leukotriene-c4 and Sneezing

Allergic rhinitis (AR) is an allergic disease induced by the T helper 2 (TH2) lymphocyte immune response, where its mediators are the primary cause of clinical symptoms. Environmental factors are the primary determinants of the allergic response in genetically susceptible individuals. This study investigates the effects of climate conditions (warm, cold, humid, and dry) on allergic rhinitis. AR models were created in mice under 4 different conditions. We investigated AR-related behavior (sneezing and nose rubbing), as well as total immunoglobulin E (IgE), histamine, interleukin-4 (IL-4), leukotriene (LT) B4 and LTC4 levels, and gene expression of CysLT1R, HRH1, and MUC5a. Nose rubbing, histamine levels, and the expression of MUC5a and HRH1 were increased in AR models in cold conditions, and sneezing was increased in AR models kept in dry conditions. LTB4 and LTC4 levels and the expression of CysLT1R in AR models kept in a wet environment also significantly increased compared with the control group. The levels of total IgE and IL-4 showed no significant changes. Air temperature and humidity affect AR pathophysiology, and weather conditions can be essential in controlling AR.

Topics: Animals; Disease Models, Animal; Histamine; Humidity; Immunoglobulin E; Interleukin-4; Leukotriene C4; Mice; Mice, Inbred BALB C; Nasal Mucosa; Ovalbumin; Rhinitis, Allergic; Sneezing; Temperature

Quantitative determinations of the inflammatory mediators in nasal secretions were performed and correlated with the objective nasal symptoms within 1 h after nasal allergen challenge (NAC). Twenty-six patients with seasonal allergic rhinitis were enrolled outside the pollen season. All measurements were performed before (as a baseline control) and at 1, 5, 10, 30, and 60 min after NAC. This study aimed to clarify the pathogenic mechanism of the early-phase reaction (EPR) by monitoring the evolution of early-phase mediators in nasal secretions and the presence of nasal symptoms during this period. The results showed that, after NAC, the maximal mediator concentration was already reached after 1 min for histamine (124 ng/g), 5 min for tryptase (56 microU/g), and 5-10 min for leukotriene C4 (40 ng/g). Itching and sneezing started as early as 20-30 s, and they were predominant symptoms within 5 min. Rhinorrhea and nasal obstruction started a few minutes after NAC and lasted until more than 1 h after NAC. There was no significant correlation between any single mediator and nasal symptoms during the sampling period. In conclusion, this study demonstrated that during the EPR the presence of nasal symptoms involves a complex mechanism, reflecting the interaction between the mediators released by inflammatory cells, and the receptors on different target organs. When evaluating symptoms during the EPR, one must consider not only the severity of these symptoms but also the time period within which these symptoms occur. For the symptoms of nasal obstruction and rhinorrhea, the early-phase reaction often lasted more than 1 h.

Topics: Adult; Allergens; Chymases; Female; Histamine; Humans; Leukotriene C4; Male; Nasal Mucosa; Nasal Obstruction; Nasal Provocation Tests; Pruritus; Serine Endopeptidases; Sneezing; Tryptases

By using a microsuction technique, a quantitative determination of chemical mediators in nasal secretions was performed in 18 hay-fever patients and in a control group of 10 healthy volunteers. The authors then compared these quantitative data for mediators with objective nasal findings counting the number of sneezes, passive anterior rhinomanometry (PAR) and nasal inspiratory peak flow. A sampling protocol was designed with a follow-up of 3 days after nasal allergen challenge (NAC) in order to investigate both early and late allergic reactions. Median baseline concentrations of five major mediators were obtained: histamine, 19 ng/g; leukotriene C4 (LTC4), 5.7 ng/g. tryptase, 0; prostaglandin D2 (PGD2), 477 pg/g; eosinophil cationic protein (ECP), 105 ng/g. Significant increases in histamine (214 ng/g), LTC4 (20 ng/g) and tryptase (28 microU/g) were found, but a significant decrease occurred in ECP (47 ng/g) and PGD (226 pg/g) immediately after NAC in the patients studied. Most ECP concentrations (94%) increased slowly 1 h after NAC and reached a significantly higher level 24 h later. In evaluating nasal symptoms, sneezes were present in a high percentage of cases (76%) during the early phase but were uncommon during the late phase (29%). Total nasal obstruction occurred in 94% during the early phase. In contrast, unilateral nasal obstruction presented in 82% during the late phase, whereas total nasal obstruction was present only in 41%. The most common type of late phase nasal obstruction shown by PAR was alternating nasal obstruction.

Topics: Adolescent; Adult; Allergens; Blood Proteins; Case-Control Studies; Chymases; Eosinophil Granule Proteins; Female; Follow-Up Studies; Histamine; Humans; Inflammation Mediators; Inhalation; Leukotriene C4; Male; Middle Aged; Nasal Mucosa; Nasal Obstruction; Nasal Provocation Tests; Prostaglandin D2; Rhinitis, Allergic, Seasonal; Ribonucleases; Serine Endopeptidases; Sneezing; Tryptases