Sadamoto Sota, Mitsui Yurika, Nihonyanagi Yasuhiro, Amemiya Kazuki, Shinozaki Minoru, Murayama Somay Yamagata, Abe Masahiro, Umeyama Takashi, Tochigi Naobumi, Miyazaki Yoshitsugu, Shibuya Kazutoshi
Department of Surgical Pathology, Toho University School of Medicine, Tokyo 143-8541, Japan.
Department of Fungal Infection, National Institute of infectious Diseases, Tokyo 162-8640, Japan.
J Fungi (Basel). 2022 Mar 24;8(4):337. doi: 10.3390/jof8040337.
Invasive fungal infection (IFI) has a high mortality rate in patients who undergo hematopoietic stem cell transplantation, and it is often confirmed by postmortem dissection. When IFI is initially confirmed after an autopsy, the tissue culture and frozen section are challenging to secure, and in many cases, formalin-fixed, paraffin-embedded (FFPE) samples represent the only modality for identifying fungi. Histopathological diagnosis is a useful method in combination with molecular biological methods that can achieve more precise identification with reproducibility. Meanwhile, polymerase chain reaction (PCR) using fungal-specific primers helps identify fungi from FFPE tissues. Autopsy FFPE specimens have a disadvantage regarding the quality of DNA extracted compared with that of specimens obtained via biopsy or surgery. In the case of mucormycosis diagnosed postmortem histologically, we examined currently available molecular biological methods such as PCR, immunohistochemistry (IHC), and in situ hybridization (ISH) to identify fungi. It is reasonable that PCR with some modification is valuable for identifying fungi in autopsy FFPE specimens. However, PCR does not always correctly identify fungi in autopsy FFPE tissues, and other approaches such as ISH or IHC are worth considering for clarifying the broad classification (such as the genus- or species-level classification).
侵袭性真菌感染（IFI）在接受造血干细胞移植的患者中死亡率很高，且往往通过尸检来确诊。当IFI在尸检后首次被证实时，获取组织培养和冰冻切片具有挑战性，在许多情况下，福尔马林固定、石蜡包埋（FFPE）样本是鉴定真菌的唯一方式。组织病理学诊断是一种有用的方法，与分子生物学方法相结合，可以实现更精确且可重复的鉴定。同时，使用真菌特异性引物的聚合酶链反应（PCR）有助于从FFPE组织中鉴定真菌。与通过活检或手术获得的标本相比，尸检FFPE标本在提取的DNA质量方面存在劣势。对于尸检组织学诊断为毛霉病的病例，我们研究了目前可用的分子生物学方法，如PCR、免疫组织化学（IHC）和原位杂交（ISH）来鉴定真菌。对PCR进行一些改进后用于鉴定尸检FFPE标本中的真菌是合理的。然而，PCR并不总是能正确鉴定尸检FFPE组织中的真菌，其他方法如ISH或IHC对于明确广泛分类（如属或种水平分类）值得考虑。
