Characteristics of peripheral lymphocyte subset alteration in COVID-19 pneumonia. intracellular GDC-0980 (Apitolisib, RG7422) inclusions of immunoglobulins (Russell body), known as Mott cells, were seen in the blood film. Two days later, his condition deteriorated with severe hypoxemic respiratory failure requiring mechanical ventilation. Repeat chest radiograph showed diffuse pulmonary infiltrations in keeping with acute respiratory distress syndrome (ARDS). Open in a separate window Physique 1. (A) Peripheral blood smear revealed a normal resting lymphocyte from healthy individual (WrightCGiemsa staining; viewed under oil immersion lens at 1,000 magnification). (B and C) Peripheral GDC-0980 (Apitolisib, RG7422) blood smears from a patient with severe COVID-19 revealed an enlarged reactive lymphocyte with dark basophilic cytoplasms with peripheral GDC-0980 (Apitolisib, RG7422) accentuation, eccentric round or indented nucleus with dense chromatin, and perinuclear Hof. They have copious cytoplasms that scallop around adjacent reddish blood cells. They are generally seen in viral infections such as dengue fever, and infectious mononucleosis. (D) This is a Mott cell, a variant of plasma cell with immunoglobulin entrapped in the endoplasmic reticulum, in a form of Russell body (WrightCGiemsa staining; viewed under oil immersion lens at 1,000 magnification). During the incubation period of COVID-19, adaptive immunity plays a crucial role in eliminating the computer virus. In immunocompromised patients, because of medical comorbidities, an effective antiviral immunity cannot be mounted, leading to a hyperinflammatory state that culminates into ARDS.1 This case illustrates the morphological evolution of lymphocyte activation seen in a patient with COVID-19. During viral contamination, B-lymphocytes are activated to become lymphoplasmacytoid lymphocytes and immunoglobulin-secreting plasma cells which have a distinctive morphology.2C4 There is emerging evidence NFIB that, in addition to elevated inflammatory markers and lymphopenia, elevated lymphoplasmacytoid lymphocytes, which correlate with antibody secreting and CD38+ antigen secreting B-lymphocytes, may predict clinical severity in COVID-19.4,5 REFERENCES 1. Ye Q, Wang B, Mao J, 2020. The pathogenesis and treatment of the Cytokine Storm in COVID-19. J Infect 80: 607C613. [PMC free article] [PubMed] [Google Scholar] 2. Foldes D, Hinton R, Arami S, Bain BJ, 2020. Plasmacytoid lymphocytes in SARS-CoV-2 contamination (COVID-19). Am J Hematol 95: 861C862. [PMC free article] [PubMed] [Google Scholar] 3. Zini G, Bellesi S, Ramundo F, dOnofrio G, 2020. Morphological anomalies of circulating blood cells in COVID-19. Am J Hematol 95: 870C872. [PMC free GDC-0980 (Apitolisib, RG7422) article] [PubMed] [Google Scholar] 4. Wang F, Nie J, Wang H, Zhao Q, Xiong Y, Deng L, Track S, Ma Z, Mo P, Zhang Y, 2020. Characteristics of peripheral lymphocyte subset alteration in COVID-19 pneumonia. J Infect Dis 221: 1762C1769. [PMC free article] [PubMed] [Google Scholar] 5. Yip CYC, Yap ES, De Mel S, Teo WZY, Lee CT, Kan S, Lee MCC, Loh WNH, Lim EL, Lee SY, 2020. Temporal changes in immune blood cell parameters in COVID-19 contamination and GDC-0980 (Apitolisib, RG7422) recovery from severe contamination. Br J Haematol 190: 33C36. [PMC free article] [PubMed] [Google Scholar].