Detection of IgG oligoclonal bands in unconcentrated CSF by means of agarose isoelectric focusing, double immunofixation peroxidase staining and avidin-biotin amplification

A longitudinal study on IL-2, sIL-2R, IL-4 and IFN-gamma in multiple sclerosis CSF and serum

The cerebrospinal fluid (CSF) and serum levels of interleukin-2 (IL-2), soluble IL-2 receptor (sIL-2R), interleukin-4 (IL-4) and interferon-gamma (IFN-gamma) were longitudinally investigated in 20 multiple sclerosis (MS) patients. There were 80 paired CSF and serum samples (range 2-8 per patient) covering a 1-5 year (mean 2.5 year) period. Increased levels of IL-2 and sIL-2R were found in 56 and 71%, respectively, of MS sera. In all patients, one or several sera (totally 89%) exhibited values above the normal range for either one of the components or both. The occurrence of IL-2 or sIL-2R positive CSF specimens was much lower, 15 and 9%, respectively. Only 3 MS sera (from one patient) had clearly detectable IL-4 and no CSF samples were definitely positive. IFN-gamma was undetectable in all serum and CSF specimens. No correlations were found between the immunological parameters and the clinical disease activity. The cytokine patterns in MS give strong support for the presence of a systemic T-cell activation. Furthermore, the data argue for a predominant activation of an IL-2- and sIL-2R-producing but not IL-4-producing T-helper (Th) lymphocyte subpopulation, Th1/CD4 + CD45R + cells.

Immunoglobulin light chain patterns in the cerebrospinal fluid. A study with special reference to the occurrence of free light chains in cerebrospinal fluid with and without oligoclonal immunoglobulin G

The immunoglobulin light chain patterns were studied in paired cerebrospinal fluid (CSF) and serum samples from 30 controls, 70 multiple sclerosis (MS) patients, 18 subjects with other inflammatory neurological diseases and 17 patients with other non-inflammatory neurological disorders. In MS, all CSF samples examined by two-dimensional gel electrophoresis exhibited clonally restricted light chain components. Isoelectric focusing and immunoblotting detected free light chains in around 90% of CSF samples from patients with MS or other inflammatory diseases. These components were clonally restricted, appeared in both mono- and dimeric forms and occurred in CSF samples with as well as without oligoclonal immunoglobulin G bands. Generally, the positive CSF samples contained kappa as well as lambda free lights chains. Such components were not detected in the sera, nor in the CSF samples from controls or patients with non-inflammatory diseases.

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.

Immune activation in multiple sclerosis: study of IL-2, sIL-2R, and gamma-IFN levels in serum and cerebrospinal fluid

Serum and cerebrospinal fluid (CSF) levels of interleukin-2 (IL-2), soluble IL-2 receptor (sIL-2R), and gamma-interferon (gamma-IFN) were measured in multiple sclerosis (MS) patients, human immunodeficiency virus type 1 (HIV-1)-infected patients and normal controls (NC). Increased levels of both IL-2 and sIL-2R were found in MS serum. Moreover, 11 of 50 MS patients showed detectable levels of IL-2 in the CSF. HIV-1-infected patients had increased levels of sIL-2R in serum and, less frequently, in the CSF. gamma-IFN was never detected in serum and CSF of all the patients studied. These findings confirm preliminary reports, further stress a systemic T-cell activation in MS, and support the hypothesis that an immunologic disorder exists in such patients.

Human immunodeficiency virus type 1 (HIV-1) infection of the central nervous system: an evaluation of cytokines in cerebrospinal fluid

Cytokines play an important role not only for initiation of immune reactivity but also for development of tissue injury. Of 38 patients infected with human immunodeficiency virus type 1 (HIV-1) interleukin-1 beta (IL-1 beta) and interleukin-6 (IL-6) were identified in cerebrospinal fluid (CSF) of 22 (58%) and 16 (42%) patients, respectively. Among the IL-1 beta- and IL-6-positive CSF were eight of 15 HIV-1 patients with no clinical signs of central nervous system involvement and four of five patients with acquired immunodeficiency syndrome (AIDS) dementia complex. The presence of IL-6 was often associated with IL-1 beta and soluble interleukin-2 receptor in CSF as well as with intrathecal IgG synthesis. In none of the CSF samples tumor necrosis factor-alpha or interleukin-2 was detected.

Tumor necrosis factor alpha (TNF alpha) and neurological diseases. Failure in detecting TNF alpha in the cerebrospinal fluid from patients with multiple sclerosis, AIDS dementia complex, and brain tumours

The presence of tumor necrosis factor alpha (TNF alpha)/cachectin was investigated in 180 paired cerebrospinal fluid (CSF) and serum samples from patients with neurological diseases, and in five paired CSF and serum samples of Macaca cynomolgus monkeys with acute monophasic experimental autoimmune encephalomyelitis (AMEAE). TNF alpha was never detected in human CSF, even when an extensive demyelination was documented (active multiple sclerosis, acquired immunodeficiency syndrome (AIDS) dementia complex). Only one Macaca with AMEAE had detectable levels of TNF alpha in CSF but not in serum, suggesting an intrathecal synthesis of this cytokine in AMEAE.

Interleukin-2 levels in serum and cerebrospinal fluid of multiple sclerosis patients

A sensitive enzyme-linked immunosorbent assay method was employed to measure interleukin-2 (IL-2) levels in cerebrospinal fluid (CSF) and sera from 30 patients with multiple sclerosis (MS) and 8 patients with other neurological diseases. Detectable levels of IL-2 were found in 6 sera and 9 CSF samples of 21 patients with acute relapse of MS. However, only 3 patients showed measurable IL-2 both in CSF and in serum. IL-2 was not detected in specimens from 9 patients with chronic-progressive MS, whereas high levels were found in 2 CSF samples from patients with aseptic meningitis. Our data suggest that systemic activation of a T-cell population is present in some MS patients; moreover, an active immune mechanism involving IL-2 production takes place within the central nervous system.

Central nervous system involvement in HIV infection

Central nervous system (CNS) involvement occurs frequently in patients with the acquired immunodeficiency syndrome (AIDS), but at present only a few reports have addressed the analysis of intrathecal IgG synthesis in human immunodeficiency virus (HIV)-seropositive patients with no signs of HIV-related neurologic syndromes. In this study, intrathecal IgG synthesis was investigated using several techniques in patients with different stages of HIV infection and then correlated with the state of the blood-brain barrier. Almost all patients had specific anti-HIV IgG synthesis within the CNS, suggesting the presence of HIV in the brain. These findings further stress that direct CNS infection occurs early in the course of systemic virus spread.

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.

Free light chains in the CSF in multiple sclerosis

The presence of free light chains (FLC) was investigated in 32 patients with clinically definite or laboratory supported definite multiple sclerosis (MS), 2 patients with neurosyphilis and 10 normal controls. The detection of FLC in unconcentrated cerebrospinal fluid (CSF) was performed by means of agarose isoelectric focusing, followed by transfer of proteins to nitrocellulose membranes, double immunofixation, avidin-biotin amplification and peroxidase staining. Bands due to FLC were clearly demonstrated in the CSF of 28 MS patients; 3 of them showed only kappa FLC, 10 only lambda FLC, while 15 had both kappa and lambda FLC. The CSF of 4 MS patients was FLC negative. In both cases of neurosyphilis FLC bands were observed. FLC were never found in normal CSF. Among the indexes of intrathecal immunological activity (IgG oligoclonal bands, FLC, IgG index, intra-blood-brain barrier IgG synthesis rate, pleocytosis) the FLC proved to be the second most frequent abnormality in MS CSF, the presence of IgG oligoclonal bands being the first. In one MS case an FLC band was found, while all the other indexes of intrathecal IgG production were negative. A high correlation was found between an elevated number of FLC and pleocytosis. The presence of FLC in MS CSF seems to indicate a recent immunological stimulation leading to increased synthesis of FLC within the CNS.

A case of multiple sclerosis with an onset mimicking the Kleine-Levin syndrome

A 20 years old patient is described, who presented two episodes of day-time hypersomnia, orthostatic hypotension and psychotic behavior. Compulsive masturbation and abnormalities of the eating habits were also present. Both episodes cleared up spontaneously in about one week. From the clinical point of view of Kleine-Levin syndrome, was suspected. However a CSF examination showed IgG oligoclonal bands and an increased IgG index. A NMR showed multiple area of increased signal intensity, suggestive of a demyelinating disease. On these elements a final diagnosis of MS was made, in spite of a normal neurological examination. This case was compared to other cases of MS in which the disease begins with acute remitting psychiatric symptoms. However cases of MS with complex episodes as observed in our patient were not found in the Literature.

Search for HTLV-I and LAV/HTLV-III antibodies in serum and CSF of multiple sclerosis patients

In order to confirm the findings on the presence of antibodies against human T-lymphotropic retroviruses in subjects affected by multiple sclerosis we studied paired serum and CSF samples from 32 MS patients. Both ELISA and Western blot procedures were employed to detect antibodies against HTLV-I and LAV/HTLV-III antigens. Negative results were obtained in all samples examined, except one which was reactive to HTLV-I in ELISA but not in Western blot.