IgG ratios and oligoclonal IgG in multiple sclerosis and other neurological disorders

Oligoclonal banding of IgG in CSF, blood-brain barrier function, and MRI findings in patients with sarcoidosis, systemic lupus erythematosus, and Behçet's disease involving the nervous system

A retrospective study of CSF and serum analysis from a total of 43 patients with sarcoidosis, 20 with systemic lupus erythematosus, and 12 with Behçet's disease with neurological involvement found local synthesis of oligoclonal IgG using isoelectric focusing and immunoblotting in 51%, 25%, and 8% respectively at some stage in their disease. Blood-brain barrier breakdown, when assessed with an albumin ratio found 47% of patients with sarcoidosis, 30% of those with systemic lupus erythematosus, and 42% of patients with Behçet's disease exhibiting abnormal barrier function at some time. Serial CSF analysis showed that clinical relapses were associated with worsening barrier function and in some patients the development of local oligoclonal IgG synthesis; conversely steroid treatment led to a statistically significant improvement in barrier function, and in two patients a loss of oligoclonal IgG bands. A higher proportion of patients had MRI abnormalities than oligoclonal IgG or blood-brain barrier breakdown, MRI being abnormal in 16 of 19 patients with sarcoidosis, three of four patients with systemic lupus erythematosus, and seven of nine patients with Behçet's disease, although this may have been due to temporal factors. In the differential diagnosis of chronic neurological disorders, locally synthesised oligoclonal IgG cannot distinguish between diseases, but the loss of bands seen in two patients contrasts with what is seen in multiple sclerosis, and thus may be a useful diagnostic clue.

The effect of large-dose prednisone therapy on IgG subclasses in multiple sclerosis

The effect of large-dose prednisone therapy (3960 mg over 56 days) on IgG subclasses in the cerebrospinal fluid and sera, as well as on their intrathecal synthesis, was studied in 15 patients with clinically definite multiple sclerosis. The concentration of IgG subclasses was measured using ELISA with monoclonal antibodies against human IgG subclasses, secondary biotinylated antibody and avidin-biotin-peroxidase complex. There was a decrease of IgG1, IgG3 and IgG4 in the CSF of MS patients after the treatment, but the differences did not reach statistical significance. The IgG index was decreased about 34% (p < 0.01) after the therapy. This was mainly due to diminished synthesis of IgG1 and IgG3. The significance of IgG subclasses in the pathogenesis of MS is discussed.

A clinico-pathoanatomical study of multiple sclerosis diagnosis

The diagnosis of multiple sclerosis (MS) is clinical and verifiable at post mortem. Neuropathological examination of 518 consecutive patients with clinically definite MS revealed a correct diagnosis in 485 cases (94%). Clinical diagnosis had been established by a neurologist in all cases. Erroneous diagnosis included a variety of other neurological disorders. Also investigated was a randomly selected series of 33 patients with a clinical diagnosis of probable MS: post mortem confirmation of MS was obtained in circa 66%, for the remainder the error pattern was similar to the above. Clinical diagnosis of definite MS was correct in 94% cases. Laboratory tests and examinations have not radically improved diagnosis. Neuropathological examination may occasionally fail to demonstrate MS plaques if the optic nerves are not investigated.

Oligoclonal and polyclonal synthesis of IgG in the central nervous system: an isoelectric focusing study

The IgG pattern in isoelectric focusing (IEF) has been studied in 90 paired samples of cerebrospinal fluid (CSF) and sera obtained from patients in which intrathecal synthesis of IgG without barrier damage was detectable by Reiber's graph and formula (1980, J. Neurol. 224, 89). Thirty patients were affected by multiple sclerosis (MS), 30 by other inflammatory nervous diseases (OID), and 30 by noninflammatory nervous diseases (NID). At IEF two distinct pathological patterns of CSF IgG were detected: oligoclonal bands (OB), prevailing in the MS group (83% of cases), and a "polyclonal"--i.e., diffuse, uniform--increase of CSF IgG, prevailing in the NID (90%). The OID group was intermediate, 57% of cases with OB and 43% with polyclonal CSF IgG patterns. Overall, only 45 of 90 patients synthesizing IgG in the CNS had CSF OB. This suggests that the CNS immune response can imply either the synthesis of IgG of restricted heterogeneity (i.e., OB) or a polyclonal IgG synthesis, giving in IEF a serum-like pattern to the CSF.

Suspected and clinically definite multiple sclerosis: the relationship between CSF immunoglobulins and clinical course

CSF immunoglobulins were examined in 103 patients with clinically definite multiple sclerosis, 106 patients with either suspected or progressive possible multiple sclerosis and 72 patients with other neurological diseases. Raised CSF IgG index and oligoclonal banding were found in 71% and 75% of clinically definite multiple sclerosis patients respectively and both tests were abnormal in 11% of patients with other neurological diseases. The CSF IgG index and the presence of oligoclonal IgG did not relate to the severity or duration of established disease in these patients. In patients with suspected and progressive possible multiple sclerosis, both a raised IgG index and the presence of oligoclonal banding were found significantly more frequently than in the OND group. Abnormalities of these parameters were significantly correlated with the presence of an abnormal evoked response in these patients (chi 2 = 10.16 p less than 0.01). When 47 patients with suspected multiple sclerosis were studied prospectively the presence of oligoclonal banding at presentation was associated with development of further disease activity.

Local and systemic immune response in multiple sclerosis: analysis of CSF inflammatory changes and peripheral blood T-cell subsets

In order to investigate the significance of the immune response in multiple sclerosis (MS), we have compared changes in peripheral blood T-cell subsets to the cellular and humoral responses in the cerebrospinal fluid. Using monoclonal antibodies defining the Leu-3a and Leu-2a phenotypes, we found a highly significant (2P less than 0.001) increase of the Leu-3a/Leu-2a cell ratio in peripheral blood T-cells of multiple sclerosis patients with disease activity (acute phase or progressive form), while patients with inactive disease did not differ from controls. No characteristic alterations in the CSF inflammatory response could be correlated with changes in T-cell subsets in the peripheral blood. There was no significant difference in the cerebrospinal fluid cell count or the mean IgG index between patients with high or low Leu-3a/Leu-2a cell ratios. We conclude that increased CSF IgG synthesis in MS is probably not a direct consequence of the apparent reduction of Leu-2a positive cells in the peripheral blood. Thus the biological significance of the change in immunoregulatory cells in the blood of multiple sclerosis patients remains unknown.