Lactate dehydrogenase as a marker of nasopharyngeal inflammatory injury during viral upper respiratory infection: implications for acute otitis media.

BACKGROUND: Acute otitis media (AOM) is a frequent complication of viral upper respiratory tract infection (URI). We hypothesized that the severity of nasopharyngeal cellular injury during URI, as measured by lactate dehydrogenase (LDH) concentrations in nasopharyngeal secretions (NPSs), is related to AOM complication. METHODS: LDH concentrations were determined in NPS samples (n = 594) that were collected at the initial visit for URI from 183 children who were followed for the development of AOM. A subset of NPS samples (n = 134) was analyzed for interleukin (IL)-1ß, IL-6, and tumor necrosis factor (TNF)-α concentrations. RESULTS: AOM complication was independently predicted by LDH concentrations (median mU/ml with AOM = 2,438 vs. without AOM = 1,573; estimate = 0.276; P = 0.02). LDH effect on AOM development was highest during the first 4 d of URI. LDH concentrations were higher in URIs due to adenoviruses, bocaviruses, and rhinoviruses as compared with virus-negative samples (P < 0.05). There was a positive correlation between concentrations of LDH and all cytokines (P < 0.001). CONCLUSION: LDH concentrations in NPS are positively associated with AOM risk, suggesting that the severity of nasopharyngeal inflammatory injury during URI contributes to the development of AOM and that reduction of inflammatory injury may reduce the risk for AOM.

[Glutamyltranspeptidase (gamma-GT) activity in the serum and pharynx tissue of nasopharyngeal carcinoma patients].

The gamma-GT activity in the serum and pharynx tissue of both NPC patients (106) and pharyngitis patients (65) were detected with method of hydrolysis gamma-glutamylnitrophenylamine. The 34 NPC patient's gamma-GT were assayed both before and after radiotherapy. The results indicated that the gamma-GT activities between the NPC patients and pharyngitis patients, and the activities before and after radiotherapy have significant differences. The investigation suggests that the determination of serum and pharynx tissue gamma-GT levels of NPC patients would help to diagnose and evaluate the curative effect for NPC.

NADPH oxidase activity in the monocytes and neutrophils of patients with rheumatic fever.

The enzyme NADPH oxidase is involved in the production of oxygen free radicals. We measured its activity in neutrophils and monocytes obtained from patients with acute rheumatic fever, chronic rheumatic heart disease, acute streptococcal pharyngitis and normal controls. Follow up studies were made at 15 days, 3 months and 6 months. Streptococcal membrane antigen, carbohydrate antigens and latex were used to stimulate the oxidative activity in the neutrophils and monocytes. These three agents caused a significant increase in the enzyme activity of the phagocytes of patients with acute rheumatic fever and chronic rheumatic heart disease (p less than 0.001) but not in acute pharyngitis. Maximal NADPH oxidase enzyme activity was observed in patients with acute rheumatic fever. During the follow-up, there was a significant decline in the enzymatic activity in patients with acute rheumatic fever but not in those with chronic rheumatic heart disease. Enzymatic activity was greater when the phagocytic cells were triggered with membrane as compared to carbohydrate antigen and latex in all the groups and at all intervals. The enzymatic response of neutrophils and monocytes was similar although the magnitude of the NADPH oxidase activity was significantly higher in neutrophils than in monocytes.