Dataset Information

Increased number of pulmonary megakaryocytes in COVID-19 patients with diffuse alveolar damage: an autopsy study with clinical correlation and review of the literature.

ABSTRACT: Pulmonary megakaryocytes participate in the pathogenesis of lung damage, particularly in acute lung injury. Although megakaryocytes are not mentioned as a characteristic histologic finding associated to pulmonary injury, a few studies reveal that their number is increased in diffuse alveolar damage (DAD). In this autopsy study, we have observed a relevant number of pulmonary megakaryocytes in COVID-19 patients dying with acute lung injury (7.61 ± 5.59 megakaryocytes per 25 high-power fields vs. 1.14 ± 0.86 for the control group, p < 0.05). We analyzed samples of 18 patients, most of whom died after prolonged disease and use of mechanical ventilation. Most patients showed advanced DAD and abnormal coagulation parameters with high levels of fibrinogen, D-dimers, and variable thrombocytopenia. For comparison, pulmonary samples from a group of 14 non-COVID-19 patients dying with DAD were reviewed. They showed similar pulmonary histopathologic findings and an increase in the number of megakaryocytes (4 ± 4.17 vs. 1.14 ± 0.86 for the control group, p < 0.05). Megakaryocyte count in the COVID-19 group was greater but did not reach statistical significance (7.61 ± 5.59 vs. 4 ± 4.17, p = 0.063). Regardless of the cause, pulmonary megakaryocytes are increased in patients with DAD. Their high number seen in COVID-19 patients suggests a relation with the thrombotic events so often seen these patients. Since the lung is considered an active site of megakaryopoiesis, a prothrombotic status leading to platelet activation, aggregation and consumption may trigger a compensatory pulmonary response.

SUBMITTER: Valdivia-Mazeyra MF

PROVIDER: S-EPMC7483503 | biostudies-literature | 2020 Sep

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Increased number of pulmonary megakaryocytes in COVID-19 patients with diffuse alveolar damage: an autopsy study with clinical correlation and review of the literature.

Valdivia-Mazeyra Mariel F MF Salas Clara C Nieves-Alonso Jesús M JM Martín-Fragueiro Luz L Bárcena Carmen C Muñoz-Hernández Patricia P Villar-Zarra Karen K Martín-López Javier J Ramasco-Rueda Fernando F Fraga Javier J Jiménez-Heffernan José A JA

Virchows Archiv : an international journal of pathology 20200911 3

Pulmonary megakaryocytes participate in the pathogenesis of lung damage, particularly in acute lung injury. Although megakaryocytes are not mentioned as a characteristic histologic finding associated to pulmonary injury, a few studies reveal that their number is increased in diffuse alveolar damage (DAD). In this autopsy study, we have observed a relevant number of pulmonary megakaryocytes in COVID-19 patients dying with acute lung injury (7.61 ± 5.59 megakaryocytes per 25 high-power fields vs. ...[more]

PMID: 32915265

Similar Datasets

Project description:Diffuse alveolar hemorrhage (DAH) can be caused by various conditions, categorized as autoimmune and non-autoimmune. Immunofactor-mediated vasculitis, such as Wegener granulomatosis, microscopic polyangiitis, Goodpasture syndrome, connective tissue disorders, and antiphospholipid antibody syndrome, are common autoimmune causes. Non-autoimmune factors include infectious or toxic exposures and neoplastic conditions. The diagnosis of DAH, resulting from excessive catecholamine release from an adrenal pheochromocytoma or extra-adrenal paraganglioma, can present diagnostic challenges and necessitate prompt treatment. In this report, we present a case of pheochromocytoma that manifested as an adrenal incidentaloma (diagnosed during the management of sudden-onset DAH after cholecystectomy). Case report: A 39-year-old female patient with adrenal incidentaloma developed DAH following a cholecystectomy procedure, presenting with sudden-onset hemoptysis and dyspnea. Administration of glucocorticoids, known to precipitate pheochromocytoma crisis (PCC), was required before the cause was determined. Intubation and mechanical ventilation were necessary due to persistent hypoxemic respiratory failure and acute respiratory distress syndrome (ARDS). The patient in this case experienced two epidoses of PCC while she was on mechanical ventilation. Subsequent work-up revealed a 26 × 25 mm left adrenal adenoma with hormonal confirmation of catecholamine hypersecretion. A laparoscopic adrenalectomy was done eight months later to excise the left adrenal gland. Subsequent examination of the tissue revealed pheochromocytoma, thereby validating the initial diagnosis. Conclusion: Adrenal incidentalomas may be pheochromocytomas (adrenal incidentalomas can manifest as pheochromocytomas), even without adrenergic symptoms. It is recommended that adrenal incidentalomas undergo evaluation for pheochromocytoma before undergoing invasive surgery or receiving corticosteroid treatment. When considering potential causes of DAH without further elucidation, including a pheochromocytoma or paraganglioma (PPGLs) in the differential diagnosis is important.

Project description:Free iron in lung can cause the generation of reactive oxygen species, an important factor in chronic obstructive pulmonary disease (COPD) pathogenesis. Iron accumulation has been implicated in oxidative stress in other diseases, such as Alzheimer's and Parkinson's diseases, but little is known about iron accumulation in COPD. We sought to determine if iron content and the expression of iron transport and/or storage genes in lung differ between controls and COPD subjects, and whether changes in these correlate with airway obstruction. Explanted lung tissue was obtained from transplant donors, GOLD 2-3 COPD subjects, and GOLD 4 lung transplant recipients, and bronchoalveolar lavage (BAL) cells were obtained from non-smokers, healthy smokers, and GOLD 1-3 COPD subjects. Iron-positive cells were quantified histologically, and the expression of iron uptake (transferrin and transferrin receptor), storage (ferritin) and export (ferroportin) genes was examined by real-time RT-PCR assay. Percentage of iron-positive cells and expression levels of iron metabolism genes were examined for correlations with airflow limitation indices (forced expiratory volume in the first second (FEV1) and the ratio between FEV1 and forced vital capacity (FEV1/FVC)). The alveolar macrophage was identified as the predominant iron-positive cell type in lung tissues. Furthermore, the quantity of iron deposit and the percentage of iron positive macrophages were increased with COPD and emphysema severity. The mRNA expression of iron uptake and storage genes transferrin and ferritin were significantly increased in GOLD 4 COPD lungs compared to donors (6.9 and 3.22 fold increase, respectively). In BAL cells, the mRNA expression of transferrin, transferrin receptor and ferritin correlated with airway obstruction. These results support activation of an iron sequestration mechanism by alveolar macrophages in COPD, which we postulate is a protective mechanism against iron induced oxidative stress.

Dataset Information

Increased number of pulmonary megakaryocytes in COVID-19 patients with diffuse alveolar damage: an autopsy study with clinical correlation and review of the literature.

Publications

Increased number of pulmonary megakaryocytes in COVID-19 patients with diffuse alveolar damage: an autopsy study with clinical correlation and review of the literature.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets