Value of central nervous system IgG daily synthesis determination in the diagnosis of multiple sclerosis

Devic's neuromyelitis optica: a clinicopathological study of 8 patients

We report the clinical, imaging, and laboratory features of 8 patients with Devic's neuromyelitis optica. All patients had severe myelopathy and optic neuritis. In no patient was the brain, the brainstem, or the cerebellum affected, even after several years of disease. Various immunosuppressive treatments failed to benefit the patients, 5 of whom died. Autopsies of these 5 patients demonstrated a severe necrotizing myelopathy with thickening of blood vessel walls and no lymphocyte infiltrates. In the appropriate clinical setting, the lack of white matter abnormalities demonstrated by magnetic resonance imaging of the head facilitates the recognition of Devic's syndrome during life. Inasmuch as Devic's myelopathy is necrotizing, rather than demyelinating, the prognosis of this syndrome is poor.

Multiple sclerosis: neuroimmunologic puzzle

Multiple sclerosis (MS), a chronic disease with a relapsing and remitting course, is the most common neuroimmunologic condition in the United States. The hallmarks of the disease are focal demyelination and inflammation within the central nervous system (CNS). Because histopathologic changes can be identified only at autopsy, attention has been directed at formulating standardized clinical and laboratory procedures to aid in MS diagnosis. Currently, there are no MS-specific clinical or laboratory tests, but detection of abnormality in cerebrospinal fluid (CSF) IgG is important in supporting clinical evidence of disease. A number of other immunologic abnormalities have been recognized in MS, including the presence of T- and B-lymphocytes within the CNS and alterations in circulating suppressor T-lymphocytes. These findings have been interpreted as indicating disturbed immunoregulation associated with a chronic autoimmune response within the CNS. Evidence implicates viral infection in the pathogenesis of MS but the cause of the disease remains unknown.

Myelin basic protein and demyelinating diseases

Myelin basic protein (MBP) is a major protein component of myelin sheath. Primarily because of its ability to induce experimental allergic encephalomyelitis (EAE) in animals, this protein has been considered to play an important role in the pathogenesis of multiple sclerosis (MS), which is one of the most common demyelinating diseases. Its precise measurement in the cerebrospinal fluid (CSF) has been uncommonly difficult, mainly due to immunoheterogeneity of MBP or MBP-like material. More recently, highly sensitive radioimmunoassay techniques utilizing well-characterized antisera have been developed that facilitated its use in the management of MS. The clinical course of MS is highly variable, and the disease is characterized by periods of remission and relapses. Many studies have demonstrated the release of MBP during relapses and elevated levels of MBP in the CSF can be detected if lumbar puncture is performed within 7 days of the onset of neurologic symptoms suggestive of MS. However, the presence of MBP is not an absolute indicator of MS, as elevated MBP levels are also frequently observed in other demyelinating diseases.

Albumin and immunoglobulin-G in the cerebrospinal fluid and the diagnosis of multiple sclerosis

Multiple sclerosis (MS) remains a diagnosis based mainly on clinical criteria. Definitive diagnostic tests are, despite numerous attempts, not available. However, some laboratory tests like electrophoresis of the cerebrospinal fluid proteins or the determination of immunoglobulin G in cerebrospinal fluid have proved useful in increasing the probability of MS. This paper describes how these laboratory tests have to be interpreted in relation to pathophysiological phenomena and how they correlate with each other. The electrophoresis of CSF proteins and the diagnostic quotients (Ralb and CSF-IgG-index) are valuable aids to the clinician. It especially can substantiate the diagnosis MS. The magnitude of the index cannot be correlated with the clinical stage of MS. The usefulness of these tests in terms of a possible gain of information in the diagnostic process is discussed.

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

We hold that the intra-blood-brain-barrier (BBB) IgG synthesis (SYN) rate can be quantitated reliably and validly. Although several formulas distinguish patients with multiple sclerosis from normal controls equally well, only the SYN rate formula has been validated in humans using isotopic tracer techniques. Our formula for the IgG SYN rate is reducible to Reiber's formula; therefore, both can be used to quantify the IgG SYN rate in a manner not possible using the IgG index. Although our SYN rate formula has been validated for a modest range of BBB abnormalities (cerebrospinal fluid/serum albumin ratios), there is evidence to suggest that it may be used even in patients having severe BBB damage. We question the acceptance of unique cerebrospinal fluid IgG bands as indisputable evidence of intra-BBB IgG SYN in the presence of a modest to severely damaged BBB. Finally, the utility of quantitation and detection of intra-BBB IgG SYN by standardized methods in a group of asymptomatic, normal individuals compared with a group of patients with clinical definite multiple sclerosis is presented.

The current status of multiple sclerosis intra-blood-brain-barrier IgG synthesis

The status of the central nervous system as an immunologic organ synthesizing IgG in several neurological diseases has been established convincingly in the past two decades. The measurement of intra-BBB IgG synthesis has been accomplished. It has been demonstrated that this synthesis is a potential marker for an abnormal immunologic process within the CNS which if manipulated may be a quantifiable aspect of disease modulation. Modulation of intra-BBB IgG synthesis is feasible, but there is no evidence yet that modulation of this synthesis is an index of effective disease control in MS. Only ACTH and corticosteroids lead to a significant and lasting depression of intra-BBB IgG synthesis, even though clonal eradication is not achieved. Based on our immunopharmacologic studies in MS we have proposed an immunokinetic model. The qualitative analysis of the specificity of IgG synthesized intra-BBB in MS has not led to the etiology of MS, but utilization of quantitative methods may. Questions raised by this review with suggested experiments to advance further our understanding of intra-BBB IgG synthesis as it relates to the etiopathogenesis of MS are included.

On the diagnostic value of different CSF investigations in multiple sclerosis

An assessment was made of the relative values of different methods of calculating intrathecal IgG synthesis in multiple sclerosis. In 60 patients with definite, probable or possible multiple sclerosis the IgG/protein and IgG/albumin ratios, the IgG index, the Tourtellotte formula and the graphic evaluation according to Reiber were applied. All the patients had oligoclonal IgG in the CSF. Reiber's method was the most sensitive, yielding 66% of abnormal findings. Only the cell count showed significant differences between active and inactive stages. There was a correlation between the cell count and the daily rate of intrathecal IgG synthesis and between the latter and the number of oligoclonal bands in CSF, but none of these parameters correlated with duration of disease or the number of previous bouts.