[Metalloproteinases in meningoencephalitis]. / Metaloproteinazy w zapaleniach opon mózgowo-rdzeniowych i mózgu.

Meningoencephalitis remains a devastating disease with high morbidity and mortality. Despite advances in antibiotic treatment and critical care, mortality rate in bacterial meningoencephalitis is close to 25%. Moreover, neurological and neuropsychological sequelae emerge in up to 50% of survivors. Adverse outcome is significantly associated with events secondary to meningitis and damage of the blood-brain barrier. Several studies conducted on animals confirmed that matrix-metalloproteinases (MMP), a family of enzymes with major actions in the remodeling of exracellural matrix components facilitate this process which results in acute neurological complications. Gelatinases (MMP-2, MMP-9), the most complex family member, through degradation of gelatine and collagen IV play an important role in the pathogenesis of brain's inflamatory diseases (e.g. Guillian-Barre syndrom) and contribute to spreading the disease beyond the central nervous system. Infection (bacterial, viral or fungal) can lead to increased concentration and activity of metalloproteinases due to excessive enzyme's secretion or decrease in level of its natural inhibitors. A detailed analysis of those enzymes could help in developing new diagnostic and prognostic markers for meningoencephalitis and could facilitate new treatment approaches.

Serum matrix metalloproteinase-2 levels indicate blood-CSF barrier damage in patients with infectious meningitis.

OBJECTIVE: Protein components in cerebrospinal fluid (CSF) are maintained at a specific concentration by a dynamic gradient between the capillary and intrathecal spaces via the blood-cerebrospinal fluid barrier (BCB) in the brain and spinal cord. Permeability to proteins increases when there is structural damage to the BCB. Matrix metalloproteinase-2 (MMP-2; gelatinase A) has been shown to degrade type IV collagen, a major component of the cellular basement membrane. We analyzed alpha2 macroglobulin (alpha2M) indices and evaluated the relationship between alpha2M, as an indicator of BCB permeability, and MMP-2, which degrades the extra-cellular matrix in patients with infectious meningitis. MATERIALS AND METHODS: Albumin levels in CSF or serum were determined by turbidimetric immunoassay, or bromcresol green assay, respectively. alpha2M levels in CSF or serum were measured with enzyme-linked immunosorbent assay, or laser-nephelometry, respectively. Serum MMP-2 levels were determined by enzyme immuno assay. We calculated the alpha2M index, i.e. the ratio of alpha2M (CSF / serum) to albumin (CSF / serum; alpha2M in CSF / alpha2M in serum x albumin in serum / albumin in CSF). RESULTS: alpha2M indices were significantly increased in infectious meningitis compared to healthy controls (p < 0.05). They were highest in bacterial meningitis, and there was a significant difference between viral or mycotic and bacterial meningitis (p < 0.05). Serum MMP-2 levels were increased in infectious meningitis, being highest in bacterial meningitis, where they were significantly different from healthy controls (p < 0.05). There was a significant positive correlation between serum MMP-2 levels and alpha2M indices (r = 0.64, p < 0.0001). CONCLUSION: Markedly increased levels of serum MMP-2 in infectious, especially bacterial, meningitis may reflect the degree of damage to the BCB.

Immunohistochemical analysis of MMP-9, MMP-2 and TIMP-1, TIMP-2 expression in the central nervous system following infection with viral and bacterial meningitis.

Matrix metalloproteinases (MMPs) are capable of degrading components of the basal lamina of cerebral vessels, thereby disrupting the blood-brain barrier and inducing leukocyte recruitment. This study provides comprehensive information regarding the cell specificity of matrix metalloproteinases (MMP-2, MMP-9) and their binding tissue inhibitors (TIMP-1, TIMP-2) in the central nervous system during viral and bacterial meningitis. Specifically, we evaluated the immunoreactivity of MMPs and TIMPs in various cell types in brain parenchyma and meninges obtained from autopsy tissues. We found that a higher proportion of endothelial cells were positive for MMP-9 during meningitis when compared to controls. In addition, the immunoreactivity of MMP-9 decreased and the immunoreactivity of TIMP-1 increased in astrocytes upon infection. Furthermore, the results of this study revealed that mononuclear cells were highly immunoreactive for TIMP-1, TIMP-2 and MMP-9 during viral meningitis and that the expression of TIMPs in polymorphonuclear cells was even higher during bacterial meningitis. Taken together the results of this study indicated that the central nervous system resident cells and inflammatory infiltrates contribute to MMPs activity and that the expression patterns vary between cell types and in response to viral and bacterial meningitis.

Rhabdomyolysis in patients with west nile encephalitis and meningitis.

Since 1999, more than 6,500 cases of West Nile virus neuroinvasive disease (WNND) have been reported in the United States. Patients with WNND can present with muscle weakness that is often assumed to be of neurological origin. During 2002, nearly 3,000 persons with WNV meningitis or encephalitis (or both) were reported in the United States; in suburban Cook County, Illinois, with 244 persons were hospitalized for WNV illnesses. The objective of this investigation was to describe the clinical and epidemiological features of identified cases of WNV neuroinvasive disease and rhabdomyolysis. Public health officials investigated patients hospitalized in Cook County, and identified a subset of WNV neuroinvasive disease patients with elevated creatine kinase levels. Cases were defined as hospitalized persons with a WNV infection, encephalitis or meningitis, and rhabdomyolysis. Retrospective medical record reviews were conducted and data was abstracted with a standardized data collection instrument. Eight patients with West Nile encephalitis and one with West Nile meningitis were identified with rhabdomyolysis. Median age of the nine patients was 70 years (range, 45-85 years), and eight were men. For all nine patients, the peak CK level was documented a median of 2 days after hospitalization (range, 1-24 days). Median CK level during hospitalization for all case-patients was 3,037 IU (range, 1,153-42,113 IU). Six patients had history of recent falls prior to admission. Although the temporal relationship of rhabdomyolysis and neurological WNV illness suggested a common etiology, these patients presented with complex clinical conditions which may have led to development of rhabdomyolysis from other causes. The spectrum of WNV disease requires further investigation to describe this and other clinical conditions associated with WNV infection.

Expression of matrix metalloproteinases, sICAM-1 and IL-8 in CSF from children with meningitis.

The combined expression of the inflammatory mediators, matrix metalloproteinases (MMPs), soluble form of intracellular adhesion molecule ICAM-1 (sICAM-1) and interleukin (IL)-8, was evaluated in children infected with bacterial or viral meningitis. MMP-2 and IL-8 were detected in all CSF samples and were enhanced in both bacterial and viral infected samples, compared to those from control children. The expression of MMP-9 as well as sICAM-1 was not detected in control CSF while observed in viral infected and further elevated in bacterial infected samples. This pilot study supports a role for MMPs, IL-8 and sICAM in infectious meningitis and suggests further research to determine their possible use as biomarkers for various forms of meningeal infection as well as the use of their specific antagonists as potential therapeutic agents for central nervous system (CNS) inflammatory processes.

Identification of a matrix-degrading phenotype in human tuberculosis in vitro and in vivo.

Tuberculous meningitis is characterized by cerebral tissue destruction. Monocytes, pivotal in immune responses to Mycobacterium tuberculosis, secrete matrix metalloproteinase-9 (MMP-9), which facilitates leukocyte migration across the blood-brain barrier, but may cause cerebral injury. In vitro, human monocytic (THP-1) cells infected by live, virulent M. tuberculosis secreted MMP-9 in a dose-dependent manner. At 24 h, MMP-9 concentrations increased 10-fold to 239 +/- 75 ng/ml (p = 0.001 vs controls). MMP-9 mRNA became detectable at 24--48 h. In contrast, tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) gene expression and secretion were similar to constitutive levels from controls at 24 h and increased just 5-fold by 48 h. In vivo investigation revealed MMP-9 concentration per leukocyte in cerebrospinal fluid (CSF) from tuberculous meningitis patients (n = 23; median (range), 3.19 (0.19--31.00) ng/ml/cell) to be higher than that in bacterial (n = 12; 0.23 (0.01--18.37) ng/ml/cell) or viral meningitis (n = 20; 0.20 (0.04--31.00) ng/ml/cell; p < 0.01). TIMP-1, which was constitutively secreted into CSF, was not elevated in tuberculous compared with bacterial meningitis or controls. Thus, a phenotype in which MMP-9 activity is relatively unrestricted by TIMP-1 developed both in vitro and in vivo. This is functionally significant, since MMP-9 concentrations per CSF leukocyte (but not TIMP-1 concentrations) were elevated in fatal tuberculous meningitis and in patients with signs of cerebral tissue damage (unconsciousness, confusion, or neurological deficit; p < 0.05). However, MMP-9 activity was unrelated to the severity of systemic illness. In summary, M. tuberculosis-infected monocytic cells develop a matrix-degrading phenotype, which was observed in vivo and relates to clinical signs reflecting cerebral injury in tuberculous meningitis.

Matrix metalloproteinases and tissue inhibitors of metalloproteinases in viral meningitis: upregulation of MMP-9 and TIMP-1 in cerebrospinal fluid.

A hallmark of viral meningitis is the invasion of monocytes, lymphocytes and, in the initial phase of the disease, neutrophils into the subarachnoidal space. By their degradation of different macromolecular components in the extracellular connective tissue, matrix metalloproteinases (MMPs) may be essential for the breakdown of the vessel wall in the meninges and the choroid plexus. In this study, the occurrence of MMP-1, MMP-2, MMP-3 and MMP-9 and the two tissue inhibitors of metalloproteinases, TIMP-1 and TIMP-2, was monitored in the cerebrospinal fluid (CSF) from patients with viral meningitis. Of the proteinases, MMP-9 was found in 13 of 39 (33%) patients, but not in controls; the levels being correlated with the neutrophil cell number in CSF. The CSF concentration of TIMP-1 was increased three-fold compared to the control group (median 233 ng/ml; range 9.4-1252.5 ng/ml) and was correlated to the levels of total protein in CSF. Of the other MMPs and TIMPs assayed, MMP-2 and TIMP-2 were constitutively expressed and not upregulated in viral meningitis. High levels of MMP-9 and MMP-2, as measured by ELISA, was associated with high proteolytic activity detected in CSF by zymography. In conclusion, invasion of the leukocytes into the CSF compartment in viral meningitis may involve MMP-9, its proteolytic effect likely being controlled by expression of TIMP-1.

[Evaluation of the value of determining lysozyme levels in cerebrospinal fluid in myeloencephalitis]. / Ocena przydatnosci oznaczania stezenia lizozymu w plynie mózgowo-rdzeniowym w przebiegu zapalen opon mózgowo-rdzeniowych.

The study aimed at assessing the value lysozyme assay in CFS as indicator of the damage to blood-cerebrospinal fluid barrier and intensification of inflammatory process in the course of meningitis. The study involved 20 patients with suppurative and 66 with viral meningitis. Control group included 26 patients without nervous system disease. To estimate the degree of blood-cerebrospinal fluid barrier damage albumin and lysozyme indicators were calculated. It was proved, that CSF lysozyme levels are bigger in the suppurative meningitis than in viral meningitis. According to the author, CSF lysozyme levels the value of lysozyme indicator may inform on intensification of the inflammatory process and the degree of blood-cerebrospinal fluid barrier damage in suppurative meningitis, whereas in the viral meningitis they inform on degree of blood-cerebrospinal fluid barrier damage, only.

[Creatine phosphokinase in the cerebrospinal fluid of patients with acute meningitis]. / Kreatinfosfokinaza v spinnomozgovoi zhidkosti u bol'nykh ostrymi meningitami.

A study is presented of the general activity and isoenzymatic spectrum of creatine phosphokinase (CPK) in the cerebrospinal fluid (CSF) in patients with acute meningitis of different etiology. The enzymatic activity proved to be increased due to the cerebral (CPK-BB) isoform. Liberation of CPK-BB from the brain tissue and its penetration into the intercellular fluid and then into the CSF was related to the functional-structural changes in the cellular membranes of the brain in meningitis.

Cerebrospinal fluid white blood cell counts and lactic acid dehydrogenase in Enterovirus type 71 meningitis.

An outbreak of aseptic meningitis involving 36 children is described. Enterovirus type 71, a recently recognized cause of central nervous system and systemic illness in children, was found to be the responsible agent. On initial lumbar puncture, cerebrospinal fluid (CSF) polymorphonuclear (PMN) cell predominance was seen in 64%, and greater than 200 CSF white blood cells (WBC)/mm3 was seen in 25% of these patients. Fifty-four per cent of the patients subjected to repeat lumbar puncture and a significant rise in the number of CSF WBC/mm3, the majority with the maintenance of a PMN cell predominance. The CSF white blood cell findings of individual patients did not allow for differentiation from patients concurrently seen with bacterial meningitis. Both initial and serial measurements of CSF lactic acid dehydrogenase reliably distinguished these two groups of patients.

Improved lysozyme assay in biological fluids.

We describe a simple, rapid, sensitive, and highly reproducible assay for lysozyme, with use of concentrated cell suspensions of Micrococcus lysodeikticus in Tris-buffered glycerol/water (40/60 by vol), pH 7.5. Stored at -20 degrees C, the cells' susceptibility to lysozyme remains unaltered over long periods. Almost identical concentration curves were obtained with different aliquots of the same preparation during eight months. Lysozyme activity was reflected in the decrease in absorbance of the reaction mixture after incubation for 15 min at 37 degrees C. Concentrations of egg-white lysozyme as low as 0.02 mg/L can be accurately assayed.

Cerebrospinal fluid lysozyme in bacterial and viral meningitis.

The concentration of lysozyme (LZM) in cerebrospinal fluid was determined in 25 patients with bacterial meningitis, in 18 patients with viral meningitis and in 25 control patients who had other fibrile illnesses. The concentration of LZM was less than 1.5 microgram/ml in all control patients, and slightly to markedly raised in 10 patients with viral meningitis and in 11 out of 13 patients with untreated bacterial meningitis. The concentration of LZM was significantly different in the viral and bacterial meningitis patients (p less than 0.001). Most raised concentrations of cerebrospinal fluid LZM persisted for at least one week after the start of antibiotic treatment. The concentrations of LZM correlated well with concentrations of lactic dehydrogenase. These results show that the determination of cerebrospinal fluid LZM is a useful tool in the differential diagnosis of meningitis, particularly when the prehospital treatment with antibiotics may be responsible for a diagnostically misleading negative bacterial culture of the cerebrospinal fluid and altered cerebrospinal fluid cytology.

Cerebrospinal fluid and serum lysozyme activity in bacterial and viral meningitis.

Cerebrospinal fluid (CSF) and serum lysozyme concentrations were determined in infants and children with and without acute infectious disease of the central nervous system. Serum lysozyme values from patients with bacterial and viral meningitis were found within the normal range. Lysozyme activity was absent or very low (below 0.5 microgram/ml) in normal CSF. High levels (4-12 microgram/ml) in patients with viral meningitis. A decrease of the lysozyme activity coincided with the clinical improvement of the bacterial meningitis. The lysozyme activity in CSF should be of significant value in detecting an inflammatory disease of the central nervous system.