CD45RA+ ICAM-3+ lymphocytes in interferon-beta1b-treated and -untreated patients with relapsing-remitting multiple sclerosis

OBJECTIVES: Multiple sclerosis (MS) is believed to be an autoimmune disease of the human central nervous system mediated by autoreactive T cells. Interferon-beta1b (IFN-beta1b) has been shown to be effective in reducing disease activity defined by clinical and magnetic resonance imaging (MRI) criteria in relapsing-remitting MS (RRMS). Yet, the exact mechanisms by which these benefits are achieved remain unknown. CD45RA is a marker for naive T lymphocytes and intercellular adhesion molecule-3 (ICAM-3) is expressed on resting lymphocytes. MATERIAL AND METHODS: Forty-eight patients with RRMS, 24 of them treated with recombinant IFN-beta1b and 24 untreated, were enrolled in this prospective study over 18 months. We investigated the percentage of CD45RA+ ICAM-3+ cells within the total lymphocyte subset in the peripheral blood serially every 3 months and in CSF once at baseline. Detailed clinical examination including Expanded Disability Status Scale (EDSS) score was performed every 3 months and cranial MRI scans were assessed every 6 months. RESULTS: We found a temporary increase in the CD45RA+ ICAM-3+ lymphocyte ratio in peripheral blood of both untreated and IFN-beta1b-treated RRMS patients. Moreover, we determined a significant negative correlation (r = -0.5874; P < 0.01) between age as well as the EDSS score (r = -0.3629; P < 0.05) and the percentages of CD45RA+ ICAM-3+ lymphocytes in peripheral blood but a positive correlation between EDSS score and the CD45RA+ ICAM-3+ ratio (r = 0.3913; P < 0.05) in the CSF at baseline. CONCLUSION: CD45RA+ ICAM-3+ lymphocyte ratio in peripheral blood might indicate immunosenescence in MS. However, from our data it cannot be finally concluded whether it is also influenced by IFN-beta1b treatment.     

T cell subsets in multiple sclerosis: a serial study

The relevance of abnormalities in the distribution of peripheral blood T lymphocyte subsets to the clinical manifestations of multiple sclerosis is not firmly established. A clinical and immunological follow-up of relapsing-remitting multiple sclerosis patients was performed in order to study the relationship of immune changes with the clinical course of the disease. Twenty patients were monitored monthly during a mean time of nine months for peripheral blood lymphocyte subsets (CD3, CD4, CD8, CD19), including the immunoregulatory subsets CD4CD29 (helper-inducer), and CD4CD45RA (suppressor-inducer) and activated T helper cells (CD4CD25) by flow cytometry. A total of 14 untreated relapses was included. The most significant observations were a decrease in T suppressor-inducer CD4⁺ CD45RA⁺ subset during clinical relapses ( P = 0.028) that was also detectable one month before ( P = 0.020) and the lack of changes in CD4⁺ CD29⁺ and CD8⁺ T cells. In addition, variations in the percentage of CD4⁺CD25⁺ activated T helper cells were not associated with clinical exacerbations. These results indicate the existence of a temporal association of immune changes in peripheral blood, but not activation, with the clinical manifestations of multiple sclerosis.     

Analysis of effector CD4 (OX-40+) and CD8 (CD45RA+CD27-) T lymphocytes in active multiple sclerosis

OBJECTIVE: Recently, effector T-cell subpopulations have been identified that can be distinguished by expression of members of the TNF-R family: CD4+OX-40+ cells are CD4 helper-effector cells CD8+CD45RA+CD27 cells are CD8-killer-effector cells. We investigated whether these lymphocyte subsets were increased in the active phase of multiple sclerosis (MS). MATERIAL AND METHODS: Multiple colour immunofluorescence staining was performed on peripheral blood lymphocytes of 28 patients with active MS and of 29 healthy controls, followed by FACS analysis. RESULTS: Frequencies of CD8-killer-effector cells showed a wide interindividual range in both groups and percentages of CD4 helper-effector cells were low. No significant difference between the groups was observed for these subsets, but CD8+CD45RA-CD27 were increased in MS. In healthy individuals, CD4 helper-effector cells correlated with the total percentages of memory cells. Moreover, CD4+ and CD8 memory cells were strongly correlated. CONCLUSION: The here described recently identified effector CD4 and CD8 lymphocyte subpopulations were not increased in clinically active MS. It is however still possible that in MS, myelin-specific encephalitogenic cells reside within these subsets.     

CD45RA+ ICAM-3+ lymphocytes in cerebrospinal fluid and blood as markers of disease activity in patients with multiple sclerosis

OBJECTIVES: Autoreactive T cells targeted against antigens of the myelin sheath are suggested to play an important role in the pathogenesis of multiple sclerosis (MS). Naive (CD45RA+) T cells and intercellular adhesion molecule-3 (ICAM-3) are markers for un-activated lymphocytes. This study was performed to investigate, whether the expression levels of these antigens both on cerebrospinal fluid (CSF) and peripheral blood lymphocytes can be used as activity markers in MS. MATERIALS AND METHODS: Corresponding blood and CSF samples were obtained from 31 patients with relapsing-remitting MS. Of the 31 MS patients 23 were suffering from acute relapses at the time of examination and all of them were treated with high-dose methylprednisolone (MP). Blood was collected again on the 10th day of therapy and after 3 months. The control group consisted of 12 healthy persons. Two-color flow cytometry was performed to evaluate the percentage of both CD45RA+ and ICAM-3+ cells within the lymphocyte population. RESULTS: The percentage of CD45RA+ ICAM-3+ cells in the CSF of MS patients with relapses was significantly increased compared to patients in remission (P<0.05). In blood, a significantly lower percentage of CD45RA+ ICAM-3+ lymphocytes was found in both patient groups compared to healthy controls (Relapse: P<0.05, Remission: P<0.10). Additionally, we found a significant increase (P < 0.01) in the percentage of CD45RA+ ICAM-3+ lymphocytes in blood of MS patients suffering from acute relapse on the 10th day of high-dose MP treatment. CONCLUSION: Our data suggest that the percentage of CD45RA+ ICAM-3+ lymphocytes in CSF can be used as marker of disease activity in MS patients.     

Fas expression on T cells and sFas in relapsing-remitting multiple sclerosis

OBJECTIVES: To investigate the proportions of peripheral blood CD4+/Fas+ and CD8+/Fas+ cells and serum sFas levels in relapsing-remitting multiple sclerosis (RRMS) patients with relapses (active RRMS), those without relapses (stable RRMS), and controls over 1 year. MATERIAL AND METHODS: Sixteen RRMS patients and 10 controls were tested monthly. Cells were analyzed by dual immunofluorescence and the sFas levels by ELISA. There were 14 relapses which occurred 1223 days after the last control visits. The measurements performed at these visits in the active RRMS patients were considered as relapse-related, while the rest were regarded as relapse-unrelated. RESULTS: In active RRMS patients the median of CD4+ Fas+ to total CD4+ and CD8+ Fas+ to total CD8+ from relapse-related measurements were higher than the median from relapse-unrelated measurements (P=0.003, 0.004, respectively). The median of CD4+ Fas+ to total CD4+ from relapse-unrelated measurements in active RRMS was higher compared with stable RRMS (P = 0.005) and controls (P = 0.004). The sFas level from relapse-unrelated measurements was also higher in active RRMS than in stable RRMS (P = 0.04) and in controls (P = 0.004). CONCLUSIONS: We suggest that increased expression of Fas antigen on CD4+ subset and increased serum sFas level are valuable markers of clinical activity in MS.     

CD95/Fas expression on peripheral blood T lymphocytes in patients with multiple sclerosis: effect of high-dose methylprednisolone therapy

Recent data indicate that the apoptotic process, mediated by the CD95/Fas cell surface receptor, is impaired in activated lymphocytes of patients with relapsing-remitting multiple sclerosis. Using flow cytometric-immunophenotyping, we analyzed the expression of CD95/Fas on peripheral blood CD4+ and CD8+ T lymphocytes (PBL) in 10 MS patients in relapse, and the effect of pulse corticosteroid therapy on the apoptosis of autoreactive lymphocytes. The proportions of CD8+ and CD8+CD95+ T lymphocytes were significantly higher in MS patients in relapse before than after pulse corticosteroid therapy. Conversely, the proportions of CD4+ and CD4+CD95+ T cells were significantly lower before than after therapy, but not significantly different from healthy persons. The different expression of CD95/Fas on peripheral blood CD8+ T lymphocytes in relapsing RRMS and in healthy controls suggests a possible involvement of apoptosis in the pathogenesis of MS. Our results also show that pulse corticosteroid therapy influences the CD95/Fas expression on CD8+ and CD4+ T lymphocytes in patients with RRMS.     

Increased muscarinic cholinergic receptor density on CD4 lymphocytes in progressive multiple sclerosis

We measured the density and affinity of muscarinic cholinergic receptors (MR) in 29 chronic progressive and ten stable multiple sclerosis (MS) patients and 27 control subjects using [3H]N-methyl-scopolamine. The density of MR on CD4+ lymphocytes was significantly higher in chronic progressive MS (CPMS) than in controls (7.9 +/- 0.7 vs. 4.5 +/- 0.4 fmol/10(6) cells, p less than 0.001). Stable patients did not differ significantly from control subjects. Receptors of the M1 subtype were measured on CD4+ lymphocytes of nine patients and seven controls with the selective antagonist [3H]methylpirenzepine: M1/total receptor ratio was 64.1% in CPMS and 81.2% in controls, suggesting a selective increase of M2-type MR in CPMS. The findings may relate to parasympathetic denervation hypersensitivity of lymphocytes or to lymphocyte activation which is known to be associated with increased MR number.     

CD4+ lymphocyte subsets in the cerebrospinal fluid of multiple sclerosis and non-inflammatory neurological diseases

Summary We studied paired cerebrospinal fluid (CSF) and peripheral blood (PB) samples from 18 inactive multiple sclerosis (MS) patients and 10 with non-inflammatory neurological diseases. By means of a dual-colour cytofluorimetric micromethod we were able to count 1500 cells on average in each CSF sample. We found a significant reduction of CD45RA+ and CD4+CD45RA+ cells in the CSF of MS patients. Similarly, CD45RA+ and CD4+CD45RA+ CSF/PB ratios were lower compared with controls. The reduction of suppressor-inducer T-cells did not correlate with CD8+ cell levels in the CSF. The CD4+ subset ratio (CD4+CD45RA–/CD4+CD45RA+) was significantly increased in the CSF of MS patients. Our data suggest that the reduction of CD4+CD45RA+ cells in the PB is not due to a segregation of such cells in the CSF. Conversely, CSF changes reflect changes in the PB similar to these found for other T-cell subsets.     

Decrease of CD4+ CD45+ T-cells in chronic-progressive multiple sclerosis

Summary Circulating lymphocyte subpopulations defined by anti-CD45 and other more common T-cell-specific monoclonal antibodies were analysed in 77 patients with multiple sclerosis and 38 healthy controls. A selective decrease of CD4+ CD45+ cell percentages and absolute numbers in chronic-progressive patients was found; in 13 out of 26 patients this subpopulation was less than 11% CD4+ CD45+ cells. Similarly, the whole CD45+ cell subset, as well as CD45+ cells expressed as percentages of CD4+ cells, were significantly reduced in chronic-progressive multiple sclerosis. CD4+ CD45+ cells, commonly termed inducer of suppression T-lymphocytes, did not correlate with percentages or numbers of CD8+ cells. It is concluded that suppressor inducer T-cells act on the CD8+ subset function rather than reducing CD8+ cell numbers. Since CD4+ CD45+ cells represent an early stage of lymphocyte maturation (naive T-cells), an under-representation of this subpopulation in active multiple sclerosis might reflect an increased conversion of naive cells into memory cells. This concept may be relevant for a better understanding of the disease pathogenesis.     

Multiple sclerosis: an immune system activation disease.

Two-color flow-cytometric analysis on peripheral blood lymphocytes of 46 untreated multiple sclerosis patients (MS), 36 other medical disease patients (OMD) and 19 healthy control subjects (HC) was performed to know the relationships between T and B cell subpopulations. In MS patients we observed an increase of total lymphocyte count and an increase of CD4+CD29+ cells, which are adjuvant to B cell in antibody production. We hypothesized this change is related to the reduction of CD21+ cells, expressing B2 antigen which disappears after B cell activation. The unperfect balance of immune system in MS was also demonstrated by the increased level of CD25+ cells in relapsing-remitting patients and by the decreased level of CD4+ CD45RA+ (suppressor inducer) cells in progressive patients.     

Fenotipos de linfocitos periféricos en las enfermedades de Alzheimer y Parkinson

IntroductionNeuroinflammation is involved in the pathophysiology of various neurological disorders, in particular Alzheimer disease (AD) and Parkinson's disease (PD). Alterations in the blood-brain barrier may allow peripheral blood lymphocytes to enter the central nervous system; these may participate in disease pathogenesis.ObjectiveTo evaluate the peripheral blood lymphocyte profiles of patients with AD and PD and their association with the disease and its progression.MethodsThe study included 20 patients with AD, 20 with PD, and a group of healthy individuals. Ten of the patients with AD and 12 of those with PD were evaluated a second time 17 to 27 months after the start of the study. Lymphocyte subpopulations and their activation status were determined by flow cytometry. All patients underwent neurological examinations using internationally validated scales.ResultsCompared to healthy individuals, patients with AD and PD showed significantly higher levels of activated lymphocytes, lymphocytes susceptible to apoptosis, central memory T cells, and regulatory T and B cells. As the diseases progressed, there was a significant decrease in activated cells (CD4+ CD38+ and CD8+ CD38 + in PD and AD, CD4+ CD69+ and CD8+ CD69+ in PD), T cells susceptible to apoptosis, and some regulatory populations (CD19+ CD5+ IL10+ in PD and AD, CD19+ CD5+ IL10+ FoxP3+, CD4+ FoxP3+ CD25+ CD45RO+ in PD). In patients with AD, disease progression was associated with lower percentages of CD4+ CD38+ cells and higher percentages of effector CD4 cells at the beginning of the study. Significant differences were observed between both diseases.ConclusionsThis study provides evidence of changes in peripheral blood lymphocyte phenotypes associated with AD and PD and their severity. Considering effective blood-brain communication, our results open new avenues of research into immunomodulation therapies to treat these diseases.     

Absence of a correlation between T lymphocyte subsets and clinical activity in relapsing-remitting multiple sclerosis

Cytofluorographic analysis of CD3+, Tac+, HLA-DR+ peripheral blood lymphocytes and CD4/CD8 ratio was performed monthly, over a 10-month period, in a group of 16 patients with multiple sclerosis (MS). No correlation was found between clinical relapses and fluctuations in the lymphocyte subsets, although patients who were in remission throughout the study showed a number of CD3+ cells and a CD4/CD8 ratio significantly lower than those in normal controls. We concluded that changes in peripheral blood lymphocyte subsets are not related to the disease process and their measurement is not helpful in monitoring the illness.     

Thymic output and peripheral T lymphocyte subsets in relapsing--remitting multiple sclerosis patients treated or not by IFN-beta

We explored the parameters of central and peripheral tolerance in patients with stable relapsing-remitting multiple sclerosis, treated or not with IFN-beta. TREC-positive T cells were lower in patients compared with controls, mainly in CD4+ subset, compatible with a thymus dysfunction or an expansion of peripheral lymphocytes. Compared to controls, the frequency of activated CD4+CD25+ T cells was higher in patients without modification of the CD4+CD25(high) T cell proportion. The IFN-beta-treatment did not modify the TREC-positive cell frequency nor the naive/memory T cell subset percentage but was associated with lower blood lymphocyte count and a lower frequency of CD4+CD45RC(high) subset.     

CD4 subsets (CD45RA/RO) exhibit differences in proliferative responses,IL-2 and γ-interferon production during intravenous methylprednisolone treatment of multiple sclerosis

Phytohaemagglutinin (PHA)-induced proliferative responses, interleukin 2 (IL-2) and -interferon production were determined in purified CD4CD45RA and CD4CD45RO lymphocytes isolated by immunomagnetic bead separations from normal subjects and multiple sclerosis (MS) patients. Significantly higher proliferative activities were observed for CD4CD45RA cells compared with the corresponding CD4CD45RO cell population in normal subjects and MS patients. CD4CD45RA lymphocyte proliferative responses declined by 50% 3 h following a single dose (500 mg) of intravenous methylprednisolone (IVMP). At 24 h, levels were similar to those determined pre-therapy, as were the levels observed 24 h after a 5-day course (500 mg daily) of IVMP. In contrast, CD4CD45RO cells were unaffected by IVMP. In vitro incorporation of methylprednisolone (10^–6 M) to cell cultures resulted in a modest reduction in proliferative activities of both CD4 subsets. In MS patients subnormal levels of IL-2 and -interferon were observed in PHA-stimulated cultures of CD4CD45RA and CD4CD45RO cells. Following 5 days of IVMP therapy, IL-2 and -interferon production was similar to that observed in CD4CD45RA and CD4CD45RO cells from normal subjects. IVMP therapy causes selective, but transient, inhibition of CD4CD45RA lymphocyte proliferative responses and enhancement of PHA-induced IL-2 and -interferon production by both CD4CD45RA and CD4CD45RO cells.     

Fluctuations of CD4+ T-cell subsets in remitting-relapsing multiple sclerosis

Patients with multiple sclerosis (MS) frequently have selective depletion of the CD45R+CD4+ T-cell subset during active phases of disease. To study the relationship between changes in this subset and the onset of objective clinical exacerbations of disease, a longitudinal study was undertaken. Two CD4+ T-cell subsets and two CD8+ T-cell subsets were monitored by two-color immunofluorescence using a fluorescence-activated cell sorter. These subsets of peripheral blood lymphocytes were monitored monthly for one year in a group of 9 patients with remitting-relapsing MS and in 11 healthy age-matched control subjects. Significant changes in the ratio of two CD4+ T-cell subsets (CD45R-/CD45R+) were detected in 7 of 9 patients with MS, but not in any of the control subjects. Of those 7 persons, 4 suffered major clinical relapses substantiated by alterations in the neurological examination. The other 3 suffered minor relapses with subjective clinical abnormalities. All 7 had increased CD4+ T-cell subset ratios (%CD4+CD45R-/%CD4+CD45R+) within the month that new symptoms were reported. Most such increases resulted from a simultaneous depletion in the number of CD45R+CD4+ T cells and an increase in the number of CD45R-CD4+ T cells. One patient suffered a major relapse with no change in the ratio of CD4+ subsets but had a depletion of all CD4+ T cells. There were no consistent changes in any of the other subsets measured. These results indicate that a subgroup of patients with MS have abnormal fluctuations of two CD4+ T-cell subsets, which may correlate with increased disease activity.     

Evidence for a missed signal to the CD8+ cells in CSF of Multiple Sclerosis patients

Peripheral blood (PB) and cerebrospinal fluid (CSF) lymphocyte subpopulations, defined by various T-cell specific monoclonal antibodies and flow cytometry, were analysed in 44 relapsing remitting multiple sclerosis (RRMS) patients (including 21 subjects in the acute phase and 23 in the stable phase), 40 chronic-progressive multiple sclerosis (CPMS) patients, and 24 patients with other neurological diseases (OND), in order to verify the presence of any abnormality in the lymphocyte subset pattern. A significant increase in the total number of T-lymphocytes and the CD4+ subpopulation was found in the PB of the MS patients in comparison with the OND group. Moreover, a not statistically significant increase in CD4⁺ cells was observed in the CSF of MS patients. A statistically significant increase was also found in the CD4⁺ Leu 8⁺ (suppressor inducer) cells in the CSF of all of the MS groups. Finally, the CD8⁺ (suppressor/cytotoxic) cell levels, were significantly lower in the CSF of CPMS and stable RMS patients than in the CSF of the OND patients. As a whole, our data suggest that the immunosuppressive deficit that seems to be a constant finding in MS is not due to a decrease in suppressor inducer cell levels, as previously suggested, but may be caused by a missed or altered signal from the suppressor inducer to CD8⁺ suppressor cells.     

T-cell subsets in the cerebrospinal fluid and peripheral blood of multiple sclerosis patients treated with high-dose intravenous methylprednisolne

To determine the effects of high-dose intravenous methylprednisolone (MP) on lymphocytes and lymphocyte subpopulations in the cerebrospinal fluid (CSF) and peripheral blood (PB) in multiple sclerosis (MS) patients, we studied 67 patients with definite MS treated with MP. They were classified according to the disease course: 32 chronic progressive (CP) patients, 25 relapsing-remitting (RR) patients, and 10 patients with a chronic progressive disease course accompanied by relapses and remissions (CP + RR). MS patients were treated with 1000 mgr intravenous MP daily for 10 consecutive days. Before and after MP treatment we simultaneously studied CSF and PB CD3 +, CD4 +, CD8 +, CD20 +, and Ial + cells subsets. Kurtzke's Expanded Disability Status Scale (EDSS) was used for clinical evaluation. Progression rate was defined as the ratio of EDSS to disease duration. Thirteen patients with lumbar disk herniation were investigated as controls. Before MP, we found in MS patients, especially in the CP group, significantly lower CD4 + T-cell percentages in the PB with respect to controls (P<0.05). The percentage of CD4 + T-cells in the CSF of MS patients was significantly higher compared with PB (p = 0.0001), and tended to be higher than in controls (p = 0.072). The CSF mononuclear cell counts were significantly correlated with higher percentages of CSF CD3 + (r = 0.40) and CD4 + (r = 0.47) T-cells and lower CSF CD8 + (r = -0.33) T-cell percentages. B-cell percentages in the CSF were significantly elevated compared with controls for all MS groups. No relation could be obtained between T- or B-cell subsets and EDSS or progression rate. After MP, a significant decrease in PB CD8 + T-cell percentage and simultaneously an increase of the percentage CD8 + T-cells in CSF was noted in the entire MS group and in the CP and RR MS patients. Except for the CP + RR MS patients, CD4 + T-cell percentages in the PB or CSF showed insignificant changes. Our findings support the view that in MS MP might affect the inflammatory process of demyelination by a selective and dissociative effect on T-suppressor/cytotoxic cells in the PB and CSF.     

Virus-specific cytotoxic T lymphocytes in multiple sclerosis: a normal mumps virus response adds support for a distinct impairment in the measles virus response

An impairment of the measles virus-specific cytotoxic T lymphocyte response in multiple sclerosis was previously reported. This response is predominantly mediated by HLA class II-restricted CD4+ cells. In the present report, virus-specific cytotoxic T lymphocyte responses in multiple sclerosis were further studied by examining the response to mumps virus. No significant difference was detected in the generation of mumps virus-specific cytotoxic T lymphocyte responses between normal individuals and multiple sclerosis patients with impaired measles virus-specific cytotoxicity. A portion of the mumps virus-specific cytotoxic T lymphocyte response could be mediated by HLA class II-restricted CD4+ cells generated from both normal controls and MS patients. This CD4+ cell-mediated portion of the response was similar in both groups. These findings support the view that there is a distinct measles virus-specific impairment in cell-mediated cytotoxicity in multiple sclerosis.     

Evidence for a missed signal to the CD8+ cells in CSF of Multiple Sclerosis patients

Peripheral blood (PB) and cerebrospinal fluid (CSF) lymphocyte subpopulations, defined by various T-cell specific monoclonal antibodies and flow cytometry, were analysed in 44 relapsing remitting multiple sclerosis (RRMS) patients (including 21 subjects in the acute phase and 23 in the stable phase), 40 chronic-progressive multiple sclerosis (CPMS) patients, and 24 patients with other neurological diseases (OND), in order to verify the presence of any abnormality in the lymphocyte subset pattern. A significant increase in the total number of T-lymphocytes and the CD4+ subpopulation was found in the PB of the MS patients in comparison with the OND group. Moreover, a not statistically significant increase in CD4⁺ cells was observed in the CSF of MS patients. A statistically significant increase was also found in the CD4⁺ Leu 8⁺ (suppressor inducer) cells in the CSF of all of the MS groups. Finally, the CD8⁺ (suppressor/cytotoxic) cell levels, were significantly lower in the CSF of CPMS and stable RMS patients than in the CSF of the OND patients. As a whole, our data suggest that the immunosuppressive deficit that seems to be a constant finding in MS is not due to a decrease in suppressor inducer cell levels, as previously suggested, but may be caused by a missed or altered signal from the suppressor inducer to CD8⁺ suppressor cells.This Work was partially supported by an IRCCS Current Research Grant 1994.     

Differences in systemic and central nervous system cellular immunity relevant to relapsing–remitting multiple sclerosis

In order to elucidate the differences between systemic and central nervous system (CNS) immunity that are relevant to exacerbations of multiple sclerosis (MS), paired peripheral blood and cerebrospinal fluid (CSF) samples obtained from 36 non-treated patients with relapsing-remitting MS (RRMS) were simultaneously examined using flow cytometry to determine the percentages of functional lymphocyte subsets, as well as enzyme-linked immunosorbent assays for measuring soluble immune mediators.Active RRMS patients (n = 27) were characterized by an increase in CD4+ CXCR3+ Th1 cells in blood as compared with inactive patients (n = 9), and this parameter was inversely correlated with plasma levels of IL-10 and IL- 12p70. In contrast, an increase in the percentage of CD4+ CD25+ cells and a decrease in the percentage of CD8+ CD11a(high) cells were features of CSF samples from those with active RRMS. Further, CSF CD4+ CD25+ cells had a close association with leukocyte counts as well as albumin and CXCL10 levels in the CSF, and, thus, could be useful as a measure for inflammatory reactions in the CNS. On the other hand, CD8+ CD11a(high) cells may function as immunoregulatory cells, as their percentage in the CSF showed a positive correlation with CSF levels of the anti-inflammatory cytokine IL-4. These findings suggest that MS relapses occur in a combination with altered cell-mediated immunity that differs between the peripheral blood and CSF compartments, while measurement of lymphocyte subsets may be helpful for monitoring disease status.