Computed tomography features of COVID-19 in children: A systematic review and meta-analysis.

BACKGROUND: There are few reports on the chest computed tomography (CT) imaging features of children with coronavirus disease 2019 (COVID-19), and most reports involve small sample sizes. OBJECTIVES: To systematically analyze the chest CT imaging features of children with COVID-19 and provide references for clinical practice. DATA SOURCES: We searched PubMed, Web of Science, and Embase; data published by Johns Hopkins University; and Chinese databases CNKI, Wanfang, and Chongqing Weipu. METHODS: Reports on chest CT imaging features of children with COVID-19 from January 1, 2020 to August 10, 2020, were analyzed retrospectively and a meta-analysis carried out using Stata12.0 software. RESULTS: Thirty-seven articles (1747 children) were included in this study. The heterogeneity of meta-analysis results ranged from 0% to 90.5%. The overall rate of abnormal lung CT findings was 63.2% (95% confidence interval [CI]: 55.8%-70.6%), with a rate of 61.0% (95% CI: 50.8%-71.2%) in China and 67.8% (95% CI: 57.1%-78.4%) in the rest of the world in the subgroup analysis. The incidence of ground-glass opacities was 39.5% (95% CI: 30.7%-48.3%), multiple lung lobe lesions was 65.1% (95% CI: 55.1%-67.9%), and bilateral lung lesions was 61.5% (95% CI: 58.8%-72.2%). Other imaging features included nodules (25.7%), patchy shadows (36.8%), halo sign (24.8%), consolidation (24.1%), air bronchogram signs (11.2%), cord-like shadows (9.7%), crazy-paving pattern (6.1%), and pleural effusion (9.1%). Two articles reported 3 cases of white lung, another reported 2 cases of pneumothorax, and another 1 case of bullae. CONCLUSIONS: The lung CT results of children with COVID-19 are usually normal or slightly atypical. The lung lesions of COVID-19 pediatric patients mostly involve both lungs or multiple lobes, and the common manifestations are patchy shadows, ground-glass opacities, consolidation, partial air bronchogram signs, nodules, and halo signs; white lung, pleural effusion, and paving stone signs are rare. Therefore, chest CT has limited value as a screening tool for children with COVID-19 and can only be used as an auxiliary assessment tool.

Mck2-dependent infection of alveolar macrophages promotes replication of MCMV in nodular inflammatory foci of the neonatal lung.

Infection with cytomegalovirus (CMV) shows a worldwide high prevalence with only immunocompromised individuals or newborns to become symptomatic. The host's constitution and the pathogen's virulence determine whether disease occurs after infection. Mouse CMV (MCMV) is an appreciated pathogen for in vivo investigation of host-pathogen interactions. It has recently been reported that a single base pair deletion can spontaneously occur in the open reading frame of MCMV-encoded chemokine 2 (MCK2), preventing the expression of the full-length gene product. To study the consequences of this mutation, we compared the Mck2-defective reporter virus MCMV-3D with the newly generated repaired Mck2(+) mutant MCMV-3DR. Compared with MCMV-3D, neonatal mice infected with MCMV-3DR showed severe viral disease after lung infection. Viral disease coincided with high viral activity in multiple organs and increased virus replication in previously described nodular inflammatory foci (NIF) in the lung. Notably, MCMV-3DR showed tropism for alveolar macrophages in vitro and in vivo, whereas MCMV-3D did not infect this cell type. Moreover, in vivo depletion of alveolar macrophages reduced MCMV-3DR replication in the lung. We proposed an Mck2-mediated mechanism by which MCMV exploits alveolar macrophages to increase replication upon first encounter with the host's lung mucosa.

Solitary cavitary pulmonary nodule may be a common CT finding in AIDS-associated pulmonary cryptococcosis.

BACKGROUND: Previous studies have demonstrated that the most common chest radiologic finding in acquired immune deficiency syndrome (AIDS)-associated pulmonary cryptococcosis (PC) is diffuse interstitial infiltrates. The aim of this study was to provide additional radiologic characterization of PC in AIDS patients. METHODS: AIDS patients from the Second Affiliated Hospital of the Southeast University who were diagnosed with cryptococcosis between February 2009 and May 2012 and who had undergone chest computed tomography (CT) scans before or at the time of diagnosis were retrospectively analyzed. RESULTS: Twelve patients met eligibility criteria. The median CD4 T-cell count was 23 cells/µl (range 2-79 cells/µl). Eleven patients had pulmonary abnormalities on imaging. Initial chest CT scans demonstrated solitary cavitary pulmonary nodules in 9 patients, pleural effusions in 2 patients, bilateral ground-glass opacities in 6 patients, patchy opacities in 1 patient, and bronchiectasis in 1 patient. Bilateral ground-glass opacities appeared to be associated with Pneumocystis pneumonia, while the presence of a pleural effusion was predictive of PC. Of the 9 solitary cavitary pulmonary nodules, 7 were PC and the other 2 were probable cases of PC. These nodules were predominantly in the peripheral lung and were either asymptomatic or caused only mild pulmonary symptoms. CONCLUSIONS: Solitary cavitary pulmonary nodule may be a common CT finding in AIDS-associated PC. All AIDS patients with solitary cavitary pulmonary nodules on chest CT should be screened for Cryptococcus infection.

Distinct epidermal growth factor receptor and KRAS mutation patterns in non-small cell lung cancer patients with different tobacco exposure and clinicopathologic features.

PURPOSE: This study evaluated the mutational profile of epidermal growth factor receptor (EGFR) and KRAS in non-small cell lung cancers in Hong Kong and determined their relation with smoking history and other clinicopathologic features. EXPERIMENTAL DESIGN: Mutational profile of exons 18 to 21 of EGFR and codons 12, 13, and 61 of KRAS were determined in 215 adenocarcinomas, 15 squamous cell (SCC), and 11 EBV-associated lymphoepithelioma-like carcinomas (LELC). RESULTS: EGFR mutations were prevalent in adenocarcinomas (115 of 215), uncommon in LELC (1 of 11), and not found in SCC (P < 0.001). Among adenocarcinomas, mutations were associated with nonsmokers (83 of 111; P < 0.001), female gender (87 of 131; P < 0.001), and well-differentiated (55 of 86) compared with poorly differentiated (11 of 41) tumors (P < 0.001). Decreasing mutation rates with increasing direct tobacco exposure was observed, with 74.8% (83 of 111) in nonsmokers, 61.1% (11 of 18) in passive, 35.7% (10 of 28) in previous, and 19.0% (11 of 58) in current smokers. There were 53% amino acid substitutions, 43% in-frame deletions, and 4% insertions. Complex patterns with 13% double mutations, including five novel substitutions, were observed. For KRAS, mutations occurred in adenocarcinoma only (21 of 215) and were associated with smokers (11 of 58; P = 0.003), men (14 of 84; P = 0.009) and poorly differentiated (7 of 41) compared with well-differentiated (4 of 86) tumors (P = 0.037). EGFR and KRAS mutations occurred in mutually exclusive tumors. Regression analysis showed smoking history was the significant determinant for both mutations, whereas gender was a confounding factor. CONCLUSION: This study shows EGFR mutations are prevalent in lung adenocarcinoma and suggests that it plays an increasing oncogenic role with decreasing direct tobacco damage.

[Bilateral pulmonary nodules in an HIV-infected patient]. / Nodules pulmonaires bilatéraux chez un patient infecté par le VIH.

INTRODUCTION: Although infectious causes are the most common source of pulmonary nodules in HIV-infected patients, malignant diseases such as Kaposi sarcoma and lymphoma must also be considered. OBSERVATION: A 40 year-old man, diagnosed with HIV infection 16 years earlier and with a satisfactory viro-immunological control, was hospitalized for bilateral pulmonary nodules and a dorsal lytic mass. Bone and pleural biopsies showed a malignant epithelioid hemangioendothelioma. COMMENT: Epithelioid hemangioendothelioma is an uncommon low grade vascular tumor. We report the first case in an HIV-infected patient. Bilateral pulmonary nodules are common in this malignant disease but are not specific. In a HIV-infected patient, such clinical presentation is associated with numerous differential diagnoses and must be interpreted in relation to the immune status. CONCLUSION: In HIV-patients without immunosuppression, pulmonary nodules are often malignant. With the increased survival of these patients, these etiologies closer to those of non-infected patients.

Epstein-Barr virus-associated posttransplant lymphoproliferative disorder after a cord blood stem cell transplantation presenting with pulmonary nodules.

Sixteen months after a cord blood stem cell transplantation, a 6-year-old girl was diagnosed with Epstein-Barr virus-associated posttransplant lymphoproliferative disorder (EBV-PTLD). A CT scan revealed nodules in both lungs, but the patient had neither lymphadenopathy nor other lesions. The diagnosis was confirmed by histopathologic evaluation and the increased level of EBV DNA in the peripheral blood. The patient was successfully treated with rituximab, and a complete regression of the tumors was achieved. This case reveals the need to include EBV-PTLD in the differential diagnosis of pulmonary nodules, as well as demonstrating that rituximab may be effective treatment of EBV-PTLD after cord blood stem cell transplantation.

Persistent multiple pulmonary nodules in a nonimmunocompromised woman after varicella-related myelitis treated with acyclovir.

Persistent multiple pulmonary nodules were observed on the chest X ray of a nonimmunocompromised woman 6 months after she was treated with acyclovir for a varicella-related myelitis without respiratory symptoms. Early antiviral therapy given for varicella infections might decrease the intensity of clinical symptoms without actually preventing the occurrence of varicella-zoster virus-related lesions such as the persistent pulmonary nodules reported here.

Multiple pulmonary nodules caused by B-cell post-transplant lymphoproliferative disorder after bone marrow transplantation: monitoring Epstein-Barr virus viral load.

We report a patient with myelodysplastic syndrome who underwent an allogeneic bone marrow transplantation during the first remission. On day 110 he had a low-grade fever and pulmonary nodules, without superficial lymphadenopathy, were observed. The pulmonary nodules gradually increased in size and in number despite administration of anti-fungal and anti-tuberculosis agents. Transbronchial lung biopsy was performed on day 204, yielding a diagnosis of polyclonal post-transplant lymphoproliferative disease (PTLD) positive for Epstein-Barr virus (EBV)-encoded RNA (EBER) and CD20. Subsequent measurement of herpesvirus viral load demonstrated a consistent elevation of EBV viral load from day 96 to day 221. After treatment with anti-CD20 monoclonal antibody (rituximab), regression of pulmonary nodules was confirmed and the number of EBV genome copies decreased to a normal range. This case suggests that monitoring the quantitative EBV viral load may be necessary in cases of EBV-associated PTLD, even in cases presenting pulmonary nodules. Solitary pulmonary nodules may be a rare symptom of PTLD, but in such cases, an aggressive approach may be necessary to obtain a correct diagnosis.