Recent Advances in the Evaluation of Serological Assays for the Diagnosis of SARS-CoV-2 Infection and COVID-19.

Introduction: Few data on the diagnostic performance of serological tests for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection are currently available. We evaluated sensitivity and specificity of five different widely used commercial serological assays for the detection of SARS-CoV-2-specific IgG, IgM, and IgA antibodies using reverse transcriptase-PCR assay in nasopharyngeal swab as reference standard test. Methods: A total of 337 plasma samples collected in the period April-June 2020 from SARS-CoV-2 RT-PCR positive (n = 207) and negative (n = 130) subjects were investigated by one point-of-care lateral flow immunochromatographic assay (LFIA IgG and IgM, Technogenetics) and four fully automated assays: two chemiluminescence immunoassays (CLIA-iFlash IgG and IgM, Shenzhen YHLO Biotech and CLIA-LIAISON® XL IgG, DiaSorin), one electrochemiluminescence immunoassay (ECLIA-Elecsys® total predominant IgG, Roche), and one enzyme-linked immunosorbent assay (ELISA IgA, Euroimmune). Results: The overall sensitivity of all IgG serological assays was >80% and the specificity was >97%. The sensitivity of IgG assays was lower within 2 weeks from the onset of symptoms ranging from 70.8 to 80%. The LFIA and CLIA-iFlash IgM showed an overall low sensitivity of 47.6 and 54.6%, while the specificity was 98.5 and 96.2%, respectively. The ELISA IgA yielded a sensitivity of 84.3% and specificity of 81.7%. However, the ELISA IgA result was indeterminate in 11.7% of cases. Conclusions: IgG serological assays seem to be a reliable tool for the retrospective diagnosis of SARS-CoV-2 infection. IgM assays seem to have a low sensitivity and IgA assay is limited by a substantial rate of indeterminate results.

Development and validation of a prediction model for severe respiratory failure in hospitalized patients with SARS-CoV-2 infection: a multicentre cohort study (PREDI-CO study).

OBJECTIVES: We aimed to develop and validate a risk score to predict severe respiratory failure (SRF) among patients hospitalized with coronavirus disease-2019 (COVID-19). METHODS: We performed a multicentre cohort study among hospitalized (>24 hours) patients diagnosed with COVID-19 from 22 February to 3 April 2020, at 11 Italian hospitals. Patients were divided into derivation and validation cohorts according to random sorting of hospitals. SRF was assessed from admission to hospital discharge and was defined as: Spo2 <93% with 100% Fio2, respiratory rate >30 breaths/min or respiratory distress. Multivariable logistic regression models were built to identify predictors of SRF, ß-coefficients were used to develop a risk score. Trial Registration NCT04316949. RESULTS: We analysed 1113 patients (644 derivation, 469 validation cohort). Mean (±SD) age was 65.7 (±15) years, 704 (63.3%) were male. SRF occurred in 189/644 (29%) and 187/469 (40%) patients in the derivation and validation cohorts, respectively. At multivariate analysis, risk factors for SRF in the derivation cohort assessed at hospitalization were age ≥70 years (OR 2.74; 95% CI 1.66-4.50), obesity (OR 4.62; 95% CI 2.78-7.70), body temperature ≥38°C (OR 1.73; 95% CI 1.30-2.29), respiratory rate ≥22 breaths/min (OR 3.75; 95% CI 2.01-7.01), lymphocytes ≤900 cells/mm3 (OR 2.69; 95% CI 1.60-4.51), creatinine ≥1 mg/dL (OR 2.38; 95% CI 1.59-3.56), C-reactive protein ≥10 mg/dL (OR 5.91; 95% CI 4.88-7.17) and lactate dehydrogenase ≥350 IU/L (OR 2.39; 95% CI 1.11-5.11). Assigning points to each variable, an individual risk score (PREDI-CO score) was obtained. Area under the receiver-operator curve was 0.89 (0.86-0.92). At a score of >3, sensitivity, specificity, and positive and negative predictive values were 71.6% (65%-79%), 89.1% (86%-92%), 74% (67%-80%) and 89% (85%-91%), respectively. PREDI-CO score showed similar prognostic ability in the validation cohort: area under the receiver-operator curve 0.85 (0.81-0.88). At a score of >3, sensitivity, specificity, and positive and negative predictive values were 80% (73%-85%), 76% (70%-81%), 69% (60%-74%) and 85% (80%-89%), respectively. CONCLUSION: PREDI-CO score can be useful to allocate resources and prioritize treatments during the COVID-19 pandemic.

Pathological post-mortem findings in lungs infected with SARS-CoV-2.

Italy was the first European nation to be massively infected by SARS-CoV-2. Up to the end of May 2020, more than 33,000 deaths had been recorded in Italy, with a large prevalence among males, those over 75 years of age, and in association with co-morbidities. We describe the lung pathological and immunohistochemical post-mortem findings at the autopsy of nine patients who died of SARS-CoV-2-associated disease. We found in the lung tissues of all patients histological changes consistent with diffuse alveolar damage in various evolution phases ranging from acute exudative to acute proliferative to fibrotic phase. Alveolar damage was associated with prominent involvement of the vascular component in both the interstitial capillaries and the mid-size vessels, with capillary fibrin micro-thrombi, as well as organized thrombi even in medium-sized arteries, in most cases not related to sources of embolism. Eosinophilic infiltrate was also seen, probably reactive to pharmacological treatment. Viral RNA of SARS-CoV-2 was detected from the lung tissues of all the nine patients. Immunohistochemistry for the receptor of the SARS-CoV-2, ACE2, and its priming activator TMPRSS2 revealed that both proteins co-localize in airway cells. In particular, the ACE2 protein was expressed in both endothelial cells and alveolar type I and II pneumocytes in the areas of histological diffuse alveolar damage (DAD). Pneumocytes, but not endothelial cells, also expressed TMPRSS2. There are no distinctive histological features of SARS-CoV-2 infection with respect to SARS-CoV-1 and other DAD with different aetiology. The identification of the cause of death in the course of SARS-CoV-2 infection is more likely multi-factorial. © 2020 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

COVID-19 in patients with HIV-1 infection: a single-centre experience in northern Italy.

BACKGROUND: Since the end of February 2020, the Coronavirus Disease 2019 (COVID-19) outbreak rapidly spread throughout Italy and other European countries, but limited information has been available about its characteristics in HIV-infected patients. METHODS: We have described a case series of patients with HIV infection and COVID-19 diagnosed at the S.Orsola Hospital (Bologna, Italy) during March and April, 2020. RESULTS: We reported a case series of 26 HIV-infected patients with COVID-19. Nineteen subjects were men, the median age was 54 years, 73% of patients had one or more comorbidities. Only 5 patients with interstitial pneumonia were hospitalized, but there were no admissions to intensive care unit and no deaths. CONCLUSIONS: In our experience, COVID-19 associated with HIV infection had a clinical presentation comparable to the general population and was frequently associated with chronic comorbidities.

Differential Diagnosis in Patients with HRCT Patterns Suspected for COVID-19 Pneumonia and RT-PCR Negative: A Multidisciplinary Approach for an Appropriate Management (preprint)

Since 11th March 2020, the World Health Organization has declared that coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 is a pandemic and a global public health emergency. One of the main problems related to the rapid spread of the pandemic was the low sensitivity of the swabs that were used, resulting in high false negative rates, and the inability of HRCT to distinguish COVID-19 pneumonia from other types of pneumonia, resulting in diagnostic delays and increased infections in the hospital units. To deal with this problem, a multidisciplinary team has been created at the Sant'Orsola-Malpighi University Hospital in Bologna, with the aim of integrating the data of each patient framed as a "COVID suspect" and to get to a correct diagnosis. We analysed some exemplary cases of patients with negative swab but highly suggestive clinical and radiological characteristics for COVID-19 that, thanks to this multidisciplinary team, were then framed as other forms of pneumonia and successfully treated.

Is it Possible to Safely Maintain a Regular Vascular Practice During the COVID-19 Pandemic?

OBJECTIVE: This study aimed to evaluate the protocol adopted during the emergency phase of the COVID-19 pandemic to maintain elective activity in a vascular surgery unit while minimising the risk of contamination to both patients and physicians, and the impact of this activity on the intensive care (IC) resources. METHODS: The activity of a vascular surgery unit was analysed from 8 March to 8 April 2020. Surgical activity was maintained only for acute or elective procedures obeying priority criteria. The preventive screening protocol consisted of nasopharyngeal swabs (NPS) for all patients and physicians with symptoms and for unprotected contact infected cases, and serological physician evaluations every 15 days. Patients treated in the acute setting were considered theoretically infected and the necessary protective devices were used. The number of patients and the possible infection of physicians were evaluated. The number and type of interventions and the need for post-operative IC during this period were compared with those in the same periods in 2018 and 2019. RESULTS: One hundred and fifty-one interventions were performed, of which 34 (23%) were acute/emergency. The total number of interventions was similar to those performed in the same periods in 2019 and 2018: 150 (33, of which 22% acute/emergency) and 117 (29, 25% acute/emergency), respectively. IC was necessary after 6% (17% in 2019 and 20% in 2018) of elective operations and 33% (11) of acute/emergency interventions. None of the patients treated electively were diagnosed with COVID-19 infection during hospitalisation. Of the 34 patients treated in acute/emergency interventions, five (15%) were diagnosed with COVID-19 infection. It was necessary to screen 14 (47%) vascular surgeons with NPS after contact with infected colleagues, but none for unprotected contact with patients; all were found to be negative on NPS and serological evaluation. CONCLUSION: A dedicated protocol allowed maintenance of regular elective vascular surgery activity during the emergency phase of the COVID-19 pandemic, with no contamination of patients or physicians and minimal need for IC resources.