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.

Routine detection of IgG oligoclonal bands and free light chains patterns by means of agarose isoelectric focusing and avidin-biotin-peroxidase complex staining in multiple sclerosis unconcentrated cerebrospinal fluid

We demonstrate the possibility of a complete routine study on unconcentrated CSF from patients with Multiple Sclerosis (MS) using agarose isoelectric focusing (AIEF) followed by avidin-biotin-peroxidase complex staining to detect IgG oligoclonal bands (OB) and free light chains (FLC). The oligoclonal IgG patterns were demonstrated by loading the gel with only 225 ng of IgG. All the specimens were then diluted to a final concentration of 15 ng/L. The method also proved to be very sensitive for the detection of FLC patterns that were an interesting feature of the CSF from MS patients in active phases of the disease. The routine detection of abnormal IgG components synthetized inside the Central Nervous System (CNS) is really improved by the application of this method.

Anion-exchange chromatography of normal and monoclonal serum immunoglobulins

Anion-exchange chromatography was used for separations of the three main immunoglobulin classes in human sera. The material included normal sera as well as sera with monoclonal immunoglobulin components. The Mono Q anion-exchange column was eluted with a stepwise gradient formed by 0.05 and 0.3 M phosphate buffers. No indications of negative effects on the sample components were observed and the protein recovery was high. A fast, easy and reproducible separation of immunoglobulins G, A and M was obtained.

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.

Nonfamilial intestinal polyposis and brain tumor in a 5-year-old girl

A 5-year-old girl with glioblastoma multiforme and simultaneous adenocarcinoma in one of multiple colonic polyps is the youngest reported case of Turcot's syndrome. A literature survey and a classification based on family pedigree and pattern of inheritance are proposed.

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.

Small-column chromatofocusing of cerebrospinal fluid and serum immunoglobulin G

Chromatofocusing performed by the Pharmacia fast protein liquid chromatographic system equipped with a specially designed small column was applied for examinations of submilligram quantities of cerebrospinal fluid and serum immunoglobulin G. The separations were based on a pH gradient between 9.5 and 6.0. Mono- or oligoclonal immunoglobulin G components having pI values within the optimal working range of the gradient were easily identified and the findings differed clearly from those of normal immunoglobulin G. The capacity to detect abnormal immunoglobulin G components compared well with previous experiences from the commercially available Mono P column. The small column offers advantages by having a shorter separation time, a decreased dilution of sample in the eluate and a lower consumption of start and eluent buffers.

Two-dimensional electrophoresis of cerebrospinal fluid proteins in normal and pathological conditions

The two-dimensional polyacrylamide gel electrophoresis technique has been adapted for the analysis of human cerebrospinal fluid proteins. Proteins were detected by Coomassie brilliant blue stain and/or by silver stain. Highly reproducible protein patterns were obtained. We analyzed ten normal CSF specimens, thirty pathological CSF specimens and the corresponding sera. We mapped the protein patterns observed by examination of serum/CSF differences and by immunofixation. Preliminary observations on the changes in protein patterns in CSF specimens from patients with neurological disorders are reported.

The cerebrospinal fluid transferrin/tau proteins. A study by two-dimensional polyacrylamide gel electrophoresis (2D) and agarose isoelectrofocusing (IEF) followed by double-antibody peroxidase labeling and avidin-biotin amplification

The cerebrospinal fluid (CSF) transferrin/Tau proteins were studied by two-dimensional polyacrylamide gel electrophoresis (2D) followed by immunoblotting and by agarose isoelectrofocusing (IEF), and subsequent double immunofixation, peroxidase staining and Avidin-Biotin Complex (ABC) amplification. The pattern of the Tau protein was similar but not equal to that of the transferrin (Tf). When a genetic variant of Tf was present in the serum, the same variant was also observed in the corresponding CSF Tf and in the Tau fraction. After neuraminidase treatment, both serum and CSF Tf moved to the Tau position on IEF and 2D. On 2D, no desialized precursors of the Tau proteins were detected, whereas the Tf precursors were always detected. No synthesis of the Tau globulin in the brain can, therefore, be inferred. In CSF not treated with neuraminidase, Tf is the only sialoglycoprotein clearly desialized, showing that the Tau fraction cannot be generated by neuraminidase action at CSF level. In fact, the treatment of serum and CSF proteins with neuraminidase produced a clear shift in the isoelectric mobility of all sialoglycoproteins. We clearly demonstrate that the Tau globulin is the result of neuraminidase activity not located in the CSF compartment. We suggest that Tf could be desialized by the action of neuraminidase at the brain level and then be "washed" into the CSF. Brain utilization of Tf, meeting the brain iron requirement, seems likely.

Examinations of cerebrospinal fluid immunoglobulin G by chromatofocusing

IgG components in the CSF and paired sera were examined by chromatofocusing. The separations were performed using the FPLC system with a mono P column and were based on a pH gradient between 9.5 and 6.0. A total amount of 0.1 mg IgG was applied to the column. All samples with oligoclonal IgG were easily identified and the findings differed clearly from those of normal IgG. The sensitivity, resolution capacity and relatively fast as well as easy performance make chromatofocusing a promising tool for investigations of IgG in the CSF.

Methods for chromatofocusing of cerebrospinal fluid and serum immunoglobulin G

Chromatofocusing programs were designed for separations of submilligram amounts of normal and abnormal human IgG. The Pharmacia FPLC system, equipped with a Mono P column or a specially designed, small column was used for the separations. Normal IgG in paired cerebrospinal fluid and serum samples, paired samples from patients with intrathecal immunoglobulin G synthesis, as well as sera with IgG M components were examined. Abnormal immunoglobulin G components, especially those with pI values greater than ca. 7.0 pH units, were easily identified.

Pancreatic carcinoma in childhood: case report of long survival and review of the literature

A case of exocrine pancreatic carcinoma in a 14-year-old boy is reported. The primary site of the tumor was in the head of the pancreas, and pathologic features were consistent with an anaplastic lesion. Ten years after curative resection the patient is still living. Extensive review of the literature has revealed 27 other cases of pancreatic carcinoma in children under 15 years of age. Aggressive surgical treatment is emphasized by the long survival observed in four patients who underwent radical operations and by this case report.