Lath Khushboo, Chatterjee Debajyoti, Saikia Uma Nahar, Saikia Biman, Minz Ranjana, De Dipankar, Handa Sanjeev, Radotra Bishan
Departments of Histopathology.
Immunopathology.
Am J Dermatopathol. 2018 Sep;40(9):661-666. doi: 10.1097/DAD.0000000000001170.
Skin is commonly affected by vasculitic process and often subjected to biopsy. Cutaneous vasculitis can be either primary or part of a systemic vasculitic process. This study was conducted to evaluate the diagnostic utility of direct immunofluorescence (DIF) in determination of etiology of cutaneous vasculitis. All histologically proven cases of cutaneous vasculitis over the past two and half years were retrospectively analyzed along with their clinical and DIF findings (IgG, IgA, IgM, and C3). Within this study period, a total of 198 cases of small-vessel vasculitis were diagnosed based on skin biopsy and DIF findings. The mean age of patients was 31.2 years (range 1-84 years) with slight male dominance (M:F ratio 1.06:1). Henoch-Schonlein purpura/IgA vasculitis was the commonest clinical diagnosis (31%), followed by urticarial vasculitis (11%) and others. Idiopathic vasculitis was suspected in 33% cases. Overall, DIF was positive in 60% (119/198) cases, with vascular deposition of IgA being commonest, followed by C3. The clinical diagnosis of Henoch-Schonlein purpura could be confirmed in 61.5% (40/65) cases by DIF, whereas another 20 unsuspected cases were picked up as IgA vasculitis based on DIF findings. DIF findings confirmed lupus vasculitis in 50% cases. Other cases showed variable nonspecific deposition of C3 and IgM in 42% cases. DIF can be highly useful to classify cutaneous vasculitis, with maximum efficacy for diagnosis of IgA vasculitis and lupus vasculitis. It can aid in the accurate diagnosis even when the histological changes are minimal. All cases of suspected cutaneous vasculitis should be subjected to DIF.
皮肤常受血管炎病变影响，且常需进行活检。皮肤血管炎可为原发性，也可为系统性血管炎病变的一部分。本研究旨在评估直接免疫荧光（DIF）在确定皮肤血管炎病因方面的诊断效用。对过去两年半内所有经组织学证实的皮肤血管炎病例及其临床和DIF检查结果（IgG、IgA、IgM和C3）进行回顾性分析。在本研究期间，根据皮肤活检和DIF检查结果共诊断出198例小血管血管炎病例。患者的平均年龄为31.2岁（范围1 - 84岁），男性略占优势（男:女比例为1.06:1）。过敏性紫癜/IgA血管炎是最常见的临床诊断（31%），其次是荨麻疹性血管炎（11%）及其他。33%的病例怀疑为特发性血管炎。总体而言，60%（119/198）的病例DIF呈阳性，其中IgA的血管沉积最为常见，其次是C3。DIF可在61.5%（40/65）的病例中确诊过敏性紫癜，另外有20例基于DIF检查结果被诊断为IgA血管炎，而之前未被怀疑。DIF检查结果在50%的病例中确诊为狼疮性血管炎。其他病例在42%的情况下显示C3和IgM的非特异性沉积。DIF对皮肤血管炎的分类非常有用，对IgA血管炎和狼疮性血管炎的诊断效果最佳。即使组织学变化轻微，它也有助于准确诊断。所有疑似皮肤血管炎的病例均应进行DIF检查。
