Beta-2-microglobulin in the cerebrospinal fluid of patients with infections of the central nervous system

Elevated levels of β2-microglobulin in cerebrospinal fluid in adult patients with viral encephalitis/meningitis

BACKGROUND

Increased cerebrospinal fluid (CSF) β2-microglobulin (β2-MG) values are attributed to immune activation, lymphoid cell turnover and release of tissue destruction in the central nervous system (CNS). We investigated plasma and CSF β2-MG levels in adult patients with viral encephalitis/meningitis and their correlations with clinical parameters.

METHOD

CSF samples from 26 patients with viral encephalitis/meningitis were collected. Moreover, 24 CSF samples from patients with non-inflammatory neurological disorders (NIND) as controls were collected. Plasma samples from 22 enrolled patients and 20 healthy individuals were collected. The β2-MG levels were measured by immunoturbidimetry on an automatic biochemical analyzer. Clinical data were extracted from an electronic patient documentation system.

RESULT

CSF levels of β2-MG, adenosine deaminase (ADA), white blood cell (WBC), lactate dehydrogenase (LDH), protein and lactate were significantly increased in patients with viral encephalitis/meningitis respectively (p < 0.001, p < 0.001, p < 0.001, p = 0.001, p < 0.001, p = 0.013). In contrast, no statistically significant difference was found in plasma levels of β2-MG. Furthermore, CSF levels of β2-MG were weakly correlated with WBC (r = 0.426, p = 0.030), lymphocyte percentage (r = 0.599, p = 0.018), ADA (r = 0.545, p = 0.004) and LDH (r = 0.414, p = 0.036), but not with lactate (r = 0.381, p = 0.055), protein (r = 0.179, p = 0.381) and plasma levels of β2-MG (r = -0.156, p = 0.537) in viral encephalitis/meningitis patients.

CONCLUSION

CSF β2-MG may be a potential inflammatory marker for viral encephalitis/meningitis in adult patients diagnosed with viral encephalitis/meningitis.

Immunologic biomarkers for bacterial meningitis

Meningitis is defined as the inflammation of the meninges that is most often caused by various bacterial and viral pathogens, and is associated with high rates of mortality and morbidity. Early detection of bacterial meningitis is essential to appropriate antibiotic therapy. Alterations in immunologic biomarkers levels have been considered the diagnostic approach in medical laboratories for the identifying of infections. The early increasing immunologic mediators such as cytokines and acute phase proteins (APPs) during bacterial meningitis have made they significant indicators for laboratory diagnosis. Immunology biomarkers showed wide variable sensitivity and specificity values that influenced by different reference values, selected a certain cutoff point, methods of detection, patient characterization and inclusion criteria, as well as etiology of meningitis and time of CSF or blood specimens' collection. This study provides an overview of different immunologic biomarkers as diagnostic markers for the identification of bacterial meningitis and their efficiencies in the differentiating of bacterial from viral meningitis.

Chronic Lymphocytic Inflammation with Pontine Perivascular Enhancement Responsive to Steroids with a Significant Elevation of β-2 Microglobulin Levels

Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) is a relapsing-remitting disorder for which steroid administration is a key to control the progression. CLIPPERS can exhibit radiological features similar to malignant lymphoma, whose diagnosis is confounded by prior steroid administration. We report a case of CLIPPERS accompanied by abnormal elevation of β-2 microglobulin in the cerebrospinal fluid (CSF). A 62-year-old man started to experience numbness in all fingers of his left hand one year ago, which gradually extended to his body trunk and legs on both sides. Magnetic resonance imaging demonstrated numerous small enhancing spots scattered in his brain and spinal cord. CSF levels of β-2 microglobulin were elevated; although this often indicates central nervous system involvement in leukemia and lymphoma, the lesions were diagnosed as CLIPPERS based on the pathological findings from a biopsy specimen. We emphasize the importance of biopsy to differentiate between CLIPPERS and malignant lymphoma because the temporary radiological response to steroid might be the same in both diseases but the treatment strategies regarding the use of steroid are quite different.

Cryptococcus neoformans meningoencephalitis in a patient with polyarteritis nodosa

Case of 59-year-old male with chronic obstructive pulmonary disease and a number of comorbidities, who has developed meningoencephalitis caused by Cryptococcus neoformans var. grubii with polyarteritis nodosa diagnosed during hospitalization, was presented. Before evidence of meningoencephalitis, the patient was being treated with ketoconazole and low doses of fluconazole (200 mg/day) for alleged candidiasis. The dosage was increased (800 mg/day) following laboratory diagnosis of C. neoformans based on positive latex agglutination test and biochemical identification of encapsulated yeast isolated from the blood and CSF. Later, the yeast identification was confirmed by sequencing analysis. Owing to inadequate clinical response, fluconazole therapy was switched to voriconazole (400 mg/day) and later to intravenous amphotericin B (1.0 mg/kg per day). Despite of a temporary stabilization and improvement, which correlated with decline of cryptococcal antigen titers (from 1:1024 to 1:8), after 6 weeks, the patient's underlying condition deteriorated due to severe pancolitis and serious nosocomial bacterial infections. The patient died of multiorgan failure several days later. Our case demonstrates a possible connection between the development of life-threatening cryptococcosis and an autoimmune vasculitis disease and emphasizes that the outcome of the management of cryptococcal meningoencephalitis is highly dependent on early diagnosis, adequate treatment, including dosage, and last but not least control of underlying disease and risk factors.

Beta2-microglobulin concentrations in cerebrospinal fluid correlate with neuroimaging findings in newborns with symptomatic congenital cytomegalovirus infection

OVERVIEW

In newborns with symptomatic congenital cytomegalovirus (CMV) infection, neuroimaging is the best available predictor of neurodevelopmental outcome. Cerebrospinal fluid (CSF) findings in congenital CMV infection have seldom been described. Neonates with central nervous system infections present high CSF Beta(2)-microglobulin (beta(2)-m) levels.

OBJECTIVES

The objectives of this study were: (1) to determine whether CSF beta(2)-m is increased in newborns with symptomatic congenital CMV infection, and (2) to examine its correlation with neuroimaging findings.

MATERIALS AND METHODS

Fourteen newborns with symptomatic congenital CMV infection admitted to La Paz Hospital from 1990 through 2004 underwent determination of CSF beta(2)-m. Ninety-three newborns, constituting the comparison group, underwent CSF beta(2)-m determination as part of a sepsis or meningo/encephalitis work-up, and at discharge had sterile cultures and normal neurological status. Neuroimaging findings were scored according to a semiquantitative system: (0) no abnormalities; (1) single punctate periventricular (PV) calcification and/or hyperechogenic areas in the thalamus and basal ganglia; (2) multiple discrete PV calcifications and/or ventriculomegaly; and (3) extensive PV calcifications and/or brain atrophy.

DISCUSSION AND CONCLUSION

CSF beta(2)-m was increased in newborns with CMV infection (median 6.21 mg/L) compared with controls (1.68 mg/L) (P<.001). beta(2)-m showed a correlation with neuroimaging scores (r (s)=0.753, P=.002). beta(2)-m was higher in patients who scored 2-3 (12.83 mg/L) than in patients who scored 0-1 (5.52 mg/L) (P=.028). CSF beta(2)-m is increased in newborns with symptomatic congenital CMV infection and correlates with neuroimaging abnormalities. beta(2)-m appears to be an indicator of the severity of brain involvement in congenital CMV infection.

Beta-2-microglobulin and ferritin in cerebrospinal fluid for evaluation of patients with meningitis of different etiologies

To determine whether or not the beta-2-microglobulin (beta2-m) and/or ferritin levels in cerebrospinal fluid (CSF) can be used as markers for the differential diagnosis of meningitis and determination of the response to treatment, 122 subjects with etiologically well-characterized diagnoses were classified into three groups: bacterial meningitis (n = 5; mean age +/- SD. 1.0+/-1.0 year), viral meningitis (n = 39; 5.9+/-3.8 years), and a non-meningitis group (n = 78; 5.2+/-4.9 years). The levels of beta2-m and ferritin in CSF were determined by means of a latex photometric immunoassay. The statistical significance of the data was analyzed with the Mann Whitney U-test. A receiver operating characteristic curve was used to evaluate the diagnostic accuracy of each prediction marker. This study indicated that (1) the levels of beta2-m and ferritin in CSF were related with age in the non-meningitis group: subjects of up to 5 months of age exhibited higher concentrations of these proteins than ones of above 6 months of age (beta2-m, 1.89+/-1.13 vs. 0.84+/-0.65 mg/l. P < 0.01; ferritin, 2.97+/-2.04 vs. 1.81+/-1.34 microg/l, P = 0.09); (2) the beta2-m level was significantly higher in the CSF of patients with viral meningitis than in ones without meningitis (2.41+/-1.23 vs. 0.84+/-0.65 mg/l, P < 0.01): the best cut-off value was 1.2 mg/l (3) the ferritin level was significantly higher in the CSF of patients with bacterial meningitis than in ones with viral meningitis (43.24+/-39.49 vs. 6.81+/-7.41 microg/l, P < (.01): the best cut-off value was 7.5 microg/l; and (4) sequential measurement of the CSF ferritin level was of value for determination of the response to antibiotic treatment for bacterial meningitis. These results only apply to patients of greater than 6 months of age. beta2-m and ferritin in the CSF can be used as an ancillary tool for diagnostic guidance in the acute phase of meningitis and determination of the response to treatment for bacterial meningitis.

Meningeal metastases: clinical aspects and diagnosis

The authors review the clinical and diagnostic aspects involved in leptomeningeal disease due to solid tumours, leukaemias and lymphomas. The importance of the combination of clinical findings with cerebral spinal fluid (CSF) examination and imaging studies in making an early diagnosis is underlined. The raising prevalence of this complication of systemic cancer deserves specific attention on the part of neurologists involved in consultation liason with general medicine and oncology.

Intrathecal production of neopterin and beta 2 microglobulin in tick-borne encephalitis (TBE) compared to meningoencephalitis of other etiology

To study the pathophysiology of tick-borne encephalitis (TBE), the kinetics of neopterin and beta 2 microglobulin (beta 2M) production were measured in sequential, cerebrospinal fluid (CSF) and serum samples in 133 patients with aseptic meningoencephalitis (TBE, n = 72; non-TBE, n = 61). Intrathecal production of neopterin was demonstrable in all patients. Neopterin levels in CSF were elevated already at day 2: geometric mean value in TBE 36 nmol/l (range 1-253), in the non-TBE group 29 nmol/l (0.2-96). At day 9 and week 6 the neopterin level was significantly higher in TBE (86 (19-725) and 17 (4-122) nmol/l) than in non-TBE (28 (5-109) and 3 (0.2-58) nmol/l) (p < 0.001). After 1 year CSF levels were within the normal range. The beta 2M response in CSF followed the pattern of neopterin. The intensity and duration of neopterin and beta 2M was not correlated to the clinical course. Neopterin seems to be a more sensitive indicator of intrathecal T-cell response and inflammatory reaction than beta 2M. The results indicate that a long-lasting strong inflammatory reaction is of pathophysiological significance in TBE.

Increased levels of beta 2-microglobulin, soluble interleukin-2 receptor, and soluble CD8 in patients with subacute sclerosing panencephalitis

We measured beta 2-microglobulin (beta 2-M), soluble interleukin-2 receptor (sIL-2R), and soluble CD8 (sCD8) antigen levels in paired cerebrospinal fluid (CSF) and sera from patients with subacute sclerosing panencephalitis (SSPE), multiple sclerosis (MS), and other neurological diseases (OND) using enzyme-linked immunosorbent assay. beta 2-M was significantly increased in CSF of the SSPE group compared to the MS or the OND group. Similarly, beta 2-M in the MS versus OND group was significantly increased in CSF. Although serum levels of beta 2-M were similar in the three groups, the CSF/serum ratios were higher in SSPE versus the MS group and in the MS versus the OND group. Levels of sIL-2R and sCD8 were higher in SSPE CSF than OND CSF; however, there were no differences between levels in SSPE and MS CSF. The levels of sIL-2R were increased in SSPE sera compared to those of MS or the OND group, whereas levels of sCD8 in serum from the three groups were similar. The findings of increased CSF/serum ratio of beta 2-M and higher levels of serum sIL-2R and CSF sCD8 in SSPE patients are consistent with those seen in patients with acute and chronic viral infections. When the levels between the initial and follow-up CSF and serum samples from SSPE patients were compared, the data showed that CSF levels of sCD8 elevated during periods of clinical worsening and decreased during clinical improvement. In contrast, serum beta 2-M decreased during periods of worsening and increased during improvement. The measurement of serum beta 2-M and CSF sCD8 may be useful in SSPE patients as markers to monitor disease activity.

Expansion of neopterin and beta 2-microglobulin in cerebrospinal fluid reaches maximum levels early and late in the course of human immunodeficiency virus infection

Elevated cerebrospinal fluid (CSF) levels of neopterin and beta 2-microglobulin (beta 2MG) reflect activation of the cellular immune response in the central nervous system (CNS). In 118 consecutive subjects [15 controls and 103 patients with human immunodeficiency virus (HIV) infection classified according to the Walter Reed staging system (WR)], neopterin and beta 2MG were determined in paired samples of CSF and serum. The permeability of the blood-CSF barrier and local release of neopterin and beta 2MG were taken into account: The molecular weight and diameter were used to determine filtration at the blood-CSF barrier. CSF neopterin levels were increased in all stages of HIV infection. beta 2MG levels were elevated in WR2 and later stages. Neopterin, beta 2MG, and cell counts similarly showed peaks in WR2, as did neopterin and beta 2MG also in the later stages WR5 and WR6. Neurologically asymptomatic patients exhibited higher neopterin CSF levels than did controls (12.67 +/- 11.6 vs. 2.34 +/- 1.05 nmol/l, P less than 0.001) and higher CSF beta 2MG (2.12 +/- 1.25 vs. 1.3 +/- 0.37 mg/l, P = 0.001). Patients with HIV encephalopathy had higher levels of beta 2MG (3.75 +/- 1.83 mg/l) than asymptomatic patients (P less than 0.01). CSF levels of neopterin were markedly different in patients with HIV encephalopathy and toxoplasmosis (P less than 0.01). A high quantity of local release of the markers neopterin and beta 2MG may reflect HIV infection of the CNS in early and late stages and additional release upon opportunistic infections.