PDF(Pubmed)
Abstract：
Digital dermatitis is a disease of the digital skin and causes lameness and welfare problems in dairy cattle. This study assessed the local and systemic inflammatory responses of cows with different digital dermatitis lesions and compared macroscopical and histological findings. Cow feet (n = 104) were evaluated macroscopically and skin biopsies histologically. Serum samples were analyzed for acute phase proteins (serum amyloid A and haptoglobin) and pro-inflammatory cytokines (interleukin-1 beta, interleukin-6, and tumor necrosis factor-alpha). Cows with macroscopically graded active lesions (p = 0.028) and non-active lesions (p = 0.008) had higher interleukin-1 beta levels in their serum compared to healthy cows. Interleukin-1 beta serum concentrations were also higher (p = 0.042) when comparing lesions with necrosis to lesions without necrosis. There was no difference when other cytokine or acute phase protein concentrations in healthy cows were compared to those in cows with different digital dermatitis lesions. A novel histopathological grading was developed based on the chronicity of the lesions and presence of necrosis and ulceration. The presence and number of spirochetes were graded separately. In the most severe chronic lesions, there was marked epidermal hyperplasia and hyperkeratosis with necrosis, deep ulceration, and suppurative inflammation. Spirochetes were found only in samples from necrotic lesions. This study established that digital dermatitis activates proinflammatory cytokines. However, this did not initiate the release of acute phase proteins from the liver. A histopathological grading that takes into account the age and severity of the lesions and presence of spirochetes was developed to better understand the progression of the disease. It is proposed that necrosis of the skin is a result of ischemic necrosis following reduced blood flow in the dermal papillae due to pressure and shear stress caused by thickened epidermis, and that the spirochetes are secondary invaders following tissue necrosis.
摘要：
数字皮炎是一种数字皮肤疾病，会导致奶牛跛行和福利问题。这项研究评估了具有不同数字皮炎病变的奶牛的局部和全身炎症反应，并比较了宏观和组织学发现。对牛脚（n=104）进行宏观评估，对皮肤进行组织学活检。分析血清样品的急性期蛋白（血清淀粉样蛋白A和触珠蛋白）和促炎细胞因子（白细胞介素-1β，白细胞介素-6和肿瘤坏死因子-α）。与健康奶牛相比，具有宏观分级的活动性病变（p=0.028）和非活动性病变（p=0.008）的奶牛血清中的白介素1β水平更高。当将具有坏死的病变与没有坏死的病变进行比较时,白细胞介素-1β血清浓度也更高(p=0.042)。将健康母牛中的其他细胞因子或急性期蛋白质浓度与具有不同指型皮炎病变的母牛中的其他细胞因子或急性期蛋白质浓度进行比较时，没有差异。根据病变的慢性性以及坏死和溃疡的存在，开发了一种新的组织病理学分级。螺旋体的存在和数量分别分级。在最严重的慢性病变中，有明显的表皮增生和角化过度伴坏死,深溃疡,化脓性炎症.仅在坏死病变的样品中发现了螺旋体。这项研究确定了数字皮炎激活促炎细胞因子。然而,这并没有启动急性时相蛋白从肝脏的释放.为了更好地了解疾病的进展，制定了考虑病变的年龄和严重程度以及螺旋体存在的组织病理学分级。有人提出，皮肤坏死是由于表皮增厚引起的压力和剪切应力，真皮乳头中的血流减少后缺血性坏死的结果。螺旋体是组织坏死后的继发性入侵者。
