SARS‐CoV‐2: a new aetiology for atypical lymphocytes

Abstract

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by a newly emerging coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). COVID-19 has a very variable clinical picture, ranging from asymptomatic to SARS that can lead to death.Our case, a 74-year-old female patient, presented with fever, moderate dyspnoea and leucocytosis (white blood cell count 21.6 9 10 9 /l, neutrophils 16.8 9 10 9 /l, lymphocytes 3.67 9 10 9 /l). Reverse transcriptase-polymerase chain reaction for SARS-CoV-2 was performed, which confirmed COVID-19.Peripheral blood film examination revealed a highly pleomorphic atypical lymphocyte population (right). Many cells were large (15-30 µm). The cytoplasm was sometimes granulated. Cytoplasmic basophilia was sometimes generalised and sometimes confined to the cytoplasmic margins. Some cells had one or more nucleoli and could have been mistaken for blast cells. Plasma cells and apoptotic cells were also present.In 5-10% of full blood counts of our hospitalised patients suffering from COVID-19 (all care sectors including intensive care), flags on our haematology analysers are present: 'MO Blast' for DXH800 (Beckman Coulter, top left) and 'Blasts Abn/lympho?' for XN10 (Sysmex, bottom left), requiring a blood film examination.Cytology in COVID-19 usually shows numerous neutrophils with either normal or decreased lymphocytes. This case illustrates the atypical lymphocytes that are often present. These cells morphologically mimic those of Epstein-Barr virus or cytomegalovirus infection, whereas plasma cells and plasmacytoid lymphocytes (present in some of our patients) are not usually a feature of these two infections.

Atypical lymphocytes in bronchoalveolar lavage fluid from patients with COVID-19 ARDS

“…We read with interest the recent paper by El Jamal and coworkers published in Pathology – Research & Practice [ 1 ] which reported that conspicuous atypical plasmacytoid lymphocytes are present in peripheral blood smears from patients with coronavirus disease 2019 (COVID-19), which is in line with other recent studies [ 2 , 3 ]. Indeed, many of the patients in these reports were critically ill and required intensive care therapy, and in one of the studies, similar cells were noted bronchoalveolar lavage fluid (BALF) [ 2 ].…”

Differential Diagnosis of COVID-19: Importance of Measuring Blood Lymphocytes, Serum Electrolytes, and Olfactory and Taste Functions

“…These suggest that leucocyte counts, which are not more than the normal range, suspect COVID-19. Weinberg et al (2020) and Gérard et al (2020) observed atypical lymphocytes in patients with COVID-19. However, atypical lymphocytes have also been observed in patients with other infections.…”

Absence of Severe Acute Respiratory Syndrome-Coronavirus-2 RNA in Human Corneal Tissues

“…So far, little is known on the clinical spectrum of ocular disease caused by SARS-CoV-2 infection. 13 , 14 However, several modes of transmission of SARS-CoV-2 involving ocular tissue and tears are being discussed. 9 – 11 The ACE-2 receptor has been found to be a binding site of SARS-CoV-2.…”