Cytokines in the gastric mucosa of children with Helicobacter pylori infection

AIM: Few studies have looked at the cytokine profile in gastric mucosa in children with Helicobacter pylori infection. This study investigated cytokines and their effects on histological abnormalities in the gastric mucosa of children with H. pylori infection. METHODS: The levels of interferon-gamma (IFN-gamma), interleukin-4 (IL-4) and IL-8 proteins were measured in biopsy specimens from the gastric antrum and corpus of children with H. pylori infection, and related to inflammatory cell infiltrations. RESULTS: The antral and corporal mucosal levels of IFN-gamma and IL-8 proteins were significantly higher in children with H. pylori infection than in uninfected children, but there was no such difference in the levels of IL-4 protein. The antral mucosal level of IL-8 protein was significantly higher than the corporal mucosal level of IL-8 protein in the infected children. Inflammatory cell infiltration was significantly higher in the infected children than in the uninfected children, but there were no significant correlations between mucosal cytokine levels and inflammatory cell infiltrations. CONCLUSION: The results suggest that the predominant Th1 cytokine response and enhanced IL-8 production in the mucosa may be involved in the gastric inflammation seen in children infected with H. pylori, as well as in adult patients.     

Increased mucosal inflammatory cytokines in children with Helicobacter pylori-associated gastritis

The concentrations of tumour necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) and IL-1-β in tissue homogenates of gastric mucosal biopsy specimens, and in gastric juice samples from Helicobacter pylori-positive and -negative children, were determined. The study population comprised 30 children with recurrent abdominal pain attending upper gastrointestinal endoscopy. Of these patients 18 were infected with H. pylori. Cytokine concentrations in gastric biopsy homogenate supernatants and in gastric juice were measured by enzyme-linked immunosorbent assay (ELISA). TNF-α levels in gastric juice and in gastric biopsy homogenate supernatants in patients with H. pylori-positive gastritis were found to be significantly higher than those in children without H. pylori infection. IL-6 levels were also higher in H. pylori -infected subjects, but the difference in IL-6 concentrations measured in gastric juice and biopsy homogenate supernatants did not reach statistical significance. IL-1-β concentrations in both specimens showed no significant difference between the two groups of children. It was suggested that increased levels of inflammatory cytokines, especially TNF-α and IL-6 generated locally within the gastric mucosa might be implicated in the pathogenesis of H. pylori-associated gastritis in childhood.     

Tumor necrosis factor alpha and interleukin 1 beta in synovial fluid of infants and children with suppurative arthritis

Tumor necrosis factor alpha and interleukin 1 beta concentrations were measured in synovial fluid of 24 infants and children with diagnoses of suppurative arthritis (n = 16) and other kinds of arthritis (n = 8). Large concentrations of tumor necrosis factor alpha (range, 100 to 85,000 pg/mL) were found in 12 (75%) of 16 patients with bacterial infection and in none of the patients with noninfectious origins. Large concentrations of interleukin 1 beta (greater than 200 pg/mL) were found in 15 (94%) of 16 patients with bacterial infection and in none of the other patients. In the latter group, small concentrations of interleukin 1 (range, 40 to 120 pg/mL) were present in 5 (63%) of 8 patients. Serum samples obtained simultaneously were negative for both cytokines. Tumor necrosis factor alpha and interleukin 1 beta concentrations correlated significantly and with leukocyte counts in synovial fluid. We conclude that large concentrations of tumor necrosis factor alpha and interleukin 1 beta are produced locally in patients with suppurative arthritis and they may be potentially useful in differentiating this condition from other kinds of arthritis.     

CSF interleukin-1 beta, tumor necrosis factor-alpha and free radicals production in relation to clinical outcome in acute bacterial meningitis

OBJECTIVE: To study the relationship of CSF IL-1 beta and TNF-alpha with free radicals in acute bacterial meningitis (ABM) and to evaluate the clinical outcome in relation to the levels of these cytokines and free radicals in CSF. DESIGN: Prospective with controls. SETTING: Referral unit of a teaching hospital. METHODS: 32 children between 3m-12 yrs of age with proven acute bacterial meningitis comprised the study group. In the control group, 20 children with febrile seizures were included. CSF cytokines- Interleukin Ib and tumour necrosis factor a,free radicals O(2)-, H(2)O(2) and enzymes SOD and CPK were measured in all the children. RESULTS: CSF IL-Ib and TNF-a concentration were markedly elevated in children with ABM (441.5 +/- 216.1 pg/ml, and 1009 +/- 529.1 pg/ml, respectively) as compared to controls (52.67 +/- 6.92 pg/ml, and 86.42 +/- 16.24 pg/ml) (p <0.0001). Free radicals viz., superoxide anion, hydrogen peroxide production and enzymes creatinine phosphokinase and superoxide dismutase were also significantly elevated in ABM as compared to controls. There was direct correlation of CSF cytokines with CSF cytology, protein and free radicals production in ABM. Patients who expired or had neurological sequelae had markedly elevated concentrations of cytokines and free radicals. CONCLUSION: IL-I beta, TNF-alpha and free radicals are significantly elevated in CSF of patients with ABM. The concentration of these cytokines correlated well with free radical production, and with routinely measured CSF parameters and had a direct bearing on outcome of ABM     

Cerebrospinal fluid prostaglandins, interleukin 1 beta, and tumor necrosis factor in bacterial meningitis. Clinical and laboratory correlations in placebo-treated and dexamethasone-treated patients

Prostaglandins (PGs), interleukin 1 beta (IL-1 beta), and tumor necrosis factor alpha (TNF alpha) are likely mediators of local inflammatory reactions. We measured PGE2, PGI2, IL-1 beta, and TNF concentrations in paired cerebrospinal fluid (CSF) samples (on admission, CSF1, and 18 to 30 hours later, CSF2) from 80 infants and children with bacterial meningitis. Forty patients received dexamethasone sodium (0.6 mg/kg per day in four intravenous doses) and 40 received an intravenous saline placebo. In CSF1, PGE2, PGI2, IL-1 beta, and TNF were detected in 90%, 56%, 98%, and 71% of specimens with mean (+/- SEM) concentrations of 462 +/- 65, 377 +/- 62, 1266 +/- 242, and 799 +/- 227 pg/mL, respectively. Concentrations of PGE2 correlated significantly with PGI2, IL-1 beta, TNF, and lactate and inversely correlated with glucose concentrations in the first CSF specimens. The PGE2, PGI2, IL-1 beta, and TNF were still detected in 40%, 18%, 97%, and 60%, respectively, of second CSF specimens obtained from placebo-treated patients. Compared with patients who had detectable PGI2 or TNF alpha concentrations in CSF2 specimens, those placebo-treated patients with no detectable PGI2 or TNF alpha activity in CSF2 had a lower incidence of neurological sequelae. Dexamethasone-treated patients had significantly lower PGE2, IL-1 beta, and lactate concentrations and higher glucose concentrations in CSF 18 to 30 hours later, shorter duration of fever, and a lower incidence of neurological sequelae than did placebo-treated patients.     

Cerebrospinal fluid levels of cytokines and soluble tumour necrosis factor receptor in acute disseminated encephalomyelitis

We determined the concentrations of interleukin-1beta (IL-1beta, IL-6, IL-10, interferon-gamma (IFN-gamma), tumour necrosis factor-alpha (TNF-alpha), and soluble TNF receptor 1 (sTNFR1) in CSF from 18 patients with acute disseminated encephalomyelitis (ADEM) to investigate the role of cytokines in the pathogenesis of the disease in the acute stage. Cytokines and sTNFR1 were measured by ELISA. The CSF IL-6, IL-10, TNF-alpha, and sTNFR1 concentrations were elevated in 16, 13, 3, and 11 of the 18 patients with ADEM, respectively. CSF concentrations of IL-10 and sTNFRI correlated positively with each other in the patients (P<0.01). Myelin basic protein levels in CSF of the patients with elevated CSF sTNFR1 levels were significantly higher than those in CSF of the patients with normal CSF sTNFR1 levels (P<0.05). IL-1beta and IFN-gamma were not elevated in CSF. Our results suggest that IL-6 and TNF-alpha mediate inflammation in the central nervous systems in ADEM. We speculated that TNF-alpha is related to demyelination and that IL-10 is induced to modulate TNF-alpha-induced inflammation in ADEM. CONCLUSION: these findings suggest that cytokines such as tumour necrosis factor-alpha, soluble tumour necrosis factor receptor 1, interleukin-6, and interleukin-10 are related to the pathogenesis of acute disseminated encephalomyelitis in the acute stage.     

Association of serum interleukin-8 levels with the degree of fibrosis in infants with chronic liver disease

OBJECTIVE: Biliary atresia is a neonatal obstructive cholangiopathy characterized by a destructive, obliterative process affecting both the intrahepatic and extrahepatic ducts of the biliary tree that uniquely presents in the first months of life. The consequence of progressive inflammatory and sclerotic reaction is the development of obstructive jaundice. To determine the proinflammatory cytokine profile in children with biliary atresia, we measured circulating levels of interleukin (IL)-1beta, IL-6, tumor necrosis factor-alpha and IL-8. METHODS: Twelve children, five males and seven females, with biliary atresia were studied. In addition, four patients with progressive familial intrahepatic cholestasis and three with Alagille syndrome were also included. Five patients with neonatal hepatitis were studied as controls of a liver disease without portal fibrosis. Serum concentration of total and conjugated bilirubin, gamma-glutamyl transferase and glutamic-pyruvic transaminase were measured by routine methods in all patients at time of sampling for the study. The degree of fibrosis in liver biopsies was scored using the histologic activity index. RESULTS: In our study IL-8 was detectable in 11 of 12 patients with biliary atresia with a median level of 262 pg/ml and a highly statistically significant difference (P < 0.0001) from controls. In patients with progressive familial intrahepatic cholestasis or with Alagille syndrome serum IL-8 levels were similarly elevated. In patients with neonatal hepatitis, IL-8 levels were marginally increased. Serum IL-8 levels were significantly correlated (Rs = 0.725, P < 0.0001) with the histologic activity index. CONCLUSIONS: Although further studies are needed to determine the role of IL-8 in portal inflammation, our results suggest that increased production of IL-8 may be a mechanism leading to the progressive portal inflammation and fibrosis in patients with chronic liver disease.     

Elevated cytokine concentrations in the nasopharyngeal and tracheal secretions of children with respiratory syncytial virus disease

BACKGROUND: Respiratory syncytial virus (RSV) is the most common cause of lower respiratory tract disease in infants. The role of inflammatory mediators in the pathogenesis of RSV disease is not well-understood. The present study was designed (1) to determine whether RANTES (regulated on activation, normal T cell expressed and presumably secreted), macrophage-inflammatory protein-1-alpha (MIP-1-alpha), interleukin (IL)-6, IL-8 and IL-10 can be detected in respiratory secretions of children with RSV infection and (2) to assess whether the concentrations of these cytokines in respiratory secretions correlate with white blood cell (WBC) counts and RSV concentrations and with disease severity. METHODS: During the 1996 to 1997 RSV season, we studied prospectively 14 intubated and 14 nonintubated children hospitalized with RSV disease. Nasal wash (NW) and tracheal aspirate (TA) samples were obtained from intubated patients on Hospital Days 1, 3 and 5. NW samples were obtained from nonintubated patients on hospital days 1 and 3. Seven healthy children undergoing elective surgery served as controls. All samples were analyzed for: (1) WBC and differential counts; (2) concentrations of RANTES, MIP-1-alpha, IL-6, IL-8 and IL-10; and (3) quantitative RSV cultures, except in control patients. RESULTS: RANTES, MIP-1-alpha, IL-6, IL-8 and IL-10 were detected in NW and TA samples from all children with RSV infection. The concentrations of these cytokines in samples obtained from children with RSV infection were significantly greater than those in samples obtained from control children. NW WBC counts significantly correlated with NW RANTES, IL-6, IL-8 and IL-10 concentrations, whereas TA WBC counts significantly correlated with TA IL-6, IL-8, IL-10 and MIP-1-alpha concentrations. NW RSV concentrations correlated with NW WBC counts and with NW cytokine concentrations. Among children with RSV infection nonintubated patients had greater NW WBC counts and NW RANTES concentrations than intubated patients. TA RANTES, IL-8 and IL-10 concentrations inversely correlated with clinical markers of RSV disease severity. CONCLUSION: The presence of cytokines in NW and TA samples of children with RSV infection suggests that they have a role in mediating the respiratory tract inflammation induced by RSV. These observations could have implications for designing new therapeutic strategies directed at immunomodulation of RSV disease.     

Cytokines in haemolytic uraemic syndrome associated with verocytotoxin-producing Escherichia coli infection

The proinflammatory cytokines tumour necrosis factor-alpha (TNF-alpha) interleukin (IL)-1 beta, IL-6, and IL-8 were measured in plasma and urine samples from 19 children with verocytotoxin-producing Escherichia coli (VTEC) induced haemolytic uraemic syndrome (HUS) and 30 controls. TNF-alpha was detected in the plasma of two cases and one control; IL-6 in the plasma of one, and the urine of two cases, and in the plasma of one control. IL-1 beta and IL-8 were each identified in eight of the 19 cases and in one and two controls respectively. Urinary IL-8 was found in seven cases, four of whom had plasma concentrations below the limit of detection suggesting renal secretion of this cytokine. Cytokine concentrations did not correlate with peripheral blood neutrophil count at onset of disease. These data confirm the systemic release of cytokines responsible for the coordination of acute inflammatory processes in some children with VTEC induced HUS.     

Meconium is a source of pro-inflammatory substances and can induce cytokine production in cultured A549 epithelial cells

Inflammation plays an important role in the pathogenesis of meconium aspiration syndrome, and pneumonitis is one of the major characteristics. We have previously shown that meconium has chemotactic properties because of the presence of IL-8. We hypothesize that IL-8 and other proinflammatory substances in meconium may amplify inflammation in meconium aspiration syndrome, inducing endogenous cytokine production by lung epithelial cells. We measured proinflammatory substances in first-pass meconium from healthy newborns and evaluated the effect of sterile meconium on cytokine production in cultured A549 alveolar epithelial cells in vitro. IL-1beta, IL-6, IL-8, and tumor necrosis factor-alpha were measured by ELISA, and heme was measured spectrophotometrically. After incubation of meconium samples with A549 cells, cytokine concentrations in the supernatant were measured. Meconium samples contained variable amounts of IL-1beta, IL-6, IL-8, tumor necrosis factor-alpha, and heme. On stimulation of A549 cells with meconium, the IL-8 concentration in the culture supernatant significantly increased above baseline measurements, whereas tumor necrosis factor-alpha showed a variable pattern and IL-1beta or IL-6 remained unchanged. There was no quantitative relationship between the concentration of the measured cytokines and heme in meconium and cytokine release by the A549 cells after meconium exposure. Meconium contains proinflammatory substances. All samples induced IL-8 release and some induced tumor necrosis factor-alpha release in cultured A549 epithelial cells. We speculate that proinflammatory substances in meconium can induce lung inflammation in meconium aspiration syndrome in two ways: directly via cytokines and heme present in meconium and indirectly by inducing cytokine release by the epithelial lung cells.     

幽门螺杆菌菌株类型与儿童上消化道疾病的关系

目的：幽门螺杆菌（Helicobacter pylori,Hp）感染已被确立为是引起慢性浅表性胃炎和消化性溃疡的重要病因，是胃癌和胃黏膜相关性淋巴样组织（MALT）淋巴瘤的重要危险因素。Hp的致病性与毒力有关，而细胞毒素相关蛋白（CagA）和空泡毒素（VcaA）是Hp的主要毒力因子之一。该研究通过了解Hp菌株类型与儿童胃十二指肠疾病类型及胃窦黏膜病理组织学变化的关系，探讨Hp感染的分型诊断是否有助于判断儿童胃十二指肠疾病的严重程度。方法：采用免疫印迹法对115例有上消化道症状的患儿进行Hp的血清学分型，并行胃镜检查，观察胃十二指肠疾病类型。取胃窦黏膜经Harris配方苏木精染色观察胃窦黏膜病理组织学变化、亚甲基蓝染色观察Hp感染情况。结果：115例患儿中检出Hp Ⅰ型菌株84例（73.0%），中间型菌株21例（18.3%），Ⅱ型菌株10例（8.7%）；Ⅰ型菌株引起胃窦黏膜中、重度炎症分别为83例、1例；中间型菌株引起胃窦黏膜中度炎症21例；Ⅱ型菌株引起胃窦黏膜轻度炎症2例，中度炎症8例，经统计学处理，各型菌株在引起胃窦黏膜炎症程度上差异有显著性（χ2=15.444，P<0.01），Ⅰ型菌株感染引起胃窦黏膜炎症程度最重，Ⅱ型菌株感染引起胃窦黏膜炎症程度最轻；而在活动性、萎缩的发生率上，各型差异无显著性（P＞0.05）；在淋巴滤泡形成的发生率上，各型差异有显著性（χ2=10.171，P<0.01）。各型菌株引起胃镜下胃、十二指肠疾病类型的构成比无明显差异（P＞0.05）。结论：该地区儿童Hp感染以Ⅰ型菌株最为多见。各型菌株100%存在胃窦黏膜组织学改变。Ⅰ型菌株感染所致胃窦黏膜炎症程度最重，且引起淋巴滤泡形成的发生率最高。Hp感染的分型诊断无助于对儿童胃、十二指肠疾病类型的判断，但有助于对儿童胃、十二指肠疾病病情的判断，Ⅰ型菌株感染者需要更为积极的治疗，对于Hp感染的儿童无论其血清分型如何，均应引起重视，并长期随访。［中国当代儿科杂志，2007，9（3）：201-204］     

Nerve growth factor expression correlates with severity and outcome of traumatic brain injury in children.

BACKGROUND: Secondary brain damage after traumatic brain injury (TBI) involves neuro-inflammatory mechanisms, mainly dependent on the intracerebral production of cytokines. In particular, interleukin 1beta (IL-1beta) is associated with neuronal damage, while interleukin 6 (IL-6) exerts a neuroprotective role due to its ability to modulate neurotrophins biosynthesis. However, the relationship between these cytokines and neurotrophins with the severity and outcome of TBI remains still controversial. AIMS: To determine whether the concentration of IL-1beta and IL-6 and neurotrophins (nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), glial-derived neurotrophic factor (GDNF)) in the cerebrospinal fluid (CSF) of children with TBI correlates with the severity of the injury and its neurologic outcome. METHODS: Prospective observational clinical study in a university hospital. CSF samples were collected from 27 children at 2h (Time T1) and 48 h (Time T2) after severe TBI, and from 21 matched controls. Severity of TBI was evaluated by GCS and neurologic outcome by GOS. CSF concentrations of cytokines and neurotrophins were measured by immunoenzymatic assays. RESULTS: Early NGF and IL-1beta concentrations (T1) correlated significantly with the severity of head injury, whereas no correlation was found for IL-6, BDNF, and GDNF. Furthermore, higher NGF and IL-6 and lower IL-1beta expression at T2 were associated with better neurologic outcomes. No significant association was found between BDNF or GDNF expression and neurologic outcome. CONCLUSIONS: NGF concentration in CSF is a useful marker of brain damage following severe TBI and its up-regulation, in the first 48 h after head injury together with lower IL-1beta expression, correlates with a favorable neurologic outcome. Clinical and prognostic information may also be obtained from IL-6 expression.     

Proinflammatory cytokines, prostaglandins and zinc in febrile convulsions

BACKGROUND: Some changes in the levels of proinflammatory cytokines, prostaglandins and zinc (Zn) in peripheral blood and cerebrospinal fluid (CSF) have been suggested to occur for the pathogenesis of febrile convulsions (FC). METHODS: In order to test this hypothesis, the levels of tumor necrosis factor (TNF)-alpha, interleukin (IL)-1 alpha, IL-1 beta and prostaglandins (PGE(2), PGF(2 alpha), PGD(2)) in the CSF and plasma and the levels of Zn in serum and CSF were investigated in children during the acute and late phases of FC. Results were compared with control subjects with meningismus. RESULTS: During the acute phase of FC, children had significantly elevated plasma levels of IL-1 beta, CSF levels of TNF-alpha, plasma levels of PGE(2), PGF(2 alpha) and PGD(2) and CSF levels of PGD(2) (P<0.05). A positive correlation between the degree of fever and plasma IL-1 beta levels was observed in both patients and controls. Three months after the acute phase of FC, plasma levels of IL-1 beta had returned to levels seen in controls. Children with FC also had significantly decreased serum Zn levels during the acute phase (P<0.05). However, there was no significant difference between the groups with respect to CSF Zn levels (P>0.05). CONCLUSIONS: During the acute phase of FC, patients had significantly increased plasma IL-1 beta and prostaglandin levels and decreased serum Zn levels. These changes may be responsible for FC pathogenesis.     

Cytokine expression in normal and inflamed esophageal mucosa: a study into the pathogenesis of allergic eosinophilic esophagitis

OBJECTIVES: We studied the expression of cytokines and inflammatory cells in normal and inflamed esophageal mucosa of children with the aim of furthering our understanding of the pathophysiology of allergic eosinophilic esophagitis (AEE). METHODS: Controls and AEE patients (>or=15 eosinophils/high-power field on esophageal mucosal biopsies) between the ages of 1 and 18 years were recruited. Esophageal biopsies were obtained for histologic examination, immunohistochemical studies, and cytokine analysis. RESULTS: Eight controls (4 males; mean age 9.99 years) and 11 AEE patients (8 males; mean age 7.15 years) were studied. mRNA expression of interferon (IFN)-gamma, interleukin (IL)-4, IL-5, IL-13, eotaxin-1, eotaxin-2, eotaxin-3, and RANTES was studied. IFN-gamma and IL-5 expressions were significantly up-regulated in AEE patients compared with controls. Expressions of IL-4 and IL-13 were similar between AEE patients and controls. Eotaxin-1 expression was significantly up-regulated in AEE patients, whereas eotaxin-2 was up-regulated in controls. Expression of RANTES and eotaxin-3 was similar between the two groups. There was increased staining for mast cells in AEE patients compared with controls. CONCLUSIONS: Our data suggests that AEE is primarily an IL-5 selective TH2 response, with a possible TH1 component, and a differential role of eosinophilic chemoattractants. The role of mast cells in the pathogenesis of AEE needs additional study.     

Cytokines in human colostrum and neonatal jaundice

Breast-fed infants have higher bilirubin levels than formula-fed infants, possibly because of variations in the composition of the breast milk. The aim of this study was to investigate whether there is a relationship between cytokine levels in the colostrum of nursing mothers and neonatal jaundice (NJ). Breast milk samples were collected from breast-feeding mothers of healthy full-term neonates, 32 with NJ and 29 without jaundice. The concentrations of IL-1beta, IL-6, IL-8, IL-10, and tumor necrosis factor (TNF)-alpha were measured by chemiluminescence enzyme immunometric assays. Mothers of infants with NJ had a higher concentration of IL-1beta in colostrum, compared with those feeding neonates without NJ, and similar trends were seen for IL-6, IL-8, IL-10, and for TNF-alpha. The concentrations of IL-1beta significantly correlated with IL-6, IL-8, IL-10, and TNF-alpha concentrations, but not with serum bilirubin levels of infants with NJ. In conclusion, the concentrations of IL-1beta were increased in colostrum from breast-feeding mothers whose infants had NJ. The correlation between the concentrations of cytokines involved in the function of hepatic uptake and excretory systems and in the enterohepatic circulation of bilirubin provides additional data to the delineation of the cascade of pathophysiological events that can lead to NJ.     

Ibuprofen affects pro- and anti-inflammatory cytokine production by mononuclear cells of preterm newborns

The in vitro effect of ibuprofen (IB) on the production of the proinflammatory cytokines interleukin (IL) 1beta, IL-6, and tumor necrosis factor alpha (TNF-alpha) and the anti-inflammatory cytokine IL-10 by cord blood mononuclear cells from preterm newborns was compared to that of peripheral blood mononuclear cells of adults. Mononuclear cells were incubated without or with lipopolysaccharide in the absence or presence of various concentrations of IB. The levels of IL-1beta, IL-6, TNF-alpha, and IL-10 in the supernatants were tested by ELISA. The mononuclear cells from the two groups responded to IB by an increased secretion of IL-6 and TNF-alpha and by a reduced production of IL-10. The pattern of response to the drug was similar following stimulation with lipopolysaccharide. The IL-1beta production was mostly unaffected by IB. It is suggested that in preterm newborns the differences observed in the in vitro proinflammatory cytokine production in response to IB, as observed in the present study, or to indomethacin, as reported previously, may affect various clinical outcomes using these two drugs.     

Correlation of interleukin-1 beta and cachectin concentrations in cerebrospinal fluid and outcome from bacterial meningitis

Because interleukin-1 beta (IL-1 beta) and cachectin (tumor necrosis factor) are thought to mediate the body's response to microbial invasion, we measured IL-1 beta and tumor necrosis factor concentrations in paired cerebrospinal fluid (CSF) samples (on admission to the hospital, CSF1; 18 to 30 hours later, CSF2) from 106 infants and children with bacterial meningitis. In CSF1, IL-1 beta was detected in 95% of samples; the mean (+/- 1 SD) concentration was 944 +/- 1293 pg/ml. Patients with CSF1 IL-1 beta concentrations greater than or equal to 500 pg/ml were more likely to have neurologic sequelae (p = 0.001). Tumor necrosis factor was present in 75% of CSF1 samples; the mean concentration was 787 +/- 3358 pg/ml. In CSF2 the mean IL-1 beta concentration was 135 +/- 343 pg/ml, and IL-1 beta concentrations correlated significantly with CSF2 leukocyte count, with glucose, lactate, protein, and tumor necrosis factor concentrations, and with neurologic sequelae. Tumor necrosis factor was detected in CSF2 specimens of 53 of 106 patients, with a mean concentration of 21 +/- 65 pg/ml. Of the 106 patients, 47 received dexamethasone therapy at the time of diagnosis. These patients had significantly lower concentrations of IL-1 beta and higher glucose and lower lactate concentrations in CSF2, and they had a significantly shorter duration of fever compared with the values in patients not treated with steroids (p less than or equal to 0.002). Our data suggest a possible role of IL-1 beta and tumor necrosis factor as mediators of meningeal inflammation in patients with bacterial meningitis, and might explain, in part, the beneficial effect of dexamethasone as adjunctive treatment in this disease.