Department of Pathology, Brigham and Women's Hospital, Boston, Massachusetts, USA.
Department of Clinical Investigation, Harvard Medical School, Boston, Massachusetts, USA.
J Clin Pathol. 2024 Aug 16;77(9):622-627. doi: 10.1136/jcp-2023-208875.
The identification of haemophagocytosis in bone marrow (BM) is recurrently identified in patients with severe COVID-19. These initial COVID-19 autopsy studies have afforded valuable insight into the pathophysiology of this disease; however, only a limited number of case series have focused on lymphoid or haematopoietic tissues.
BM and lymph node (LN) specimens were obtained from adult autopsies performed between 1 April 2020 and 1 June 2020, for which the decedent had tested positive for SARS-CoV-2. Tissue sections (H&E, CD3, CD20, CD21, CD138, CD163, MUM1, kappa/lambda light chains in situ hybridisation) were examined by two haematopathologists, who recorded morphological features in a blinded fashion. Haemophagocytic lymphohistiocytosis (HLH) was assessed based on HLH 2004 criteria.
The BM demonstrated a haemophagocytic pattern in 9 out of 25 patients (36%). The HLH pattern was associated with longer hospitalisation, BM plasmacytosis, LN follicular hyperplasia and lower aspartate aminotransferase (AST), as well as ferritin at demise. LN examination showed increased plasmacytoid cells in 20 of 25 patients (80%). This pattern was associated with a low absolute monocyte count at diagnosis, lower white cell count and lower absolute neutrophil count at demise, and lower ferritin and AST at demise.
Autopsy results demonstrate distinct morphological patterns in BM, with or without haemophagocytic macrophages, and in LN, with or without increased plasmacytoid cells. Since only a minority of patients met diagnostic criteria for HLH, the observed BM haemophagocytic macrophages may be more indicative of an overall inflammatory state.
在严重 COVID-19 患者的骨髓（BM）中经常发现噬血细胞现象。这些最初的 COVID-19 尸检研究为该疾病的病理生理学提供了宝贵的见解；然而，只有少数病例系列专注于淋巴或造血组织。
从 2020 年 4 月 1 日至 2020 年 6 月 1 日期间进行的成人尸检中获得 BM 和淋巴结（LN）标本，死者的 SARS-CoV-2 检测呈阳性。两名血液病理学家检查了组织切片（H&E、CD3、CD20、CD21、CD138、CD163、MUM1、κ/λ 轻链原位杂交），并以盲法记录形态特征。噬血细胞性淋巴组织细胞增生症（HLH）根据 HLH 2004 标准进行评估。
25 例患者中有 9 例（36%）BM 表现出噬血细胞模式。HLH 模式与住院时间延长、BM 浆细胞增多、LN 滤泡增生以及天冬氨酸转氨酶（AST）和死亡时铁蛋白降低有关。LN 检查显示 25 例患者中有 20 例（80%）浆细胞增多。这种模式与诊断时绝对单核细胞计数低、白细胞计数和死亡时绝对中性粒细胞计数低以及死亡时铁蛋白和 AST 低有关。
尸检结果表明 BM 中存在或不存在噬血细胞巨噬细胞以及 LN 中存在或不存在浆细胞增多的不同形态模式。由于只有少数患者符合 HLH 的诊断标准，因此观察到的 BM 噬血细胞巨噬细胞可能更能说明总体炎症状态。
