Sublingual immunotherapy for 4 years increased the number of Foxp3+ Treg cells, which correlated with clinical effects.

OBJECTIVE: At least 3 years of sublingual immunotherapy (SLIT) is required to achieve long-term clinical tolerance for allergens. However, immunological changes with more than 3 years of SLIT have not yet been elucidated in detail. The present study investigated whether the numbers of regulatory T (Treg) cells and regulatory B (Breg) cells increased with 4 years of SLIT and if these increases correlated with clinical effects for pollinosis. METHODS: Seven Japanese cedar pollinosis patients received SLIT in 2014 or 2015 and continued treatment until May 2019. In May 2017 and May 2019, peripheral blood mononuclear cells (PBMCs) were collected from the patients, and analyzed by flow cytometer. RESULTS: (1) The visual analogue scale (VAS) was significantly higher in 2019 than in 2017. (2) The percentages of Foxp3+ Treg cells, type 1 regulatory T (Tr1) cells, and Breg cells in PBMCs were significantly higher in 2019 than in 2017. (3) The percentage of Foxp3+ Treg cells in PBMCs positively correlated with VAS, whereas those of Tr1 cells and Breg cells did not. CONCLUSIONS: These results suggest that 4 years of SLIT is needed to achieve sustained increases in Foxp3+ Treg cells, which are closely associated with the efficacy of SLIT.

Regulatory T and B cells in peripheral blood of subcutaneous immunotherapy-treated Japanese cedar pollinosis patients.

AIM: The aim of this study was to clarify whether there are more regulatory T (Treg) and regulatory B (Breg) cells, and higher levels of IL-10-related transcription factors in subcutaneous immunotherapy (SCIT)-treated pollinosis patients than in non-SCIT-treated patients. METHODS: Japanese cedar pollinosis patients undergoing SCIT had received treatment for at least 2.8 years. Peripheral blood mononuclear cells were used for flow cytometer analyses and mRNA measurement. RESULTS: The numbers of type 1 regulatory T (Tr1)-like cells and Breg cells, and expression of E4BP4 mRNA by peripheral blood mononuclear cells in SCIT-treated patients were higher than those in non-SCIT-treated patients. CONCLUSION: Tr1-like cells, Breg cells and E4BP4 may be involved in the effectiveness of SCIT.

The 1st step initiation essential for allergen-specific IgE antibody production upon the 2nd step: Induction of non-specific IgE+ small B cells containing secondly-sensitized allergen-specific ones in mice firstly-sensitized with an allergen.

There was a significant amount of non-specific, but not of allergen (e.g., papain, mite feces and four kinds of pollen)-specific, IgE antibodies (Abs) in the sera of normal mice. An i.n. injection of each allergen without adjuvant into mice caused an increase in total IgE Ab titers with a similar time course in the serum. However, the stage of initiation of allergy varied from allergen to allergen. Submandibular lymph node cells from normal mice contained papain-, but not mite feces- or pollen-specific IgE+ cells and an i.n. injection of papain induced papain-specific IgE Abs in the serum. In contrast, one (i.n.) or two (i.n. and s.c) injections of mite feces induced neither mite feces-specific IgE+ cells in the lymph nodes nor mite feces-specific IgE Abs in the serum. I.n. sensitization with cedar pollen induced cedar pollen-specific IgE+ small B cells in the lymph nodes on Day 10, when non-specific IgE Ab titers reached a peak in the serum, implying induction of related allergen-specific IgE+ small cells as well. In fact, a second (s.c.) injection of ragweed (or cedar) pollen into mice sensitized i.n. once with cedar (or ragweed) pollen, but not with mite feces, induced a large amount of ragweed (or cedar) pollen-specific IgE Abs in the serum. These results indicate that when firstly-sensitized non-specific IgE+ small B cells in mouse lymph nodes include some secondly-sensitized allergen-specific ones, mice produce IgE Abs specific for the secondly-injected allergen.

Continuous 6-year follow-up study of sensitization to Japanese cedar pollen and onset in schoolchildren.

BACKGROUND: Intra individual longitudinal data has been lacking for IgE-mediated seasonal allergic rhinitis (SAR), especially in young children. Little is known about the development and natural course of SAR in terms of prevalence and incidence rates in schoolchildren. METHODS: In May or June each year from 1994 to 2007, schoolchildren were assessed for serum Japanese cedar pollen (JCP)-IgE and house dust mite (HDM)-IgE levels, and surveyed regarding nasal symptoms. RESULTS: Among the 220 children initially assessed in the first grade, 69 (31.4%) were already sensitized to JCP at first grade and 119 (54.1%) did not develop JCP sensitivity during the 6-year study at all. In the first grade children who were HDM-sensitized but JCP non-sensitized, JCP-IgE level was significantly elevated compared to the JCP and HDM non-sensitized group. This seems to indicate that HDM sensitization was very strongly associated with JCP sensitization. CONCLUSIONS: Elevated serum IgE is a consequence of specific sensitization to HDM and HDM sensitization appeared to develop prior to the start of primary school which distinguishes HDM sensitization from JCP sensitization.

Essential role of macrophages in the initiation of allergic rhinitis in mice sensitized intranasally once with cedar pollen: regulation of class switching of immunoglobulin in B cells by controlling interleukin-4 production in T cells of submandibular lymph nodes.

The production of allergen-specific IgE antibodies (Abs) in allergen-sensitized patients or animals has a mutual relationship with the immunologic response leading to allergic rhinitis. We recently reported that, after an intranasal injection of cedar pollen into mice, an interleukin-4 (IL-4)-dependent increase in serum nonspecific IgE Abs was a prerequisite for the production of serum allergen-specific IgE Abs. Here, we explored which lymphoid organs were responsive to the intranasally injected allergen and how IL-4 and IgE Abs were produced in the lymphocytes. Time-dependent changes in the total cell numbers and in in vitro IgE Ab production in various lymphoid organs revealed that the submandibular lymph nodes were the main responsible organ. After treatment with allergen (for IgE production) or allergen and complete Freund's adjuvant (for IgG production), we separated submandibular lymph node cells into macrophage-, lymphocyte-, and granulocyte-rich populations by discontinuous Percoll density-gradient centrifugation. Unexpectedly, bulk cells, but not the lymphocyte- or macrophage-rich populations, produced significant amounts of IL-4, IgE, and IgG; whereas production was restored by addition of Mac-1(+) cells from the macrophage-rich to the lymphocyte-rich fraction. Furthermore, a combination of the lymphocyte-rich population (for IgG [or IgE]) production) and the macrophage-rich population (for IgE [or IgG]) production) produced a large amount of IgE (or IgG). These results indicate that, in the initiation of allergic rhinitis, macrophages in the submandibular lymph nodes are essential not only for IL-4 or immunoglobulin production, but also for class switching of immunoglobulin in lymphocytes.

Evaluating the effects of testing period on pollinosis symptoms using an allergen challenge chamber.

BACKGROUND: We previously built a pollen challenge test unit (allergen challenge chamber: ACC) to collect objective data about Japanese cedar pollinosis. In this study, we investigated adequate conditions for pollen challenge using the ACC. METHODS: The study consisted of two parts. The first part was conducted in November, which is not in pollen season. Subjects were exposed to Japanese cedar pollen at a concentration of 50,000 grains/m3 in the chamber for 120 min each day over the course of three consecutive days. The second part was conducted in April, which is just after pollen season. Subjects were exposed to Japanese cedar pollen at the same concentration (50,000 grains/m3) in the chamber for 90 min on a single day. Subjects recorded nasal and ocular symptoms before challenge and every 15 min after challenge initiation. The minimum cross-sectional area in the nasal cavity was measured using acoustic rhinometry before and after challenge as an indicator of nasal obstruction. Inflammatory markers in nasal lavage fluid and serum were also measured before and after challenge. RESULTS: Nasal and ocular symptoms were significantly exacerbated after challenge on all days of the single and 3-consecutive-day challenge tests, particularly on the third day of the consecutive challenge test. Nasal and ocular symptoms were also quickly induced with challenge immediately after the end of pollen season. No significant changes in inflammatory markers were seen. CONCLUSIONS: Care is needed with regard to pollen challenge conditions in the ACC, including timing of the challenge, to induce pollinosis symptoms that accurately reflect chronic inflammation.

[Clinical study of the paranasal sinuses of patients with Japanese Cedar pollinosis].

To clarify paranasal sinus change in patients with Japanese cedar pollinosis, we studied reactions to medical treatment via X-ray images of patients during the 2000 cedar pollen season. Medication was administered to 577 patients consulting facilities in 3 regions--Kyoto, Fukui and Osaka--having different pollen counts i.e., 4555/cm2 in Fukui, 801/cm2 in Kyoto and 531/cm2 in Osaka. The paranasal sinus was X-rayed by Water's method, and the degree of positivity was classified by Katagiri'shadow classification. Patients were grouped into 334 suffering extensive Fukui pollen dispersion and 243 suffering relatively limited Kyoto and Osaka pollen dispersion. At 3-4 weeks after pollen dispersion, contrast shadow positivity was 22.2%, with no difference before pollen dispersion (22.2%) in Kyoto and Osaka. In Fukui, positivity was 39.7%, a clear increase over pre pollen dispersion (19.2%). In the initial treatment group, positivity was 25.8% in Fukui and 28.6% in Kyoto and Osaka. Our results suggest that the incidence of sinusitis in patients with Japanese cedar pollinosis tended to increase with exposure to extensive pollen dispersion and to be suppressed by initial treatment.