Genetic variants in the immunoglobulin heavy chain locus are associated with the IgG index in multiple sclerosis.

OBJECTIVE: Intrathecal synthesis of immunoglobulin gamma (IgG) synthesis is frequently observed in patients with multiple sclerosis (MS). Whereas the extent of intrathecal IgG synthesis varies largely between patients, it remains rather constant in the individual patient over time. The aim of this study was to identify common genetic variants associated with the IgG index as a marker of intrathecal IgG synthesis in MS. METHODS: We performed a genome-wide association study of the IgG index in a discovery series of 229 patients. For confirmation we performed a replication in 2 independent series comprising 256 and 153 patients, respectively. The impact of associated single nucleotide polymorphisms (SNPs) on MS susceptibility was analyzed in an additional 1,854 cases and 5,175 controls. RESULTS: Significant association between the IgG index and 5 SNPs was detected in the discovery and confirmed in both replication series reaching combined p values of p = 6.5 × 10(-11) to p = 7.5 × 10(-16) . All identified SNPs are clustered around the immunoglobulin heavy chain (IGHC) locus on chromosome 14q32.33 and are in linkage disequilibrium (r(2) range, 0.71-0.95). The best associated SNP is located in an intronic region of the immunoglobulin gamma3 heavy chain gene. Additional sequencing identified the GM21* haplotype to be associated with a high IgG index. Further evaluation of the IGHC SNPs revealed no association with susceptibility to MS in our data set. INTERPRETATION: The extent of intrathecal IgG in MS is influenced by the IGHC locus. No association with susceptibility to MS was found. Therefore GM haplotypes might affect intrathecal IgG synthesis independently of the underlying disease.

Síndrome paraneoplásico cerebeloso asociado con carcinoma de ovario / Paraneoplastic syndrome with cerebellar degeneration associated with ovarian carcinoma

Presentamos el caso de una paciente afectada de un síndrome paraneoplásico con degeneración cerebelosa, como primera manifestación de un tumor ovárico en la que todos los estudios resultaron normales, a excepción de la presencia de un autoanticuerpo anti-Yo, que reconoce antígenos citoplasmáticos de las células de Purkinje del cerebelo. La sospecha de un tumor ovárico fue confirmada microscópicamente tras la extirpación de los dos anejos. (AU)

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.

Oligoclonal immunoglobulin G in cerebrospinal fluid of myasthenia gravis patients.

Immunoglobulin G (IgG) band patterns were investigated in cerebrospinal fluid (CSF) from 19 patients with myasthenia gravis (MG) in a search for abnormalities indicating central nervous system (CNS) involvement in this disorder. Using the isoelectric focusing (IEF) technique and antiserum immunoblotting against IgG, we found no evidence of the presence of oligoclonal IgG in CSF from most of MG patients. In 2 cases, the positive findings of oligoclonal IgG in CSF may have reflected a manifestation of an associated disease, which has already been associated with immune abnormalities within the CNS. Further investigations with more sophisticated techniques are required to give additional insight into humoral immune events within the CNS in MG patients.

Intrathecal synthesis of immunoglobulin G in vascular dementia.

Serum and CSF from 53 vascular dementia (VD) patients and 50 controls were analysed to investigate the possibility of an intrathecal synthesis of IgG, defined as an elevated IgG index (greater than or equal to 7) and/or presence of oligoclonal IgG in cerebrospinal fluid (CSF), but not in serum. Five (9%) patients and no controls exhibited an intrathecal synthesis of IgG. The IgG index increased with the degree of dementia (p less than 0.05). It was positively related to presence/absence of hypertension (p less than 0.05) and correlated positively with diastolic blood pressure (p less than 0.05). The findings suggest that immunological factors might be involved in the pathogenesis of VD.

Experimental allergic encephalomyelitis in the monkey: humoral immunity and blood-brain barrier function.

Acute monophasic experimental autoimmune encephalomyelitis (AMEAE) was induced in 5 Macacus cynomolgus monkeys. Serum and cerebrospinal fluid (CSF) paired samples were collected before and four weeks after immunization, time of complete development of AMEAE clinical picture. After immunization the CSF/serum albumin ratio and the IgG index were markedly increased. Agarose isoelectric focusing (AIEF) followed by immunofixation revealed faint IgG oligoclonal bands in both serum and CSF of all monkeys, which became more evident after Kappa and Lambda assessment. Intrathecal synthesis of IgG oligoclonal bands was detected in only one CSF. Affinity-driven immunoblotting failed to detect anti-myelin basic protein (MBP) oligoclonal IgG. No free light chain (FLC) patterns or IgA and IgM oligoclonal bands were detected.

Isoelectric focusing studies of serum and cerebrospinal fluid in patients with antecedent poliomyelitis.

The post-poliomyelitis syndrome (PPS) refers to symptoms of new weakness, fatigue, and pain years after recovery from acute poliomyelitis. Oligoclonal IgG bands have been reported in the cerebrospinal fluid (CSF) from PPS patients, suggesting that the syndrome is immune mediated or caused by persistent viral infection. We studied 15 paired serum and CSF samples and 6 unpaired CSF samples from a total of 21 patients with a prior history of poliomyelitis. Quantitative immune studies failed to show evidence for increased intrathecal IgG production relative to patients with noninflammatory central nervous system (CNS) disease. We found definite oligoclonal IgG bands in the CSF from only 1 patient, who also carried a diagnosis of multiple sclerosis. An isoelectric focusing poliovirus antigen overlay study showed evidence that suggested a CNS-specific antipoliovirus immune response in only 1 patient. Our results fail to support a dysimmune or persistent viral cause for post-poliomyelitis progressive muscular atrophy or PPS.

Diagnostic investigations in MS: which is the most sensitive?

In an attempt to establish the efficacy of the different diagnostic tests, 41 multiple sclerosis (MS) patients at different stages of the disease were studied by means of visual evoked potential (VEP) recording, T-lymphocyte subset determination cerebrospinal fluid (CSF) analysis and magnetic resonance (MR) imaging. MR and CSF oligoclonal bands (OB) were the most sensitive techniques for the diagnosis of MS, being positive in 88% of patients, while VEP and helper/suppressor (H/S) T-cell ratio were altered in 54% and 46% of patients respectively. Low significant agreement coefficient were found among the 4 tests and the major value, even though "fairly" significant, was between MR and OB.

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.

Effect of hyperbaric oxygen treatment on immunological parameters in multiple sclerosis.

Hyperbaric oxygen (HBO) treatment has been reported to cause amelioration of clinical symptoms in patients with multiple sclerosis (MS). We have treated 10 MS patients with hyperbaric oxygen (100% O2 at 2 atmospheres absolute for 90 min daily for a total of 20 exposures), and performed immunological studies on peripheral blood and cerebrospinal fluid (CSF). After treatment there was a significant increase in total and helper T lymphocyte counts in peripheral blood, as well as an increase in both E, Fc gamma and C3b receptor-bearing lymphocytes. The responses to the mitogens PHA, con A and PWM were unchanged. Granulocytes showed an increased proportion of Fc gamma receptor and C3b receptor positive cells after treatment. The O2 consumption of granulocytes also increased, but phagocytosis, as measured by chemiluminescence, was unchanged. Serum IgA levels were slightly increased, while IgG and IgM concentrations remained unchanged after treatment. Cerebrospinal fluid cell counts, protein and IgG concentrations, as well as IgG indexes remained unchanged.

Sensory (VEP, BAEP, SEP) and motor-evoked potentials, liquoral and magnetic resonance findings in multiple sclerosis.

In order to define the most suitable instrumental protocol for the diagnosis of multiple sclerosis (MS), 41 patients with definite (D = 14), probable (P = 14) and suspected (S = 13) MS were examined with CSF immunology, brain MRI and multimodal evoked potentials. The central motor tracts were also tested. The following alteration rates were found: MRI = 78%, CSF = 63.6%, VEP = 70.0%, median nerve SEP = 50%, peroneal nerve SEP = 68.0%, BAEPs = 35.7%, motor-evoked potentials (MEPs) = 74.0%. Altogether, EPs were abnormal in 90% of cases. Normal MRI with altered EPs were found in 22% of cases, whilst a normal EP battery with defective CSF or MRI findings were found in 7%. Twenty-six out of 27 patients with P or S forms were reclassified into a D one when considering EPs and MRI features.

IgG paraproteinemias: a comparative CSF and serum study.

In 10 neurologic patients routine isoelectric focusing of CSF and serum revealed monoclonal IgG paraproteinemia (3 multiple myelomas and 7 benign monoclonal gammopathies). Quantitative protein study showed blood-brain barrier damage in 7 out of 10 patients; 2 patients had intrathecal synthesis of IgG measurable by Reiber's formula. Each case showed identical monoclonal IgG pattern in CSF and serum at isoelectric focusing and immunofixation. We suppose that monoclonal IgG detectable in the CSF usually derive from the serum across the intact or damaged barrier. The occurrence of quantifiable intrathecally synthesized IgG in 2 patients, both with skeletal lesions close to the subarachnoid spaces, and the identical patterns of IgG in CSF and serum suggest that tumoral plasma cells secrete monoclonal IgG into blood and CSF from the bone location.

Autoantibody responses in the cerebrospinal fluid of guinea pigs with chronic relapsing experimental allergic encephalomyelitis.

We report the use of the ELISA technique to measure IgG specific for whole cord, myelin, myelin basic protein and Mycobacterium tuberculosis in the cerebrospinal fluid (CSF) of Strain 13 guinea pigs in different stages of chronic relapsing experimental allergic encephalomyelitis (CR-EAE). Specific antibody levels to all 4 antigen preparations were related to the severity of clinical signs, with the highest levels of IgG in the CSF of guinea pigs in relapse or in stable chronic disease. Total IgG levels in the CSF, though elevated throughout the course of CR-EAE, did not show any association with the category of disease. Control animals inoculated with complete Freund's adjuvant (CFA) alone showed CSF IgG levels specific for M. tuberculosis that were not significantly different from those in animals with chronic EAE, indicating that CFA may itself induce a late-acting increase in blood-brain barrier permeability.

Human immunodeficiency virus infection of the brain. II. Detection of intrathecally synthesized antibodies by enzyme linked immunosorbent assay and imprint immunofixation.

Sera and CSF from 29 patients in early and late stages of HIV infection were analysed for intrathecal antibody production. Elevated CSF-IgG indices indicating intrathecal IgG synthesis were demonstrated in 9 patients while 4 of 18 patients tested had oligoclonal IgG bands in the CSF. Analysis of HIV-specific antibodies by enzyme-linked immunosorbent assay (whole antigen and site-directed ELISA) and calculation of "antibody indices" (CSF/serum antibody quotient divided by CSF/serum albumin quotient) indicated intrathecal HIV antibody synthesis in 19 patients. Analysis of serum and CSF antibodies by an imprint immunofixation (IIF) method showed intrathecal synthesis of predominantly polyclonal HIV-IgG antibodies in 11 of 13 patients examined. IIF analysis of antibodies to six other infectious agents showed no intrathecal antibody production except in one patient who had minor fractions of intrathecally synthesized IgG antibodies to varicella zoster virus. The present results demonstrate that an intrathecal HIV-specific antibody response may be present in both early and late stages of HIV infection, and indicates that HIV may reach the brain at an early stage of infection.

An isoelectric focusing study in herpes simplex virus encephalitis.

To establish an early reliable diagnostic test for herpes simplex virus (HSV) type 1 encephalitis (HSVE), we used isoelectric focusing (IEF) and an IEF-overlay technique with radiolabeled HSV glycoprotein B (gB) to study 7 serum and 12 cerebrospinal fluid (CSF) samples from 12 patients with presumed or biopsy-proved HSVE. Blood-brain barrier damage and increased intra-blood-brain barrier IgG synthesis were detected in 5 of the 7 patients with HSVE. CSF oligoclonal bands were found in 6 of 11 patients. Using an IEF-overlay technique, we detected anti-gB antibody in all serum (7 of 7) and in 10 of 12 CSF samples. Anti-gB antibody was found in 4 of 6 CSF specimens obtained within the first week of disease (days 3 to 5) and in all samples collected later in the disease. The pH range of anti-gB antibody activity was broad (4.5 to 9.5), indicating a heterogeneous immune response to HSV. A hematogenous origin of the CSF antibody was suggested because anti-gB antibody appeared in serum before matched CSF and because both serum and matched CSF had a similar antibody IEF pattern. Local production of anti-gB antibody was suggested in some cases because of a greater prominence of anti-gB antibody in CSF than in matched sera and because CSF oligoclonal bands had anti-gB antibody activity. In contrast, only one of 6 CSF samples from patients with multiple sclerosis had gB antibody activity; in this case, anti-gB antibody activity did not correspond in isoelectric point location to oligoclonal bands.(ABSTRACT TRUNCATED AT 250 WORDS)

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.

Unusual findings in Creutzfeldt-Jakob disease. Case report.

We present a definite case of Creutzfeldt-Jakob disease (CJD) with visual evoked response (VER) and CSF oligoclonal band abnormalities and discuss the neurobiological significance and diagnostic value of these findings.

Anti-galactocerebroside antibodies in human cerebrospinal fluids determined by enzyme-linked immunosorbent assay (ELISA).

The standard ELISA technique was improved for the detection of antigalactocerebroside antibody in biological fluid. Mouse monoclonal antigalactocerebroside antibody was used to demonstrate specificity and sensitivity of the technique. After optimization of the assay, the usefulness of this measurement for the evaluation of patients with multiple sclerosis was assessed. The presence of antigalactocerebroside antibodies in the cerebrospinal fluid of 20 patients with multiple sclerosis, 10 with other neurological diseases and 10 normal individuals was determined. All the CSF samples from normal individuals were negative. In patients with multiple sclerosis 14 of the 20 samples had elevated levels of antigalactocerebroside antibody, whereas with other neurological diseases 5 out of 10 were positive. Antigalactocerebroside levels were lower in samples from patients during an acute relapse than in those from more chronic cases. These results indicate that the presence of antigalactocerebroside antibody in cerebrospinal fluid is not specific to MS but may reflect previous damage to myelin.

Blood-brain barrier damage restricts the reliability of quantitative formulae and isoelectric focusing in detecting intrathecally synthesized IgG.

The demonstration of intrathecally synthesized IgG constitutes one of the most important aids in the diagnosis of multiple sclerosis (MS). This can be done either by the application of empirical formulae or by analytical electrophoretic migration of IgG. However, all methods are influenced by the presence of blood-brain barrier (BBB) damage, as confirmed by the present study. We compared the results achieved by the application of 3 formulae (IgG index, intra-BBB IgG synthesis rate, IgG hyperbolic function) to those by isoelectric focusing (IEF) of unconcentrated cerebrospinal fluid (CSF). The most reliable method to detect intrathecal IgG production was IEF followed by specific immunofixation; even so, this method was subjected to pitfalls due to BBB damage. All formulae gave incorrect and misleading results, especially in case of BBB damage. Therefore, this limiting factor should be considered when formulae are used for clinical purposes.