犬全身型盘状红斑狼疮（10例病例）的临床及显微特征-（3） - 宠医帮

Generalized DLE affected various breeds of dogs and their crosses with an equal representation of male and female dogs. In humans with GDLE, women are affected more often than men (female-to-male ratio of 1.5). Interestingly, and surprisingly, German shepherd dogs, a breed predisposed to develop several forms of LE, such as SLE, localized facial DLE and MCLE, were not represented in this population. This discrepancy may be explained by the German shepherd dog breed not being predisposed to GDLE, by the small size of our study group or by a possible clinical misdiagnosis of this disease as“idiopathic lichenoid dermatoses”based on histopathological identification of a“lichenoid tissue reaction” in dogs. Indeed, one dog from our series had been initially diagnosed and referred with such a diagnosis. The age of onset of GDLE was variable, with most dogs exhibiting their first skin lesions in mid to late adulthood. A comparable age of onset is reported for humans with DLE, as the disease most commonly develops in the fourth to fifth decade.

各种品种的犬及其杂交犬都会患GDLE，雌雄比例相当。在人GDLE中，女性发病率高于男性（女性与男性比例为1.5）。耐人寻味的是，德国牧羊犬，这种倾向于患几种LE（如SLE、局部面部DLE和MCLE）的品种，并未患GDLE。这种差异可能是德国牧羊犬这个品种不倾向于GDLE，或因我们研究规模较小，或因根据犬“苔藓样变组织反应“的组织病理学鉴定，而在临床上可能误诊为“特发性苔藓样变皮肤病”。的确，我们病例报告里有1只犬在最初诊断为这种疾病。GDLE的发病年龄各不相同，多数犬在中年至中老年出现第一次皮肤病变。据报道，人DLE的年龄差异不大，通常在40-50岁发病。

Figure 6. Histopathology of canine GDLE. A marked, subepidermal, band-like (lichenoid) infiltrate of lymphocytes with fewer plasma cells is associated with a lymphocytic interface dermatitis reaction. Basal keratinocyte vacuolation and apoptosis (inset, arrows) are moderate to marqked and are associated with pigmentary incontinence. The hyperplastic epidermis is multifocally attenuated. Basement membrane zone thickening is present (inset, arrowhead). The middle and deep dermis have minimal perivascular inflammation. Case 2; haematoxylin and eosin, magnification 100x, inset magnification 400x.

As defined by our inclusion criteria (i.e. lesions resembling those of human GDLE), erythematous disc-like plaques with adherent scaling that extended into hair follicles and dyspigmentation were seen in all of our cases. The central loss of normal skin texture and scarring that occurred as the result of long term persistent DLE activity was present in the centre of skin lesions of all but one dog. Follicular plugging (i.e. comedones) was a prominent feature of canine GDLE, as it is in the human disease. However, the characteristic “carpet tack” sign seen in human DLE, which are follicular-sized keratotic spikes similar in appearance to carpet tacks at the under surface of removed adherent scales, unfortunately was not assessed in these cases. However, papular, corneocyte-plugged follicles within areas of hyperpigmentation in the concave pinnae and caudal (lateral) ear margin, a pattern highly specific for human DLE, was also seen in several of the canine cases. Although any ethnic group can be affected with human DLE, collective data indicate that skin lesions with typical inflammatory hypo- and hyperpigmentation are more frequent in darker-skinned individuals, whereas in patients with light skin, plaques usually appear grey or have minimal pigment alteration. Interestingly, a diffuse reticulated hyperpigmentation on the ventral abdomen and lateral thorax was present in two dogs. Such an unique pigmentation pattern has been reported in a dog with an alopecic variant of CCLE, dogs with MCLE and recently in a dog with a presumptive idiopathic EM.

根据我们的纳入标准（即类似于人GDLE的病变），我们所有的病例里可见红斑性盘状斑块，伴随着延伸至毛囊的粘附性皮屑和色素沉着异常。除1只犬外，其他所有犬的皮肤病变中央存在由于长期持续的DLE活跃导致的正常皮肤结构中央缺失和斑痕。毛囊栓塞（即黑头粉刺）是犬GDLE标志特征，跟人相似。但人DLE中可见的“地毯钉”标志特征，即毛囊大小的角化棘刺，其外观与去除粘附性皮屑后表面下的地毯钉相似，可惜的是在这些犬的病例中未做评估。然而一些犬病例中可见在耳廓凹面和耳缘尾侧（外侧）的色素沉着区出现了丘疹、角化细胞堵塞的毛囊，对人DLE有高度特异性。尽管任何种族的人都有可能患DLE，但集体数据表明典型炎症性色素减退和色素沉着的皮肤病变常出现在肤色较深的个体中，而在肤色较浅的患者中，斑块通常为灰色或最轻度的色素改变。有趣的是，在2只犬的腹侧和胸侧出现了弥散性网状色素沉着。这种奇特的色素模式在CCLE的脱毛亚型、MCLE和最近假定为特发性EM的犬中均有过报道。

erosive skin lesions, sometimes with peripheral hyperpigmentation, that are restricted to mucocutaneous regions predominate, but the depigmentation and scarring of GDLE are typically not seen in these dogs. Remarkably, one dog with GDLE and liver-associated NME developed classical DLE lesions of depigmentation, erythema, scarring and crusting at perioral, periocular and perianal areas, long after the development and apparent healing of the initial NME-associated oedematous and erosive lesions. The occurrence of DLE lesions in this dog at previous NME-associated mucocutaneous locations could be evidence suggesting that GDLE lesions, similarly to those of human DLE, can follow any form of cutaneous trauma, a response known as the Koebner phenomenon.

在人DLE中，离散的斑块可发展为鼻部、结膜和生殖器的黏膜。虽然本研究的4只犬在皮肤黏膜区有典型的DLE病变，常见生殖器/生殖器周围，但它们的特征与犬MCLE的病变有显著差异。MCLE主要是特征性大面积广泛糜烂的皮肤病变，有时伴有周围色素沉着，主要受限于皮肤黏膜区，但这些犬中未见GDLE典型的色素减退和瘢痕。值得注意的是，一只GDLE和伴有+肝脏相关NME患犬，发展为经典DLE病变犬，即在最初NME相关的水肿和糜烂病变明显愈合很久之后，在口周、眼周和肛周区域出现色素减退、红斑、瘢痕和结痂。这只犬在以前NME相关皮肤黏膜区域出现DLE病变证明了GDLE病变，类似于人DLE，可以有任何形式的皮肤损伤，被称为Koebner现象。

In humans affected with the generalized variant of DLE, a positive ANA titre is frequently found, and it represents a risk factor for development of SLE within 5 years after the initial diagnosis of skin lesions. Seven dogs in this report had a low positive ANA serum titre, but a progression to the exhibition of additional criteria for SLE was not seen in any dog within a median follow-up of 2.5 years (range from 0.5 to 6 years). To the best of the authors’knowledge, the progression from a CCLE variant to SLE has been reported only in one dog.

The histology of DLE in humans is characterized by a lichenoid interface dermatitis reaction pattern, which was an inclusion criterion in this study (i.e. cell-rich, lymphocytic interface dermatitis). Like typical, fully developed DLE in humans, interface dermatitis occurred in a hyperplastic epidermis with focal areas of epidermal atrophy, epidermal hyperpigmentation or depigmentation, and pigmentary incontinence.Similarly to human GDLE, the interface reaction (vacuolar degeneration, apoptosis and loss of basal cells) was well developed and more severe than is typical of localized DLE in dogs. As a consequence of this severity, microscopic intrabasal clefts were observed in two cases. Apoptosis of suprabasal keratinocytes occurs in canine and human CLE and was common in our dogs with GDLE. Interface dermatitis and basement membrane thickening were more prominent than suprabasal apoptosis and satellitosis; the latter two findings typically are also seen in the context of EM and toxic epidermal necrolysis. Interestingly, occasional foci of grouped suprabasal apoptosis, in conjunction with lymphocytic satellitosis, were observed and mimicked an EM-type reaction pattern in a few skin sections. Similar observations of increased suprabasal apoptosis were identified in association with skin chronicity in ECLE of German shorthaired pointers, and they have been reported for canine localized DLE as well. With the addition of these cases, suprabasal keratinocyte apoptosis is now recognized in several different forms of CCLE in dogs, including localized DLE, GDLE, MCLE and ECLE. It should be noted that solar injury is an additional factor that both exacerbates LE lesions in dogs and humans, and sun induced damage could contribute to the development of apoptosis of suprabasal keratinocytes.

人DLE的组织学表现为特征性的苔藓样变界面性皮炎反应，此为本研究的一个纳入标准（即富含细胞的淋巴细胞界面性皮炎）。像是人典型的、成熟的DLE，表现为表皮层增生出现界面性皮炎，伴随着局部表皮萎缩、表皮色素沉着或色素减退和色素失禁。类似于人GDLE，界面性反应（空泡变性、细胞凋亡和基底细胞缺失）发育良好且比犬典型的局部DLE更为严重。由于其严重性，2例病例中观察到显微镜基底内开裂。犬和人CLE常发生基底上层角质细胞凋亡，犬GDLE中常见。界面性皮炎和基底膜增厚比基底上层细胞凋亡和卫星现象更明显；基底上层细胞凋亡和卫星现象也常见于EM和中毒性表皮坏死性松懈症（TEN）。有趣的是，偶见基底上层细胞凋亡灶，伴有淋巴细胞卫星现象，少数皮肤切片上观察类似EM的反应模式。在德国短毛指示犬的ECLE中发现了与皮肤慢性相关的基底上层细胞凋亡增加的类似观察结果，在犬局部DLE中也有报道。随着这些病例的增加，基底上层角质细胞凋亡在犬CCLE的不同亚型（包括局部DLE、GDLE、MCLE和ECLE）中都有发现。值得注意的是，日光损伤是加剧犬和人LE病变的另一因素，日光诱导的损伤有助于基底上层角质细胞凋亡。

Lichenoid inflammation, a subepidermal band of lymphocytic infiltration, predominated in our cases with GDLE, and similarly to late stage DLE lesions in humans, this band was sometimes greatly diminished in areas of superficial dermal fibrosis. Additionally, a lichenoid band was absent in two cases, which is a feature of early DLE lesions in humans. In our dogs, a perivascular pattern of inflammation was mild superficially and usually absent in the middle and deep dermis, which is similar to dogs with localized DLE. This is in contrast to humans with localized DLE or GDLE where perivascular inflammation is often well developed throughout the dermis.

Thickening of the BMZ occurred in 60% of our cases and this is a characteristic, but not specific, feature of CCLE in dogs and humans. Clinical scarring was attributed to the superficial dermal fibrosis observed histologically. Increased epidermal and dermal mucin deposits have been proposed as an additional diagnostic factor for localized DLE in the dog; however, the detection of skin mucin deposits alone has limited specificity in humans and is common in other dermatoses such as EM, lichen planus and fixed drug reactions. Detailed studies characterizing skin mucin distribution and deposition in canine CLE variants (localized DLE, GDLE, ECLE, VCLE, MCLE) and other diseases (EM variants, ischemic dermatopathy) are necessary to elucidate whether mucin deposition in the skin of dogs with CLE is a specific finding and is able to distinguish between different disease entities. Similarly to human CLE forms, in which histopathological findings can overlap and may not clearly differentiate between subtypes, our study suggest that biopsy findings alone do not differentiate GDLE from other forms of canine CCLE (localized DLE, MCLE and ECLE) or SLE.

60%的病例发生了BMZ增厚，这是犬和人CCLE的一个并不是特定的特征。临床瘢痕病变是组织学上观察到的真皮浅层纤维化所致。表皮和真皮黏蛋白沉积的增加被建议作为犬局部DLE的另一诊断性因素；然而，仅检测皮肤黏蛋白沉积在人中的特异性有限，也常见于其他皮肤病，如EM、扁平苔藓和特定药物反应。有必要详细研究来描述犬CLE变异型（局部DLE、GDLE、ECLE、VCLE、MCLE）和其他疾病（EM亚型、缺血性皮肤病）的皮肤黏蛋白的分布和沉积，以阐明犬CLE皮肤的黏蛋白沉积是一个特别的发现，并可区分不同的疾病种类。与人CLE类型相似，组织病理学部分相同，可能没办法明确区分亚型，我们研究表明，仅活检结果没办法把GDLE与犬CCLE的其他类型（局部DLE、MCLE和ECLE）或SLE区分开来。

Scarring alopecia occurs on the head in localized DLE in dogs but histological descriptions of follicular changes are lacking. In humans, when localized DLE involves the scalp, scarring alopecia is relatively common, occurring in 34% of DLE skin sections in one study; it is associated with lymphocytic interface folliculitis and follicular atrophy. Human DLE is classified as a primary scarring (cicatricial) alopecia because permanent alopecia occurs clinically and direct lymphocytic targeting of the follicle(interface folliculitis) is associated with follicular atrophy and, ultimately, loss of the follicular epithelium- the follicular scarring event. Concentric laminar fibrosis occurs around the infundibulum and mid-follicle but it is a mild, late stage event and is not the main reason for classification of DLE as a scarring alopecia. In our study of canine GDLE, alopecia occurred in nearly all cases and lymphocytic interface folliculitis involved the infundibulum and extended into the isthmus as for human DLE. Lymphocytic mural folliculitis was also common, usually milder and involved the infundibulum, isthmus and inferior hair follicle segments, typically sparing the bulb. This mural pattern mirrors that of human DLE, where it is also called a panfollicular pattern, but it is considered to be minimal and poorly described. Follicular atrophy was present in all cases and ranged from partial to complete. The combination of lymphocytic interface folliculitis, advanced follicular atrophy and lack of hair regrowth in a subset of dogs supports the classification of canine GDLE as a primary scarring alopecia. Perifollicular fibrosis was not a feature in our study, however. Follicular hyperkeratosis, plugging and dilation occurred in our cases clinically, as is reported in human DLE, but related histological changes in follicles were very limited, a clinicopathological discrepancy that some authors have noted for human DLE. Appropriate biopsy site selection for GDLE lesions is at the periphery of the lesion, which presumably has less advanced follicular injury than older central areas, and this could explain the limited infundibular changes and perifollicular fibrosis histologically in the present study. Sebaceous gland atrophy in our cases was sometimes complete and often mild and partial, which is similar to descriptions of human DLE, but lacked the mild glandular lymphocytic infiltrate that can occur. In dogs with ECLE, partial to complete sebaceous gland atrophy occurs in synchrony with follicular atrophy; it is associated with a mild lymphocytic periglandular infiltrate, which we did not see in our cases.

犬局部DLE头部出现瘢痕性脱毛，但缺乏毛囊变化的组织学描述。在人上局部DLE涉及到头部，瘢痕性脱毛相对常见，在一项研究中DLE皮肤切片出现这种现象的占34%；与淋巴细胞界面性毛囊炎和毛囊萎缩相关。人DLE归类于原发性瘢痕性脱毛，因为临床上会发生永久性脱毛，且淋巴细胞直接靶向作用毛囊（界面性毛囊炎）与毛囊萎缩相关，最终导致毛囊上皮缺失即毛囊瘢痕。在毛囊漏斗部和毛囊中部周围发生同心片状纤维化，但这是一种轻度、晚期症状，不是DLE瘢痕性脱毛的主要原因。在我们犬GDLE研究中，几乎所有病例都会出现脱毛，淋巴细胞界面性毛囊炎涉及了毛囊漏斗部，并延伸至毛囊峡部，与人CLE一致。亦常见淋巴细胞毛囊壁炎，一般较轻，涉及了毛囊漏斗部、毛囊峡部和毛囊下部，通常不涉及毛球部。这种毛囊壁炎模式也反映在人DLE中，亦被称之为泛发性毛囊炎，但认为是最轻度的，描述不充分。所有病例都存在从局部到完全的毛囊萎缩。在一组犬中淋巴细胞界面性毛囊炎、晚期毛囊萎缩和无毛发再生，三者结合支持了犬GDLE应归类于原发性瘢痕性脱毛。然而，在我们的研究中毛囊周纤维化并不是一个特征。在我们的临床病例中出现了毛囊角化过度、栓塞和扩张，在人中亦有报道，但相关的毛囊组织学改变非常有限，一些作者注意到人DLE中有临床病理差异。对于GDLE病变，适当活检位置的选择是在病变边缘，这可能是由于与时间较久的中央区相比，边缘毛囊损伤较轻，这可在组织学上解释在本研究中有限的漏斗部变化和毛囊周纤维化。在我们病例中有时出现完全的皮脂腺萎缩通常是轻度、局部，与人DLE相似，但可能缺乏轻度的腺体淋巴细胞浸润。犬ECLE，局部到完全的皮脂腺萎缩伴随着毛囊萎缩同时发生；这与轻度淋巴细胞腺体周浸润相关，但在我们病例中未发现。

The LBT initially was considered to be quite specific for human CLE but controversies regarding terminology(number of different deposits at dermo-epidermal junction) and standardization (lesional versus nonlesional skin,sun exposed versus sun protected skin) have clouded its diagnostic value. A positive LBT in sun protected nonlesional skin appears to have the highest diagnostic specificity for clinical association with SLE. Furthermore, most authors agree that the LBT specificity and predictive value increases with the number of immunoreactants detected at the dermal epidermal junction. In our series, a linear deposition of IgG and IgM at the dermo-epidermal basement membrane zone (i.e. a positive LBT) of lesional skin was found in 90% of cases, resembling the findings seen in human DLE lesions. Interestingly, the most commonly detected immunoreactant deposited in facial-predominant canine localized DLE was C3 (90-100%), whereas IgG and IgM were revealed in 40-70% of cases, respectively. These variable results between canine localized and generalized DLE could be related to differences in tissue fixation techniques (frozen versus formalin), antigen retrieval methods and/or immunofluorescence staining protocols. To investigate the value of performing DIF in canine CLE diagnostic investigation, future studies regarding the sensitivity and specificity of a positive LBT for the diagnosis of CLE variants are warranted.

此外，多数作者认为LBT的特异性和预测值随着真皮-表皮交界处检测到的免疫反应物数量的增加而增加。本研究中，90%的病例的皮肤病变在真皮-表皮基底膜区发现lgG和lgM的线性沉积（即LBT阳性），类似于人DLE的病变。有趣的是，在犬面部DLE中最常见的免疫反应物沉积为C3（90%-100%），lgG为40%，lgM为70%。犬局部和全身型DLE的不同结果可能与组织固定技术（冷冻与福尔马林）、抗原提取方法和/或免疫荧光染色方法的差异相关。为了研究DIF在犬CLE诊断中的价值，有必要进一步研究LBT阳性在犬CLE变异型诊断的敏感性和特异性。

Currently, there are no medications approved specifically for the treatment of human CLE. Besides photoprotection, glucocorticoids and/or calcineurin inhibitors remain the classic topical approach for localized DLE, whereas the systemic drug of choice is the antimalarial drug HCQ. In this report, various treatment regimens were successfully used to treat dogs with GDLE. Oral HCQ in conjunction with topical tacrolimus application helped to induce and maintain remission of skin lesions in two dogs with this disease. Although retinal toxicity limits the use of HCQ in humans, it was not observed in any dog in this case series or in dogs with ECLE. In our study, a remarkable improvement or a complete remission in GDLE skin lesions followed treatment with ciclosporin along with a short course of glucocorticoids at its onset. Given that ciclosporin and tacrolimus share a similar mechanism of action on T-lymphocytes, and that tacrolimus ointment has been used successfully for topical treatment of human and canine localized DLE, we had inferred that ciclosporin might be beneficial for treatment of canine GDLE. Interestingly, ciclosporin is no longer recommended for treatment of human CLE due to a relatively unfavourable risk-benefit profile.

目前，还没有批准专门用于人CLE治疗的药物。除防晒外，糖皮质激素和/或钙调磷酸酶抑制剂仍是局部DLE的经典外部治疗，而全身药物选择是抗疟药HCQ。本报告中，各种治疗方案成功用于犬GDLE的治疗。在2只这种疾病犬中口服HCQ+外用他克莫司有助于诱导和维持皮肤病变缓解。虽然视网膜毒性限制了HCQ在人上的使用，但本研究的病例的所有犬或ECLE犬中未观察到出现视网膜毒性。本研究中，使用环孢素治疗以及发病时短期糖皮质激素治疗，GDLE皮肤病变明显改善或完全缓解。鉴于环孢素和他克莫司对T淋巴细胞的作用机制相似，且他克莫司软膏已成功用于人和犬局部DLE的外部治疗，我们推测环孢素可能对犬GDLE治疗有效。有趣的是，环孢素不再推荐用于人CLE的治疗，因为相对不利的利弊权衡。

Since 1992, antibiotics of the tetracycline family along with niacinamide have been suggested to be beneficial for treatment of canine immune-mediated skin diseases, including the CLE variants; localized DLE, ECLE and MCLE. In our case series, one dog did not respond to a 4 month combination of doxycycline and niacinamide, whereas another dog had a complete remission of signs with tetracycline and niacinamide. In humans, evidence exists on the equipotency of different tetracycline for therapy of bullous pemphigoid, as some authors successfully used doxycycline or minocycline as an alternative to tetracycline. Although tetracycline and doxycycline were shown to be relatively similar in effectiveness to treat canine lupoid onychodystrophy (idiopathic onychitis/ ), there are no data on which of the tetracyclines is more effective, and whether niacinamide is of synergistic value for treatment of CLE variants in dogs; this needs to be studied further.

自1992年来，四环素类抗生素联合烟酰胺已被建议用于治疗犬免疫介导性皮肤病，包括CLE亚型；局部DLE、ECLE和MCLE。我们的病例报告中，1只犬使用4个月多西环素+烟酰胺治疗未见效，另1只使用四环素+烟酰胺治疗后症状完全缓解。在人中，存在不同四环素在治疗大疱性类天疱疮等效性证据，如一些作者成功地用多西环素或米诺环素替代了四环素。虽然对比四环素和多西环素在治疗犬类狼疮甲变形时（特发性甲床炎/甲脱落）疗效相似，但尚未有数据表明哪一种四环素更有疗效，烟酰胺对治疗犬CLE亚型是否有协同价值；尚需要进一步研究。

In conclusion, we report herein 10 dogs with an unique clinical phenotype as well as histological and immunofluorescence findings that resemble the features of generalized human DLE patients. Skin lesions of canine GDLE appear to respond to a wide range of treatments, but half of the cases experienced relapses upon the tapering of drug dosages. Our limited outcome data suggest that ciclosporin should be considered as a potentially effective therapeutic option for canine GDLE, especially for dogs refractory to HCQ, niacinamide and tetracycline therapy.