[A middle to long-term clinical study on pars flaccida and pars tensa cholesteatoma using survival analysis].

The current clinical study was performed on 311 cases of pars flaccida and 89 cases of pars tensa cholesteatoma which were treated with canal wall reconstructed tympanoplasty between 1991 and 2012. The average follow-up time of these patients was 5.3 years. Since follow-up periods were different in each case and some censored patients were involved, we used survival analysis on this study to discuss the cumulative rates of disease-free successful cases and the rates of recurrent cholesteatoma throughout the postoperative course. The disease-free successful cases were defined as those cases in which patients were both out of re-operation with recurrent and residual cholesteatoma and out of revision operation with another problem, furthermore, maintained good hearing outcome. Based on the criteria set by the Japan Otological Society (2010), the cases that satisfied the following were evaluated as good hearing results; (a) a successful case in which preoperative bone conduction was used, and (b) a case in which the postoperative air-bone gap was within 20dB after tympanoplasty for chronic otitis media. The analysis results were shown for each of (a) and (b). 1. In pars flaccida cholesteatoma, the 5-year survival rate of successful case was (a) 76.1% and (b) 83.9%, the 10-year survival rate was (a) 58.9% and (b) 73.0%. In pars tensa cholesteatoma, the 5-year survival rate of successful cases was (a) 57.7% and (b) 63.5%, the 10-year rate was (a) 42.1% and (b) 56.9%. A significant difference was seen between pars flaccida and pars tensa cholesteatoma (p < 0.001). 2. In pars flaccida cholesteatoma, the 5-year recurrence rate was 7.6% and the 10-year rate was 15.3%, and the recurrence rate increased gradually throughout the follow-up period. On the other hand, in pars tensa cholesteatoma, the increase in the recurrence rate reached a peak 15.8% at 5.5 years after the surgery. A long-term follow-up is necessary when evaluating the clinical results after tympanoplasty.

Arachidonate 5-lipoxygenase establishes adaptive humoral immunity by controlling primary B cells and their cognate T-cell help.

In this study, we report the unique role of arachidonate 5-lipoxygenase (Alox5) in the regulation of specific humoral immune responses. We previously reported an L22 monoclonal antibody with which human primary resting B cells in the mantle zones of lymphoid follicles are well-defined. Proteomics analyses enabled identification of an L22 antigen as Alox5, which was highly expressed by naive and memory B cells surrounding germinal centers. Cellular growth of mantle cell lymphoma cells also seemed to depend on Alox5. Alox5(-/-) mice exhibited weak antibody responses specific to foreign antigens at the initial and recall phases. This was probably attributable to the low number of follicular and memory B cells and the functional loss of interleukin-21-mediated responses of follicular B cells. Moreover, Alox5(-/-) mice could not fully foster the development of follicular B helper T (Tfh) cells even after immunization with foreign antigens. Further experiments indicated that Alox5 affected mortality in experimentally induced enterocolitis in germ-prone circumstances, indicating that Alox5 would endow immunologic milieu. Our results illustrate the novel role of Alox5 in adaptive humoral immunity by managing primary B cells and Tfh cells in vivo.

p63 induces CD4+ T-cell chemoattractant TARC/CCL17 in human epithelial cells.

To preserve immunosurveillance, epithelial cells support T-cell trafficking toward inflammatory foci. However, how epithelial cells are enrolled in recruiting T cells has not been fully elucidated. In this study we investigated the function of p63, a p53 family member, in the regulation of the expression of various types of chemokine ligands by focusing on the property of p63 as an epitheliotropic transcription factor. As assessed by experiments using three different human epithelial cell lines with small-interfering RNAs or plasmids of p63, certain CC chemokine ligands were found to be under the control of p63. In these CC chemokine ligands, p63 had the common capacity to upregulate TARC/CCL17 in the different cell lines, whose receptor CCR4 was preferentially presented on CD4(+) T cells such as memory, regulatory, IL-17-producing and type II helper T cells. More interestingly, when cells were stimulated with transforming growth factor-beta (TGF-beta) or epidermal growth factor (EGF) as observed during tissue repair process, the expression of p63 and TARC/CCL17 was concomitantly suppressed. This implies that, in local inflammatory regions with general epithelial tissue remodeling, the p63-TARC/CCL17 axis may participate in the engagement of efficient immune reactions by specified T-cell subsets.