Department of Anatomic Pathology, Pathological Sciences, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan.
Department of Dermatology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi- ku, Fukuoka, 812-8582, Japan.
Sci Rep. 2024 Oct 3;14(1):22973. doi: 10.1038/s41598-024-74556-5.
PRAME (PReferentially expressed Antigen in MElanoma) was first identified as a malignant melanoma-specific antigen. Recently, a few cases of fibrosarcomatous dermatofibrosarcoma protuberans (FS-DFSP) were shown to have positivity for PRAME, while conventional dermatofibrosarcoma protuberans (C-DFSP) was negative. Because PRAME may be of diagnostic utility in FS-DFSP and is raising expectations as a new immunotherapy target, we examined the positivity of PRAME in FS-DFSP. Twenty-one cases of FS-DFSP and age/sex/location-matched cases of C-DFSP as a control group were examined by immunohistochemistry for CD34 and PRAME. The results were then evaluated by H-score, which was objectively and semi-quantitatively calculated using the open-source bioimaging analysis software QuPath. The results revealed that the PRAME H-score in FS-DFSP was significantly higher than that in C-DFSP (p = 0.0137). As for CD34, the H-score in FS-DFSP was significantly lower than that in C-DFSP (p < 0.001). Using these two immunohistochemical analyses in combination, the sensitivity and specificity for the diagnosis of FS-DFSP were 86% and 90%, respectively. Double staining of CD34 and PRAME revealed that PRAME-positive and CD34-positive areas did not overlap. This is the largest study to examine PRAME expression in FS-DFSP, and it confirmed the usefulness of PRAME in diagnosing this condition.
PRAME（黑色素瘤中优先表达的抗原）最初被鉴定为一种恶性黑色素瘤特异性抗原。最近，一些纤维肉瘤样隆突性皮肤纤维肉瘤（FS-DFSP）病例被证明对 PRAME 呈阳性，而传统隆突性皮肤纤维肉瘤（C-DFSP）则呈阴性。由于 PRAME 在 FS-DFSP 中可能具有诊断效用，并作为一种新的免疫治疗靶标而备受关注，我们研究了 PRAME 在 FS-DFSP 中的阳性表达。通过免疫组织化学方法检测了 21 例 FS-DFSP 和年龄/性别/部位匹配的 C-DFSP 对照病例的 CD34 和 PRAME 阳性表达。然后使用开源生物成像分析软件 QuPath 计算的 H 评分对结果进行了客观和半定量评估。结果表明，FS-DFSP 中的 PRAME H 评分明显高于 C-DFSP（p=0.0137）。对于 CD34，FS-DFSP 中的 H 评分明显低于 C-DFSP（p<0.001）。使用这两种免疫组织化学分析相结合，FS-DFSP 的诊断灵敏度和特异性分别为 86%和 90%。CD34 和 PRAME 的双重染色显示，PRAME 阳性和 CD34 阳性区域不重叠。这是研究 FS-DFSP 中 PRAME 表达的最大研究，证实了 PRAME 在诊断这种疾病中的有用性。
