The basis of intra-blood-brain-barrier IgG synthesis

Cerebrospinal fluid indices as predictors of treatment response in autoimmune encephalitis

BACKGROUND

Cerebrospinal fluid (CSF) indices reflecting intrathecal antibody production and blood-brain barrier impairment are not routinely assessed in patients with autoimmune encephalitis (AE). We aimed to study CSF indices and their association with the prognosis of AE.

METHODS

This retrospective cohort study conducted at Amrita Institute of Medical Sciences (AIMS), Kochi, India, included 60 patients aged more than 18 years with definite/probable/possible AE admitted to the Department of Neurology from August 2016 to November 2021. We introduced a classification of treatment response based on modified Rankin Scale change over time and treatment modalities.

RESULTS

In our cohort of 60 patients (six [10%] seropositive cases), a good rapid treatment response was associated with CSF white blood cell count of more than 4 cells/mm3 (OR, 4.57; 95% CI 1.31-15.96; P = .02) and positive immunoglobulin G (IgG) Local Synthesis (OR, 7.27; 95% CI 1.56-33.86; P = .01). Albumin Index had association with a poor Glasgow Coma Scale score at the nadir of the disease (OR, 1.17; 95% CI 1.01-1.34; P = .04). Similar results were yielded in the seronegative cohort. IgG Local Synthesis appeared to be a strong predictor for good rapid treatment response in both univariate and multivariate (adjusted OR, 28.71; 95% CI 2.12-389.22; P= .01) analysis. Time to immunotherapy was reversely correlated with good response overall (in the cohort with outliers removed [N = 49]: unadjusted OR 0.97, 95% CI 0.95-0.99; P= .01; adjusted OR 0.97; 95% CI 0.95-0.99; P= .008).

CONCLUSION

CSF indices reflecting intrathecal antibody production and blood-brain barrier impairment appear to be promising predictors of disease severity and therapeutic response in patients with autoimmune encephalitis.

Impact of blood-brain barrier disruption on clinical features and treatment response in patients with newly diagnosed autoimmune encephalitis

AIMS

Blood-brain barrier (BBB) breakdown is an essential mechanism in inflammatory diseases of the central nervous system. However, the association between BBB integrity and autoimmune encephalitis (AE) has not been investigated. Our study aimed to analyze this relationship in patients with AE between BBB integrity with clinical manifestations and therapeutic responses.

METHODS

Our study enrolled 147 patients with AE who were newly diagnosed at the First Affiliated Hospital of Zhengzhou University between August 2015 and December 2021. Patients were classified into normal or damaged BBB groups based on cerebrospinal fluid (CSF) albumin/serum albumin (QAlb). To evaluate the severity of the illness, we used the modified Rankin Scale (mRS) and the Clinical Assessment Scale for Autoimmune Encephalitis (CASE).

RESULTS

We found a higher proportion of males, higher CSF protein, immunoglobulin IgG, and 24-h intrathecal IgG synthesis rate in the damaged BBB group. The improvement rate was lower in the damaged BBB group, but we found that double- or triple-combination immunotherapy had better clinical outcomes than single immunotherapy. In addition, there was a positive correlation between the CASE score and mRS score, and a positive correlation between the CASE score or mRS score and QAlb on admission.

CONCLUSIONS

BBB integrity is closely related to the clinical features and treatment responses of newly diagnosed AE. Patients with AE and a damaged BBB may benefit from combination immunotherapy.

The Correlation Among the Immunoglobulin G Synthesis Rate, IgG Index and Albumin Quotient in Guillain-Barré Syndrome and Chronic Inflammatory Demyelinating Polyradiculoneuropathy: A Retrospective Case–Control Study

Background: The immunoglobulin G synthesis rate (IgG SR) and immunoglobulin G (IgG) index are indicators of abnormal intrathecal humoural immune responses, and the albumin quotient (QALB) is an indicator used to evaluate the completeness of the blood-cerebrospinal fluid barrier (BCB). No systematic reports regarding differences in Guillain-Barré syndrome (GBS) and chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) are available. We assessed differences in the IgG SR, IgG index and QALB between GBS and CIDP patients in a Chinese cohort.

Methods: A total of 234 patients were retrospectively enrolled in this study, and 167 clinically confirmed GBS and CIDP patients were selected. Meanwhile, 67 non-GBS and non-CIDP patients requiring cerebrospinal fluid (CSF) examination were enrolled as the control group. The IgG SR, IgG index and QALB were calculated using formulas. The relevant clinical data were subjected to statistical analysis.

Results: Among the GBS and CIDP study groups and the control group, the QALB had the highest positive rate (80.00%) in the CIDP group (P < 0.01). The QALB stratification analysis showed that the ranges of 10 < QALB ≤ 30 were dominant in the GBS and CIDP groups, and the positive rate of CIDP was higher than that of GBS. Furthermore, a QALB ≤ 7 was dominant in the control group, and a QALB > 30 was dominant in the CIDP group. In receiver operating characteristic (ROC) curve analysis with the CIDP group as the trial group and the GBS group as the control group, the differences in the QALB were statistically significant (P < 0.01). To achieve a high specificity of 98~99%, the diagnostic cut-off value for the QALB was above 57.37 (sensitivity: 9.33%) or below 0.60 (sensitivity: 4.35%). Multivariate logistic regression analysis showed that the CIDP patients had a QALB higher than 57.37, and compared with that in the GBS patients, the difference in the QALB was statistically significant (P < 0.01).

Conclusion: QALB elevation was associated with CIDP, while QALB values above 57.37 or below 0.60 had high specificity in differentiating between GBS and CIDP. In CIDP, the BCB is generally moderately to severely damaged; in GBS, the BCB is generally moderately damaged.

Cerebrospinal fluid biomarkers in patients with neurological symptoms but without neurological diseases

BACKGROUND

Elevated levels of the cerebrospinal fluid (CSF) neuronal injury markers (neurofilament light chain [NF-L] and total tau protein [t-tau]) and of the astroglial marker glial fibrillary acidic protein (GFAP) are found in etiologically different neurological disorders affecting the peripheral and the central nervous system.

AIMS

To explore the role of CSF biomarkers in the clinical management of patients admitted for alarming neurological symptoms, but in whom neurological disorders could be excluded.

METHODS

Study participants were patients seeking medical attention for neurological symptoms primarily considered to be caused by a neurological diagnosis and investigated according to clinical routine. Demographic, clinical, and CSF data were extracted retrospectively from medical records. Patients with a final neurological diagnosis were excluded.

RESULTS

Out of 990 patients, 900 with a neurological diagnosis were excluded leaving 90 patients without a final neurological diagnosis. Sixty-eight (75.6%) were females. Median (range) age at lumbar puncture was 34.7 (16.9-65.1) years. Age-adjusted CSF-NF-L, CSF-t-tau, and CSF-GFAP concentrations were normal in 89 (98.9%), 86 (95.6%), and 87 (96.7%) patients, respectively.

CONCLUSION

In patients with significant neurological symptoms but in whom a neurological diagnosis could not be made, the CSF markers NF-L, t-tau, and GFAP did not indicate signs of neuronal or astroglial cell damage close to symptom onset. Consequently, increased levels of CSF markers are not expected in this patient group and, if present, should raise suspicion of underlying neurological disorders and motivate further investigations.

Free Light Chains and Intrathecal B Cells Activity in Multiple Sclerosis: A Prospective Study and Meta-Analysis

Background. The presence of CSF oligoclonal bands (OBs) is an independent prognostic factor for multiple sclerosis (MS), but the difficulties in the standardization of the test and the interlaboratory variation in reporting have contributed to its limited use in the diagnosis of the disease. Standard nephelometric assays to measure free light chains (FLC) levels have been recently developed and the test may improve the detection of intrathecal B cells activity. Methods. The presence of OBs, kappa and lambda FLC levels, and standard indices of intrathecal inflammation were assessed in 100 consecutive patients, including patients with MS, clinically isolated syndromes (CIS), other inflammatory diseases of the CNS, and other noninflammatory diseases. Results. Both KFLC and LFLC correlated strongly with the presence of OCBs and with all common tests for intrathecal inflammation (p < 0.001 for all comparisons). KFLC and LFLC were significantly different in patients with MS and CIS compared to the other groups (p < 0.001 and p < 0.001, resp.) and had a better diagnostic accuracy than all the other tests (area under the curve 82.3 % for KFLC index and 79.3 % for LFLC index). Conclusion. Nephelometric assays for KFLC in CSF reliably detect intrathecal immunoglobulin synthesis and discriminate MS patients.

IL-6 and CCL2 levels in CSF are associated with the clinical course of MS: implications for their possible immunopathogenic roles

Biological markers would provide valuable tools for tracking disease activity, immunopathological processes or therapeutic efficacy in MS. In this study we analysed a panel of Th(1)/Th(2) cytokines and the chemokine CCL2 in serum and CSF from MS patients and healthy controls. Increased levels of IL-6 (p<0.05) and decreased levels of CCL2 (p<0.001), with the lowest levels during acute relapses, was found in CSF from patients with relapsing-remitting MS. CSF levels of CCL2 correlated with indices for intrathecal IgG production and the CSF level of the neurofilament light protein, a marker for axonal damage, indicating a immunopathogenic role for CCL2.

Evaluation of intrathecal synthesis of IgG in neurocysticercosis

Neurocysticercosis is a world public health problem. An increase in immunoglobulin G (IgG) concentration in the cerebrospinal fluid of patients with neurocysticercosis has been described but the reasons for this finding are unknown. Our hypothesis is that the increase in IgG concentration in cerebrospinal fluid is due to exclusive intrathecal synthesis of IgG and this process is associated with the inflammatory phases of the disease. We studied IgG concentration in cerebrospinal fluid in 16 patients with neurocysticercosis comparing with a control group of 19 patients to verify which pattern of increase in IgG concentration in cerebrospinal fluid occurs in neurocysticercosis. In the neurocysticercosis group, intrathecal synthesis of IgG was detected in 12 (75%) and 5 (31.2%) patients by quantitative and qualitative methods, respectively. When compared with the control group the neurocysticercosis patients had the same pattern of intrathecal synthesis of IgG as multiple sclerosis patients. Intrathecal synthesis of IgG was not associated with any variable indicative of an inflammatory process. We conclude that the increase in IgG concentration in neurocysticercosis is due to intrathecal synthesis, as is also the case for multiple sclerosis, and that this process is not related to the inflammatory stage of NCC.

Differences in systemic and central nervous system cellular immunity relevant to relapsing-remitting multiple sclerosis

In order to elucidate the differences between systemic and central nervous system (CNS) immunity that are relevant to exacerbations of multiple sclerosis (MS), paired peripheral blood and cerebrospinal fluid (CSF) samples obtained from 36 non-treated patients with relapsing-remitting MS (RRMS) were simultaneously examined using flow cytometry to determine the percentages of functional lymphocyte subsets, as well as enzyme-linked immunosorbent assays for measuring soluble immune mediators. Active RRMS patients (n = 27) were characterized by an increase in CD4+ CXCR3+ Th1 cells in blood as compared with inactive patients (n = 9), and this parameter was inversely correlated with plasma levels of IL-10 and IL- 12p70. In contrast, an increase in the percentage of CD4+ CD25+ cells and a decrease in the percentage of CD8+ CD11a(high) cells were features of CSF samples from those with active RRMS. Further, CSF CD4+ CD25+ cells had a close association with leukocyte counts as well as albumin and CXCL10 levels in the CSF, and, thus, could be useful as a measure for inflammatory reactions in the CNS. On the other hand, CD8+ CD11a(high) cells may function as immunoregulatory cells, as their percentage in the CSF showed a positive correlation with CSF levels of the anti-inflammatory cytokine IL-4. These findings suggest that MS relapses occur in a combination with altered cell-mediated immunity that differs between the peripheral blood and CSF compartments, while measurement of lymphocyte subsets may be helpful for monitoring disease status.

HIV-associated dementia, Alzheimer's disease, multiple sclerosis, and schizophrenia: gene expression review

RNA and protein gene expression technologies are revolutionizing our view and understanding of human diseases and enable us to analyze the concurrent expression patterns of large numbers of genes. These new technologies allow simultaneous study of thousands of genes and their changes in regulation and modulation patterns in relation to disease state, time, and tissue specificity. This review summarizes the application of this modern technology to four common neurological and psychiatric disorders: HIV-1-associated dementia, Alzheimer's disease, multiple sclerosis, and schizophrenia and is a first comparison of these diseases using this approach.

Immune parameters associated with early treatment effects of high-dose intravenous methylprednisolone in multiple sclerosis

To determine the immunological effects of high-dose intravenous methylprednisolone (IVMP) and elucidate immune measurements used for evaluation of its therapeutic effect, we analyzed lymphocyte subsets and humoral immune parameters in peripheral blood and cerebrospinal fluid (CSF) samples, before and within 2 weeks of treatment during 19 acute exacerbations in 16 relapsing-remitting multiple sclerosis (MS) patients. In addition to decreases in CSF albumin and IgG levels, treatment resulted in an increase of CD8(+)CXCR3(+) cells as well as a decrease in CD4(+) subsets expressing CD25, CD29, and CCR4 in the CSF. Further, the percentage of circulating CD4(+)CXCR3(+) Th1 cells also decreased. Clinical improvement was achieved following 15 of the 19 treatment occasions. Early (<2 weeks of treatment) clinical improvement was significantly associated with a decrease in CSF CD4(+)CD29(+) helper inducer T cells, whereas they were nearly unchanged in four patients who showed no improvement. Changes in other parameters following IVMP treatment were not different between the responder and non-responder groups.

Chemokine receptors associated with immunity within and outside the central nervous system in early relapsing-remitting multiple sclerosis

Thirty-four patients with early relapsing-remitting multiple sclerosis (RRMS) were studied to clarify the differences in chemokine receptor usage by blood and cerebrospinal fluid (CSF) lymphocytes relevant to the pathogenesis of MS. A total of 45 examinations (33 active and 12 inactive stages) revealed that circulating CD4+CXCR3+ T helper 1 (Th1) cells were increased in active MS patients and correlated with the number of gadolinium-enhanced lesions on magnetic resonance (MR) images. In contrast, CSF samples obtained during active stages were characterized by a decrease in the percentage of CD8+CXCR3+ T cells, which was inversely correlated with CSF cell count and intra-blood-brain barrier (BBB) IgG production.

Esquistossomose medular: análise de 80 casos

O objetivo deste estudo é analisar dados clínicos e laboratoriais de 80 casos de esquistossomose medular (EM) que possam contribuir para melhorar o diagnóstico e tratamento dessa doença. Em 59 pacientes o estudo foi de maneira prospectiva, em 79 pacientes o diagnóstico foi catalogado como altamente provável, presuntivo, baseado em critérios clínico e laboratoriais. Em um paciente houve confirmação anatomo-patológica. Houve predominância do sexo masculino (63,7%), faixa etária entre 21 e 40 anos (63,7%), procedência nordestina (85%), trabalhador em construção civil (31,2%), esforço abdominal prévio (57,5%), início subagudo (61,2%), forma clínica mielorradiculítica e lesão no cone medular e cauda equina (72,5%). O estudo do líquido cefaloraquidiano mostrou pleocitose e taxas elevadas de proteínas em 100% dos casos, da gamaglobulina em 76.5%, positividade de reações imunológicas específicas (imunofluorescência e/ou ELISA) em 100% dos casos (titulo médio de 1/16 e 61u/dl, respectivamente). Costicosteróides e drogas esquistossomicidas foram administrados em todos os pacientes com evolução satisfatória em 80% dos casos.

Diagnóstico da esquistossomose medular: contribuição da ressonância magnética e eletroneuromiografia

OBJETIVO: Analisar os resultados obtidos pela ressonância magnética (RM) e eletroneuromiografia (ENMG) em pacientes com diagnóstico de esquistossomose medular (EM). MÉTODO: Foram analisadas 18 RM da coluna vertebral tóraco-lombar e 24 ENMG dos membros superiores e inferiores de pacientes com diagnóstico definido ou altamente provável de EM nas suas formas clínicas mielorradiculítica e mielítica. RESULTADOS: Entre as 18 RM realizadas, 16 (88,8%), mostraram alterações caracterizadas por imagens hipointensas em aquisições pesadas em T1, hiperintensas em T2, com captação heterogênea do contraste gadolínico e/ou realce das meninges e cauda equina. Entre as 24 ENMG, 23 (95,8%) mostraram quadro de multirradiculopatia bilateral das raízes nervosas L2, L3, L4, L5, S1, S2, assimétrico em 10 casos (41,6%). CONCLUSÃO: A RM e a ENM demonstraram ser exames úteis para o diagnóstico da EM ao revelarem anormalidades que se repetiram sob um determinado padrão em 88,8% e 95,8% dos casos, respectivamente. Apesar de não terem especificidade para a EM, estes procedimentos devem ser realizados rotineiramente com o objetivo de fortalecer o diagnóstico presuntivo desta doença.

IgG intrathecal synthesis and specific antibody index in patients with neurocysticercosis

We analyzed cerebrospinal fluid (CSF) and blood serum from 55 patients with neurocysticercosis (NC) at different clinical stages. According to inflammatory activity in the CSF, three stages were identified: (1) reactive, when there was at least an increase in the number of cells; (2) weakly reactive, when significant alterations were found in the CSF, including an increase in gamma globulins, albeit without hypercytosis; (3) non-reactive, when there was neither hypercytosis nor increase in gamma globulins. Nineteen patients had the reactive form; 18 had the weakly reactive form; 18 displayed the non-reactive form. Local immunoproduction was intense in the reactive group, moderate in the weakly reactive group, and absent in the non-reactive group. The specific antibody index was raised in approximately 2/3 of patients with the reactive form, 2/3 in those with the weakly reactive form, and 1/3 in those with the non-reactive form.

IN CONCLUSION

(1) the classical CSF syndrome in NC can present both in complete and partial modes; (2) local immunoproduction can occur in weakly reactive forms; (3) a raised specific antibody index can occur in the absence of an inflammatory reaction in the CSF.

Autoantibodies in neurodegenerative diseases: antigen-specific frequencies and intrathecal analysis

The frequency of autoantibodies (AAbs) was surveyed in several neurodegenerative diseases, other neurological diseases, and controls using antigen-specific EIAs for neurofilament heavy subunit, tubulin, glial fibrillary acidic protein, S100 protein, tau, beta-amyloid peptide, myelin basic protein, and heparan sulfate proteoglycan. High frequencies of sera and cerebrospinal fluid tubulin AAbs were found in Alzheimer disease (62% and 69%, respectively), Parkinson disease (27% and 70%), amyotrophic lateral sclerosis (54% and 67%), and in sera from multiple sclerosis (50% and 67%), optic neuritis (85%), Guillain-Barré syndrome (88%), and vascular dementia (52%). High frequencies of neurofilament heavy subunit AAbs were detected in Guillain-Barré syndrome, chronic peripheral neuropathy (88%) and optic neuritis (62%); whereas, some Alzheimer's disease (33%) and vascular dementia (44%) patients had glial fibrillary acidic protein AAbs. Lower frequencies of other AAbs were found in patient groups. AAb results were also compared to functional assessment of blood-brain barrier integrity in Parkinson's disease and Alzheimer's disease. The relevance of these AAbs to pathogenesis and/or course of neurologic diseases merits further study with particular reference to subgrouping and prognosis.

Detection of JC virus DNA in cerebrospinal fluid from multiple sclerosis patients

JC virus (JCV), the causative agent of progressive multifocal leukoencephalopathy (PML), has been proposed as a possible aetiopathogenic factor in multiple sclerosis (MS). We performed a study to search the LT region of JCV genome by nested PCR in cerebrospinal fluid (CSF), peripheral blood mononuclear cell (PBMC) and urine samples collected from 121 MS patients, 24 patients with other neurological disorders (OND), 30 non neurological patients (NND) and in PBMCs and urine of 40 healthy subjects. JCV DNA has been found in the CSF of 11 MS patients (9%) while all the CSFs from the 24 OND and the 30 NND cases were negative. No significant differences have been observed as regard to the frequency of JCV DNA detection in PBMCs and urine between the MS patients and the control groups. Nucleotide sequences analysis of seven JCV CSF isolates showed that five strains were identical the prototypal strain, while the other two had a base mutation (T-->C) in 4286 nucleotide (nt). The finding of JCV DNA in the CSF of MS patients suggest that JCV could play a role in the triggering and/or in the maintenance of MS aetiopathogenic process, and therefore it should be taken in consideration when monitoring this disease.

Acute optic neuritis: combined immunological markers and magnetic resonance imaging predict subsequent development of multiple sclerosis. The Optic Neuritis Study Group

The diagnostic significance of intrathecally synthesized IgG and virus-specific antibodies to measles, rubella and varicella-zoster (MRZ) in cerebrospinal fluid (CSF) remains controversial in cases of acute optic neuritis (AON). This study evaluates the prognostic value of baseline CSF and serum markers in AON, and correlates them with magnetic resonance imaging (MRI) and progression to multiple sclerosis (MS). Paired CSF and serum samples from 36 AON patients, 26 MS patients and 22 controls were analyzed for albumin, IgG, oligoclonal IgG (OI), MRZ antibodies, and blood-CSF barrier function; baseline MRI scanning of the head was also performed. The most sensitive parameter for detection of intrathecal inflammation in AON was OI (75%). Baseline MRI scans revealed abnormalities in 46% of the 28 patients with AON. Fifty percent of AON patients developed MS over the following 4 years. Ninety four percent of patients progressing to MS were positive for either OI, MRI or both. Of the AON patients initially positive for MRI and intrathecally-produced MRZ antibodies, 86% developed MS after 4 years. Only 17% of AON patients with negative results for OI and MRI developed MS. Six patients with abnormal OI but normal MRI progressed to MS. CSF and serum analyses, together with MRI, are the methods of choice for prognostic evaluation of patients with AON.

Comprehensive investigation of the presence of JC virus in AIDS patients with and without progressive multifocal leukoencephalopathy

Progressive multifocal leukoencephalopathy (PML), a viral-induced demyelinating disease, is becoming relatively common, while many diagnostic and pathogenetic aspects remain to be clarified. A study was therefore undertaken in 64 AIDS patients suffering from various neurological disorders, including PML (12 subjects), with the specific objective of searching for JC virus (JCV) DNA by nested PCR (n-PCR) in cerebrospinal fluid (CSF), peripheral blood mononuclear cells (PBMCs), and urine collected from all patients. CSF examination, CD4 and CD8 counts, neurological examinations, and neuroradiological investigations were undertaken. JCV DNA was detected in 92% of CSF specimens in 75% of the PBMCs and urine samples from the PML patients, whereas among the non-PML patients JCV DNA was not detected in any CSF samples, but was found in 10% of PBMCs and in 39% of the urine specimens. BKV and JCV DNA viruria was observed simultaneously in 6% of the AIDS patients without PML. The routine CSF tests including IgG oligoclonal bands, the Link, and Tourtellotte IgG indexes, did not show a typical pattern in PML cases. The data obtained clearly indicate that the detection of JCV DNA in CSF constitutes an efficient marker for PML diagnosis. The simultaneous presence of JCV DNA in the CSF, PBMCs, and urine samples from the PML patients, who did not differ from controls with regard to their immunosuppressive status, suggests that JCV could be carried into the central nervous system (CNS) by infected PBMCs.

Cephalosporin-induced recurrent aseptic meningitis

A 66-year-old woman had several episodes of aseptic meningitis associated with exposure to cephalexin, cefazolin, and ceftazidime. The cerebrospinal fluid IgG index was elevated, specific IgG-ceftazidime binding was shown, and skin allergy testing with cefazolin provoked a recurrence of meningitis. We postulate an acute hypersensitivity reaction involving an antigen-specific humoral immune response.

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 immunoglobulin G and Mycobacterium tuberculosis-specific humoral immune response in tuberculous meningitis

Local synthesis of immunoglobulin G (IgG) in the central nervous system was investigated in 10 patients with tuberculous meningitis (TBM), 15 patients with aseptic meningitis (AM), and 15 patients with pulmonary tuberculosis only (PTBO). The IgG synthesis rate for patients with TBM was 56.4 +/- 18.9 mg/day (mean +/- standard deviation), which was significantly higher than that for patients with AM (8.0 +/- 6.7 mg/day, P < 0.001) and that for patients with PTBO (7.5 +/- 4.4 mg/day, P < 0.001). Therefore, the increased IgG synthesis rate in the central nervous system provided supporting evidence for differentiating the diagnosis of TBM from that of AM (sensitivity, 100%; specificity, 83.3%). Simultaneous measurement by enzyme-linked immunosorbent assay of IgG seroreactivity to lipoarabinomannan and purified protein derivative antigens in cerebrospinal fluid (CSF) demonstrated seropositivity in all 6 patients with TBM, 4 of 15 patients with AM, and 4 of 10 patients with PBTO. All patients showing false-positive reactivity in CSF demonstrated seropositivity in sera and normal ranges for IgG synthesis rates in CSF. Also, the semiquantitive measurement of IgG antibody (Ab) titers in these patients demonstrated higher IgG Ab titers in serum than in CSF except for one patient with a highly elevated albumin quotient, suggesting a leaky blood-brain barrier. The results strongly suggested that the Mycobacterium tuberculosis-specific IgG Abs were diffusible through the blood-brain barrier, which addresses the pitfall of serological tests for the early diagnosis of TBM. The serological detection of IgG Abs to lipoarabinomannan and purified protein derivative antigens in CSF could be misleading in the presence of simultaneously elevated of IgG Abs in serum.

Elevated cerebrospinal fluid proteins in sciatica caused by disc herniation

We carried out a study of cerebrospinal fluid (CSF) proteins in 180 patients with sciatica caused by lumbar disc herniation to elucidate further the degree and mechanisms of protein elevations. The 63 controls were patients with tension headache or migraine without aura. The CSF/serum albumin ratios were higher in the patients (mean 8.84, SD 5.16) than in the controls (mean 5.60, SD 2.33). Similar differences were found for the CSF/serum IgG ratios and the CSF-total proteins. The CSF/serum albumin ratios, CSF/serum IgG ratios and the CSF-total protein concentrations were higher in men than in women among the patients. We suggest that the significant difference in ratio parameters between patients and controls indicates a leak of plasma albumin, most likely IgG, into the CSF in patients with sciatica. The leak was more pronounced in men. Also in the control group the CSF/serum albumin and CSF/serum IgG ratios were higher in men.

Formulas for the quantitation of intrathecal IgG production. Their validity in the presence of blood-brain barrier damage and their utility in multiple sclerosis

There are several formulas for the quantitative determination of intrathecal IgG production: Reiber and Felgenhauer's formula (IgG(loc)), the Extended IgG index, Tourtellotte's formula (TOURT), Schuller and Sagar's formula (SCHULL), the IgG index, the Log IgG index, and Blennow and co-workers' formula (IGGPROD). To evaluate the utility of these formulas in the presence of blood-brain barrier (BBB) damage, we present the results from a study of serum and cerebrospinal fluid (CSF) samples from 125 healthy individuals, 18-88 years of age; 1072 consecutive patients without oligoclonal IgG bands (OCBs) in the CSF, 683 without BBB damage (CSF/S: albumin ratio < 9.8) and 389 with BBB damage (CSF/S albumin ratio 9.8-30); and 106 patients with definite multiple sclerosis (MS). The relation between the CSF/S albumin ratio and the CSF/S IgG ratio was remarkably linear in both healthy individuals (r = 0.95; P < 0.0001) and patients without oligoclonal bands in the CSF (r = 0.95; P < 0.0001). Therefore, IgG(loc) and the Extended IgG index, two formulas based on a nonlinear relation between the CSF/S albumin ratio and the CSF/S IgG ratio, yielded biased results (lower values) in the presence of BBB damage. TOURT and SCHULL also yielded biased (higher) values in the presence of BBB damage, probably because of incorrect constants in these formulas. There were no significant correlations between the CSF/S albumin ratio (i.e. the BBB function) and the IgG index or the Log IgG index, two dimensionless quotients for the detection of intrathecal IgG production, or between the CSF/S albumin ratio and IGGPROD, an empirical formula for the determination of intrathecal IgG production in mg/l.(ABSTRACT TRUNCATED AT 250 WORDS)

Trans-blood-brain-barrier albumin leakage and comparisons of intrathecal IgG synthesis calculations in multiple sclerosis patients. Multiple Sclerosis Study Group, Alpha Interferon Study Group, and Azathioprine Study Group

We compared four equations for estimating intrathecal IgG synthesis (Tibbling and Link IgG index (T/L), Schuller and Sagar (S/S), Reiber and Felgenhauer (R/F), and Tourtellotte (T) equations) using data from chronic progressive MS patients. For normal albumin leakage (AL) (< 75 mg/day-intact BBB), T (r = 0.15) and R/F (r = 0.10) showed comparable positive correlations with trans-BBB AL, T/L (r = -0.10) was negative and S/S was uncorrelated (r = 0.05). For abnormal AL (> or = 75 mg/day), the R/F (r = -0.24), S/S (r = -0.37) and the T/L (r = -0.22) equations overcorrected, whereas the T (r = 0.07) equation values did not correlate with AL. The albumin index and trans-BBB albumin leakage rate formulae gave essentially identical estimates of BBB leakage (r = 0.99, P = 0.0001). We conclude that in chronic progressive MS patients the R/F, T/L and S/S formulae overcompensate for large abnormal T-BBB albumin leakage rates. The T formula corrected best for IgG transudate at high AL rate values in MS.

Effect of treatment on oligoclonal IgG bands and intrathecal IgG synthesis in sequential cerebrospinal fluid and serum from patients with subacute sclerosing panencephalitis

Oligoclonal IgG bands were analyzed in matching pairs of cerebrospinal fluid (CSF) and serum from 12 subacute sclerosing panencephalitis (SSPE) patients, using isoelectric focusing and immunofixation. Each patient was given isoprinosine, and four of the 12 patients were given alpha-interferon in addition. Two to 4 serial CSF and serum samples were collected from each SSPE patient during periods ranging from 1 to 16 months. In 3 SSPE patients a small number of new oligoclonal bands were seen in the follow-up CSF samples. In the other 9 SSPE patients there was no change in CSF band patterns between initial and follow-up specimens. Band patterns in serum remained unchanged between initial and follow-up samples. Although all 12 SSPE cases had higher IgG indices and increased rate of intra blood-brain barrier (BBB) IgG synthesis in comparison to patients with other neurological diseases, the values did not significantly differ between the first and follow-up specimens. We conclude that treatment of SSPE patients with isoprinosine or with isoprinosine and alpha-interferon had no significant effect on the CSF oligoclonal band profiles or IgG synthesis within the central nervous system.

Blood-brain-barrier in a geriatric population: barrier function in degenerative and vascular dementias

Albumin and IgG were determined in serum and cerebrospinal fluid (CSF) of patients with early-onset Alzheimer's disease (AD, n. 13), senile dementia of Alzheimer type (SDAT, n. 33), vascular dementia divided into multi-infarct (MID, n. 9) and probable vascular (PVD, n. 11) dementia. Albumin and IgG ratio and IgG index were calculated. CSF albumin and albumin ratio were significantly higher in MID patients indicating an increased BBB permeability. IgG ratio and IgG index did not show any significant difference among groups. These results do not provide evidence for BBB damage in AD/SDAT, while in MID the increase of CSF albumin and albumin ratio is suggestive of BBB dysfunction.

Methylprednisolone in multiple sclerosis exacerbation: changes in CSF parameters

Twenty-six patients with multiple sclerosis (MS) received a total of 45 courses of intravenous methylprednisolone daily for seven days, for acute neurological deterioration. Changes in CSF parameters and clinical status following methylprednisolone were determined and first and repeat courses were compared. There were significant reductions in CSF IgG, CSF albumin, serum IgG and serum albumin levels and CSF IgG synthesis rate in the first and repeat treatment groups. CSF IgG index fell significantly with initial methylprednisolone treatment but not with subsequent courses. Oligoclonal bands disappeared in three patients. Definite clinical improvement followed 30 methylprednisolone courses, possible improvement followed six and no change followed seven. Clinical response was not predicted by pre-treatment CSF IgG synthesis status and did not correlate with its degree of reduction.

Laboratory investigation of cerebrospinal fluid proteins

Analysis of CSF proteins is useful in the diagnosis and management of neurological diseases in the following situations: 1. In inflammatory conditions when there is breakdown of blood-CSF barrier integrity. Meningitis is a medical emergency, with CSF total protein measurement being only a screening test. 2. In the detection of immune responses within the CNS. This is by far the most important application in a routine clinical setting, as it is now a firmly established criterion in the diagnosis of multiple sclerosis. Oligoclonal bands restricted to the CSF are the only reliable indicators of intrathecal immunoglobulin G synthesis and are practically always associated with inflammatory disease of the CNS. The method fo choice for detecting oligoclonal bands is isoelectric focusing with immunofixation. Quantitative measurement of IgG in the CSF is of no value in diagnostic pathology. 3. In destructive brain diseases when brain-specific proteins are released into the CSF, measurement of these proteins can give prognostic information.

Helping patients live with multiple sclerosis. What primary care physicians can do

Patients with multiple sclerosis (MS) may experience progressive problems of many kinds, often over decades. Ambulation, muscle strength and coordination, bladder function, vision, behavior, and cognition may eventually be affected. The diagnosis is based on clinical features and laboratory studies, but no definitive test exists. The rate of misdiagnosis may be as high as 30%. Treatment consists of pharmacotherapy for symptoms, therapy for the disease itself, and experimental therapies. Long-term management of MS can be a worthwhile challenge for primary care physicians. Helpful resources include neurologists with an interest in the disease, regional treatment and rehabilitation centers, and local MS societies.

Efficacy and toxicity of cyclosporine in chronic progressive multiple sclerosis: a randomized, double-blinded, placebo-controlled clinical trial. The Multiple Sclerosis Study Group

Patients with clinically definite multiple sclerosis, mild to moderately severe neurological disability (entry score on the Expanded Disability Status Scale (EDSS) between 3.0 and 7.0), and a progressive course defined by an increase in the EDSS of between 1 and 3 grades in the year prior to entry were randomized to receive either cyclosporine (n = 273) or placebo (n = 274) in a 2-year, double-blinded, multicenter trial. Treatment groups at entry proved balanced for age, gender, duration of illness, and neurological disability. Cyclosporine dosage was adjusted for toxicity and a median trough whole-blood level was maintained between 310 and 430 ng/ml. The mean increase in EDSS score was 0.39 +/- 1.07 grades for cyclosporine-treated patients and 0.65 +/- 1.08 grades for placebo-treated patients from entry until the time of early withdrawal or completion of the study (p = 0.002). Of three primary efficacy criteria, cyclosporine delayed the time to becoming wheelchair bound (p = 0.038; relative risk, 0.765), but statistically significant effects were not observed for "time to sustained progression" or on a composite score of "activities of daily living." Active treatment did have a favorable effect on several secondary measures of disease outcome. A large and differential withdrawal rate (44% for cyclosporine-treated patients, 32% for placebo-treated patients) complicated the analysis but did not appear to explain the observed effect of cyclosporine in delaying disease progression. Multivariate analysis did not show institutional effects but did demonstrate substantial effects of baseline neurological disability on outcome. Nephrotoxicity and hypertension were common troublesome toxicities and accounted for most of the excess loss of patients in the cyclosporine arm of the study. Thus, chronic cyclosporine therapy was associated with a statistically significant but clinically modest delay of progression of disability in a group of patients with multiple sclerosis selected for moderately severe and progressive disease. Close supervision by physicians familiar with cyclosporine is mandatory to minimize known adverse effects, particularly nephrotoxicity, when considering the use of this immunosuppressant.

Blood-brain-barrier and intrathecal immunoglobulin changes in tuberculous meningitis and demyelinating disorders: a preliminary report from a south Indian hospital

Sixty-three paired serum and CSF samples (15 controls and 48 patients) were studied for CSF albumin quotient, IgG index and synthesis rate. Control values for albumin quotient and IgG index were less than 10.0 and less than 0.6 respectively. IgG synthesis rate/day was calculated according to the Tourtellotte formula and a value of greater than 3.0 mg/day is considered high. Our findings in patients with central demyelinations, subacute sclerosing panencephalitis, Guillain Barré Syndrome and cerebrovascular accidents are comparable to earlier studies. Fifteen tuberculous meningitis patients were studied and could be separated into 2 groups, 9 with elevated albumin quotients and 6 with normal albumin quotients. Three patients with elevated albumin quotients and 4 with normal albumin quotients showed increased intrathecal IgG synthesis.

Solid-phase immunofluorometric assay for quantification of CSF immunoglobulins. Determination of normal reference values

Because a highly sensitive method is required to quantify low concentrations of immunoglobulin (Ig) classes in cerebrospinal fluid (CSF), there have been a few papers reporting normal values of CSF IgG, IgA and IgM determined in the same samples. Enzyme immunoassay (EIA) is most frequently used, but has such drawbacks as susceptibility of enzyme to inhibition and denaturation and the requirement for additional incubation with a substrate. Therefore, solid-phase immunofluorometric assay was evaluated for quantification of CSF IgG, IgA and IgM in the nanogram range. We found this to be rapid and reproducible. The mean (SD) values of normal CSF samples obtained from 22 subjects with tension headache were 23.9 (7.6) micrograms/ml for IgG, 2.00 (0.90) microgram/ml for IgA and 197 (87) ng/ml for IgM. The normal mean (SD) values of indexes were 0.51 (0.10) for IgG, 0.25 (0.05) for IgA and 0.044 (0.017) for IgM. These values agreed quite well with those determined by EIA. The values of CSF albumin correlated significantly with those of CSF IgG or IgA, but did not with those of CSF IgM. Levels of each of the three Ig classes in CSF and serum were significantly correlated. When CSF/serum ratio was introduced, a significant correlation between the albumin ratio and each Ig ratio was found. These results suggest that the Ig content of normal CSF may depend upon that of serum and upon the characteristics of the Ig molecule.

Chronic polyradiculoneuropathy associated with human T-cell lymphotropic virus type I infection

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Late onset globoid leukodystrophy: unusual clinical and CSF findings

During a febrile upper respiratory tract illness this 4 year old boy developed left hemiparesis, which progressed to loss of walking and even of sitting finally to tetraplegia. The cerebrospinal fluid protein pattern showed blood-brain barrier damage with additional intrathecal IgG synthesis. The symptoms responded to steroid therapy but resumed and worsened on withdrawal. Only late, when visual evoked potentials and nerve conduction velocity proved to be impaired, was Krabbe disease diagnosed on the assay of cultured fibroblasts for galactocerebroside-beta-galactosidase. We discuss the significance of possible endogenous production of IgG in the CNS.

Intrathecal Ig synthesis. Its detection by isoelectric focusing and IgG index

In a retrospective study on 999 patients, the likelihood ratios of the IgG index, Tourtellotte formula and IgG concentration in CSF and in serum, the albumin concentration in CSF and in serum, and the total protein in CSF, were compared in predicting intrathecal Ig synthesis. This synthesis was detected with isoelectric focusing (IEF). No patient was included more than once in the data collection. All patients with high IgG and other abnormalities in serum, as well as all xanthochromic and blood-tinged CSF specimens, were excluded from the study. Construction of ROC curves established that the IgG index, Tourtellotte formula and CSF IgG yield the same information: these parameters indicate the presence of intrathecal IgG synthesis. The likelihood ratio for the IgG index at a cut-off point of 0.80 for a positive test is 20; at a cut-off point of 0.5 for a negative test it is 5. For the Tourtellotte formula, it was found that the likelihood ratio reached a maximal value of 7 at a cut-off value of synthesis of 10 mg/day for a positive test. For a negative result, the formula had a likelihood ratio of 6 at a cut-off value of -5. For CSF IgG, it was found that the likelihood ratio was 4 for a positive test with a cut-off value of 0.1 g/l. For a negative outcome, the determination of CSF IgG is only meaningful at a very low cut-off value (0.03 g/l). The other parameters studied (serum IgG concentration, albumin concentration in CSF and in serum, and total protein in CSF) showed a likelihood ratio equal to 1. It is concluded that only the IgG index, the Tourtellotte formula and the CSF IgG concentration have predictive value for intrathecal Ig synthesis as recorded with IEF.

Molecular analysis of IgA in multiple sclerosis

IgA plays an important role in immune-mediated and anti-viral responses, and is the major antibody in external mucosal secretions. We used enzyme-linked immunosorbent assay (ELISA) and immunoblot to examine IgA in tears and parotid saliva of 21 multiple sclerosis (MS) patients and 19 normal controls. No significant difference in absolute levels were noted and both groups showed a wide range in values. However, 16 of 21 MS patients had detectable changes in molecular form of their IgA. Monomeric IgA was found in 52% of MS tears (P less than 0.001) and 45% of MS parotid saliva (P less than 0.05). Among normals, monomeric IgA was noted in only two saliva samples. IgA in secretions consisted of both A1 and A2 subclasses, although 14% of the monomeric MS IgA samples were restricted to a single subclass. Free secretory component was found in the secretions of all subjects with the exception of a single MS patient. However, immunoblot staining of secretory component was decreased in MS patients compared to controls. This study notes changes in IgA in two distinct external secretions in MS patients compared to controls. These changes are consistent with local mucosal inflammation. Impaired mucosal barriers have important implications in MS with regard to susceptibility to infectious agents, environmental antigen processing, and lymphocyte activation.

Normal rat serum cytotoxicity against syngeneic oligodendrocytes. Complement activation and attack in the absence of anti-myelin antibodies

The role of complement in mediating oligodendrocyte and myelin injury has been investigated by studying the effects of normal adult rat serum on syngeneic cultured neonatal glial cells. Rat serum has cytotoxic activity directed against oligodendrocytes but not astrocytes, the potency of which increases with cell maturation. The effects of heat inactivation, decomplemented rat serum, EGTA treatment, removal of any possible anti-myelin antibody by absorption using syngeneic myelin and absence of surface staining for immunoglobulins on serum-treated oligodendrocytes, C9 depletion and reconstitution, and oligodendrocyte staining for surface C9 demonstrate that this cytotoxicity is mediated by complement via antibody independent activation of the classical pathway and is membrane attack complex dependent. These findings significantly extend the previous demonstration of complement activation by extracted myelin, and may have significance for the pathogenesis of demyelinating diseases.

Multiple sclerosis intra-blood-brain-barrier IgG synthesis: effect of pulse intravenous and intrathecal corticosteroids

Nine severely disabled clinically definite chronic progressive multiple sclerosis (MS) patients who had at least one determination of intra-blood-brain-barrier (BBB) IgG synthesis rate of greater than 7 mg/day (upper limit of normal = 3.3) participated in this study. Seven patients were given 1 gram of methylprednisolone sodium succinate (MP) by intravenous infusion over 30 minutes once a day for 3 days. Statistically significant (p less than .05) reduction in intra-BBB IgG synthesis (mg/day) was seen in 4/7 patients, but in only 2 were normal levels of synthesis rate (less than 3.3 mg/day) attained. Rebound of IgG synthesis to premedication rates occurred within 30 days in 2/4 patients. There was no change in intensity or pattern of cerebrospinal fluid (CSF) oligoclonal IgG bands by isoelectric focusing, immunofixation, and silver staining. A subsequent course of intrathecal methylprednisolone acetate (MPA) (80 mg twice a week for 5 weeks) was given to 5 of the 7 patients and to 2 additional patients not previously treated. In spite of signs of subarachnoid inflammation, a statistically significant depression of intra-BB synthesis, which far exceeded that from the pulse treatment occurred in all 7, including the 2 patients whose intra-BBB IgG synthesis rates were previously resistant to pulse steroid administration. Normal levels of synthesis were rapidly reached in 4/7 patients; however, an IgG synthesis rebound occurred in 3/7 patients which was just as rapid. One out of 7 patients showed a temporary reduction in the number of cathodic IgG oligoclonal bands in the CSF. Two patients required discontinuation of treatment due to aseptic meningitis in one and progressive weakness in the other. Clinically, these severely afflicted patients with fixed deficits remained unchanged with either treatment protocol. While MPA and ACTH have similar initial effect on the central nervous systems (CNS) inflammatory response in MS, the well documented risk of serious adversities with MPA prohibit its clinical use in MS in its present form.

Protein gradients in the cerebrospinal fluid and the calculation of intracerebral IgG synthesis

When six successive samples of 2.5 ml cerebrospinal fluid (CSF) were withdrawn from eight multiple sclerosis (MS) and 12 other neurological disease (OND) patients, the IgG index rose continuously between 2.9 and 24.0%, while both the Tourtellotte as well as the Reiber/Felgenhauer formulas were less affected.

The long march of the cerebrospinal fluid profile indicative of clinical definite multiple sclerosis; and still marching

Much progress has been made, especially in the last two decades, in laboratory aids to diagnosis and to follow the course of patients with multiple sclerosis (MS). The cerebrospinal fluid (CSF) profile indicative of MS, though not pathognomonic of MS, is present in almost every case of clinical definite MS in a chronic progressive phase (probably also true for early MS). The cardinal aspect of the profile is intra-blood-brain barrier (BBB) IgG synthesis which can be qualitatively detected by determining unique CSF oligoclonal IgG bands and quantitated by rate formula, mg/day. We believe that intra-BBB IgG synthesis is caused by a persistent antigen, most likely a virus, possibly measles. A number of issues about the profile are proposed and opportunities are presented to resolve them.

Oligoclonal IgG bands in cerebrospinal fluid and serum during asymptomatic human immunodeficiency virus infection

Serum and cerebrospinal fluid (CSF) samples from asymptomatic patients seropositive for human immunodeficiency virus (HIV) showed frequent evidence of intrathecal IgG synthesis and oligoclonal IgG bands, with different isoelectric focusing patterns in serum and CSF; 2 of 7 had a CSF pleocytosis. The results suggest frequent, early, chronic central nervous system infection following HIV infection.

Intrathecal synthesis of immunosuppressive acidic protein (IAP) in patients with multiple sclerosis and other inflammatory neurological diseases

Immunosuppressive acidic protein (IAP), an immunosuppressive substance produced mainly by macrophages, has previously been shown to increase in the serum of patients with inflammatory neurological diseases. In this study we assayed the IAP levels in cerebrospinal fluid (CSF) by a passive hemagglutination-inhibition test. CSF-IAP levels increased significantly in patients with multiple sclerosis (MS) during both the active and inactive stages and in patients with Guillain-Barré syndrome (GBS) or Miller Fisher syndrome (MFS) as compared with those of control patients, but not in patients with amyotrophic lateral sclerosis or spinocerebellar degeneration. During the active stage of MS, increased CSF-IAP levels together with the elevated IAP% (CSF-IAP/total CSF protein) and IAP index [(CSF-IAP/serum IAP)/(CSF albumin/serum albumin)] suggested the intrathecal synthesis of IAP. In contrast, in patients with GBS or MFS, increased CSF-IAP levels without elevation of IAP% could be attributed largely to increased total CSF protein levels. In patients with neuro-Behçet's disease, CSF-IAP levels and IAP% were elevated during the active stage, but remained normal levels during the inactive stage. Assaying CSF-IAP could provide useful information about inflammatory or immunopathological events within the central nervous system.

Detection of human T-cell lymphoma/leukemia virus type I DNA and antigen in spinal fluid and blood of patients with chronic progressive myelopathy

The presence of antibodies to human T-cell lymphoma/leukemia virus Type I (HTLV-I) has been associated with chronic progressive myelopathy. We attempted to isolate the virus from the blood and spinal fluid of patients with chronic progressive myelopathy and to define the clinical, radiologic, and electrophysiologic features of this disease. Ten of 13 patients from tropical countries and 2 of 8 from the United States had serum antibodies to HTLV-I. The virus was detected in cultures of peripheral-blood lymphocytes from three of seven patients by means of Southern blot hybridization. Using a sensitive in vitro enzymatic gene-amplification technique, we detected HTLV-I sequences in fresh peripheral-blood mononuclear cells of all of 11 patients tested who were positive for the antibody, and in cell cultures of the spinal fluid from 3 of the 11 tested. Magnetic resonance imaging of the cranium revealed periventricular lesions in the white matter of 3 of the 12 antibody-positive patients. Five of these patients had mild axonal sensorimotor polyneuropathy, and one had bilateral lumbar radiculopathy. Visual evoked potentials were abnormal in three seropositive patients, and brain-stem evoked responses were abnormal in two. The detection of the DNA and proteins of HTLV-I strengthens the proposition that this virus is involved in the pathogenesis of a subset of cases of chronic progressive myelopathy.