Giuseppe Meucci

High tumor necrosis factor-α in levels in cerebrospinal fluid of cobalamin-deficient patients

We studied 14 patients with neurological manifestations of subacute combined degeneration (SCD) and 40 control patients not cobalamin (Cbl)‐deficient. The cerebrospinal fluid (CSF) markers of Cbl deficiency (Cbl and total homocysteine [tHCYS] levels) and the CSF levels of tumor necrosis factor (TNF)‐α and epidermal growth factor (EGF) were measured. Significantly higher levels of tHCYS and TNF‐α, and significantly lower levels of Cbl and EGF were found in the SCD patients. In human CSF, as in human serum and the rat central nervous system, decreased Cbl concentrations are concomitant with an increase in TNF‐α and a decrease in EGF‐levels. Ann Neurol 2004;56:886–890

Lymphocyte subsets in multiple sclerosis A study with two-colour fluorescence analysis

Multiple sclerosis (MS) is postulated to be an immunopathologically mediated disease. This concept is supported by the finding of abnormally distributed peripheral blood T-cell subsets and a decreased T-suppressor function. Thirty-seven MS patients have been selected according to the criteria for definite MS. Fluorescein- or phycoerythrin-conjugated monoclonal antibodies have been used to define different lymphocyte subsets: CD4+, CD5+, CD8+, CD19+, CD38+, CD45RA+, CD4+CD45RA+, CD19+CD5+, CD8+CD38+. In relapsing-remitting (RR)-MS patients a significantly decreased percentage of CD19+ cells and in progressive MS patients a significantly increased percentage of CD19+CD5+ cells have been found. During a relapse in RR-MS, a significantly decreased percentage of CD4+CD45RA+ cells and a significantly increased percentage of CD8+CD38+ cells have been observed. Moreover, in RR-MS patients a significantly increased percentage of CD38+ cells and significantly high IgM amounts have been found. The increased percentage of CD19+CD5+ and CD38+ cells (together with high IgM levels) and the reduced percentage of CD4+CD45RA+ lymphocytes could be related to an activation of both cellular and humoral immune response in acute MS.

Laser nephelometric evaluation of albumin, IgG and α2-macroglobulin: applications to the study of alterations of the blood-brain barrier

Cerebrospinal fluid and serum levels of albumin, immunoglobulin G and alpha 2-macroglobulin were determined by laser nephelometer in various pathological conditions: Guillain-Barré syndrome amyotrophic lateral sclerosis, lumbar disc herniation. These proteins are different due to their molecular weight, spacial conformation, CSF and serum concentrations and their CSF/serum quotient reflects the status of the blood-brain barrier. In the subjects group comparisons, albumin quotient and IgG quotient show a significant differentiations. The linear regression of albumin quotient compared to alpha 2-macroglobulin quotient behaves differently in the individual groups. The protein CSF/serum quotients are helpful in distinguishing the causes of alterations in the blood-brain barrier.

Discordant effect of IFN-β1a therapy on anti-IFN antibodies and thyroid disease development in patients with multiple sclerosis

Interferon-beta1b (IFN-beta1b) therapy is associated with a relatively high risk of developing thyroid disease. IFN-beta1a is regarded as less immunogenic than IFN-beta1b because of its structural homology to natural IFN-beta. We assessed the effect of 1 year of IFN-beta1a treatment on thyroid function and autoimmunity in 14 multiple sclerosis (MS) patients. The results were compared with those obtained in a series of 31 MS patients treated with IFN-beta1b. The prevalence of positive binding antibody (BAb) titer and neutralizing (NAb) anti-IFN antibody titer in the two groups was also assessed. The BAb and NAb positivity rate in IFN-beta1a-treated patients was significantly lower than in the group submitted to IFN-beta1b therapy (7% vs. 84% and 0% vs. 30%, respectively). Although the incidence of thyroid dysfunction was slightly higher in IFN-beta1b-treated patients than in those undergoing IFN-beta1a treatment (33% vs. 23%, respectively), it did not reach statistical significance. Thyroid disease was unrelated to the presence of positive serum BAb or NAb titer in both the group undergoing IFN-beta1a therapy and in that treated with IFN-beta1b. In both groups, thyroid disease developed mostly in women (71%) against a background of preexisting thyroiditis and a diffuse hypoechoic ultrasound thyroid pattern (80%). IFN-beta1a treatment was associated with a significantly lower prevalence of both BAb and NAb-positive titers than was IFN-beta1b. Conversely, thyroid disease was similar and unrelated to the presence of positive anti-IFN-beta antibody titer. Therefore, routine thyroid assessment may be advised during IFN-beta1a treatment, especially in patients with preexisting thyroiditis.

Increased T-lymphocyte interleukin-6 binding in patients with multiple sclerosis.

Multiple sclerosis (MS) represents a T‐cell‐mediated autoimmune demyelinating disease of the central nervous system associated with altered immunoregulation. Interleukin (IL)‐6 is a cytokine that has several effects on the neuroimmune system. Specific IL‐6 receptors have been found in human lymphocytes and neuroglial cells. The aim of the present study was to assay IL‐6 binding on peripheral blood T lymphocytes in MS patients. We found that T cells from MS patients had significantly more IL‐6 receptors [Bmax: 279 ± 7 vs. 246 ± 8 (mean ± SEM) receptors/cell, in patients and controls, respectively], whereas Kd values were similar to those of healthy subjects [26.8 ± 0.7 vs. 25.4 ± 0.6 (mean ± SEM) pM, in patients and controls, respectively]. Significant (P < 0.05) differences in IL‐6 binding values were observed between stable patients and those relapsing (272 ± 9 vs. 300 ± 12 (mean ± SEM) receptors/cell, respectively). We found significantly (P < 0.001) higher amounts of IL‐6 receptors on CD4+ T cells from MS patients than on CD4+ lymphocytes from controls (434 ± 11 vs. 363 ± 9 (mean ± SEM) receptors/cell, respectively); CD8+ T cells showed very few IL‐6 receptors in both patients and controls. These data are discussed in terms of MS immune pathogenesis and pathophysiology, because T‐cell activation seems to be linked to increased IL‐6 binding. The upregulated IL‐6 system might be involved in antibody‐mediated demyelinating pathways, because IL‐6 is well known to enhance humoral immune response.

T‐cell tumor necrosis factor‐α receptor binding in patients with multiple sclerosis

MS is a T-cell-mediated demyelinating disease of the CNS, in which the cytokine network may be deranged, leading to an altered immunoregulation. Tumor necrosis factor alpha (TNF-α) is a cytokine with several effects on the neuroimmune system. There are specific TNF-α receptors on human lymphocytes and other cell types, even in the CNS. We assayed TNF-α binding on peripheral blood T cells from MS patients compared with healthy subjects. T cells from MS patients have significantly more TNF-α receptors than those from control subjects (Bmax, 955 ± 31 versus 126 ± 3 [mean ± SEMI receptors per cell). Such TNF-α binding sites are of the same type in patients and healthy subjects (Kd, 68.7 ± 4.8 versus 70.2 ± 24.1 [mean ± SEM] pM). We discuss these results in terms of MS immunopathogenesis, because activated T cells have increased amounts of TNF-α receptors.

T‐cell interleukin‐6 receptor binding in interferon‐β‐1b‐treated multiple sclerosis patients

Multiple sclerosis (MS) is a T‐cell‐mediated autoimmune demyelinating disease of the central nervous system, associated with an altered cytokine network. We previously assayed peripheral blood T‐lymphocyte binding for two prototypic cytokines, tumour necrosis factor‐α (TNF‐α) and interleukin‐6 (IL‐6), and found that T cells from MS patients had significantly more TNF‐α and IL‐6 receptors than those from healthy controls. In the present work, paralleling a previous one on T‐cell TNF‐α binding, we studied the effect of interferon (IFN)‐β‐1b treatment on T‐lymphocyte IL‐6 binding in patients with relapsing–remitting MS. T cells from MS patients had significantly (P < 0.001) higher amounts of IL‐6 receptors than those from controls [292 ± 6 vs. 228 ± 8 (mean ± SEM) receptors per cell, respectively], whereas the ligand‐receptor affinity values were similar in the two groups [26.2 ± 0.7 and 25.7 ± 0.4 (mean ± SEM) pmoles/l, respectively]. After a 3‐month IFN‐β‐1b treatment, they showed a significant decrease in IL‐6 binding [266 ± 7 (mean ± SEM) receptors per cell]. After 6 and 9 months, T‐cell IL‐6 Bmax values were even lower [258 ± 8 and 251 ± 8 (mean ± SEM) receptors per cell]. Since an increased IL‐6 binding might be linked to a lymphocyte activation, our data give further support for an enhanced immune response in patients with MS. Our data seem to demonstrate that the major effects of IFN‐β‐1b treatment result in a decrease of T‐cell activation.

T-lymphocyte immunointerferon receptors in patients with multiple sclerosis

Multiple sclerosis (MS) is a T-cell-mediated autoimmune demyelinating disease of the central nervous system (CNS), associated with an altered immunoregulation. Interferon (IFN)-γ, also known as immune IFN, is a cytokine with several effects on the immune system. Specific IFN-γ receptors have been found on human lymphocytes, as well as on other cell types (e.g. gliocytes), even in the CNS. The aim of the present study was to evaluate IFN-γ binding on peripheral blood T-lymphocytes from MS patients, compared with those from healthy subjects. Thirty-two patients were selected according to the classical criteria for definite MS; as controls, 21 healthy subjects were studied. We have found that T-lymphocytes from MS patients bear a significantly smaller amount of IFN-γ receptors than those from controls [Bmax: 568, 18 vs 708, 14 (mean, SE) receptors/cell]. Such IFN-γ binding sites are of the same type in patients and healthy subjects [Kd: 1.0, 0.05 vs 0.9, 0.02 (mean, SE) nM]. These findings are discussed in terms of immunopathogenesis of MS, since it has been reported that activated T-lymphocytes have decreased amounts of IFN-γ receptors.