Histopathological Lung Findings in COVID-19 B.1.617.2 SARS-CoV-2 Delta Variant

Abstract

Background: The Delta variant (Pango lineage B.1.617.2) is one of the most significant and aggressive variants of SARS‑CoV‑2. To the best of our knowledge, this is the first paper specifically studying pulmonary morphopathology in COVID-19 caused by the B.1.617.2 Delta variant. Methods: The study included 10 deceased patients (40-83 years) with the COVID-19 Delta variant. The necrotic lung fragments were obtained either by biopsy (six cases) or autopsy (four cases). Tissue samples were subjected to virology analysis for identification of the SARS-CoV-2 variant, histopathology, and immunohistochemistry (anti-SARS coronavirus mouse anti-virus antibody). Results: Virology analysis identified B.1.617.2 through genetic sequencing in eight cases, and in two cases, specific mutations of B.1.617.2 were identified. Macroscopically, in all autopsied cases, the lung had a particular appearance, purple in color, with increased consistency on palpation and abolished crepitations. Histopathologically, the most frequently observed lesions were acute pulmonary edema (70%) and diffuse alveolar damage at different stages. The immunohistochemical examination was positive for proteins of SARS-CoV-2 in 60% of cases on alveolocytes and in endothelial cells. Conclusions: The histopathological lung findings in the B.1.617.2 Delta variant are similar to those previously described in COVID-19. Spike protein-binding antibodies were identified immunohistochemically both on alveolocytes and in the endothelial cells, showing the potential of indirect damage from thrombosis.

Flurona: The First Autopsied Case

“…Being rich in B lymphocytes ( Figure 3 K), we consider that bronchitis/bronchiolitis is likely due to the influenza virus. Additionally, in our previous studies, we observed that COVID-19 infection generally does not produce intense histological inflammation in the bronchial structures [ 23 , 24 ]. The involvement of bronchial structures has been reported in infections with influenza, adenovirus, herpes, varicella-zoster, and respiratory syncytial virus [ 25 ].…”

A Pictorial Essay Describing the CT Imaging Features of COVID-19 Cases throughout the Pandemic with a Special Focus on Lung Manifestations and Extrapulmonary Vascular Abdominal Complications

“…In the acute phase, a tendency towards dense consolidation involving the dependent posterior lower lobes while mostly sparing the anterior or non-dependent area has been observed [37,103] (Figure 15). ARDS in COVID-19 patients has been frequent since the Delta variant [37,99,[104][105][106]. However, the risk of ARDS was lower during the Omicron variant [107].…”

“…Some rare cases of ARDS were reported after COVID-19 vaccinations as possible consequences of antibody-dependent enhancement (ADE) [108,109] (Figure 16). ARDS in COVID-19 patients has been frequent since the Delta variant [37,99,[104][105][106]. However, the risk of ARDS was lower during the Omicron variant [107].…”

“…ARDS in COVID-19 patients has been frequent since the Delta variant [ 37 , 99 , 104 , 105 , 106 ]. However, the risk of ARDS was lower during the Omicron variant [ 107 ].…”

Postmortem Minimally Invasive Autopsy in Critically Ill COVID-19 Patients at the Bedside: A Proof-of-Concept Study at the ICU

“…Conventional autopsies helped at the beginning of the pandemic to define COVID-19-related organ damage, such as thromboembolism and diffuse alveolar damage [7][8][9][10]. Despite these new insights, autopsy rates remained low during the pandemic, leaving our knowledge of COVID-19 disrupted by considerable gaps [11,12].…”