Demonstration of SARS-CoV-2 in bone marrow cells and changes in the hematopoietic cell lines

Tuba Hacıbekiroğlu¹, Yasin Kalpakcı², Tuğçe Nur Yiğenoğlu³,  Kubilay İşsever⁴, Gülay Trak⁵, İlhan Hacıbekiroğlu6, Yusuf Aydemir⁷, Hande Toptan⁸, Cenk Sunu² ,Oğuz Karabay⁹, Mustafa Kösem¹⁰, Mehmet Köroğlu⁸

¹Department of Hematology, Faculty of Medicine, Sakarya University, Sakarya, Turkey - ²Department of Hematology, Sakarya University, Research and Training Hospital, Sakarya, Turkey - ³Department of Hematology and Bone Marrow Transplantation Center University of Health Sciences, Ankara Oncology Training and Research Hospital, Ankara, Turkey - ⁴Department of Internal Medicine, Sakarya University, Research and Training Hospital, Sakarya, Turkey - ⁵Department of Microbiology, Sakarya University, Research and Training Hospital, Sakarya, Turkey - ⁶Department of Medical Oncology, Faculty of Medicine, Sakarya University, Sakarya, Turkey- ⁷Department of Pulmonology, Faculty of Medicine, Sakarya University, Sakarya, Turkey - ⁸Department of Microbiology, Faculty of Medicine, Sakarya University, Sakarya, Turkey - ⁹Department of Infection Disease, Faculty of Medicine, Sakarya University, Sakarya, Turkey - ¹⁰Department of Pathology, Faculty of Medicine, Sakarya University, Sakarya, Turkey

Introduction: SARS-CoV-2 binds to angiotension coverting enzyme-2 (ACE-2) receptors on the surface of the the host cells. ACE receptors are found in bone marrow (BM). SARS-CoV-2 can reduce hematopoiesis in all cell lines by infecting the BM cells directly and by changing the local RAS in addition to the suppression by cytokines during the course of COVID-19. However, there has been no study that could demonstrate the presence of SARS-CoV-2 in BM. Therefore in this study, we aim to demonstrate SARS-CoV-2 in the BM and investigate the changes in the BM of critically ill COVID-19 patients.

Materials and method: This study is single center research and six critically ill COVID-19 patients were included in the study. Flowcytometry and RT-PCR were studied in BM aspiration samples. Histopathological evaluation of bone marrow biopsy materials was performed.

Results: The most striking finding in BM was reactive plasmacytosis. CD4 / CD8 ratio of 3 patients was reversed (<1). There was an average of 90% CD14+ CD16- classical monocyte. In 1 patient SARS-CoV-2 was demonstrated in BM cells by RT-PCR.

Conclusion: To the best of our knowledge, this is the first study which demonstrated SARS-CoV-2 in the BM. In our study revealed an increase in polyclonal plasma cells, CD14+ CD64+ CD68+ active monocytes in BM and demonstrated SARS-CoV-2 in the BM by RT-PCR analysis in 1 patient. Evaluation of flowcytometric analysis of the BM in COVID-19 patients may help the scientists to understand the pathogenesis of SARS-CoV-2 and its effects on hematopoietic cells.