Nasal response to a single antigen challenge in patients with allergic rhinitis — inflammatory cell recruitment persists up to 48 hours

BACKGROUND: Allergen challenge in some patients with respiratory allergy is followed by an early and a late reaction. OBJECTIVE: To evaluate the duration of mediator release and inflammatory cell recruitment during the late antigen-induced nasal response. METHODS: Eight patients with seasonal allergic rhinitis due to grass pollen underwent local challenge with the relevant allergen, a non-relevant allergen (Parietaria judaica), and nebulized saline solution. Nasal lavages were performed at baseline and 6, 24, 48, 72 h after challenge. Eosinophil cationic protein (ECP), leukotriene C4 (LTC4), leukotriene B4 (LTB4) myeloperoxidase (MPO) and prostaglandin D2 (PGD2) levels were radioimmunoassayed and histamine concentration was measured by an automated fluorometric method. RESULTS: Nasal challenge with the relevant antigen induced a response 6 h after stimulation, which subsided within 24 h. Eosinophilia, observed in the nasal lavages collected from 6 to 24 h after this challenge, was accompanied by ECP release. Neutrophilia were found in the nasal lavages collected from 6 to 24 h after challenge. The increase in neutrophil number correlated with MPO levels and LTB4 concentrations, but not with the intensity of nasal obstruction. Antigen challenge also induced significant recruitment of mononuclear cells 48 h after provocation. The challenge significantly raised histamine, but not PGD2, levels in the nasal lavages collected 6 h after provocation. A trend towards an increase in LTC4 levels in the nasal lavages collected 6 h after specific antigen challenge was also found. Nasal challenge with a non-relevant allergen or with saline solution did not cause either inflammatory cell recruitment or mediator release. CONCLUSION: Nasal challenge with the relevant antigen can induce a late response characterized by local accumulation of eosinophils, neutrophils and mononuclear cells persisting for 48 h and accompanied by release of ECP, MPO, LTB4 and histamine. These results indicate that a single antigen challenge in patients with allergic rhinitis causes prolonged inflammatory alterations which may contribute to the development of airway hyperreactivity.     

Hepatitis C virus genotype in patients with essential mixed cryoglobulinaemia

We studied 54 patients with essential mixed cryoglobulinaemia(EMC), (23 males, 31 females) mean age 61 years (range 28–77).Forty-one (76%) had type II cryoglobulinaemia and 13 (24%) typeIII. Antibodies to HCV were detectable by second-generationELISA in 49 patients (91%) with confirmed or indeterminate RIBAresults. HCV RNA was detected byRT PCR using 5' UTR nested primers;HCV genotypes 1a, 1b, 2 and 3a were identified by genotype-specificcore-region nested primers. All patients (49) with antibodiesto HCV in their serum were HCV-RNA positive; 27 (55.1%) hadHCV subtype 1b and 21 (42.8%) type 2. In one patient the HCVgenotype could not bedetermined. The genotype distribution wasnot differentfrom that found in patients with chronic hepatitisC without cryoglobulinaemia. However, the presence of HCV subtype1b correlated significantly with signs of chronic hepatitisand presence of peripheral neuropathy. Severity of disease tendedto be worse in patients infected with HCV subtype 1b, but thiswas mainly due to liver disease. HCV genotypes may influencethe clinical expression and, in particular, the severity ofliver involvement in patients with EMC. Extent and severityof EMC disease in general may also be affected by the differentHCV genotypes.These findings may have therapeutical implications,since the different HCV genotypes respond differently to interferontreatment.