C4d and C3d immunohistochemical evaluation on formalin-fixed paraffin-embedded tissue for the diagnosis of bullous pemphigoid: systematic review of the literatures

Several methods are available for the diagnosis of autoimmune bullous disease. Since the immunohistochemistry of complement component is easy and more accessible compared to other methods, it is thought that this technique as an efficient method can replace other difficult, and time-consuming procedures. Therefore, in this study we aimed to systematically review the literatures in which the diagnostic value of complement component 3d (C3d) and C4d had been investigated in bullous pemphigoid.
A systematic search was conducted in the PubMed, Google scholar, and Scopus using following search method (((C3d OR C4d OR complement component 3d OR complement component 4d immunohistochemistry)) OR (C3d OR C4d marker OR complement component 3d OR complement component 4d marker)) AND (bullous pemphigoid OR cutaneous pemphigoid) to evaluate the diagnostic value of C3d and/or C4d for early and accurate detection of bullous pemphigoid on November 2015. Subsequently, the extracted data were described.
Total of 28 documents were collected and reviewed based on the purpose of this study. Of the collected articles, 21 documents were excluded in several steps of article selection process and only 7 relevant articles were included for data assessment. The results showed that the deposits of C3d and/or C4d in skin biopsies were found in 125 of 134 patients, indicating that immunohistochemistry is a reliable technique for the diagnosis of inflammatory skin diseases.
The results of this review showed that C3d and/or C4d immunohistochemistry in skin biopsies is a reliable technique for the diagnosis of inflammatory skin diseases, particularly bullous pemphigoid.