NOx (nitrite/nitrate) in cerebral spinal fluids obtained from patients with influenza-associated encephalopathy

It has become evident that the number of patients with a new type of influenza-associated encephalopathy is increasing in Japan. Nitric oxide (NO), a simple free radical gas, elicits a wide range of physiological and pathophysiological effects. We measured the nitrite/nitrate (NOx) levels in cerebral spinal fluid obtained from patients with influenza-associated encephalopathy in order to evaluate the correlation between the NO production and the process of influenza-associated encephalopathy. Fifteen children were enrolled, aged from 1 to 9 years. As control we used 14 cerebral spinal fluids obtained from patients with urinary tract infection, respiratory infection or mumps meningitis without any sequela. NO3 in influenza-associated encephalopathy was significantly higher than that of control group. On the other hand NO2 was not significantly higher than that of control group. In particular, 4 out of 5 fatal cases revealed high NO2 or NO3. One case having normal levels in NO2 and NO3 showed that NH3 was high. These results revealed that NO plays a role in influenza-associated encephalopathy through indirect effects of NO.