Multiple sclerosis patients show an increased spontaneous activity of their peripheral blood monocytes as measured by chemiluminescence

Natural killer cell number and activity in multiple sclerosis

Natural killer (NK) cell percentage among cells appearing in lymphocytic flow-cytometric gate, and their concentration per unit volume of peripheral blood, as well as NK-cell in vitro activity, were determined in 45 patients with multiple sclerosis (MS, 34 with definite and 11 with probable diagnosis). Two age- and sex-matched control groups consisted of 27 healthy individuals and 19 individuals with other neurological diseases, respectively. NK cells were identified on the basis of their reaction with monoclonal antibody NKH-1, and NK-activity on the basis of their spontaneous killing of K-562 erythroleukemia target cells with mononuclear cells from peripheral blood. MS patients were analyzed in regard to the phase (active, stable inactive, stable progressive) and course (remittent, remittent-progressive, progressive) of the disease. In general, MS patients tended to have both lower number and activity of natural killer cells than either of the two control groups. A statistically significant decrease was found for the concentration of NKH-1+ cells in the blood of all MS patients, for the number of lymphocytes in the blood of patients with remittent course of the disease, and for the number of NKH-1+ cells in the blood of patients with progressive course of the disease. It appeared that more profound defects were associated with the progression of the disease; NK-cell number always appeared more affected than NK-cell activity. In MS patients, NK-cell activity correlated significantly with NK-cell percentages among lymphocytes but poorly with the concentration of NKH-1+ cells in the blood. In healthy controls, neither of the two correlations was significant.(ABSTRACT TRUNCATED AT 250 WORDS)

In vitro study of mediators of inflammation in multiple sclerosis

Prostaglandin E levels have previously been demonstrated to be elevated in multiple sclerosis (MS). We have further investigated other products of activated macrophages related to inflammation. We report here on prostaglandin E and its relationship to interleukin 1, tumor necrosis factor, and leukotriene B4 produced by macrophages from blood and cerebrospinal fluid of MS patients and controls in vitro. Interleukin and tumor necrosis factor are elevated significantly after stimulation in MS, while leukotriene B4 production by blood macrophages is depressed compared to other neurological disease and normal healthy controls. In 40% of MS patients tested, peripheral blood macrophages spontaneously produced elevated levels of interleukin 1. All mediators of inflammation are produced in increased amounts by MS cerebrospinal fluid leukocytes after stimulation. Macrophages from MS blood are not as sensitive as controls to nonsteroidal inhibitors specific for lipoxygenase or cyclo-oxygenase pathways. Positive correlations of elevations in production of such mediators of inflammation as prostaglandin E, interleukin 1, and tumor necrosis factor in MS were significant. Elevated production of these mediators in combination with insensitivity to inhibitors of inflammation suggests a role for activated macrophages in the demyelination process.

MS: a localized immune disease of the central nervous system

The precise role of T cells in multiple sclerosis (MS) remains to be defined. No MS-specific antigen has been found. The autoimmune hypothesis for MS rests on immune changes seen in the spinal fluid and brain and on the demonstration, in an experimental animal model, that T cells raised to myelin basic protein transfer demyelination. In this review, Virginia Calder and colleagues focus on recent studies suggesting that in MS, the initial T-cell response occurs within the central nervous system and that the blood poorly reflects this immune activity. This contrasts with the animal model, experimental allergic encephalomyelitis, where the initial immune response is peripheral.

Monocyte and polymorphonuclear leukocyte toxic oxygen metabolite production in multiple sclerosis

Lipid-laden macrophages, which are predominantly derived from blood monocytes, are present at sites of active multiple sclerosis demyelination and are assumed to be involved in the demyelinating process. These inflammatory cells produce a variety of toxic oxygen metabolites which can mediate host tissue destruction. We measured production of two oxygen metabolites by monocytes and polymorphonuclear leukocytes in MS patients and controls. Stimulated monocytes produced significantly more hydrogen peroxide, superoxide, and chemiluminescence in the MS group than controls. The polymorphonuclear leukocyte, an inflammatory cell that appears to contribute little to MS demyelination, did not demonstrate increased production of toxic oxygen metabolites in the MS patients as compared to controls. These results suggest that blood monocytes in MS patients are primed to produce increased amounts of cytotoxic oxygen metabolites when exposed to inflammatory stimuli.

NK activity and NK-like non-specific cytolysis after PPD, rubella and measles antigen stimulation in multiple sclerosis

Blood samples were collected from 14 pairs of multiple sclerosis (MS) patients and from age- and sex-matched healthy controls. The cytotoxic activity of peripheral blood mononuclear cells was tested against the K562 cell line on the day of collection and again after 3 days in vitro culture with medium or with purified protein derivative of tuberculin (PPD), inactivated rubella virus or inactivated measles virus antigen. Lymphocytes from MS patients had a lower spontaneous cytotoxic activity compared to the controls both on the day of collection (P less than 0.025) and after 3 days in culture with medium alone (P less than 0.025). The activity decreased during in vitro culture in both groups, but the decrease was greater among MS patients (P less than 0.05). In cultures with antigens, a strong increase of NK-like cell-mediated cytolysis (NK-like CMC) was noted especially in cultures stimulated with PPD. There were no significant differences in the increase of the activity among MS patients and control subjects. A significant correlation between the increase of NK-like CMC and the lymphocyte blast transformation response induced by each antigen was found.

Indications of the occurrence of inflammatory reactions in the clinical improvement phase in multiple sclerosis patients

In patients with multiple sclerosis (MS) the spontaneous burst activity (BA) of peripheral blood mononuclear cells was related to the clinical course of the disease. In five patients clinical improvement was found while the BA was significantly increased (more than 300% of the controls). During the appearance of new or deteriorating signs and in the period without clinical changes, the BA was not at all or not markedly increased. In two patients without clinical improvement the BA did not reach levels above 300% of the controls. Our findings suggest that inflammatory reactions represented by the BA occur in the phase of clinical improvement. Since burst-stimulating activity was found in the serum of MS patients, cytokines produced by activated immuno-competent cells are assumed to cause the increased BA. A possible role of prednisone and ACTH on the BA of peripheral mononuclear leucocytes is discussed.

Correlation of the chemiluminescence-activity of peripheral blood monocytes with CSF parameters of inflammation and the clinical course of patients with lymphocytic meningoencephalitis

The chemiluminescence-activity (CL-A) of peripheral blood monocytes (MO) was measured in eight patients with lymphocytic meningitis or meningoencephalitis and compared to CSF parameters and the clinical course. The initial maximum CL-A was around four times above the control and decreased to normal values within approximately 20 days. Poor correlations were found when the CL-A was compared to CSF parameters in the total group of patients. With regard to the CSF parameters in individual patients the CL-A was closely related to the cell count, to a lesser degree to the protein content, but not to the IgG content. Finally, a very good correlation of the CL-A was found with the clinical course in individual patients. This preliminary data suggests the clinical usefulness of CL-measurements and supports the conception that the CL-A predominantly reflects the specific cellular phase of inflammation, which is dominated by T cells.