Coxsackieviral infections involved in aseptic meningitis: a study in Slovakia from 2005 to 2009

A wide range of diseases is associated with enteroviruses.They are reported to be responsible for viral meningitis, especially in children, but also in adults.This study analysed infection with eight selected coxsackievirus serotypes as the cause of aseptic meningitis in 480 patients in Slovakia from 2005 to 2009,using a quantitative assay for the detection of intrathecal antibodies. Intrathecal production of antibodies against selected coxsackieviruses was proved in 21%of these patients. A significant decrease from 35% in 2005 to 8,5% in 2009 (p=0.004) in the proportion of patients with proven intrathecal production of virus specific antibodies was observed during the study period. We conclude that coxsackievirus B4 was the endemic serotype in Slovakia and was responsible for most cases of coxsackieviral meningitis in the study period.

Diagnostic value of serum procalcitonin levels in children with meningitis: a comparison with blood leukocyte count and C-reactive protein

OBJECTIVES

To determine the level of serum procalcitonin, blood leukocyte count (TLC) and C-reactive protein (CRP) in children with bacterial and non bacterial meningitis and document their efficacy in differential diagnosis. Also described are procalcitonin levels variation during treatment.

METHODS

From March 2005 to February 2008, we evaluated 38 clinically suspected meningitis patients in the paediatric departments, Al-Jedaany Hospital, Jeddah, KSA, for Serum procalcitonin, CRP, TLC and Lumbar punctures and CSF analysis. Patients were classified into bacterial meningitis group I (18) and non bacterial meningitis group II (20).

RESULTS

Serum PCT levels were significantly higher in bacterial meningitis (BM) {mean 4.8 +/- 3.85 ng/ml (2.9-11.6)} compared with non bacterial meningitis (NBM) {mean 0.38 +/- 0.25 ng/ml (0.31-0.61)} {P < 0.001}. Mean of all CSF parameters, TLC {15,000 +/- 2,900 cell/ml(BM) & 9500 +/- 1105 cell/ml (NBM)} and CRP {20 +/- 6.8 mg/l (BM) & 12.5 +/- 12.0 mg/l (NBM)} showed a zone of overlapping between the two groups. There is a positive correlation between serum PCT, TLC and CRP in bacterial and non bacterial meningitis cases but this relation becomes highly significant with bacterial meningitis positive group. Day 3 and day 6 treatment serum PCT was less than on admission levels (P < 0.001).

CONCLUSION

PCT can be used in the early diagnosis of bacterial meningitis and may be a useful adjunct in differentiating bacterial and non bacterial meningitis than CRP or TLC and diminishing the value of lumbar puncture performed 48-72 hours after admission to assess treatment efficacy.

The value of serial plasma nuclear and mitochondrial DNA levels in adult community-acquired bacterial meningitis

BACKGROUND

Increased levels of plasma nuclear and mitochondrial DNA have been reported in critically ill patients. We tested the hypothesis that plasma nuclear and mitochondrial DNA are substantially increased in acute bacterial meningitis and decrease after antimicrobial therapy, and that plasma nuclear and mitochondrial DNA levels can predict treatment outcomes.

METHODS

We examined serial plasma nuclear and mitochondrial DNA levels in 22 adult community-acquired bacterial meningitis (ACABM) patients. The plasma nuclear and mitochondrial DNA levels were also evaluated in 11 aseptic meningitis patients and 22 volunteer subjects during the study period.

RESULTS

All of the both bacterial and aseptic meningitis groups had a higher plasma DNA levels on admission as compared with those of volunteer groups. Levels of plasma nuclear and mitochondrial DNA in ACABM cases were significantly increased initially and substantially decreased thereafter. Both plasma nuclear DNA and plasma mitochondrial DNA levels at presentation are significantly negative correlate with modified Barthel Index (average) (r = -0.639, P = 0.004 and r = -0.551, P = 0.018) at 3 months after discharge (average), respectively, in this study. Both higher plasma nuclear (cutoff value of >169 ng/ml) and mitochondrial DNA levels (cutoff value of >58.9 ng/ml) at presentation were associated with poor outcome in ACABM patients.

CONCLUSION

Based on our results, the higher plasma DNA levels were associated with a poorer outcome. Therefore, we look forward to more prospective multicenter investigations specifically to confirm the predictive value of plasma DNA levels in outcome prediction.

Identifying low-risk patients for bacterial meningitis in adult patients with acute meningitis

OBJECTIVE

To derive and validate a clinical prediction model with high sensitivity for differentiating aseptic meningitis (AM) patients from bacterial meningitis (BM) patients.

METHODS

We developed the model using the derivation cohort in a community rural hospital in Okinawa and assessed its performance using the validation cohort in a metropolitan urban hospital in Tokyo. There were 66 (39.5%) and 5 (17.9%) adult patients with BM among the derivation (n=167) and the validation cohort (n=28), respectively. Recursive partitioning analysis was used to determine the important classification variables and to develop a sensitive model to safely exclude BM.

RESULTS

The model produced high- and low-risk groups based on the following: 1) Gram stain, 2) CSF neutrophil percent < or =15%, 3) CSF neutrophil count < or =150 cells/mm(3), and, 4) mental status change. Among the derivation cohort, there were 65 patients with BM in the high-risk group (n=76), while only one patient with BM was noted (sensitivity, 99%) in the low-risk group (n=91). Among the validation cohort, there were 5 patients with BM in the high-risk group (n=7), while no patient was classified with BM (sensitivity, 100%) in the low-risk group (n=21).

CONCLUSION

This simple and sensitive model might be useful to safely identify low-risk patients for BM who would not require antibiotic treatment.

[Epidemiologic and etiologic characteristic of enterovirus infections in Khabarovsk region]

Results of epidemiologic, virologic, and serologic studies of enterovirus infections in Khabarovsk region from 1975 to 2006 were analyzed. Patterns of epidemic process of these infections were established: periodic change of dominating type of pathogen in the population; onset of the large epidemic peaks of incidence during emergence of circulation of new for the given area serotypes of enteroviruses; possibility of realization of several routes of virus transmission. Role of water factor in the progress of the epidemic process was revealed. Etiology of the large epidemic rise of aseptic meningitis incidence in Khabarovsk region in 2006 was established--the leading pathogens were ECHO viruses serotypes E6 and E30.

[Level of lactoferrin in serum and cerebrospinal fluid of patients with meningitis]

Study showed 9-fold increase of concentration of lactoferrin (LF) in serum of patients with bacterial meningitis (BM) compared with normal concentration and 5-fold increase of LF concentration in patients with aseptic meningitis (AM). Level of LF in cerebrospinal fluid (CSF) of patients with BM and AM was 200-fold and 22-fold higher than in control group respectively. In 71% of patients with AM concentration of protein in CSF did not exceed minimal level observed in patients with BM. Level of LF in serum and CSF during treatment statistically significantly decreased. Concentration of LF (the latter is marker of neutrophilic granulocytes activation) can be used as a characteristic of acuteness and intensity of inflammatory process in central nervous system, whereas detection of LF in CSF--as additional criterion in differential diagnostics between bacterial and viral meningitis. Furthermore, repeated measurement of LF level can be useful for monitoring of disease course and assessment of effect of treatment.

Serum procalcitonin and other biologic markers to distinguish between bacterial and aseptic meningitis

OBJECTIVE

To identify the biologic tests that best distinguish between bacterial and aseptic meningitis in an emergency department (ED).

STUDY DESIGN

All children hospitalized for bacterial meningitis between 1995 and 2004 or for aseptic meningitis between 2000 and 2004 were included in a retrospective cohort study. Predictive values of blood (C-reactive protein, procalcitonin [PCT], white blood cell [WBC] count, neutrophil count) and cerebrospinal fluid (CSF) findings (protein, glucose, WBC count, neutrophil count) available in the ED were determined. Tests with the best predictive value were identified by using univariate and multivariate analyses and ROC curves comparison.

RESULTS

Among the 167 patients included, 21 had bacterial meningitis. The CSF gram-stain and bacterial antigen test had 86% and 60% sensitivity rates, respectively. PCT (>/=0.5 ng/mL) and CSF protein (>/=0.5 g/L) were the best biologic tests, with 89% and 86% sensitivity rates, 89% and 78% specificity rates, adjusted odds ratios of 108 (95% CI, 15-772) and 34 (95% CI, 5-217), and areas under the ROC curves of 0.95 and 0.93, respectively.

CONCLUSION

PCT and CSF protein had the best predictive value to distinguish between bacterial and aseptic meningitis in children.

Etiology of aseptic meningitis and encephalitis in an adult population

OBJECTIVE

To investigate the etiology of aseptic meningitis and encephalitis in an adult population using modern microbiologic methods.

METHODS

Consecutive patients (ages > or =16) with aseptic meningitis or encephalitis treated in Turku University Hospital, Finland, during 1999 to 2003 were included in the study. Microbiologic tests were performed, including CSF PCR tests for enteroviruses, herpes simplex virus (HSV) 1, HSV-2, and varicella zoster virus (VZV), as well as serum and CSF antibody analysis for these viruses. Antibody testing was also performed for other pathogens commonly involved in neurologic infections. Virus culture was performed on CSF, fecal, and throat swab specimens.

RESULTS

Etiology was defined in 95 of 144 (66%) patients with aseptic meningitis. Enteroviruses were the major causative agents (26%), followed by HSV-2 (17% of all, 25% of females) and VZV (8%). Etiology was identified in 15 of 42 (36%) patients with encephalitis, VZV (12%), HSV-1 (9%), and tick-borne encephalitis virus (9%) being the most commonly involved pathogens. Etiologic diagnosis was achieved by PCR in 43% of the patients with meningitis and in 17% of those with encephalitis.

CONCLUSIONS

Enteroviruses and HSV-2 are the leading causes of adult aseptic meningitis, and PCR is of diagnostic value. However, in most cases of encephalitis, the etiology remains undefined.

Serum cortisol levels in children with acute bacterial and aseptic meningitis

OBJECTIVE

To study serum cortisol levels in acute childhood meningitis with respect to the severity of illness and the outcome.

DESIGN

Prospective observational study.

SETTING

Pediatric services of a tertiary care teaching and referral hospital.

SUBJECTS

A total of 30 consecutive children, 2 months to 12 yrs of age, with suspected bacterial meningitis.

METHODS

Serum cortisol levels (by enzyme-linked immunosorbent assay) obtained at admission were correlated with clinical characteristics (including Glasgow Coma Scale and Pediatric Risk of Mortality scores) recorded at admission and with neurologic and hearing status 2 months after discharge using SPSS 10.0.

RESULTS

Mean +/- sd serum cortisol was 467 +/- 251 ng/dL in patients with bacterial (n = 16) and 319 +/- 159 ng/dL in aseptic meningitis (n = 14, p = .068). Glasgow coma scale score, systolic blood pressure, age, Pediatric Risk of Mortality, and cerebrospinal fluid protein were significant independent predictors of serum cortisol on stepwise multivariate regression analysis (each had an R change of >5%). Patients with neurologic or hearing sequelae had significantly higher median serum cortisol (450 ng/mL, n = 12) than those without sequelae (300 ng/mL, n = 17; p = .043 by Mann-Whitney U test). On multivariate logistic regression analysis, a serum cortisol of >/=420 ng/mL (odds ratio, 0.022; 95% confidence interval, 0.01-0.43) and systolic blood pressure (odds ratio, 1.35; 95% confidence interval, 1.04-1.74) were significant independent predictors of neurologic and hearing sequelae.

CONCLUSION

Low serum cortisol is uncommon in acute bacterial meningitis of nonmeningococcal pathogenesis. Very high levels are likely to be associated with sequelae.

C reactive protein for differentiating bacterial from aseptic meningitis in Thai patients

OBJECTIVES

To evaluate the efficacy of serum CRP level differentiating between bacterial and aseptic meningitis in Thai patients.

MATERIAL AND METHOD

The authors measured the serum CRP level in patients who were diagnosed clinically as bacterial and aseptic meningitis.

RESULTS

The authors evaluated 32 subjects, 12 with bacterial meningitis (all males) and 20 with aseptic meningitis (13 males, 7 females). The mean serum CRP level in the bacterial meningitis and aseptic meningitis group was 209.25 +/- 105.34 (range, 65 to 420) and 67.05 +/- 40.81 (range, 10 to 169) mg/L, respectively (p < 0.001).

CONCLUSIONS

Serum CRP can help differentiate between bacterial and aseptic meningitis.

Thrombopoietin in the Cerebrospinal Fluid of Patients with Aseptic and Bacterial Meningitis

Despite the recent evidence of the localization of thrombopoietin (TPO) and its receptor in the central nervous system (CNS), TPO protein concentrations in the cerebrospinal fluid (CSF) remained to be clarified. We previously reported that serum TPO is increased in children with meningitis. To determine changes in TPO concentrations in the CSF by meningitis and to explore the relationship between serum and CSF TPO concentrations, we measured TPO concentrations in 110 CSF samples and 33 serum/CSF pairs from 11 bacterial meningitis, 49 aseptic meningitis, and 50 nonmeningitis children. In only 12% (13 of 110) of CSF samples (0 bacterial meningitis, 8 aseptic meningitis, and 5 controls), TPO concentrations could be determined (24.1 +/- 29.0 pg/ml). CSF TPO concentrations did not significantly differ among the three groups and did not correlate with age. TPO concentrations in all serum samples were detectable, and mean concentrations in bacterial meningitis (510.6 +/- 237.0 pg/ml) were significantly higher than those in aseptic meningitis (136.6 +/- 71.6, p < 0.01) and controls (181.3 +/- 88.3, p < 0.01). These findings suggest that TPO is not produced in the CNS of patients with meningitis and that TPO did not cross the blood-brain barrier even during meningeal infection.

[Specific clinical, epidemiological patterns and laboratory diagnostics of enterovirus infection in the Republic of Belarus]

The clinical and epidemiological patterns as well as the results of the laboratory verification of the outbreak of enterovirus infection (EVI) in Minsk during the period of summer-autumn, 2000, are presented. During this outbreak a variety of clinical forms were observed, the serous meningitis being prevalent (57.5%). Practically simultaneous occurrence of infection on the territory of all administrative districts of the city, the predominant involvement of children aged up to 14 years into the outbreak, a high proportion of simultaneous casualities in the multiple foci. A number of circulating enteroviruses (EV)--ECHO 30, ECHO 6 of three serotypes and Coxsackie B5--were simultaneously isolated from clinical material. EV of the same serotypes were isolated from tap drinking water, and neutralizing antibodies to these serotypes were often detected in the patients blood sera. Infectious EV were also present in samples of bottled water and in water reservoirs used for bathing. The routes of EV transmission and the improvement of EVI control are discussed.

Severe symptomatic aseptic chemical meningitis following myelography: The role of procalcitonin

Symptomatic aseptic, chemical meningitis is a rare complication of myelography. Its acute clinical course and standard laboratory findings are indistinguishable from those of bacterial meningitis. The authors present a case of severe postmyelographic chemical meningitis and compare CSF and serum inflammatory markers to a group of seven patients with proven bacterial meningitis. As in viral meningitis, procalcitonin might be able to discriminate between bacterial and chemical causes of CNS inflammation.

Human herpesvirus 7-associated meningitis and optic neuritis in a patient after allogeneic stem cell transplantation

A 9-year-old boy who received allogeneic stem cell transplantation began to vomit from day 10 after transplantation. In addition to vomiting, the patient had a fever (from day 26) and severe headache (from day 34). His cerebrospinal fluid (CSF) (day 41) demonstrated pleocytosis with an absence of leukemic cells. Although the patient's symptoms were resolved with further supportive care, abrupt onset of bilateral decreased vision occurred at day 54. He was diagnosed with bilateral optic neuritis, due to the presence of disc edema and redness. Concomitant with the occurrence of aseptic meningitis, the human herpesvirus 7 (HHV-7) antibody titer increased significantly in this patient. Although neither HHV-6 nor cytomegalovirus (CMV) DNA was detected in CSF collected at day 41, HHV-7 DNA was detected in the sample. Viral DNA was not detected in CSF collected at day 93.

Development and validation of a multivariable predictive model to distinguish bacterial from aseptic meningitis in children in the post-Haemophilus influenzae era

CONTEXT

Children with meningitis are routinely admitted to the hospital and administered broad-spectrum antibiotics pending culture results because distinguishing bacterial meningitis from aseptic meningitis is often difficult.

OBJECTIVE

To develop and validate a simple multivariable model to distinguish bacterial meningitis from aseptic meningitis in children using objective parameters available at the time of patient presentation.

DESIGN

Retrospective cohort study of all children with meningitis admitted to 1 urban children's hospital from July 1992 through June 2000, randomly divided into derivation (66%) and validation sets (34%).

PATIENTS

Six hundred ninety-six previously healthy children aged 29 days to 19 years, of whom 125 (18%) had bacterial meningitis and 571 (82%) had aseptic meningitis.

INTERVENTION

Multivariable logistic regression and recursive partitioning analyses identified the following predictors of bacterial meningitis from the derivation set: Gram stain of cerebrospinal fluid (CSF) showing bacteria, CSF protein > or =80 mg/dL, peripheral absolute neutrophil count > or =10 000 cells/mm3, seizure before or at time of presentation, and CSF absolute neutrophil count > or =1000 cells/mm3. A Bacterial Meningitis Score (BMS) was developed on the derivation set by attributing 2 points for a positive Gram stain and 1 point for each of the other variables.

MAIN OUTCOME MEASURE

The accuracy of the BMS when applied to the validation set.

RESULTS

A BMS of 0 accurately identified patients with aseptic meningitis without misclassifying any child with bacterial meningitis in the validation set. The negative predictive value of a score of 0 for bacterial meningitis was 100% (95% confidence interval: 97%-100%). A BMS > or =2 predicted bacterial meningitis with a sensitivity of 87% (95% confidence interval: 72%-96%).

CONCLUSIONS

The BMS accurately identifies children at low (BMS = 0) or high (BMS > or =2) risk of bacterial meningitis. Outpatient management may be considered for children in the low-risk group.

Circulating sodium in acute meningitis

BACKGROUND

In acute meningitis hyponatremia is common and traditionally attributed exclusively to inappropriate water retention. However, the exact mechanisms underlying hyponatremia are unknown.

METHODS

The files of 300 pediatric patients with acute bacterial (n = 190) or aseptic (n = 110) meningitides were retrospectively analyzed.

RESULTS

The plasma sodium level ranged from 122 to 148 mmol/l and was low (<133 mmol/l) in 97 patients. Fluid volume contraction was significantly more pronounced in hyponatremia (median 6.0. 10(-2)) than in normonatremia (median 2.0. 10(-2)). The fractional sodium excretion was less than 1.00. 10(-2) in the 26 hyponatremic children with this measurement.

CONCLUSION

In acute meningitis hyponatremia is not exclusively brought about by inappropriate water retention.

RT-nested PCR for the detection of enterovirus in biological samples from patients with suspected enteroviral infections

In this study, we have tested a reverse transcription (RT) nested polymerase chain reaction (nPCR) for detection of enterovirus (EV) RNA in cerebrospinal fluid (CSF), serum samples, and conjunctival swabs (CS) from patients with suspected enterovirus infections. A specific 113-bp fragment was amplified using primers designed based on 5' non coding region of the enterovirus genome. The enterovirus RT-nPCR was able to detect 0.001 plaque forming unit (pfu)/ml. Since no PCR product was detected in each of the CSF, CS and serum samples from patients with proven-non-enterovirus viral infections, this method was found to be specific. EV RNA was detected in all 30 culture-confirmed CSF samples and yielded positive results in 5 out of 7 additional cases of culture-negative CSF samples with other evidences of enterovirus infection. Overall, EV RNA was detected in 95% of the patients with clinical diagnosis of viral central nervous system (CNS) disease and confirmed enterovirus infection. Furthermore, we were able to detect EV RNA in 24 (47%) out of 51 CSF samples from patients with clinical diagnosis of viral CNS disease and negative laboratory evidence of viral infection. The percentage of positive EV RNA detection in paired CSF and serum samples from 11 patients with an enterovirus isolate in CSF was 100% (11 of 11) and 73% (8 of 11), respectively. In addition, EV-specific IgM was detected in 64% (7 of 11) of the sera tested. The method was also tested against 136 samples of CS from patients with clinical diagnosis of acute hemorrhagic conjunctivitis. Ninety nine of them resulted positive (73%), while only 27 (20%) had been positive for viral culture. In summary, our study shows the importance of enterovirus RT-nPCR for the diagnosis of enterovirus associated disease in different kind of biological samples and different types of diseases.

Serum C-reactive protein in the differential diagnosis of childhood meningitis

BACKGROUND

Although determination of serum C-reactive protein (CRP) is considered one of the most useful tests for differentiating between bacterial and aseptic meningitis, its diagnostic accuracy in comparison with other laboratory parameters is yet to be further evaluated.

METHODS

A total of 192 pediatric cases, aged between 2 months and 14 years, comprising patients with bacterial meningitis (n = 66) and aseptic meningitis (n = 126), were retrospectively analyzed on the basis of data from the initial examination. The area under the best fit binormal curve of the receiver operating characteristics (Az) for CRP was determined and compared with that for several other analytic parameters, including white blood cell count and erythrocyte sedimentation rate of peripheral blood, standard cerebrospinal fluid analysis variables and the combination test (probability of acute bacterial meningitis (pABM)) derived from Hoen's model.

RESULTS

Compared with each of the other variables, the Az for serum CRP (0.97 +/- 0.02) was found to be significantly greater (P < 0.01) for all except pABM (0.99 +/- 0.01; P > 0.05). False-negative cases among the CRP test results were found to have been examined too early.

CONCLUSIONS

The diagnostic accuracy of a single CRP determination was found to be equivalent to that of the most effective combination test. Patients with meningitis in whom serum CRP values are determined at least 12 h after the onset of fever and are < 2 mg/dL are far less likely to have bacterial meningitis.

Management of children with aseptic meningitis in the emergency department

OBJECTIVE

To review the emergency department management of children with aseptic meningitis and compare the clinical features, laboratory findings, and short-term follow-up of those who were hospitalized or discharged to determine guidelines for discharge.

DESIGN

Retrospective chart review study.

SETTING

Emergency department of an inner-city teaching, level III, children's hospital during an outbreak of aseptic meningitis from, March through December 1993.

METHODS

The medical records of children < or = 18 years of age diagnosed in the emergency department with aseptic meningitis after lumbar puncture were retrospectively reviewed and analyzed. Thirty-four parameters were recorded for each child including demographic (2), epidemiologic (5), clinical (2), laboratory (10), and short-term follow-up data (5).

RESULTS

Of the 158 eligible patients, 99 (62.7%) were hospitalized, and 59 (37.3%) were discharged. Compared to the hospitalized group, children who were discharged were significantly older (5.7 years vs. 4.7 years, P < 0.05) and experienced a more benign course, with lower rates of headache (54.7 vs. 85.7%, P < 0.05), vomiting (38.2 vs. 69.7%, P < 0.05), and irritability (1.8 vs. 8.1%, P < 0.05). They also had significantly (P < 0.05) lower mean peripheral and cerebrospinal fluid leukocyte counts (13,233 vs. 11,498/mm3 and 293.91 vs. 105.29/mm3, respectively). Interestingly, 30 (50.8%) of children in the discharged group had over 50% polymorphonuclears in their cerebrospinal fluid (CSF) cell count. The hospitalization rate during the day was significantly (P < 0.05) lower than that for the evening and night shifts (51.5 vs. 66.7%, respectively). In the discharged group, symptoms of headache, fever, and vomiting resolved after an average of 3.05 days, 2.25 days, and 1.3 days, respectively. The average hospitalization time was 3.5 days. There were no significant complications in either group. More important, in neither group were there any misdiagnoses of bacterial meningitis as aseptic meningitis. During the study period, the ambulatory management of the 59 patients cost $51,625 less than the hospitalization of an equal number of children.

CONCLUSION

It is feasible, clinically safe and less costly to treat a subgroup of children with aseptic meningitis in an ambulatory setting. Although absolute criteria for ambulatory follow-up could not be defined, age >1 year, a nontoxic clinical appearance, normal white blood cell count, mild cerebrospinal fluid pleocytosis (even with a high percentage of polymorphonuclear cells), negative CSF Gram stain, and a reliable family setting could serve as guidelines for decision-making regarding emergency department discharge. Further prospective research is needed to better specify these criteria.

Aseptic meningitis in the newborn and young infant

When a toxic newborn or young infant presents with fever and lethargy or irritability, it is important to consider the diagnosis of meningitis even if the classic localizing signs and symptoms are absent. Cerebrospinal fluid should be obtained (unless lumbar puncture is clinically contraindicated) to enable initial therapy to be planned. Initial results of cerebrospinal fluid testing may not conclusively differentiate between aseptic and bacterial meningitis, and antimicrobial therapy for all likely organisms should be instituted until definitive culture results are available. Comprehensive therapy, including antibacterial and antiviral agents, should continue until a cause is identified and more specific therapy is initiated, an etiology is excluded or the patient improves considerably and the course of antimicrobial therapy is completed. Group B streptococcus is the most common bacterial etiologic agent in cases of meningitis that occur during the first month after birth. Etiologies of aseptic meningitis include viral infection, partially treated bacterial meningitis, congenital infections, drug reactions, postvaccination complications, systemic diseases and malignancy. Long-term sequelae of meningitis include neuromuscular impairments, learning disabilities and hearing loss. Prompt diagnosis and treatment are essential to improved outcome.

Cytokine autoantibodies in multiple sclerosis, aseptic meningitis and stroke

BACKGROUND

We have recently described the induction of anti-cytokine autoantibodies during bacterial infections and autoimmune diseases as a mechanism for cytokine regulation.

METHODS

Herein, we study the occurrence of autoantibodies to pro- and anti-inflammatory cytokines in cerebrospinal fluid and plasma from patients with multiple sclerosis, aseptic meningitis and stroke.

RESULTS

Increased levels of autoantibodies to interferon gamma, tumour necrosis factor alpha, interleukin 4 and interleukin 10 were detected in both compartments of multiple sclerosis and aseptic meningitis patients. Interestingly, in cerebrospinal fluid from stroke patients, only autoantibodies to interleukin 4 and interleukin 10, but not interferon alpha or tumour necrosis factor alpha were detected. No significant autoantibody levels were registered in plasma from stroke patients against all four cytokines compared with healthy control subjects. The latter revealed very low autoantibody levels in plasma and no detectable autoantibodies in cerebrospinal fluid.

CONCLUSIONS

Our data show for the first time the occurrence of cytokine autoantibodies in these diseases, but their biological significance is unclear.

High human immunodeficiency virus type 1 RNA load in the cerebrospinal fluid from patients with lymphocytic meningitis

Thirty-seven matched cerebrospinal fluid (CSF) and plasma samples from 34 human immunodeficiency virus type 1 (HIV-1)-infected patients with suspected meningitis were analyzed for levels of HIV-1 RNA and markers of inflammation. Patients with tuberculous (n = 9) or cryptococcal (n = 6) meningitis had the highest CSF virus loads, which in many cases exceeded the levels in plasma, compared with patients with meningococcal meningitis (n = 3), aseptic meningitis (n = 8), tuberculoma (n = 2), or AIDS dementia complex (n = 4) or with normal lumbar punctures (n = 3). CSF virus load correlated significantly with the number of infiltrating lymphocytes (r = .60, P < .001) but not with plasma virus load, the levels of beta2-microglobulin in the CSF, or the integrity of the blood-brain barrier. These data suggest significant intrathecal HIV-1 replication in patients with lymphocytic meningeal infections such as tuberculous and cryptococcal meningitis.

[Laboratory and clinical variables in the differential diagnosis of aseptic and pyogenic meningitis in children]

We reviewed the charts of 573 children with a final diagnosis of pyogenic or aseptic meningitis, who were hospitalized in a large reference hospital for the treatment of infectious disease, from January 1990 to December 1992. Seizures, decreased consciousness, nuchal rigidity were more frequent in bacterial than in aseptic meningitis. A cerebrospinal fluid (CSF) glucose level lower than 45 mg/dL, a protein level equal or greater than 140 mg/dL and cell count greater than 600/mm3 were predictors of pyogenic meningitis. Receiver operating characteristic curve analysis was used to assess the best point in CSF measures of leukocytes, glucose and protein that could predict bacterial meningitis. These results suggest that clinicians should differentiate bacterial from aseptic meningitis in children with greater accuracy utilizing only clinical and simple CSF data.

The production of IL-8 in cerebrospinal fluid in aseptic meningitis of children

Neutrophils accumulate initially in the cerebrospinal fluid (CSF) of aseptic meningitis, perhaps because of increased levels of granulocyte colony-stimulating factor (G-CSF), macrophage inflammatory protein-1alpha (MIP-1alpha), and IL-8 in the subarachnoid space. We studied levels of these cytokines in children with aseptic meningitis using ELISA. When meningeal symptoms existed, IL-8 levels (1399 +/- 1600 ng/l, n = 32) in the CSF were significantly higher than those either after meningeal symptoms disappeared (61 +/- 56 ng/l, n = 18) or in controls (44 +/- 63 ng/l, n = 27) (P < 0.0001). High levels of IL-8 on admission dropped sequentially. Significant correlations were found between IL-8 levels and either neutrophil counts (r = 0.612), G-CSF levels (r = 0.873) or MIP-1alpha levels (r = 0.623) in the CSF of the affected patients (P < 0.0001). IL-8 values in serum were lower than in the corresponding CSF samples from all individuals with meningeal symptoms. The IL-8 mRNA was detectable by reverse-transcribed polymerase chain reaction (PCR)-assisted amplification in fresh leucocytes from the CSF, but not from the peripheral blood of a healthy volunteer. The culture of CSF mononuclear cells produced high levels of IL-8 (approximately 2750 ng/l). These data indicate that IL-8 levels rise transiently at the initial stage of aseptic meningitis, and that mononuclear cells that migrate into the CSF are a cellular source of this chemokine. We suppose that IL-8, in addition to G-CSF and MIP-1alpha, contribute to the localized neutrophil accumulation during the disease.

2',5'-Oligoadenylate synthetase activity and T cell subset in the cerebrospinal fluid and peripheral blood of aseptic meningitis

2',5'-oligoadenylate synthetase activity, which is assumed to be induced by interferon, is reported to be one of the useful markers reflecting interferon activity. The enzyme activity of patients with aseptic meningitis and febrile convulsion were compared in order to evaluate interferon activity as one of the local immuno-defense mechanisms of aseptic meningitis. The surface antigen of mononuclear cells in cerebrospinal fluid and peripheral blood of some patients with aseptic meningitis was also measured. The enzyme activity of patients with aseptic meningitis was 191.4 pmol/dL in the cerebrospinal fluid and 395.8 pmol/dL in the serum during the acute phase, while that of patients with febrile convulsion was 45.2 pmol/dL in the cerebrospinal fluid and 326.0 pmol/dL in the serum. The enzyme activity of the former patients significantly decreased during the recovery phase in both the cerebrospinal fluid and serum. CD3 positive cells in the peripheral blood were 56.3% of the total mononuclear cells during the acute phase and 65.2% during the recovery phase, whereas in the cerebrospinal fluid mononuclear cells, they were 87.1 and 85.5%, respectively. During the acute phase, CD4 positive cells were the predominant T lymphocyte subset in the cerebrospinal fluid cells, while CD8 positive cells were predominant during the recovery phase. The relative proportions of CD4 positive and CD8 positive cells during the acute and recovery phase in the cerebrospinal fluid mononuclear cells were quite high compared to the recovery phase, although that ratio of peripheral blood mononuclear cells was not changed throughout the course. It was concluded that T lymphocytes and increased 2',5'-oligoadenylate synthetase activity in the cerebrospinal fluid may be one of the important components in the local inflammatory process independent of the systemic host defense mechanism in aseptic meningitis.

Soluble tumor necrosis factor (TNF) receptors conserve TNF bioactivity in meningitis patient spinal fluid

The content of tumor necrosis factor (TNF)-alpha antigen and the bioactivity of soluble TNF receptor type II (sTNF-RII) in cerebrospinal fluid (CSF) from 29 patients with meningeal symptoms and fever were examined. Immunoreactive TNF was demonstrated in CSF from 4 of 7 patients with bacterial meningitis. In 3 of 8 patients with aseptic meningitis, CSF also contained TNF, but TNF bioactivity was confined to samples from patients with bacterial meningitis. Bioactive TNF was exclusively in high-performance liquid chromatography fractions containing 30- to 60-kDa proteins. Lipopolysaccharide induced down-regulation, possibly after shedding of granulocyte surface membrane TNF-RII. Consistently, there was a statistically significant correlation between sTNF-RII and CSF leukocyte counts. Bioactive TNF was found only in CSF containing >1 ng of sTNF-RII/mL; samples without TNF bioactivity contained less sTNF-RII. Thus, a stabilizing effect of sTNF-RII on the oligomeric cytokine in vivo is plausible.

Multivariate approach to differential diagnosis of acute meningitis

A previously reported statistical model based on a combination of four parameters (total polymorphonuclear cell count in cerebrospinal fluid (CSF), CSF/blood glucose ratio, age and month of onset) appeared effective in differentiating acute viral meningitis (AVM) from acute bacterial meningitis (ABM). The objectives of this study were to validate this model on a large independent sample of patients with acute meningitis and to build and validate a new model based on this sample. Of 500 consecutive cases of community-acquired meningitis reviewed retrospectively, 115 were ABM, 283 were AVM and 102 were of uncertain etiology. For each of the ABM and AVM cases, the probability of ABM versus AVM (pABM) was calculated for both models. Sensitivity, specificity and predictive values as well as areas under the receiver operating characteristic (ROC) curves were calculated for both models. The original model proved an accurate and reliable diagnostic test. Its area under the ROC curve was 0.981. For pABM = 0.1, its negative and positive predictive values were 0.99 and 0.68, respectively. The new model retained four slightly different independent variables: CSF protein level, total CSF polymorphonuclear cell count, blood glucose level and leukocyte count. Its area under the ROC curve was 0.991 and, for pABM = 0.1, its negative and positive predictive values were 0.99 and 0.85, respectively. In conclusion, both models provide a valuable aid in differentiating AVM from ABM. They should be further evaluated in a prospective appraisal of their contribution to therapeutic decision making.

Transient elevation of granulocyte colony-stimulating factor levels in cerebrospinal fluid at the initial stage of aseptic meningitis in children

At the early stage of aseptic meningitis, there is a transient increase in neutrophil counts in the cerebrospinal fluid. Some factors in the cerebrospinal fluid might induce migration of neutrophils into the cerebrospinal fluid. Granulocyte colony-stimulating factor (G-CSF) plays an important role, not only as a hemopoietic factor but also as a regulating factor for a biologic defense system by neutrophils in the foci of infection. To analyze the role of G-CSF on accumulating neutrophils in the cerebrospinal fluid, we have measured G-CSF levels in the cerebrospinal fluid of children with aseptic meningitis, paying particular attention to the phasal transition. Within the first 2 d from the onset, G-CSF levels in the cerebrospinal fluid were 223 +/- 97 ng/L, significantly higher than those of the patients without meningitis (p < 0.01). Beyond the second day after the onset, the G-CSF levels rapidly decreased to below the detectable level, even though the patients manifested meningeal signs and symptoms. There was a direct relationship between G-CSF levels and neutrophil counts in the cerebrospinal fluid (r = 0.763, p < 0.01). During the first 2 d after the onset, the G-CSF level in the cerebrospinal fluid in each case was remarkably higher than that in the serum. This finding suggests that the G-CSF in the cerebrospinal fluid was produced in the spinal cavity. From our results, the transient elevation of G-CSF levels might lead to the transient increase in neutrophil counts in the cerebrospinal fluid by recruiting them from the peripheral blood at the initial stage of aseptic meningitis.

T cell subsets in peripheral blood and cerebrospinal fluid from children with aseptic meningitis

T cell subsets in peripheral blood (PB) and cerebrospinal fluid (CSF) obtained from patients with aseptic meningitis were studied using quantitative two-color fluorescence analysis with a flow cytometer. The percentage of HLA-DR+/CD3+ lymphocytes (activated T cells) in CSF was significantly increased in the recovery phase when compared to the acute phase, while no significant change in the activated T cells in PB was observed. More interestingly, CD4+ T lymphocytes in CSF were increased in the acute phase and subsequently decreased in the recovery phase. Instead, CD8+ T lymphocytes gradually accumulated into the CSF in the recovery phase, resulting in a successive decrease in the CD4/CD8 ratio. On the other hand, the CD4/CD8 ratio in PB remained normal during the course of aseptic meningitis. The present results suggest that T lymphocytes (CD4+ subset in the acute phase and CD8+ in the recovery phase) could be infiltrated and further activated at the site of inflammation, possibly in the subarachnoid space in the patients with aseptic meningitis.

Lipoprotein alterations in children with bacterial meningitis

Abnormalities in serum lipids, including hypertriglyceridemia, are common during infectious disorders. However, the lipoprotein pattern during infections, particularly in children, has been investigated to only a limited extent. We have monitored alterations in serum lipoproteins in eight children with a severe bacterial infection (meningitis) by a quantitating method measuring cholesterol and triglycerides in each major class. The levels of triglycerides in serum and in low-density lipoproteins were markedly elevated during the infection, whereas the amount of cholesterol in high-density lipoproteins was decreased. The cholesterol to triglyceride ratio was decreased in low-, as well as in high-density lipoproteins. These lipoprotein abnormalities may, at least in part, be explained by a depressed lipolytic activity of lipoprotein lipase, the key enzyme for removal of triglycerides in man. Serum triglycerides and the levels of cholesterol in high-density lipoproteins, as well as the ratio between these parameters, may be used as indicators of inflammatory activity.

Human macrophage colony-stimulating factor levels in cerebrospinal fluid

Macrophage colony-stimulating factor (M-CSF) levels in the cerebrospinal fluid of 14 patients with meningitis and of 14 patients suffering from a disease other than meningitis were measured using an enzyme-linked immunosorbent assay. All four bacterial meningitis patients had M-CSF levels in the cerebrospinal fluid which exceeded 1540 U/ml, and the mean value was 3333 +/- 1481 U/ml. The mean M-CSF level in the cerebrospinal fluid of the ten aseptic meningitis patients was 393 +/- 175 U/ml, which was higher than that of patients who suffered from a disease other than meningitis (179 +/- 90 U/ml) (P < 0.01). There was no clear correlation between the M-CSF levels and the numbers of white blood cells, granulocytes, or monocytes in the cerebrospinal fluid. These elevated M-CSF levels were thought to be of a local origin, since most patients with high M-CSF levels in the cerebrospinal fluid had relatively low M-CSF levels in the serum.

High concentrations of intrathecal interleukin-6 in human bacterial and nonbacterial meningitis

Interleukin-6 (IL-6) is multipotent cytokine that acts in a network of factors directing the inflammatory reaction of purulent bacterial meningitis (PBM). However, little is known about the role of IL-6 in aseptic or "viral" meningitis (AM). IL-6 was assayed by RIA in cerebrospinal fluid (CSF) and serum samples obtained from patients with AM (n = 65), PBM (n = 8), and lymphocytic bacterial meningitis (LBM, n = 11). Of patients with AM, 89% had detectable IL-6 in CSF, with high IL-6 titers (median, 2160 pg/mL; 95% confidence interval [CI], 1320-2540 pg/mL) compared with 100% in patients with PBM (median, 6575 pg/mL; 95% CI, 450-32,000 pg/mL) and 90.9% in patients with LBM (median, 875 pg/mL; 95% CI, 150-2180 pg/mL). There was a highly symmetrical correlation between IL-6 and the percentage of polymorphonuclear cells in CSF of patients with PBM (r = .97, P = .01) and AM (r = .49, P = .002). In conclusion, this study shows evidence that IL-6 is released into the meningeal space in aseptic meningitis and is correlated with the local acute inflammatory response.

The changing spectrum of neonatal meningitis over a fifteen-year period

One hundred seventy-seven cases of neonatal meningitis treated at the University of Texas Medical Branch at Galveston over a 15-year period (1974-1988) were reviewed. Over this period, the incidence of bacterial meningitis decreased, the incidence of aseptic meningitis remained stable, and the diagnosis of enteroviral meningitis increased in frequency. During 1984-1988, enterovirus was the most common cause of meningitis in neonates older than seven days and accounted for one third of all cases of neonatal meningitis. Half of all neonates with bacterial meningitis had negative blood cultures. We recommend that 1) diagnostic lumbar puncture remain part of the routine assessment of the neonate with suspected sepsis, and 2) CSF be cultured for enterovirus as well as for bacteria when a neonate older than seven days presents with suspected sepsis.

Serum C-reactive protein in childhood meningitis in countries with limited laboratory resources: a Chilean experience

Quantitative C-reactive protein (CRP) was determined sequentially by nephelometry and photometry from a finger prick serum sample in 67 children with bacterial meningitis (BM) and 16 children with aseptic meningitis (AM). The initial mean CRP value of 180 mg/liter in children with BM differed significantly from the 12 mg/liter found in those with AM (P less than 0.001). In BM a slow descent instead of rapid normalization or a secondary increase in sequential CRP values were early indicators of complications during recovery, such as resistance to the antibiotic. A significant difference in the mean CRP values between uneventful and complicated courses of BM was observed from the fourth day on (P less than 0.001). The measurements obtained with nephelometry correlated reliably with the more widely available photometry (r = 0.99). Easily performed rapid CRP determinations can considerably improve the quality of care in meningitis patients, especially in those situations where facilities for performing bacterial cultures or antibiotic susceptibility testing are not available.

Vasopressin levels in infants during the course of aseptic and bacterial meningitis

We measured urine vasopressin (VP) once daily on days 1 through 3 in 18 patients hospitalized with meningitis. Urine VP values were 215 +/- 100, 116 +/- 44, and 69 +/- 23 pg/mL on days 1 through 3, respectively, for children with bacterial meningitis and 34 +/- 14, 20 +/- 4, and 15 +/- 4 pg/mL for those with aseptic meningitis. Urinary VP levels of infants with bacterial meningitis were significantly greater than those of healthy ambulatory subjects (n = 18) on all three study days; VP values of infants with bacterial meningitis were also greater than those of infants with aseptic meningitis on study days 2 and 3. The VP levels for the subjects with aseptic meningitis were significantly greater than those of the controls on day 1 only. None of the infants exhibited the clinical syndrome of inappropriate antidiuretic hormone secretion.

Use of high performance liquid chromatography in defining the abnormalities in the free amino acid patterns in the cerebrospinal fluid of patients with aseptic meningitis

Free amino acids were quantitatively determined in cerebrospinal fluid (CSF) and plasma samples from patients with aseptic meningitis by a newly developed high performance liquid chromatographic (HPLC) method. The method of analysis was based on precolumn derivatization of orthophthaladehyde in the presence of 2-mercaptoethanol and detection was made at Eex = 340 nm and Eem = 450 nm. The method was sensitive and the limit for detection was less than 1 pmol for most of the amino acids. It took 45 min to separate 26 amino acids with highly reproducible results, giving a coefficient of variance for retention times and integrated areas less than 0.4% and 2%, respectively, after five replicate runs. The results accumulated in 10 patients were compared statistically with 11 age-matched healthy controls. Among the amino acids almost all the neurotransmitter candidates, such as aspartic acid, glutamic acid, glutamine, glycine, tyrosine, phenylalanine and gamma-aminobutyric acid (GABA), were significantly increased in the patients' CSF, whereas arginine and threonine were low. No change was observed in plasma amino acids in patients as compared to healthy controls. The higher levels of most of the neurotransmitters, especially GABA, aspartic acid and glutamic acid, could be used diagnostically in assessing the progression and remission in aseptic meningitis.

Peripheral white blood cell counts and bacterial meningitis: implications regarding diagnostic efficacy in febrile children

In order to investigate the clinical value of peripheral white blood cell variables for the diagnosis of bacterial meningitis among young, febrile children, we compared total peripheral white counts, total segmented neutrophil counts, total band counts, and the ratio of immature-to-total neutrophils (I:T ratio) among 46 children with bacterial meningitis, 130 children with aseptic meningitis, and 56 febrile children with culture confirmed extrameningeal bacterial infection. Children with bacterial meningitis were comparable to those with aseptic meningitis with respect to median total white blood cell counts and median total segmented neutrophil counts but had a significantly higher median total band count (1760/microliters vs 378/microliters, P = 0.0001) and a significantly higher median I:T ratio (0.40 vs 0.09, P less than 0.001). In contrast, children with bacterial meningitis were comparable to those with an extrameningeal bacterial infection with respect to median total band count but had a significantly lower median total peripheral white count (10,650/microliters vs 15,300/microliters, P = 0.0013), a lower median total segmented neutrophil count (4511/microliters vs 6796/microliters, P = 0.023), and a significantly higher median I:T ratio (0.40 vs 0.15, P less than 0.001). Children with meningitis who were bacteremic at presentation had a significantly lower total white cell count (P = 0.001) and significantly higher I:T ratio (P = 0.005) when compared with children who had an extrameningeal infection and concurrent bacteremia at presentation.(ABSTRACT TRUNCATED AT 250 WORDS)

Recurrent encephalitis due to trimethoprim intake

We wish to report a 76-year-old woman with 2 episodes of meningitis related to the intake of trimethoprim. On both occasions the patient demonstrated encephalitic symptoms and a pathological electroencephalogram with cerebral function disturbances. A similar case with encephalitic symptoms due to trimethoprim has not been reported earlier.

Determination of interleukin-2 (IL-2) and soluble IL-2 receptors (S-IL-2R) in serum and cerebrospinal fluid does not discriminate purulent and aseptic meningitis

Elevated levels of soluble interleukin-2 receptors (S-IL-2R) but not interleukin-2 (IL-2) activity were found in sera from patients with aseptic meningitis, purulent meningitis, and meningism. Elevated levels of S-IL-2R in serum was also observed in 4/4 patients with bacterial pneumonia and 2/2 patients with infectious mononucleosis. The inflammation of the meninges was only reflected by an increase in S-IL-2R in cerebrospinal fluid (CSF) in 1/14 patients with aseptic meningitis and 3/10 patients with purulent meningitis. Further, IL-2 activity was only demonstrated in CSF from 2 patients with aseptic meningitis and 3 patients with purulent meningitis. In conclusion, neither S-IL-2R nor IL-2 in serum or CSF seem to have any value in the diagnosis of or discrimination between purulent meningitis and aseptic meningitis. Further, the elevation of S-IL-2R in serum is not specific for infections primarily fought by cytotoxic T-lymphocytes such as viral infections, but seems merely to reflect an unspecific activation of the immune system.

Terminal component of complement C9 in CSF and plasma of patients with MS and aseptic meningitis

A sensitive sandwich ELISA was applied to the measurement of the terminal component of complement C9 in CSF and plasma from 40 tension headache patients (reference group), 33 affected by clinically definite MS and 10 by aseptic meningitis. The levels of C9 in plasma were increased in aseptic meningitis. The determinations of CSF/plasma C9 ratio and C9 index, equal to (CSF C9/plasma C9): (CSF albumin/plasma albumin), thus accounting for changes of plasma C9 levels as well as damaged blood brain barrier, documented the existence of local consumption of C9 in aseptic meningitis. In contrast, only borderline alterations were evident in MS. The results indicate that local consumption of total C9 in CSF is an additional variable reflecting an acute inflammation within the CNS, but not demonstrable in MS, a chronic inflammatory CNS disorder.

CBC differential profile in distinguishing etiology of neonatal meningitis

A retrospective study of 72 infants under four weeks of age with meningitis evaluated over almost four years was performed to determine the predictive value of the CBC differential ratio (% lymphocytes + % monocytes/% polymorphonuclear leukocytes + % band forms) profile in distinguishing those with bacterial from those with a nonbacterial etiology. Of 18 neonates with bacterial meningitis, all had a radio lower than one; of 54 neonates with aseptic or viral meningitis, 46 (85%) had a ratio greater than one. The difference between mean ratio values of the two groups was highly significant (P less than 0.001). A CBC differential ratio less than one was more sensitive (100%) in initially identifying neonates with bacterial meningitis than were other traditionally utilized parameters, eg, presence of fever (50%), ill appearance (50%), hypoglycorrhachia (61%), elevated CSF protein (55%), or CSF Gram-stained smear revealing pathogenic organisms (45%). Statistical analysis revealed that a CBC differential ratio less than 1.5 will accurately predict all cases of neonatal bacterial meningitis with a confidence of 99.95%. The CBC differential ratio is an accurate index for distinguishing neonates with bacterial meningitis from those with nonbacterial meningitis. Utilization of this parameter in conjunction with other traditional factors is efficacious in predicting outcome.

Leukocyte types in cerebrospinal fluid and peripheral blood enumerated immunoenzymatically in aseptic meningitis and the Guillain-Barré syndrome

To study celltype distribution simultaneously in peripheral blood (PB) and cerebrospinal fluid (CSF) from patients with aseptic meningitis (AM) (n = 14) and Guillain-Barré syndrome (GBS) (n = 9) we used an immunoenzymatic method that enabled the use of several monoclonal antibodies, also in CSF samples with normal cellcounts. In both patient groups a different cell-distribution in CSF compared to PB was found with regard to pan T cells (CD5+/anti-Leu1+), T cell subpopulations (CD4+/anti-Leu3+, CD8+/anti-Leu2+), B cells (OKB2+, OKB7+), monocytes/macrophages (CD11+/OKM1+) and HLA/DR expressing cells, whereas the distribution of HLA/DC+ cells was similar in CSF and PB. Thus, the CSF cell distribution does not reflect the distribution in PB. The proportion of T cells was higher and the proportion of B-cells was lower in CSF than in PB in both patient groups, which is a finding similar to that in patients with multiple sclerosis. The OKT9 marker, labelling proliferating cells expressing the transferrin receptor, was not useful as marker of local proliferation.

Cerebrospinal fluid and peripheral blood leukocyte subsets in acute inflammation of the CNS

Leukocyte subsets in CSF and peripheral blood (PB) were determined in 21 patients with acute inflammation of the CNS using the monoclonal antibodies OKT3, OKT4, OKT8, Leu12, and OKM1 in an immunoperoxidase slide assay. There was a predominance of OKT3-positive cells in nearly all samples. Significant differences between acute aseptic and bacterial meningitis only were found in CSF and represented by a higher Leu12 and a lower OKT3 percentage in aseptic inflammation and a higher absolute amount of OKT4-, OKM1- and Leu12-positive cells in bacterial meningitis. Comparison between CSF and PB showed significant differences only in aseptic meningitis with a higher percentage of Leu12-positive cells and a lower percentage of OKT8-positive cells in CSF. The OKT4/OKT8 ratio seems to be generally lower in aseptic meningitis but significant differences only were found in comparison with healthy blood donors. In a case of herpes simplex encephalitis the ratio was strongly increased in CSF during the early phase of specific antibody production because of an absolute rise of OKT4-positive cells.