Figure 4.

Signs of sepsis-acquired immunodeficiency and relative development of bone marrow morphology according to the interval from onset of symptoms to death in three COVID-19 deceased patients with abscess-forming superinfection of viral pneumonia. (A) Expression levels of immunological markers, (B) cell types and presence of morphological characteristics, (C) morphological results of bone marrow evaluation in each patient.

Abbreviations: HLA-DR, human leukocyte antigen DR isotype; APC, antigen-presenting cells; PD-L1, programmed death ligand 1; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2; MPS, monocyte–macrophage system; MC, myeloid cells; HPF, high-power field.