Cerebrospinal fluid neopterin as a biomarker of neuroinflammatory diseases

The elevation of neopterin in cerebrospinal fluid (CSF) has been reported in several neuroinflammatory disorders. However, it is not expected that neopterin alone can discriminate among different neuroinflammatory etiologies. We conducted an observational retrospective and case-control study to analyze the CSF biomarkers neopterin, total proteins, and leukocytes in a large cohort of pediatric patients with neuroinflammatory disorders. CSF samples from 277 subjects were included and classified into four groups: Viral meningoencephalitis, bacterial meningitis, acquired immune-mediated disorders, and patients with no-immune diseases (control group). CSF neopterin was analyzed with high-performance liquid chromatography. Microbiological diagnosis included bacterial CSF cultures and several specific real-time polymerase chain reactions. Molecular testing for multiple respiratory pathogens was also included. Antibodies against neuronal and glial proteins were tested. Canonical discriminant analysis of the three biomarkers was conducted to establish the best discriminant functions for the classification of the different clinical groups. Model validation was done by biomarker analyses in a new cohort of 95 pediatric patients. CSF neopterin displayed the highest values in the viral and bacterial infection groups. By applying canonical discriminant analysis, it was possible to classify the patients into the different groups. Validation analyses displayed good results for neuropediatric patients with no-immune diseases and for viral meningitis patients, followed by the other groups. This study provides initial evidence of a more efficient approach to promote the timely classification of patients with viral and bacterial infections and acquired autoimmune disorders. Through canonical equations, we have validated a new tool that aids in the early and differential diagnosis of these neuroinflammatory conditions.

L-lactate in cerebrospinal fluid can be used as a biomarker of encephalitis in cattle

Cerebrospinal fluid (CSF) changes are significant for antemortem diagnoses of some neurological diseases. The aim of this study was to evaluate if the concentration of L-lactate in CSF could be used to differentiate healthy from encephalitic cattle. Cerebrospinal fluid samples from healthy cattle (n = 10) and from those naturally affected by rabies (n = 15), bovine herpesvirus type 5 meningoencephalitis (n = 16), histophilosis (n = 6), or bacterial encephalitis (n = 4), including 1 case of listeriosis, were collected and analyzed. Physical, biochemical (i.e., protein and glucose), and cellular analyses were performed in fresh samples. L-lactate, electrolytes (sodium, potassium, and chloride), calcium, and magnesium concentrations were measured in CSF samples that were kept frozen. L-lactate concentrations were also measured in plasma. Analysis of variance was used for comparison between groups and receiver operating characteristic analysis was performed considering L-lactate in CSF of healthy versus encephalitic cattle. The CSF L-lactate concentration was significantly higher in cattle with bacterial encephalitis than in healthy cattle; however, it did not differ between viral and bacterial encephalitis. The calcium concentrations were lower in cattle with encephalitis. L-lactate concentration in CSF > 3.6 mmol/L can be accepted as a cut-off value to indicate encephalitis. Thus, L-lactate in CSF is important for the diagnosis of encephalitis in cattle. Despite the small number of cases of bacterial encephalitis, it is suggested that L-lactate was not important for the differentiation between viral and bacterial encephalitis. Additional studies with a greater number of observations are necessary to clarify this, specifically in cases of listeriosis.

Molecular diagnosis of central nervous system opportunistic infections in HIV-infected Zambian adults

BACKGROUND

Knowledge of central nervous system (CNS) opportunistic infections (OIs) among people living with human immunodeficiency virus (HIV) in sub-Saharan Africa is limited.

METHODS

We analyzed 1 cerebrospinal fluid (CSF) sample from each of 331 HIV-infected adults with symptoms suggestive of CNS OI at a tertiary care center in Zambia. We used pathogen-specific primers to detect DNA from JC virus (JCV), varicella zoster virus (VZV), cytomegalovirus (CMV), Epstein-Barr virus (EBV), herpes simplex virus (HSV) types 1 and 2, Mycobacterium tuberculosis, and Toxoplasma gondii via real-time polymerase chain reaction (PCR).

RESULTS

The patients' median CD4(+) T-cell count was 89 cells/µL (interquartile range, 38-191 cells/µL). Of 331 CSF samples, 189 (57.1%) had at least 1 pathogen. PCR detected DNA from EBV in 91 (27.5%) patients, M. tuberculosis in 48 (14.5%), JCV in 20 (6.0%), CMV in 20 (6.0%), VZV in 13 (3.9%), HSV-1 in 5 (1.5%), and HSV-2 and T. gondii in none. Fungal and bacteriological studies showed Cryptococcus in 64 (19.5%) patients, pneumococcus in 8 (2.4%), and meningococcus in 2 (0.6%). Multiple pathogens were found in 68 of 189 (36.0%) samples. One hundred seventeen of 331 (35.3%) inpatients died during their hospitalization. Men were older than women (median, 37 vs 34 years; P = .01), more recently diagnosed with HIV (median, 30 vs 63 days; P = .03), and tended to have a higher mortality rate (40.2% vs 30.2%; P = .07).

CONCLUSIONS

CNS OIs are frequent, potentially treatable complications of AIDS in Zambia. Multiple pathogens often coexist in CSF. EBV is the most prevalent CNS organism in isolation and in coinfection. Whether it is associated with CNS disease or a marker of inflammation requires further investigation. More comprehensive testing for CNS pathogens could improve treatment and patient outcomes in Zambia.

[Low-manifest infections with CNS damage in patients in prolonged unconscious state of non-inflammatory etiology]

AIM

Study of specter of low-manifest infections (LMI) with central nervous system (CNS) damage and their role in patients in prolonged unconscious state (PUS) of noninflammatory etiology.

MATERIALS AND METHODS

32 patients (23 male, 9 female; age 14-58) in PUS of various etiology were examined. The main group (18 patients) received therapy against all infectious diseases including LMI; control group (14 patients)--only against common and nosocomial microflora. Patients were immunologically, infectologically and neurologically examined in dynamic. The data obtained were treated by using STATISTICA for Windows (version 5.5).

RESULTS

Significant differences in immune and infectologic status depending on the nature of primary CNS damage were not detected. Immunodeficiency was detected in all patients; 94% of patients had increased non-specific IgM and IgE. Among LMI agents Chlamydia spp. were predominant. Cultural and/or PCR methods detected this microorganism during the primary examination in cerebrospinal fluid samples in 56% patients and in blood samples in 56%; during the second diagnostics or autopsy--only in 13 and 25%, respectively. Detection of Bacteroides fragilis, Human Herpes Virus (HHV-6), Virus Epstein Barr (VEB), Cytomegalovirus (CMV) in cerebrospinal fluid, blood and on mucous membranes of nasopharynx and conjunctiva was grouped more frequently with the presence of Chlamydia spp. in the CNS (p < 0.05) than with other LMI agents. Sanation of CNS from LMI was significantly accompanied by regeneration of communicative activity in comparison with the control group.

CONCLUSION

In patients with PUS high frequency of CNS infection by various LMI agents and primarily Chlamydia spp. should be considered. Sanation from LMI can become a "window" for effective neuro-regenerative treatment.

Human guanylate binding protein-1 is a secreted GTPase present in increased concentrations in the cerebrospinal fluid of patients with bacterial meningitis

Interferon-gamma-induced GTPases are key to the protective immunity against microbial and viral pathogens. As yet, the cell interior has been regarded as the exclusive residence of these proteins. Here we show that a member of this group, human guanylate binding protein-1 (hGBP-1), is secreted from cells. Secretion occurred in the absence of a leader peptide via a nonclassical, likely ABC transporter-dependent, pathway, was independent of hGBP-1 GTPase activity and isoprenylation, and did not require additional interferon-gamma-induced factors. Interestingly, hGBP-1 was only secreted from endothelial cells but not from any of the nine different cell types tested. Clinically most important was the detection of significantly (P<0.001, Mann-Whitney U-test) increased hGBP-1 concentrations in the cerebrospinal fluid of patients with bacterial meningitis (n=32) as compared to control patients (n=74). In this first report of a secreted GTPase, we demonstrate that secreted hGBP-1 may be a useful surrogate marker for diagnosis of bacterial meningitis.

Transient acute obstructive hydrocephalus of unknown origin in a 13-month-old infant

We report on a case of a 13-month-old female infant who was admitted to our department with the chief complaints of drowsiness and vomiting. A history of an unspecified viral infection was reported. Clinical examination was negative for focal neurological signs or signs of central nervous system infection. Initial CT scan revealed obstructive hydrocephalus, and shunting was scheduled. Dexamethasone treatment was started. Eight hours after admission the child almost restored his baseline mental status and the operation was postponed. The dexamethasone treatment was discontinued 3 days later. Follow up CT and MRI scans were normal. We discuss the case and the possible causes of transient hydrocephalus in children.

Childhood encephalopathy: viruses, immune response, and outcome

This study examined children with an acute encephalopathy illness for evidence of viral infection, disordered blood-brain barrier function, intrathecal immunoglobulin synthesis, and interferon (IFN) production, and related their temporal occurrence to outcome. A prospective study of 22 children (13 males, 9 females; age range 1mo to 13y, median 2y 4mo), recorded clinical details, with serum and cerebrospinal fluid (CSF) analysis near presentation and then on convalescent specimens taken up to day 39 of the neurological illness. Outcome was assessed with standard scales between 18 months and 3 years after presentation. A history consistent with viral infection was given in 17 children but laboratory evidence of viral infection was found in only 7 (7/17). In 18 out of 21 children, an elevated CSF:serum albumin ratio indicative of impairment of the blood-CSF and blood-brain barriers was detected at some stage of the illness. In 14 of the 15 children with a raised immunoglobulin G index, and in 12 of the 14 children where the CSF was positive for oligoclonal bands, this was preceded by, or was observed at the same time as, an abnormal albumin ratio. Sixteen children (16/18) had elevated IFN-alpha levels in serum, or CSF, or in both. We conclude that these findings indicate an initial disruption of the blood-brain barrier followed by intrathecal antibody production by activated lymphocytes, clonally restricted to a few antigens. This is the first in vivo study to show this as an important pathogenetic mechanism of encephalitis in children. Poor outcome was associated with young age, a deteriorating electroencephalogram pattern from grade 1 to grade 2, and the degree of blood-brain barrier impairment, particularly when prolonged, but not with Glasgow Coma Scale score. The persistence of IFN-alpha was associated with a good prognosis.

Factors affecting delivery of antiviral drugs to the brain

Although the CNS is in part protected from peripheral insults by the blood-brain barrier and the blood-cerebrospinal fluid barrier, a number of human viruses gain access to the brain, replicate within this organ, or sustain latent infection. The efficacy of antiviral drugs towards the cerebral viral load is often limited as both blood-brain interfaces impede their cerebral distribution. For polar compounds, the major factor restricting their entry lies in the tight junctions that occlude the paracellular pathway across these barriers. For compounds with more favourable lipid solubility properties, CNS penetration will be function of a number of physicochemical factors that include the degree of lipophilicity, size and ability to bind to protein or red blood cells, as well as other factors inherent to the vascular and choroidal systems, such as the local cerebral blood flow and the surface area available for exchange. In addition, influx and efflux transport systems, or metabolic processes active in both capillary endothelial cells and choroid plexus epithelial cells, can greatly change the bioavailability of a drug in one or several compartments of the CNS. The relative importance of these various factors with respect to the CNS delivery of the different classes of antiviral drugs is illustrated and discussed.

[Polymerase chain reaction in the diagnosis of viral infections in the newborn]

Two hundred and ten newborns from among a high risk group were examined for intrauterine infections by polymerase chain reaction (PCR) with the aim of assessing the clinical information density of the method in the diagnostic sphere. The patients were examined for the presence of DNA/RNA viruses and bacteria. Genetic samples of various causative agents were detected in 49% of the newborns. No correlation was established between the clinical pattern and the presence of DNA of certain microorganisms. The most severe condition of newborns was noted in cases when a DNA causative agent was found in several different biological samples. The highest mortality (in per cent) was registered in the group of newborns with detected DNA of Herpesviridae viruses. The PCR clinical value was affirmed for establishing a disease etiology in newborns.

Molecular analysis of cerebrospinal fluid in viral diseases of the central nervous system

The use of nucleic acid (NA) amplification techniques has transformed the diagnosis of viral infections of the central nervous system (CNS). Because of their enhanced sensitivity, these methods enable detection of even low amounts of viral genomes in cerebrospinal fluid. Following more than 10 years of experience, the polymerase chain reaction or other NA-based amplification techniques are nowadays performed in most diagnostic laboratories and have become the test of choice for the diagnosis of several viral CNS infections, such as herpes encephalitis, enterovirus meningitis and other viral infections occurring in human immunodeficiency virus-infected persons. Furthermore, they have been useful to establish a viral etiology in neurological syndromes of dubious origin and to recognise unusual or poorly characterised CNS diseases. Quantitative methods have provided a valuable additional tool for clinical management of these diseases, whereas post-amplification techniques have enabled precise genome characterisation. Current efforts are aiming at further improvement of the diagnostic efficiency of molecular techniques, their speed and standardisation, and to reduce the costs. The most relevant NA amplification strategies and clinical applications of to date will be the object of this review.

Etiology of central nervous system infections in the Philippines and the role of serum C-reactive protein in excluding acute bacterial meningitis

OBJECTIVES

The value of measurements of serum C-reactive protein (CRP) in differentiating central nervous system (CNS) infections of varying etiologies in the Philippines was investigated.

METHODS

A wide array of bacteriologic and virologic methods as well as computed tomography, typical clinical presentation, and autopsy were used for etiologic diagnosis.

RESULTS

Among 103 patients with CNS infection, etiology was identified in 60 (58%) cases. Bacteria were found in 19 (including 7 Streptococcus pneumoniae, 5 Haemophilus influenzae, 3 Neisseria meningitidis), tuberculosis in 4, viruses in 38 (including 20 coxsackievirus, 8 measles, 4 adenovirus, and 4 poliovirus infections), and brain abscess in 3 patients. C-reactive protein was elevated on admission in all 18 cases of bacterial meningitis tested, exceeding 50 mg/L in 17 (94%), and was not affected by prior antibacterial treatment. The mean CRP was significantly higher in the bacterial group than in the viral group (207 +/- 111 mg/L vs. 39 +/- 34 mg/L; P < 0.001). In the viral group one third had CRP above 50 mg/L. In patients with tuberculous meningitis, brain abscess, or cryptococcal meningitis, CRP was moderately to highly elevated.

CONCLUSIONS

In the presence of a normal CRP concentration (below 10 mg/mL) acute bacterial meningitis is excluded even in a developing country setting and antimicrobial therapy is not warranted.

Improved silica-guanidiniumthiocyanate DNA isolation procedure based on selective binding of bovine alpha-casein to silica particles

DNA purified from clinical cerebrospinal fluid and urine specimens by a silica-guanidiniumthiocyanate procedure frequently contained an inhibitor(s) of DNA-processing enzymes which may have been introduced by the purification procedure itself. Inhibition could be relieved by the use of a novel lysis buffer containing alpha-casein. When the novel lysis buffer was used, alpha-casein was bound by the silica particles in the first step of the procedure and eluted together with DNA in the last step, after which it exerted its beneficial effects for DNA-processing enzymes. In the present study we have compared the novel lysis buffer with the previously described lysis buffer with respect to double-stranded DNA yield (which was nearly 100%) and the performance of DNA-processing enzymes.

Overstimulation of nerve growth factors in postinfectious and autoimmune diseases

Nerve growth factor (NGF) in cerebrospinal fluid was measured by ELISA in ten children with postinfectious diseases and in five children with diseases suggested to be of autoimmune etiology. Three groups of patients were studied: (1) those with moderately elevated concentrations (50.67 +/- 17.02 pg/mL, mean and SEM), (2) those with high concentrations (mean 424.25 +/- 125.41 pg/mL, mean and SEM), and (3) those with enormously high concentrations (mean 2,745 +/- 1,819.46 pg/mL, mean and SEM). We suggest that CSF-NGF could be used as an immunologic marker of an ongoing CNS process. Uncontrolled signaling of NGF receptors may lead to long-term inflammatory and autoimmune responses, which in turn can lead to disease.

Diagnosis of viral infections of the central nervous system: clinical interpretation of PCR results

BACKGROUND

Standard laboratory techniques, such as viral culture and serology, provide only circumstantial or retrospective evidence of viral infections of the central nervous system (CNS). We assessed the diagnostic accuracy of PCR of cerebrospinal fluid (CSF) in the diagnosis of viral infections of the CNS.

METHODS

We examined all the CSF samples that were received at our diagnostic virology laboratory between May, 1994, and May, 1996, by nested PCR for viruses associated with CNS infections in the UK. We collected clinical and laboratory data for 410 patients from Oxford city hospitals (the Oxford cohort) whose CSF was examined between May, 1994, and May, 1995. These patients were classified according to the likelihood of a viral infection of the CNS. We used stratified logistic regression analysis to identify the clinical factors independently associated with a positive PCR result. We calculated likelihood ratios to estimate the clinical usefulness of PCR amplification of CSF.

FINDINGS

We tested 2233 consecutive CSF samples from 2162 patients. A positive PCR result was obtained in 143 patients, including 22 from the Oxford cohort. Logistic regression analysis of the Oxford cohort showed that fever, a virus-specific rash, and a CSF white-cell count of 5/microL or more were independent predictors of a positive PCR result. The likelihood ratio for a definite diagnosis of viral infection of the CNS in a patient with a positive PCR result, relative to a negative PCR result, was 88.2 (95% CI 20.6-378). The likelihood ratio for a possible diagnosis of viral infection of the CNS in a patient with a negative PCR result, relative to a positive PCR result, was 0.10 (0.03-0.39).

INTERPRETATION

A patient with a positive PCR result was 88 times as likely to have a definite diagnosis of viral infection of the CNS as a patient with a negative PCR result. A negative PCR result can be used with moderate confidence to rule out a diagnosis of viral infection of the CNS. We believe that PCR will become the first-line diagnostic test for viral meningitis and encephalitis.

Viral etiology of acute childhood encephalitis in Beijing diagnosed by analysis of single samples

OBJECTIVE

To understand the viral etiology of acute childhood encephalitis in Beijing.

METHODS

Ninety-seven Chinese children (between 7 months and 13 years of age) with acute encephalitis were retrospectively investigated. They were treated in Beijing Children's Hospital between June, 1991, and October, 1994. Different serologic methods (immunofluorescence assay, enzyme-linked immunosorbent assay, solid phase reverse immunosorbent test) were used for detection of IgM antibody to enteroviruses, herpesviruses, mumps, measles, rubella and Japanese encephalitis virus. The viral DNA of six herpesviruses was detected by polymerase chain reaction.

RESULTS

Viral etiology was identified in 35 of 97 (36.0%) cases. The most frequently identified pathogens were enteroviruses (15; 15.4%), followed by mumps (7; 7.2%), rubella (6; 6.1%), Japanese encephalitis virus (5; 5.1%), human herpesvirus 6 (2; 2.0%), herpes simplex virus (2; 2.0%) and Epstein-Barr virus (1; 1.0%). IgM antibody in cerebrospinal fluid was detected for enterovirus, mumps and rubella viruses.

CONCLUSIONS

Enteroviruses were the most frequent viral pathogens of acute childhood encephalitis in Beijing. Detection of IgM in cerebrospinal fluid may be useful for diagnosis in certain cases of viral encephalitis.

Intrathecal production of specific IgA antibodies in CNS infections

Cerebrospinal fluid (CSF) and serum from subjects with herpes simplex encephalitis, herpes zoster, mumps meningitis and neuroborreliosis were analysed for the presence of immunoglobulin A (IgA) and G (IgG) antibodies to the corresponding four antigens. Specific intrathecal IgA antibody synthesis as manifested by an elevated index was a frequent finding. Higher IgA index values than the corresponding IgG was seen in one third of the samples from subjects with herpes simplex encephalitis and herpes zoster. Correlation between specific IgG and IgA index was most pronounced for varicella-zoster virus (r = 0.66, P < 0.001). In subjects with mumps meningitis a strong intrathecal IgA and IgG antibody response to Borrelia burgdorferi was demonstrated. Specific herpes simplex and varicella-zoster virus IgA was not found to contain secretory component, thus contradicting an active secretion into the CNS compartment. In conclusion, our data indicate that specific IgA is intrathecally produced in herpes simplex encephalitis, herpes zoster and mumps meningitis but is a rare finding in neuroborreliosis.

Intrathecal synthesis of interleukin-10 (IL-10) in viral and inflammatory diseases of the central nervous system

The intrathecal synthesis of interleukin 10 (IL-10) was investigated in 120 paired cerebrospinal fluid (CSF) and serum specimens from patients with various inflammatory and non-inflammatory diseases of the central nervous system (CNS). IL-10 was not demonstrated in the sera, but detectable levels were found in the CSF from: patients with acute viral ("aseptic") meningitis, but only within 48-72 h of symptom onset; human immunodeficiency virus type 1 (HIV)-infected patients with HIV-related encephalitis/leukoencephalopathy or cryptococcal meningitis; a patient with primary B cell lymphoma of the CNS, and a patient with encephalomeningeal sarcoidosis (in whom IL-10 was demonstrated in all CSF collected over a period of 6-months). In chronic meningeal infections/inflammations, IL-10 seems to be continuously produced within the CSF. Our findings suggest that IL-10, a cytokine which exerts many immunosuppressive actions, may play different immunomodulatory roles in CNS diseases; in particular, its intrathecal synthesis may explain why some infectious and inflammatory meningeal diseases may have slow development and chronic evolution.

Clinical, cerebrospinal fluid, and histological data from twenty-seven cats with primary inflammatory disease of the central nervous system

The purpose of this report is to present the clinical, cerebrospinal fluid (CSF) and histological data from 27 cats with inflammatory disease of the central nervous system (CNS). The cats were part of a study of 61 cats admitted to two university clinics over an eight-year period because of signs of CNS disease. The most frequent diseases were feline infectious peritonitis (FIP) (12/27) and suspected viral disease other than FIP (10/27). Typical CSF findings in cats with FIP were a protein concentration of greater than 2 g/L (200 mg/dL) and a white cell count of over 100 cells/microL, which consisted predominantly of neutrophils. In contrast, the CSF of cats with suspected viral disease had a protein concentration of less than 1 g/L (100 mg/dL) and a total white cell count of less than 50 cells/microL. In general, cats with FIP or suspected viral disease were less than four years of age. Neurological signs were usually multifocal in cats with FIP, but focal in cats with suspected viral disease. The CSF findings were variable in five other inflammatory diseases represented. Two cats with protozoan infection had normal CSF total cell counts but abnormal differential counts. The CSF findings were invaluable in differentiating FIP from other causes of inflammatory CNS disease.

[The correlation of cerebrospinal fluid circulatory and venous circulatory cerebral disorders in patients with the sequelae of neural infections]

Clinico-functional study was carried out encephalographically and echoencephalographically in 45 patients aging from 29 to 56 with sequels of neuroinfection. Data on clinical and functional manifestations of liquorocirculatory and venous dyscirculatory cerebral disorders were obtained. Liquorocirculatory disorders were demonstrated to be were some connection between them. It was pointed out that disorders of venous blood more frequent and clinically evident as compared to venous dyscirculation although there flow acquire particular importance in patients with moderate dyscirculation of liquor while mattering considerably less in pronounced intracranial hypertension or its absence.

[The therapeutic efficacy of reaferon in meningoencephalitis]

There have been under observation 63 patients with meningoencephalitis at the age of 15-52 years whose complex treatment included reaferon and 42 patients with the same disease who were not given the drug. Reaferon was noted to be effective in meningoencephalitis. It shortened the period of clinical manifestation of the disease, hastened sanation of the liquor, influenced beneficially interferon production and modulated activity of the natural killers.

[Etiologic structure and clinical characteristics of acute viral infections of the central nervous system with hyperproteinorachia]

Clinical syndrome of acute viral meningitis and meningoencephalitis may be induced by different viruses. Etiologic diagnosis may be set by the isolation of the virus from the liquor and by the detection of specific antibodies in the blood and liquor. Our aim was to determine viral etiology of AVI with special reference to hyperproteinorachia. The study was conducted in 55 patients treated at the Clinic of Infectious Diseases in Novi Sad, with clinical picture of acute meningitis or meningoencephalitis, with pleocytosis above 50 ml in the cerebrospinal fluid. Depending on the levels of proteinorachia the patients were divided into the group with proteinorachia levels below 1g/l (34 patients) and above 1 g/l (21 patients). In the first group the most common was herpes simplex- and adenoviral etiology while in the second group most frequently found were choriolymphocytic meningitis virus (LCM) and herpes simplex virus. The protein level was in correlation with the severity of the clinical features and the duration of the treatment.

[Detection of interferon-gamma and IL-6 producing cells in cerebrospinal fluid cells in the central nervous system infectious diseases using immunocytochemistry]

To evaluate the relationship between cytokines and cerebrospinal fluid (CSF) cells, we detected interferon (IFN)-gamma and interleukin (IL)-6 producing cells in CSF from the patients with central nervous system (CNS) infectious diseases by immunocytochemistry. Five CSF cell smears from three herpes encephalitis patients, three from a patient with EB virus radiculoneuritis, four from the three patients with purulent meningitis, five from five patients with viral meningitis were obtained during early or subacute stages of diseases. Control CSF cell smears were taken from twenty seven patients with motor neuron disease, Parkinson's disease and spinocerebellar degeneration. Immunocytochemistry using specific polyclonal anti-IFN-gamma and IL-6 sera were used to detect each producing cell. Simultaneously, individual positively immuno-reactive cells were morphologically classified macrophage or lymphocyte. The IFN-gamma positive cells immunostained with specific antibody showed brown-colored deposits within the cytoplasm whereas no deposit was in the nucleus (Fig. 1). These phenotype of IFN-gamma positive cells were considered to be lymphocytes or macrophages. However, IFN-gamma-positive macrophages were predominantly seen at the early stages of herpes simplex encephalitis and purulent meningitis. The percent of IFN-gamma positive cells in total CSF cells obtained from the patients with the CNS infectious diseases was 2.3-38.7 as shown in Table 1. The IL-6 positive cells (Fig. 2) were also found early in the course and in subacute stages in the CNS infectious diseases and ranged from 2.5-50 percent in total CSF cells (Table 1). In contrast neither IFN-gamma- nor IL-6-positive cells were detected in non-inflammatory diseases (Table 1).(ABSTRACT TRUNCATED AT 250 WORDS)

Classical and modern methods of cerebrospinal fluid analysis. Report on the First All-German Symposium of the Society for Laboratory Medicine (FRG) and the Study Group for CSF Analysis and Clinical Neurochemistry of the Society for Psychiatry and Neurology (formerly GDR) in Marburg a. d. Lahn, October 5-6, 1990

The aim of the symposium was to prepare an inventory of cerebrospinal fluid (CSF) analysis used in Germany, and to evaluate them in comparison with modern methods. From the large field of CSF analysis, four main topics were selected, all related to the practical application of the methods. The following conclusions were drawn: Classical techniques of cytodiagnosis are clinically important. Therefore, manual and mechanized techniques must be further improved with respect to counting, collection, and differentiating of CSF cells. As cytokines and complement factors are early mediators of diverse processes in CNS, highly sensitive techniques must be developed for their routine analysis e.g. in CNS inflammation. Recent efforts to detect specifically viral and bacterial agents (e.g. by polymerase chain reaction, Particle Counting Immuno-Assay, Enzyme Immuno-Assay) or antibodies (e.g. affinity-mediated immunoblot, specific antibody index) in CSF must be continued in order to develop definite and practicable assays for daily routine. For the detection of intrathecally produced antibodies, qualitative procedures appear to be more reliable then quantitative ones, provided that the former are highly sensitive and specific.

Central nervous system involvement in the erythrophagocytic disorders of infancy: the role of cerebrospinal fluid neopterins in their differential diagnosis and clinical management

In two children with familial erythrophagocytic lymphohistiocytosis accompanied by neurologic symptoms, total neopterin concentrations in cerebrospinal fluid were 200 times higher than in controls and 10 to 20 times higher than in five children with presumed neurologic disease due to primary viral infections (human immunodeficiency virus, herpes simplex, measles) of the CNS. In one child with familial erythrophagocytic lymphohistiocytosis, clinical remission was accompanied by a fall in neopterin concentrations to normal; in a second child, who died, total neopterin concentrations remained high. In two other children with a diagnosis of infection-associated hemophagocytic syndrome without any neurologic disturbance, neopterin concentrations were also elevated but only to 10 times the concentrations in controls. Total neopterin concentrations in cerebrospinal fluid provide a measure of the severity of macrophage infiltration and activation within the CNS, and are useful in assessing the need for intensive chemotherapy and monitoring the response to treatment.

[Cerebrospinal fluid lysozyme in meningitis in children. Value in establishing the etiologic diagnosis]

Cerebrospinal fluid lysozyme (CSF-LZM) concentrations were determined in 62 controls, 28 viral meningitis and 22 bacterial meningitis, as compared to CSF lactic acid routinely used. CSF-LZM measurement was performed by a rapid turbidimetric assay which required 50 microliters CSF only. The mean CSF-LZM concentration of the control group was 0.23 mg/l, the highest value being 0.65 mg/l. The mean LZM levels in viral meningitis were 1.10 mg/l, never exceeding 3 mg/l. The range of pretreatment LZM levels in bacterial meningitis was 7.2 to 65 mg/l and above 3 mg/l in all cases 48 h after treatment. On the 6th day after admission, 12 of 16 samples showed abnormal values. The CSF-LZM assay seems to be of more value than that of lactic acid. Thus, before treatment, LZM concentrations were 10 to 100 fold higher than that of the normal values, with persistent high levels on the 2nd and even on the 6th day of treatment (whereas lactic acid values were all normal on day 6).

[Possibilities in the virological laboratory diagnosis of CNS infections]

Viral infections of the central nervous system (CNS) are investigated by the use of a great lot of laboratory methods preferring organ-specific patients' material, f. e. cerebrospinal fluid (CSF). Beside of the improvement of virus isolation procedures, antigen tests and assays on nucleic acid will get more importance for rapid viral diagnosis. Pathognomonic intrathecal antibody formation can be demonstrated by immunoglobulin class and subclass differentiation in CSF specimens. However, some of the slow virus diseases must still be retrospectively analysed by the means of a neuropathological laboratory.

The spinal tap: a new look at an old test

The spinal tap, or lumbar puncture, has indisputable value; opinions differ, however, on the amount of that value. The procedure has variable utility depending on the clinical indications and the results of tests on the cerebrospinal fluid. Its greatest value is in the evaluation of infectious or malignant meningitis; for most other diseases, it provides additional, but not essential, information. Because of the potential risk of the spinal tap, decisions about when to do the procedure must be made carefully. A probability analysis is provided to elucidate the usefulness of data from cerebrospinal fluid tests.

Quantitative levels of C-reactive protein in cerebrospinal fluid in patients with bacterial meningitis and other conditions

We measured levels of C-reactive protein (CRP) in the cerebrospinal fluid in 145 children, using a solid-phase radioimmunoassay. The CRP levels in 49 patients with culture-proved bacterial meningitis ranged from 0 to 51,000 ng/ml (median 1460 ng/ml). In 33 patients with aseptic meningitis, values were much lower range 0 to 438 ng/ml; (median 17 ng/ml). In patients with CSF pleocytosis (greater than 10 WBC/microliter), CRP greater than 100 ng/ml was 95% accurate in identifying those with bacterial meningitis. However, a few patients with bacterial meningitis and little or no CSF pleocytosis had low levels of CRP at admission. Among the 63 patients with nonmeningitic conditions, those with bacterial infections frequently (10 of 13 had CRP greater than 100 ng/ml, whereas CRP elevations were infrequent (seven (18%) of 40) in patients with viral infections and other conditions. CRP diffuses into the CSF as readily as other proteins, but in bacterial meningitis the CSF/serum ratio of CRP was lower than that of albumin and IgG. The measurement of CRP in CSF is potentially a very useful diagnostic tool, but certain inherent limitations must be recognized, because some patients may fail to mount a prompt inflammatory response.

Unreliability of beta-2-microglobulin in early detection of central nervous system relapse in acute lymphoblastic leukemia

The value of serial determination of the cerebrospinal fluid (CSF) beta-2-microglobulin (Beta 2m) level for early detection of acute lymphoblastic leukemia (ALL) in the central nervous system (CNS) has been prospectively studied in 30 children. Beta 2m was determined by micro-ELISA assay. Results demonstrated a sensitivity of 40% (95% confidence interval, 5.3-85.3%) and a predictive value of 8% (95% confidence interval, 1.0-26.0%). In post-irradiation syndrome, as well as in viral infection with cytopathological changes of white cells in CSF, beta 2m values proved to be significantly higher than in incipient CNS relapse, and these conditions, or an unknown cause, are more often associated with beta 2m elevation than CNS relapse. No relation was found between CSF white cell counts and beta 2m levels. It is concluded that beta 2m is not an appropriate test for early detection of CNS involvement in children with acute lymphoblastic leukemia.

Intrathecal synthesis of different alpha-interferons in patients with various neurological diseases

CSF and sera from 238 newborns and children with various neurological diseases were assayed on bovine cells for the presence of alpha-interferon (IFN). An intrathecal synthesis of pH 2-resistant alpha-IFN was recovered in all newborns and in more than 90% of children with herpes encephalitis. It was also observed in one case of mumps encephalitis and in one case of encephalitis associated with Influenza A infection. An acid-labile alpha-IFN production was detected in CSF from more than one half of patients with viral meningitis or active congenital rubella and in those with neurological complications of systemic lupus erythematosus. This alpha-IFN subtype was also detected in CSF from only 2/37 children with measles encephalitis. In contrast, no alpha-IFN (less than 2 IU) in CSF was found among patients with subacute sclerosing panencephalitis, Guillain-Barré syndrome, Reye's syndrome, acute cerebellar ataxia, infantile spasms or facial paralysis of unknown origin.

How useful are serum and CSF interferon levels as a rapid diagnostic aid in virus infections?

Specimens from a total of 162 patients were studied prospectively using a rapid nucleic acid synthesis inhibition assay and a plaque-reduction assay to detect interferon levels in serum and cerebrospinal fluid. The specificity, consistency, and diagnostic applications of the rapid assay were evaluated by intensively investigating each patient for possible viral illness. Forty-one percent of patients with proven acute virus infections (excluding those with acute hepatitis and infectious mononucleosis) had unequivocal detectable interferon in serum or cerebrospinal fluid, compared with only two patients with bacterial infections (7%) who had equivocal interferon in the serum. Retrospective analysis showed the test to have high specificity for virus infections, but in patients with clinical syndromes of uncertain aetiology the test was not a particularly sensitive indicator of the presence of subsequently detected virus. The presence of interferon was not related to the time during the illness at which the sample was taken, nor to the numbers of lymphocytes in the cerebrospinal fluid, nor to the patients' general symptoms.

Detection and identification of virus-specific, oligoclonal IgG in unconcentrated cerebrospinal fluid by immunoblot technique

A technique is described which allows the detection of virus-specific oligoclonal IgG in unconcentrated cerebrospinal fluid (CSF) from patients with virus infections of the central nervous system. CSF is isoelectrically focused in agarose gels and immunoglobulins are blotted to nitrocellulose filters, passively loaded with either anti-human IgG or viral antigen. Transferred total IgG, as well as virus-specific IgG, is identified by the use of peroxidase-labelled anti-human IgG and 4-chloro-1-naphthol as a precipitating peroxidase substrate. Application of this assay in cases of SSPE, mumps meningitis and herpes simplex encephalitis demonstrates sensitivity and possible suitability of this technique for use in diagnosis of virus infections of the CNS.

Multivariate analysis of the serum-cerebrospinal fluid-protein-relation for the diagnosis of neurological diseases of the central nervous systems

In a population comprising 197 patients, serum and CSF proteins were assayed using the radial immunodiffusion technique devised by Mancini. Multiple discriminants analysis was applied to investigate whether the measured CSF/serum protein relations and their ratios could be regarded as an indicator of specific neurological diseases. One significant finding was that the slope angle alpha of the regression line between the serum/CSF relation and molecular weight may represent an important indicative parameter. A small angle is suggestive of enhanced permeability of the BBB, a large angle of a correspondingly lowered permeability. Further, the analyses demonstrated that the combined use of several predictors can markedly improve differential diagnosis. The study also demonstrates the potential of a statistical analytic technique that is still rarely applied in medicine.

Immunoglobulin levels in serum and cerebrospinal fluid in certain viral infections of the central nervous system

It is seriously debated whether the presence of immunoglobulins in CSF is due to local production, diffusion of proteins through the blood-brain barrier, or both. Tourtellotte et al [1] strongly suggest that in both healthy and diseased individuals, immunoglobulins are synthesized extravascularly and subsequently diffuse into the CSF. Cohen and Bannister [2] demonstrated that lymphocytes from the CSF of patients with multiple sclerosis could produce IgA and IgG in vitro. Although such evidence suggests the likelihood of local production of immunoglobulins, others believe that elevated protein levels in CSF are due to migration of immunoglobulins from serum to CSF because of damage to the blood-brain barrier [3]. Thus, the elevated IgG level in CSF could be an expression of such an impaired blood-brain barrier. A further implication of this hypothesis is that the more the function of this barrier is impaired, the more extensive is the transudation. This includes the migration of large molecules such as IgM during the inflammatory state, a condition which increases not only the number of theoretical filters but also the size of the pores. IgG levels in CSF and serum were elevated in all five infections studied except viral encephalitis, in which this value remained normal. The serum IgA level was elevated in all five lesions, but the IgA level in CSF was elevated only in viral encephalitis, Guillain-Barré syndrome, and meningeal carcinomatosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Lactoferrin, lysozyme, and beta 2-microglobulin levels in cerebrospinal fluid: differential indices of CNS inflammation

The CSF levels of lactoferrin, lysozyme, and beta 2-microglobulin (beta 2 mu) were measured in patients with evident, probable, or possible inflammatory CNS reactions and compared to those found in neurologically apparently healthy patients. Patients with viral CNS infections had significantly raised beta 2 mu and lysozyme levels but normal lactoferrin levels, indicating a local activation of lymphocytes and monocytes but not of granulocytes. Patients with bacterial CNS infections had significantly raised levels of all three cell markers, but the increase of lysozyme and lactoferrin was relatively more pronounced than that of beta 2 mu, indicating that the inflammatory response to bacterial agents is dominated by monocytes and granulocytes. Patients with primary or secondary malignant brain tumors were characterized by a moderate increase of beta 2 mu and a considerable increase in both lysozyme and lactoferrin, i.e., the same protein pattern as observed in bacterial CNS infection. The lysozyme levels were moderately increased in half the patients with benign cerebral tumors while the levels of beta 2 mu and lactoferrin were normal, indicating that benign and malignant brain tumors induce different local inflammatory CNS reactions. Half the patients with pituitary gland adenoma had elevated beta 2 mu and lysozyme levels but normal lactoferrin levels, suggesting that immunological mechanisms are associated with the adenoma development. Patients with MS had moderately but significantly raised CSF levels of beta 2 mu and lysozyme and a third of them also had raised levels of lactoferrin, a protein pattern suggesting a low-active inflammatory process in CNS involving mononuclears and granulocytes. A similar protein pattern was found in Guillain-Barré syndrome. In cerebrosarcoidosis we noted considerably increased lysozyme and beta 2 mu but normal lactoferrin levels, consistent with the idea that the sarcoid granuloma mass is dominated by monocytic inflammatory cells. The data obtained indicate a clinical value of lactoferrin, lysozyme, and beta 2 mu as differential indices of inflammatory cell reactions taking place in various CNS processes.

Parotitis: clinical presentations and management

Although mumps virus is the most common and, therefore, best known cause of parotitis, other causes are not infrequent and need to be distinguished from mumps. Knowledge of the various clinical presentations of parotitis and judicious use of a few ancillary tests will facilitate differential diagnosis.

The cytopathology of cerebrospinal fluid. I. Nonneoplastic conditions, lymphoma and leukemia

In this review, the historical background of cerebrospinal fluid (CSF) cytopathology is presented, with particular emphasis on the technical and cytopreparatory advances that have increased the sensitivity and accuracy of this technique. Normal cells, contaminants and nonneoplastic processes, including a broad spectrum of inflammatory conditions, are discussed. The role of central nervous system (CNS) cytopathology in the management of patients with leukemia and lymphoma is presented. This discussion includes the natural history, cytologic presentation and diagnostic pitfalls that are associated with these hematologic diseases.

The clinical relevance of ferritin concentration in the cerebrospinal fluid

By means of a new technique (Particle Counting Immunoassay), we have determined the level of ferritin in 470 samples of cerebrospinal fluid of patients with various neurological disorders. The median value obtained in a control group was 2.3 ng/ml with an upper limit at 5.5 ng/ml. the concentrations in the serum and cerebrospinal fluid were independent, but that in cerebrospinal fluid correlated with its total protein content. High values of ferritin were found in infectious meningo-encephalitis, in vascular diseases of the central nervous system, and, unexpectedly, in several cases of dementia without obvious vascular pathology.

The detection of activated cerebrospinal fluid B lymphocytes by peroxidase conjugated antibodies

A method for the preparation of a potent and specific peroxidase-labelled antihuman IgG antibody is described. CSF cells from patients with various neurological diseases were stained. Only in cases of inflammatory diseases was IgG detectable. The stained cells were so-called lymphoid cells. As the demonstrable IgG can be regarded as a product of intracellular synthesis, it is justified to call these cells activated B lymphocytes. The relative portion of activated B cells tends to be high in the first half of the mononuclear phase and depends upon the type of disease. It is low in most cases of bacterial and benign viral meningitis whereas high B cell numbers were found in Bannwarth meningopolyneuritis, mumps meningitis and herpes simplex encephalitis. Albeit there exists a time lag between the maximal number of activated B lymphocytes and the demonstration of the secretory immunoglobulin fraction, quantitative correlation between these two inflammation parameters were demonstrated in cases of acute meningoencephalitis. These correlations were not seen in chronic inflammatory diseases.

[Diagnostic significance of lactate concentration in CSF in patients with meningitis (author's transl)]

White-cell count and differential blood count, total protein, lactate dehydrogenase activity (E.C. 1.1.1.27) and lactate concentration were determined in 496 CSF samples, obtained by lumbar puncture. Lactate was measured with a new enzymatic test. Reference values were determined for lactate and lactate dehydrogenase (90% limits: 1.2-2.1 mmol/l and 6-26 U/l, respectively). Lactate content proved to be best in the differential diagnosis between acute bacterial and abacterial meningitis: concentrations of 3.5 mmol/ml and above were found exclusively in bacterial meningitis. As for other diseases, markedly increased lactate concentrations were measured only in patients with brain tumour or cerebrovascular disease (up to 9.3 mmol/l). Determination of lactate concentration alone would have led to a misdiagnosis of acute bacterial meningitis in 3% of cases. If the CSF contains 3.5 mmol/l lactate or more and the leucocyte cell count is above 800/microliter, brain tumour or cerebrovascular disease can be practically excluded and the diagnosis of bacterial meningitis made with a high degree of reliability.