly associated with RT-PCR and CT classes.

We assessed the impact of chest CT body composition parameters on outcomes and disease severity at hospital presentation of COVID-19 patients, focusing also on the possible mediation of body composition in the relationship between age and death in these patients. Chest CT scans performed at hospital presentation by consecutive COVID-19 patients (02/27/2020-03/13/2020) were retrospectively reviewed to obtain pectoralis muscle density and total, visceral, and intermuscular adipose tissue areas (TAT, VAT, IMAT) at the level of T7-T8 vertebrae. Primary outcomes were: hospitalization, mechanical ventilation (MV) and/or death, death alone. Secondary outcomes were: C-reactive protein (CRP), oxygen saturation (SO2), CT disease extension at hospital presentation. The mediation of body composition in the effect of age on death was explored. Of the 318 patients included in the study (median age 65.7 years, females 37.7%), 205 (64.5%) were hospitalized, 68 (21.4%) needed MV, and 58 (18.2%) died. Increased muscle density was a protective factor while increased TAT, VAT, and IMAT were risk factors for hospitalization and MV/death. All these parameters except TAT had borderline effects on death alone. All parameters were associated with SO2 and extension of lung parenchymal involvement at CT; VAT was associated with CRP. Approximately 3% of the effect of age on death was mediated by decreased muscle density. In conclusion, low muscle quality and ectopic fat accumulation were associated with COVID-19 outcomes, VAT was associated with baseline inflammation. Low muscle quality partly mediated the effect of age on mortality.

Objective. Chronic periaortitis (CP) usually responds to glucocorticoids, but some patients have glucocorticoid-refractory disease or contraindications to glucocorticoid therapy. This study was undertaken to evaluate treatment with the anti-interleukin-6 receptor (anti-IL-6R) antibody tocilizumab in 2 patients with CP, one with refractory disease and the other with contraindications to glucocorticoids, and to assess IL-6 levels in an additional cohort of patients with CP.Methods. Both patients were given intravenous tocilizumab (8 mg/kg) once every 4 weeks for 6 months. Serum IL-6 was measured in 22 patients with active CP and 16 healthy controls. Tissue IL-6 expression was assessed by confocal microscopy in biopsy specimens obtained from 6 patients with CP.Results. In the first patient, whose disease was refractory to various immunosuppressive treatments, tocilizumab added to ongoing therapy with prednisone and methotrexate allowed prednisone withdrawal and induced resolution of symptoms, acute-phase reactant normalization, and reduction in 18 F-fluorodeoxyglucose ( 18 F-FDG) uptake on positron emission tomography. The patient experienced a relapse 7 months later and was successfully retreated with tocilizumab. In the second patient, who was unable to tolerate glucocorticoids because of psychiatric side effects, tocilizumab monotherapy induced sustained clinical and laboratory remission, 18 F-FDG uptake disappearance, and CP shrinkage. Serum IL-6 levels were significantly higher in patients with active CP than in controls (P < 0.0001), and IL-6 was abundantly expressed in biopsy specimens from CP patients, particularly by T cells, B cells, histiocytes, fibroblasts, and vascular smooth muscle cells.Conclusion. Tocilizumab may be a therapeutic option for CP. The systemic and tissue up-regulation of IL-6 in CP, together with the clinical benefit of IL-6R blockade observed in our 2 patients, suggest that IL-6 may contribute to CP pathogenesis.