scholarly journals Covid-19 Interstitial Pneumonia: Histological and Immunohistochemical Features on Cryobiopsies

Respiration ◽  
2021 ◽  
pp. 369-379
Author(s):  
Claudio Doglioni ◽  
Claudia Ravaglia ◽  
Marco Chilosi ◽  
Giulio Rossi ◽  
Alessandra Dubini ◽  
...  

Background: The pathogenetic steps leading to Covid-19 interstitial pneumonia remain to be clarified. Most postmortem studies to date reveal diffuse alveolar damage as the most relevant histologic pattern. Antemortem lung biopsy may however provide more precise data regarding the earlier stages of the disease, providing a basis for novel treatment approaches. Objectives: To ascertain the morphological and immunohistochemical features of lung samples obtained in patients with moderate Covid-19 pneumonia. Methods: Transbronchial lung cryobiopsy was carried out in 12 Covid-19 patients within 20 days of symptom onset. Results: Histopathologic changes included spots of patchy acute lung injury with alveolar type II cell hyperplasia, with no evidence of hyaline membranes. Strong nuclear expression of phosphorylated STAT3 was observed in >50% of AECII. Interalveolar capillaries showed enlarged lumen and were in part arranged in superposed rows. Pulmonary venules were characterized by luminal enlargement, thickened walls, and perivascular CD4+ T-cell infiltration. A strong nuclear expression of phosphorylated STAT3, associated with PD-L1 and IDO expression, was observed in endothelial cells of venules and interstitial capillaries. Alveolar spaces macrophages exhibited a peculiar phenotype (CD68, CD11c, CD14, CD205, CD206, CD123/IL3AR, and PD-L1). Conclusions: Morphologically distinct features were identified in early stages of Covid-19 pneumonia, with epithelial and endothelial cell abnormalities different from either classical interstitial lung diseases or diffuse alveolar damage. Alveolar type II cell hyperplasia was a prominent event in the majority of cases. Inflammatory cells expressed peculiar phenotypes. No evidence of hyaline membranes and endothelial changes characterized by IDO expression might in part explain the compliance and the characteristic pulmonary vasoplegia observed in less-advanced Covid-19 pneumonia.

1989 ◽  
Vol 17 (4_part_2) ◽  
pp. 737-742 ◽  
Author(s):  
Sabine Rehm ◽  
Jerrold M. Ward

Alveolar type II cell tumors were induced transplacentally by intraperitoneal injection of pregnant C3H/HeNCr MTV– or Swiss Webster mice with N-nitrosoethylurea at a dose of 0.5 mmol/kg and 0.74 mmol/kg. At different time points after birth (1–32 weeks), the entire lungs from 40 of the male offspring were inflated with Bouin's fixative, separated into lobes, and sectioned at 5 μm serially to detect every microscopic lesion. Results were compared with those obtained from examining only every 10th, 20th, or a single mid-level section from the same material. On average, 150 serial sections were prepared per mouse lung. Initially, only purely solid/alveolar or purely tubulopapillary types were observed but with tumor progression, papillary structures developed within solid tumors resulting in mixed neoplasms. Analyzing mouse lungs in step sections of every 10th section (50–60 μm), 5/238 (2%) of the tumors were missed, in step sections of every 20th section (100–120 μm), 16/238 (7%) of the tumors were not detected and usually less than half of the tumors were seen in the single mid-level section. The approximate size of the neoplasms is indicated by the total number of sections per tumor. The dimensions of tumors evaluated with step sections of 10 or 20 were comparable to the size observed with serial sections. It is concluded that the evaluation of mouse lung tumors in steps of approximately 50 μm is basically equivalent to the study of serial sections and appears to be a feasible method to assess the complete incidence, histological type, and size of all proliferative processes throughout the entire lung.


2010 ◽  
Vol 68 (1) ◽  
pp. 57-62 ◽  
Author(s):  
Monique E de Paepe ◽  
Sheila A Haley ◽  
Zacharie Lacourse ◽  
Quanfu Mao

2001 ◽  
Vol 281 (2) ◽  
pp. L509-L516 ◽  
Author(s):  
Yuma Hoshino ◽  
Tadashi Mio ◽  
Sonoko Nagai ◽  
Hiroyuki Miki ◽  
Isao Ito ◽  
...  

Injury of the alveolar epithelium by cigarette smoke is presumed to be an important process in the pathogenesis of smoking-related pulmonary diseases. We investigated the cytotoxic effects of cigarette smoke extract (CSE) on an alveolar type II cell-derived cell line (A549). CSE caused apoptosis at concentrations of 5% or less and necrosis at 10% or more. When CSE was exposed to air before application to A549 cells, the cytotoxic effects were attenuated. CSE caused cell death without direct contact with the cells. Acrolein and hydrogen peroxide, two major volatile factors in cigarette smoke, caused cell death in a similar manner. Aldehyde dehydrogenase, a scavenger of aldehydes, and N-acetylcysteine, a scavenger of oxidants and aldehydes, completely inhibited CSE-induced apoptosis. CSE and acrolein increased intracellular oxidant activity. In conclusion, apoptosis of alveolar epithelial cells may be one of the mechanisms of lung injury induced by cigarette smoking. This cytotoxic effect might be due to an interaction between aldehydes and oxidants present in CSE or formed in CSE-exposed cells.


1997 ◽  
Vol 272 (4) ◽  
pp. L739-L744 ◽  
Author(s):  
S. M. Oakes ◽  
Y. Takahashi ◽  
M. C. Williams ◽  
M. Joyce-Brady

gamma-Glutamyltransferase (gamma-GT) is a key enzyme in the metabolism of glutathione and glutathione-substituted molecules. The gamma-GT gene is expressed in two epithelial cells of the adult lung, the bronchiolar Clara cell and the alveolar type II cell. Because pulmonary glutathione metabolism may be important in the perinatal period, we studied gamma-GT ontogeny in the developing rat lung. In the late fetal and early postnatal lung, gamma-GT mRNA was below detectable limits on Northern blots. Pulmonary gamma-GT protein and enzyme activity were present at low levels after fetal day 18. gamma-GT protein appeared as a high-molecular-mass band (>95 kDa), with small amounts of enzymatically active gamma-GT heterodimer. Between the 2nd and 3rd postnatal wk, pulmonary gamma-GT mRNA expression increased in association with an increase in gamma-GT protein and enzyme activity that reached adult lung levels. At this time, gamma-GT protein appeared predominantly in the heterodimeric form with small amounts of the >95-kDa protein. Immunocytochemistry revealed that, in the fetal and early postnatal lung, gamma-GT was expressed only in the alveolar type II cell, whereas the Clara cell became the major site of gamma-GT mRNA and protein expression by 2-3 wk and in the adult. Type II cells isolated from the fetal lung express gamma-GT mRNA and synthesize the >95-kDa form of gamma-GT in excess of the heterodimer. These studies demonstrate that the alveolar type II cell is the only cell producing gamma-GT in the newborn lung and that it synthesizes a form of gamma-GT that appears to differ from that produced at a later time point by the Clara cell.


1996 ◽  
Vol 62 (1) ◽  
pp. 302-314 ◽  
Author(s):  
Richard J. Novick ◽  
Kenneth E. Gehman ◽  
Imtiaz S. Ali ◽  
John Lee

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