Images for AGM1 and AGM2 showed a diffuse alveolar pattern along the right lung; in AGM2, the left lung lobe contained a mild alveolar pattern. These observations was significantly contrasted by the physical examinations of the two animals from the day before, indicating a rapid progression of the viral disease. 

Thoracic Radiographs

Examination of AGM1 and AGM2 showed significant consolidation and edema in the right caudal lung lobe, representative of bronchointerstitial pneumonia. AGM3 had multifocal pleural adhesions between the left caudal lung lobe and the diaphragm. RM1 had a pulmonary scar in the right caudal lung lobe that was characterized by acute hemorrhage. The lungs of AGM4, RM2, RM3 and RM4 were normal.  

Gross Postmortem Examination

Histopathologic findings of the lungs of AGM1 and AGM2 were signified by alveoli filled with fibrin, hemorrhage and proteinaceous fluid. Alveoli contained multinucleated syncytial cells. Fluorescent immunohistochemistry showed low levels of SARS-CoV-2 infected cells in AGM1 but not AGM2. The animals which had survived to the study’s end point had minimal to moderate interstitial inflammation. RM1, RM2 and RM4 had evidence of aspiration pneumonia due to foreign material within the bronchioles. Histopathologic lesions in the other tissues of the eight animals were characterized as insignificant. 

Histopathologic Findings

- Thoracic Radiographs
- Gross Postmortem Examination 
- Histopathologic Findings 


Tulane University

- Clinical Measurements of Lung Damage
- Production of Cytokines 


Clinical Manifestations of ARDS Observed in Post-Exposure Analysis

Blair, R. V., Vaccari, M., Doyle-Meyers, L. A., Roy, C. J., Russell-Lodrigue, K., Fahlberg, M., . . . Rappaport, J. (2021). Acute respiratory distress in aged, sars-cov-2–infected african green monkeys but not rhesus macaques. The American Journal of Pathology, 191(2), 274-282. doi:10.1016/j.ajpath.2020.10.016

Acute Respiratory Distress in Aged, SARS-CoV-2–Infected African Green Monkeys but Not Rhesus Macaques

Clinical Measurements of Lung Damage

Cytokines similar to those in humans infected with Covid-19 had been upregulated in the two animals, AGM1 and AGM2, that progressed to ARDS. Elevated cytokines included IFN-γ, IL-6, IL-4/IL-13, IL-8, IL-1β, and tumor necrosis factor-α, indicative of a cytokine storm. AGM4 had a similar increase in cytokine concentrations but did not progress to ARDS. Contrastingly, RMs had moderate changes in cytokine expression at 7 DPI, despite extensive viral loads. IFN-γ concentrations were high in AGM1 and AGM2 during an acute infection and associated with viral RNA in the bronchi. IgG antibodies were not observed in AGM1, but all remaining animals had observable antibody concentrations by 21 DPI. 

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