Department of Dermatology, Archet 2 Hospital, Nice, France; INSERM U895 Team 1, Nice, France.
Department of Dermatology, Archet 2 Hospital, Nice, France.
J Am Acad Dermatol. 2013 Apr;68(4):e111-e116. doi: 10.1016/j.jaad.2011.08.010. Epub 2011 Oct 2.
Patients with infantile nephropathic cystinosis have progressive accumulation of cystine in tissues leading to delayed extrarenal complications. No simple tool is available to evaluate the level of body cystine accumulation.
We sought to determine the value of in vivo reflectance confocal microscopy of the skin in patients with infantile nephrogenic cystinosis.
Nine patients and control subjects were recruited for this study. Images were acquired by means of a near-infrared reflectance confocal laser scanning microscope.
Scattered bright particles within the papillary dermis were observed in all patients but not in control subjects. The density of particles ranged from numerous (+++) to very few (+/-) and their distribution was heterogeneous. Electron microscopy confirmed that these particles corresponded to cystine crystal deposits within dermal fibroblasts. The density of cystine crystals within the dermis was greater in older patients, in patients with a high leukocyte cystine concentration, and with delayed cysteamine therapy. There was no correlation between the density of cystine deposits and renal disease or hypopigmentation but high levels of deposition occurred in association with extrarenal manifestations.
This is a preliminary study on a small sample of patients. Repeated examination and longer follow-up is necessary.
In vivo reflectance confocal microscopy of the skin appears to be a noninvasive means of assessing body cystine accumulation in infantile cystinosis and could be used as a complementary marker of treatment response in addition to leukocyte cystine measurement.
婴儿型肾源性胱氨酸贮积症患者体内组织胱氨酸不断蓄积，导致多种肾外并发症发生。目前尚无简单的方法来评估胱氨酸在体内的蓄积水平。
评估皮肤近红外反射共聚焦激光扫描显微镜（reflectance confocal microscopy of the skin，RCM）在婴儿型肾源性胱氨酸贮积症患者中的应用价值。
本研究纳入了 9 名患者和健康对照者，应用近红外反射共聚焦激光扫描显微镜采集皮肤图像。
所有患者的乳头真皮层均可见散在分布的高亮颗粒，而健康对照者无此表现。高亮颗粒的密度从很多（+++）到很少（+/ -）不等，分布不均。电镜证实这些颗粒为真皮成纤维细胞内的胱氨酸结晶沉积。真皮内胱氨酸结晶的密度与患者年龄、白细胞胱氨酸浓度、胱氨酸治疗时间相关，年龄较大、白细胞胱氨酸浓度高、胱氨酸治疗延迟的患者其结晶沉积较多。皮肤内胱氨酸沉积的密度与肾脏疾病或皮肤色素减退无相关性，但与肾外表现相关。
本研究为小样本初步研究，需要进一步重复检查和长期随访。
皮肤 RCM 可能是一种评估婴儿型胱氨酸贮积症患者体内胱氨酸蓄积的非侵入性方法，可与白细胞胱氨酸测量一起作为治疗反应的补充标志物。
