Absolute humidity as a deterministic factor affecting seasonal influenza epidemics in Japan.

Influenza epidemics occur periodically during the winter season in temperate areas. Characteristic features of winter include low temperature and low humidity. Humidity is expressed in two different ways: absolute humidity (AH) defined as absolute amount of water in the air, and relative humidity (RH) defined as the relative proportion of water in the air in comparison to the maximum water vapor. There have been many arguments for RH as a determinant factor for influenza epidemics. On the other hand, we have been putting emphasis on AH on the basis of our epidemiological observations. In this context, a recent experimental and theoretical study by other investigators has shown that AH correlates with influenza survival, transmission, and seasonality. Accordingly, we collected meteorological and influenza epidemiological data from 46 prefectures in temperate Japan for 1991-1995 and 1999-2009, and analyzed 2,392 sets of weekly compiled data for each season year by using multiple linear regression analysis, in which the numbers of influenza cases were regarded as a function of AH and RH. We found that the standardized partial regression coefficient for AH was consistently stronger than that for RH with statistical significance. In addition, AH increased and decreased significantly at the time of the epidemic onset and subsidence in seven and twelve out of fourteen influenza seasons, respectively, whereas RH did so in none and two out of fourteen influenza seasons. Thus, we have substantiated our quarter-century-old assertion that AH strongly correlates with the onset and subsidence of influenza epidemics.

Analysis of the comorbidity of bronchial asthma and allergic rhinitis by questionnaire in 10,009 patients.

BACKGROUND: Bronchial asthma (BA) and allergic rhinitis (AR) are thought to share a common pathogenesis. However, reports concerning the comorbidity of the two diseases in a large-scaled population are rare in Japan. In the present study, we performed an analysis on the two diseases using questionnaires that addressed the diagnosis, symptoms and period of occurrence in more than 10,000 patients with BA or AR. METHODS: Patients with BA (adult: n = 2,781, childhood: n = 3,283) and AR (n = 3,945) were enrolled in the present study during the 3 months from August 1, 2006 to October 31, 2006. RESULTS: Sixty one percent of the patients with adult BA showed symptoms of AR. Among them, 68% of the patients were diagnosed with AR. Among the patients with childhood BA, 68% showed AR symptoms and 60% were diagnosed with AR. On the other hand, 49% of AR patients showed BA symptoms and 35% of them were diagnosed with BA. The symptoms of both BA and AR in the BA and AR patients were frequent in two seasons, March and April, and September and October. In addition, BA and AR symptoms often co-occurred in the patients with BA and AR. CONCLUSIONS: Comorbidity of BA and AR was high in both populations of BA and AR. The symptoms of both BA and AR co-occurred on both a daily and seasonal basis. These results suggested that BA and AR share a common immuno-pathogenesis in the airway and need to be treated as a single airway disease.

Serum antibody against granulocyte/macrophage colony-stimulating factor and KL-6 in idiopathic pulmonary alveolar proteinosis.

Here we describe a case of idiopathic pulmonary alveolar proteinosis (I-PAP), in which anti-granulocyte/macrophage colony-stimulating factor (GM-CSF) antibody and high level of KL-6 were found in the serum. Anti-GM-CSF antibody is responsible for I-PAP, and KL-6 is a serum marker for the activity of diffuse interstitial lung disease. A 38-year-old woman, who had no symptoms, was found to have an abnormal shadow on chest radiograph 5 years previously at a health check up. Chest radiograph showed a patchy shadow in the left lower lung field. Thoracoscopic biopsy was performed because the shadow had gradually expanded during the 5 years. Histological examination revealed proteinous material filling the alveoli and positive staining by the PAS method, suggesting PAP. Anti-GM-CSF antibody and a high level of KL-6 were detected in the serum at the time of diagnosis. Three years later, the shadow disappeared spontaneously. During this period, the level of KL-6 dramatically decreased, although that of GM-CSF antibody remained unchanged. The present case suggests that the serum level of the anti-GM-CSF antibody represents a useful marker for the diagnosis but not for follow-up of the clinical course. On the contrary, KL-6 is an excellent marker for the assessment of the clinical course of I-PAP.

Development of a novel Ag-specific immunotherapy using CpG oligodeoxynucleotides in a new, unique mouse cutaneous eosinophilic inflammation model.

The number of patients with severe atopic dermatitis (AD) has been on the rise recently. We are therefore urgently in need of a treatment that can suppress Th2 cell-mediated responses in an Ag-specific fashion. Oligodeoxynucleotides (ODN)containing CpG motifs (CpG ODN) have been highlighted as immunomodulators that reduce Th2-mediated responses. To determine the effect of CpG ODN on Th2-mediated skin inflammation, we first developed a reproducible murine model of protein Ag-induced eosinophilic inflammation that is accompanied by epidermal acanthosis and increased serum IgE levels as seen in AD. In this model we found that treatment with CpG ODN during epicutaneous sensitization in previously i.p.-primed mice prevented the development of Th2-mediated responses. Furthermore, to evaluate the therapeutic effect of CpG ODN on established eosinophilic inflammation, mice were treated with a course of the immunotherapy at a skin site remote from the area of Ag application prior to the second 1-wk epicutaneous exposure to Ag. Therapeutic treatment with CpG ODN plus Ag, but not that with CpG ODN alone, could reverse the established eosinophilic inflammation. The presented results provide strong evidence for the feasibility of a novel Ag-specific immunomodulator to treat cutaneous eosinophilic inflammation such as that characteristically found in patients with severe AD.

Peritumoral CpG oligodeoxynucleotide treatment inhibits tumor growth and metastasis of B16F10 melanoma cells.

Although melanoma mostly affects the skin, it is notorious for its propensity to easily develop metastasis. Metastatic melanoma is highly resistant to a variety of therapies. We examined the anti-metastatic potential of peritumoral monotherapy against murine cutaneous B16F10 melanoma with synthetic oligodeoxynucleotides (ODN) containing unmethylated CpG motifs. We demonstrated that repeated peritumoral injections of CpG ODN significantly reduced skin tumor size. Peritumoral CpG ODN-treatment of skin tumors prevented the development of pulmonary B16F10 colonies. Adoptive transfer of splenocytes obtained from CpG ODN-treated mice markedly reduced the number of previously established pulmonary colonies in recipient naïve mice. T-lymphocyte depletion studies indicated that the anti-metastatic effect was dependent on both CD4+ and CD8+ T cells. These results suggest that CpG ODN are promising as a preventive and therapeutic anti-metastatic measure against melanoma.

Oligodeoxynucleotides without CpG motifs work as adjuvant for the induction of Th2 differentiation in a sequence-independent manner.

The outcomes of immune responses are regulated by various parameters including how Ags are handled by APCs. In this study, we describe the intrinsic immunomodulatory characteristics of oligodeoxynucleotides (ODNs) that improve the Ag presentation by APCs. ODNs (20-mer) containing CpG motifs induced strong Th1-skewed responses. In contrast, those without CpG motifs enhanced cytokine production by effector Th cells without particular skewing toward Th1 responses or induced the differentiation of unprimed CD4(+) T cells toward Th2 cells. These functional features were prominently envisaged when ODNs were conjugated to the Ag, and were underlain by the facilitated binding of ODN-conjugated Ag to Ia(+) cells. Despite the functional differences between ODNs with CpG motifs and those without CpG motifs, both ODNs bound to Ia(+) cells with similar affinity and kinetics. Immunoenhancing activities of the ODNs were not sequence-dependent; the characteristics, including the facilitation of Ag capture, enhancement of effector Th cell responses, and induction of Th2 cells, were shared by randomly synthesized ODNs conjugated to Ag. This is the first study suggesting that ODNs, independent of the sequences, enhance immune responses through the promoted capture of ODN-conjugated Ag by APCs.

B cells capturing antigen conjugated with CpG oligodeoxynucleotides induce Th1 cells by elaborating IL-12.

APCs initiate T cell-mediated immune responses against foreign Ags. Dendritic cells are professional APCs that play unique roles, including Ag-nonspecific capture, priming of naive T cells, and Th1 induction, whereas B cells generally lack these functions. In this study we uncovered novel aspects of murine B cells as APCs using CpG oligodeoxynucleotides (CpG) conjugated with an Ag. B cells served as efficient APCs independently of surface Igs. This characteristic was underlaid by the CpG-mediated Ag uptake and presentation, which were functional only when CpG were covalently conjugated to Ag. The B cells cultured with CpG-conjugated Ag not only enhanced IFN-gamma formation by Th1 cells, but also induced Th1 differentiation from unprimed T cells. These effects paralleled with the increase in the expression of CD40, CD86, and class II molecules on B cells and the coordinated production of IL-12 by the cells. To our knowledge this is the first report revealing that B cells share with dendritic cells common intrinsic characteristics, such as the Ag-nonspecific capture and presentation, and the induction of Th1 differentiation from unprimed T cells.