Department of Dermatology.
Department of Applied Pharmacology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama 930-0194, Japan.
Eur J Dermatol. 2019 Jun 1;29(3):268-273. doi: 10.1684/ejd.2019.3560.
Mycosis fungoides (MF) is the most common variant of cutaneous T-cell lymphomas (CTCL). Itching can be a major symptom for patients with CTCL, however, itching associated with MF is not relieved by conventional therapy using anti-histamines, suggesting that histamine is not the main pruritogen. Therefore, the underlying mechanisms of itching in MF patients remain unclear.
To investigate the clinical and histopathological features associated with MF-related itching.
Skin sections from MF patients and healthy subjects were used for pathophysiological analysis and evaluation of protease activity. These results were compared with the degree of itching.
Of the MF patients, 40% did not report itching and 60% reported itching (moderate itching: 40%; strong itching: 20%). The number of eosinophils, but not mast cells, that infiltrated into skin was increased in the group with strong itching. In the skin of patients, both serine protease activity and immunoreactivity to kallikrein 5 (KLK5), a known itch mediator, increased relative to the grade of itching.
These results suggest that KLK5 and eosinophil infiltration may be involved in itching in patients with MF.
蕈样肉芽肿（MF）是皮肤 T 细胞淋巴瘤（CTCL）中最常见的变异型。瘙痒可能是 CTCL 患者的主要症状，然而，MF 相关的瘙痒不能通过使用抗组胺药的常规治疗得到缓解，这表明组胺不是主要的瘙痒原。因此，MF 患者瘙痒的潜在机制仍不清楚。
探讨与 MF 相关瘙痒相关的临床和组织病理学特征。
使用 MF 患者和健康受试者的皮肤切片进行病理生理学分析和蛋白酶活性评估。将这些结果与瘙痒程度进行比较。
在 MF 患者中，40%的患者没有报告瘙痒，60%的患者报告有瘙痒（中度瘙痒：40%；强烈瘙痒：20%）。强烈瘙痒组中浸润的嗜酸性粒细胞数量增加，而肥大细胞数量没有增加。在患者的皮肤中，丝氨酸蛋白酶活性和对已知瘙痒介质 KLK5 的免疫反应性均相对于瘙痒程度增加。
这些结果表明 KLK5 和嗜酸性粒细胞浸润可能参与了 MF 患者的瘙痒。
