We therefore decided to undertake experimental work to characterize the nature of infiltrating lymphoid cells in order to gain insight into the mechanism of autoreactivity in vitiligo. Ten patients with active disseminated vitiligo who had been diagnosed within 3 months prior to their inclusion in the study (early disease) and 10 other patients who had been diagnosed more than 2 years previously (late disease) were enrolled into the study. None had ever received topical or systemic immunosuppressant therapy, and ‘early disease’ cases had had no therapy. PLX4032 in vitro All patients were aware of the risks and signed a Clinical Investigation Agreement to participate in the study. The study

protocol was approved by the Research and Ethics Committee of the Centro de Hematología y Medicina Interna de Puebla, Laboratorios Cínicos de Puebla, and Laboratorios Clínicos de Puebla de Bioequivalencia. Punch skin biopsies were obtained from all patients. All biopsies were fixed in 10% buffered

formaldehyde and paraffin-embedded by routine methods. Sections were then rehydrated by sequential immersion in xylene and decreasing water solutions of ethanol for immunochemical staining. Antibodies to CD1a, CD2, CD3, CD4, CD5, CD8, CD20, CD25, CD30, CD56, CD68 and CD79a were used to characterize the lymphoid infiltrates in all biopsies. Citrate pH6 buffer (Citrates®; Cell Marque, Rocklin, CA, USA) was used for Daporinad concentration antigenic recovery of CD3, an ethylenediamine tetraacetic acid (EDTA) Parvulin pH8 buffer (Trilogy®; Cell Marque) for the recovery of CD1a, CD2, CD4, CD5, CD8, CD20, CD30 and CD56 and an EDTA pH6 buffer (Decleare®; Cell Marque) for CD25, CD68 and CD79a. Immunochemical staining was performed with the aid of an automated platform (Dakoautostainer plus®; Dako, Glostrup, Denmark), and an alkaline

phosphatase polymer (UltraVision Labeled Polimer®; Labvision) and Fast Red C were used to unravel the binding of the different antibodies [1, 27-29]. Different positive and negative control tissue samples were run simultaneously to ascertain the sensitivity and specificity of each antigen–antibody reaction in the system. Two independent and skilled professionals counted the proportions of cells expressing each of the antigens in each of the biopsies. At least 200 cells were counted to determine the percentages of infiltrating cells expressing each of the CD antigens that were searched. A statistical t-test for paired observations was used to compare the mean values of the percentages of the different cell types between early and late disease lesions infiltrates. The MedCalc® (Ostend, Belgium) software package was used for this purpose. Table 1 summarizes the mean values and standard deviations of such figures in both biopsies from early and late disease biopsies. Figure 1 depicts the main changes in the proportions of cell subsets in biopsies from patients with lesions less than 3 months old (Fig.