Cerebrospinal fluid interleukin 8 concentrations and the subsequent development of postherpetic neuralgia.
OBJECTIVE
Other than age, the risk factors for postherpetic neuralgia are not well established. We studied whether the concentration of interleukin 8 in the cerebrospinal fluid is associated with the risk of postherpetic neuralgia.


METHODS
We enrolled 170 patients more than 50 years old who had a typical painful and nontrigeminal herpetic rash. Patients were treated with acyclovir; no corticosteroids were given. Cerebrospinal fluid was taken for analysis of interleukin 8 during and at full crusting of the herpetic rash. Age, sex, comorbid conditions, prodromal pain, localization and severity of herpetic rash, number of skin lesions, and degree of pain were recorded. We used multivariate logistic regression modeling to identify significant predictive factors. Receiver operating characteristic (ROC) curves were evaluated to determine the contribution of each factor.


RESULTS
Six months after healing, 31 patients (18%) had postherpetic neuralgia; 27 patients still had it after 1 year. Only three variables-age (odds ratio [OR] = 2.7 per 10-year increase; 95% confidence interval [CI]: 1.2 to 6.2), acute pain (OR = 1.8 per unit increase in visual analog scale; 95% CI: 1.2 to 2.8), and interleukin 8 concentration in the cerebrospinal fluid at full crusting of the herpetic rash (OR = 1.6 per 20-microg/L increase; 95% CI: 1.3 to 2.0)-were significant predictors of postherpetic neuralgia at 1 year. Interleukin 8 concentration also had the highest area under the ROC curve at these evaluation points (P <0.001).


CONCLUSIONS
Our results suggest that interleukin 8 concentration in the cerebrospinal fluid at full crusting of herpetic rash may be useful for identifying patients who are likely to develop intractable postherpetic neuralgia.
Kotani
Naoki
N
Department of Anesthesiology, Yamagata University, Japan. kotani@med.id.yamagata-u.ac.jp
Kudo
Ryoko
R
Sakurai
Yutaka
Y
Sawamura
Daisuke
D
Sessler
Daniel I
DI
Okada
Hiroshi
H
Nakayama
Hiroto
H
Yamagata
Toshifumi
T
Yasujima
Minoru
M
Matsuki
Akitomo
A
D000368:Aged; D015415:Biomarkers / Q000134:cerebrospinal fluid; D005260:Female; D006562:Herpes Zoster / Q000134:cerebrospinal fluid / Q000150:complications* / Q000188:drug therapy; D006801:Humans; D016209:Interleukin-8 / Q000134:cerebrospinal fluid*; D016015:Logistic Models; D008297:Male; D009437:Neuralgia / Q000134:cerebrospinal fluid / Q000175:diagnosis* / Q000821:virology; D010147:Pain Measurement; D012372:ROC Curve; D012307:Risk Factors
D015415:Biomarkers; D016209:Interleukin-8