Abstract:
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).
摘要:
侵袭性真菌感染(IMF)在接受造血干细胞移植的患者中具有较高的死亡率,通常通过验尸证实。当在尸检后最初确认FI时,组织培养和冷冻切片很难安全,在很多情况下,福尔马林固定,石蜡包埋(FFPE)样品是鉴定真菌的唯一方式。组织病理学诊断是与分子生物学方法相结合的有用方法,可以实现更精确的鉴定,具有可重复性。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。尸检FFPE标本与通过活检或手术获得的标本相比,在提取的DNA质量方面存在缺点。在死后组织学诊断的毛霉菌病的情况下,我们检查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。适当修改的PCR对于鉴定尸检FFPE标本中的真菌是有价值的。然而,PCR并不总是正确识别尸检FFPE组织中的真菌,以及ISH或IHC等其他方法值得考虑,以澄清广泛的分类(例如属或物种级分类)。