Department of Dermatology, Copenhagen University Hospital - Bispebjerg and Frederiksberg, Denmark.
Department of Biology, University of Copenhagen, Denmark.
Photodiagnosis Photodyn Ther. 2022 Mar;37:102629. doi: 10.1016/j.pdpdt.2021.102629. Epub 2021 Nov 16.
Erythropoietic protoporphyria (EPP) is a rare genetic photodermatosis caused by loss-of-function mutations in the gene for ferrochelatase leading to accumulation of the fluorescent protoporphyrin IX (PpIX) in erythrocytes. The mutations are most often inherited mutations present in all cells causing inherited EPP. In very rare cases EPP are acquired in association with myelodysplastic syndromes or myeloproliferative neoplasms, conditions with genetic instability.
We report a case of acquired EPP in association with hematological disease. We followed erythrocyte PpIX concentration over a year and measured PpIX fluorescence in individual erythrocytes in a blood sample from the case using flow cytometry. The major proportion of erythrocytes did not fluoresce (84%), whereas 13% contained low PpIX fluorescence, 1% contained medium fluorescence, and 2% contained high fluorescence.
Our observation of the very skewed PpIX distribution in erythrocytes supports the description that acquired EPP is caused by a somatic mutation effecting a clone of hematopoietic cells.
红细胞生成性原卟啉症（EPP）是一种罕见的遗传性光皮病，由亚铁螯合酶基因的功能丧失突变引起，导致荧光原卟啉 IX（PpIX）在红细胞中积累。这些突变最常见于所有细胞中存在的遗传突变，导致遗传性 EPP。在极少数情况下，EPP 与骨髓增生异常综合征或骨髓增生性肿瘤相关获得，这些疾病存在遗传不稳定性。
我们报告了一例与血液疾病相关的获得性 EPP 病例。我们在一年多的时间里跟踪红细胞 PpIX 浓度，并使用流式细胞术测量来自该病例的血液样本中单个红细胞中的 PpIX 荧光。大多数红细胞没有荧光（84%），而 13%的红细胞含有低 PpIX 荧光，1%的红细胞含有中荧光，2%的红细胞含有高荧光。
我们对红细胞中 PpIX 分布非常偏斜的观察结果支持这样的描述，即获得性 EPP 是由影响造血细胞克隆的体细胞突变引起的。
