Lysosomal hydrolases in CSF of patients with multiple sclerosis

A thermodynamic study of beta-N-acetylhexosaminidase enzyme heterogeneity in cerebrospinal fluid from patients with multiple sclerosis

BACKGROUND

ss-N-acetylhexosaminidase (Hex) is a lysosomal hydrolase, whose determination in the cerebrospinal fluid (CSF) of patients with multiple sclerosis (MS) has provided discordant results.

METHODS

Total Hex and its isoenzymes Hex A and Hex B were determined using a thermodynamic procedure in the CSF of 27 patients with definitive MS, 8 with possible MS, 9 with meningitis, 14 with other neurological diseases, and in 10 controls without any neurological disease.

RESULTS

In the group of patients with definitive MS, the total Hex and Hex A were significantly higher than in the control group (p<0.001), with a possible association of greater enzymatic activities with the presence of oligoclonal bands and recent relapse; however, an overlap was detected for the activities of total Hex and its isoenzymes between the groups of patients with different neurological diseases. A significant correlation was obtained for neuron-specific enolase (NSE) with total Hex and Hex A and Hex B isoenzymes (p<0.001); however, in the partial correlation statistical significance was only obtained between NSE and Hex A (p<0.001) which is the most abundant Hex isoenzyme in the brain.

CONCLUSIONS

Although the inflammatory process in MS mainly takes place in the perivascular zone, with little activity in the cerebral parenchyma, the significant increase of NSE and Hex A isoenzyme in CSF reveals a neuronal damage. The disease status may have effect on the CSF Hex activity.

Lysosomal hydrolases in cerebrospinal fluid of multiple sclerosis patients. A follow-up study

The change in activity of lysosomal hydrolases in the brain tissue of patients with demyelinating disease has been suggested to reflect the demyelination process. In this study we measured neutral proteinase (NP), acid proteinase (AP), and beta-glucuronidase (BG) activities in CSF of 32 patients with multiple sclerosis (MS) (remitting, remitting and relapsing, or chronic progressive course of the disease), 62 controls, and 4 patients with chronic inflammatory disease of central nervous system (ID). Samples from MS patients were taken at different clinical conditions of the disease during the 22-month follow-up. Elevated NP activity was found in patients with relapsing course of MS and also in patients with ID (P less than 0.05). NP activity correlated with the number of leucocytes in CSF of both MS (P less than 0.005, r = 0.50) and control (P less than 0.05, r = 0.21) patients. AP activity decreased in the MS group, especially in patients with remitting or remitting and relapsing courses of the disease (P less than 0.05), but even more in patients with ID (P less than 0.01). During the follow-up the increase in NP activity seemed to be associated with the clinical relapses of MS patients. Other enzymes did not fluctuate with the disease. This study suggests that the change in activity of lysosomal hydrolases is not specific for MS. The increase in NP activity in CSF is associated with clinical relapse of individual MS patients during the follow-up and may indicate immunological activation of the demyelination process in the brain. The large intra- and interindividual variation in enzyme activities in the CSF, however, makes the use of these enzymes difficult for diagnosis of MS and follow-up of MS activity.

Some immunochemical aspects of HD-brain extracts

Cortical gray matter extracts of patients with Huntington's disease (HD) were investigated for their antigenic properties with serum from both HD patients and normal controls. Both patient and control sera appeared to precipitate two closely migrating proteins of MW 14.4K and 15K, which could be found in normal brain preparations only at much lower concentrations, as precipitation of these proteins could not effectively be inhibited by a concentrated "cold" normal brain extract. It is shown that these molecules are hemoglobin and lysozyme, which to a certain extent bind specifically to the immunoprecipitates. The increase in hemoglobin level, which amounted to about 20% of the total protein concentration, might be explained either as an epiphenomenon to the disease process, in which degeneration of the HD brain leads to a relative increase of the arterial and capillary blood system, or as an artifact due to the preparation of the brain extracts. The lysozomal increase is a feature shared by many degenerative neurological diseases. No measurable humoral reactivity could be demonstrated in patient sera against a presumed mutant HD-specific protein. In addition, using antisera to the viral structural protein p30, no evidence could be found for the involvement of a retrovirus in HD.

Lymphocyte subpopulations in the cerebrospinal fluid and peripheral blood in multiple sclerosis

Subpopulations of lymphocytes in the CSF and peripheral blood were studied in 30 patients with MS, 16 with other neurological diseases (OND) and 15 control subjects without any neurological abnormalities. In patients with relapse of MS, the absolute numbers of total lymphocytes, alpha-naphthyl acid esterase (ANAE) positive, E-rosette forming and bearing the "avid" FcIgG receptor lymphocytes were significantly increased in the CSF as compared with stable or slowly progressive MS patients, patients with other OND and control subjects. The relative number of ANAE-positive cells was higher, and "avid"FcIgG receptor bearing cells lower in the CSF of all patients with MS than in the two other groups. The significance of the finding is unclear. The imbalance between lymphocyte subpopulations may reflect a primary defect in MS, or may be secondary, due to the presence of circulating immune complexes. In peripheral blood no substantial differences in lymphocyte behavior were observed between MS patients and other groups.