No basophils were detected in the control specimens. Open in a separate window Fig. a monoclonal antibody against a basophil marker ProMBP1 we investigated the Rabbit Polyclonal to AIG1 number and distribution of basophils in the KD lesions. By double immunohistochemistry we analyzed the colocalization of IL-4 in basophils. Results There was an increased number of basophils infiltrating the KD parotid gland lesions as compared to that in normal control parotid tissue. By double-immunofluorescence we found that approximately 7% of IL-4-positive cells in KD patients’ parotid glands were basophils. Conclusion Basophils may also play a role in the Picroside II pathogenesis of KD, leading to the induction of IgE synthesis and eosinophil infiltration. value of less than 0.05 was considered statistically significant. RESULTS Subjects’ characteristics The age ranges of the KD and control patients showed no significant difference. The number of blood eosinophils (3,499.1/L [1,207C8,628/L]) ( 0.01) in the KD patients was significantly higher than that (82.5/L Picroside II [31C290/L]) in the controls. The serum total IgE level (5196.6 IU/mL [410C16,000 IU/mL]) ( 0.01) in KD patients were significantly higher than that (125.0 IU/mL [6C595 IU/mL]) in the controls. The number of blood basophils (76.3/L [39C127/L]) tended to be higher in the KD patients than that (25.5/L [20C111/L]) in the controls, but without statistical significance. Number and distribution of eosinophils The number of eosinophils (Congo red staining) was significantly greater in the KD patients’ parotid glands (median, 272.0/mm2; range, 24.8C589.6/mm2) than in the control subjects’ parotid glands, which contained no detectable eosinophils (median, 0; range, 0C0; 0.01). Eosinophils were localized mainly between the lymphoid follicles. Number and distribution of basophils The number of ProMBP1-positive cells (i.e., basophils) was significantly greater in KD patients’ parotid glands (median, 77.6/mm2; range, 16.0C140.0/mm2) compared with the control subjects’ parotid glands ( 0.01) (Figs. 1, ?,2).2). Basophils had infiltrated between the lymphoid follicles in KD (Fig. 2A, B). No basophils were detected in Picroside II the control specimens. Open in a separate window Fig. 1 Numbers of proMBP1-positive cells in KD and normal parotid glands. Box plots represent the median values with 25% and 75% interquartiles. The error bars represent the 10th and 90th percentiles. Each group, n = 6. * 0.01. proMBP1, pro-form of major basic protein 1. Open in a separate window Fig. 2 Immunolocalization of proMBP1 in the parotid lesion of Kimura disease. (A) Low magnification and (B) high magnification. (C) Same tissue stained with control antibody. LF, lymphoid follicle; proMBP1, pro-form of major basic protein 1. Percentage of IL-4-positive cells that were basophils ProMBP1-positive cells (i.e., basophils) comprised 6.8% (median; range, 2.6%C17.8%) of the IL-4-positive cells in KD patients’ parotid glands (Fig. 3). No IL-4 positive cells were detected in the control specimens. Open in a separate window Fig. 3 Immunohistochemical identification of interleukin (IL)-4-positive, proMBP1-positive cells in the Kimura disease parotid gland by the double-immunofluorescence method. Images staining positive for IL-4 (red) (A), proMBP1 (green) (B), and their merger (C). The yellow signal (arrow) in panel C indicates colocalization of IL-4 and proMBP1. proMBP1, pro-form of major basic protein 1. DISCUSSION The present study exhibited for the first time, that basophils infiltrate the parotid gland lesions of KD. The basophils were found to infiltrate between the lymphoid follicles. Also basophils infiltrating the KD parotid gland lesions were positive for IL-4 protein. Our findings indicate that this infiltrating basophils are functionally involved in the pathogenesis Picroside II of the Th2 inflammation of KD by enhancing IgE production, eosinophil infiltration, etc., at the lesional sites. Since the discovery of basophils, their functions were not well defined. There were various reasons for the inability to elucidate the functions, including the fact that: basophils account for only 0.5% of peripheral blood mononuclear cells. Moreover unlike mast cells, there are no animal models that are deficient only in basophils. Basophils have few specific surface markers and basophils were difficult to differentiate from mast cells. A number of basophil-specific antibodies, such as BSP-1 [10], 2D7 [11], 97A6 [12], and BB1 [13,14], have been established. However, although BSP-1 and 97A6 recognize basophil surface markers, Picroside II they have problems such as inadequate sensitivity, also recognize mast cells, etc. [11,12]. 2D7 and BB1 specifically recognize basophils, but their ligands are unknown [11,13]. However, a monoclonal antibody against the proMBP1 was developed, and it is said to be specific for basophils [15]. We used monoclonal antibodies specific for tryptase and proMBP1 to perform double-immunofluorescence staining of the same tissue specimens, and we were able to clearly differentiate between tryptase-positive cells (mast cells) and proMBP1-positive cells (basophils) (data not.