Article Text
Abstract
Background Secondary haemophagocytic lymphohistiocytosis (sHLH) is characterised by a hyper activation of immune system that leads to multiorgan failure. It is suggested that excessive immune response in patients with COVID-19 could mimic this syndrome. Some COVID-19 autopsy studies have revealed the presence of haemophagocytosis images in bone marrow, raising the possibility, along with HScore parameters, of sHLH.
Aim Our objective is to ascertain the existence of sHLH in some patients with severe COVID-19.
Methods We report the autopsy histological findings of 16 patients with COVID-19, focusing on the presence of haemophagocytosis in bone marrow, obtained from rib squeeze and integrating these findings with HScore parameters. CD68 immunohistochemical stains were used to highlight histiocytes and haemophagocytic cells. Clinical evolution and laboratory parameters of patients were collected from electronic clinical records.
Results Eleven patients (68.7%) displayed moderate histiocytic hyperplasia with haemophagocytosis (HHH) in bone marrow, three patients (18.7%) displayed severe HHH and the remainder were mild. All HScore parameters were collected in 10 patients (62.5%). Among the patients in which all parameters were evaluable, eight patients (80%) had an HScore >169. sHLH was not clinically suspected in any case.
Conclusions Our results support the recommendation of some authors to use the HScore in patients with severe COVID-19 in order to identify those who could benefit from immunosuppressive therapies. The presence of haemophagocytosis in bone marrow tissue, despite not being a specific finding, has proved to be a very useful tool in our study to identify these patients.
- COVID-19
- bone
- bone marrow
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Footnotes
MP-V and MG-C are joint senior authors.
CN-T and AF-G are joint first authors.
Handling editor Mary Frances McMullin.
Contributors AF-G and CN-T have contributed equally as principal investigator. MG-C and MP-V have contributed equally as senior author. AF-G, EMM, BP-M, JP and MG-C participated in the autopsy procedure. CN-T, AF-G, MP-V and MG-C recollected the data. CN-T, AF-G, MP-V, MG-C and JP drafted the manuscript. All authors contributed to the final approved version of this manuscript.
Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
Competing interests None declared.
Patient consent for publication Not required.
Ethics approval This work has been reviewed and approved by the Ramón y Cajal Hospital Ethics Committee.
Provenance and peer review Not commissioned; externally peer reviewed.
Data availability statement All data relevant to the study are included in the article.