The immune profile of multiple sclerosis: T-lymphocyte effects predominate over all other factors in cyclophosphamide-treated patients

Stability of immunophenotypic markers in fixed peripheral blood for extended analysis using flow cytometry

The analysis of whole blood samples by flow cytometry for pharmacodynamic and biomarker assessments in clinical studies has been limited by the necessity to test these samples within a short time frame after blood collection. In most clinical studies, blood specimens are shipped to a centralized testing facility; it is critical to demonstrate specimen stability over a period of time which will encompass the time elapsed between specimen collection and testing. A possible solution to overcome this limitation is the use of a fixative to preserve the cell surface antigen stability in whole blood. We examined the stability of markers for T lymphocytes (CD3, CD4, CD8, CD45RA, and CD45RO), B lymphocytes (CD19), NK cells (CD16+CD56), activation (CD25 and HLA-DR), chemokine receptors (CCR5 and CXCR3) and skin homing (CLA) in fixed blood over 7 days and used this information to select the markers for global clinical studies. These assays with selected markers were further validated using fit-for-purpose approach (Lee et al., 2006) and to set the sample acceptability criteria for use in clinical sample testing. Most of the markers examined were stable when collected in Cyto-Chex® BCT for one week with the exception of the activation markers on T cells.

Haplotypes of the interleukin 7 receptor alpha gene are correlated with altered expression in whole blood cells in multiple sclerosis

IL7 regulates T cell survival, differentiation and proliferation. The alpha chain of its receptor, CD127, is polymorphic, and its haplotypes are associated with recovery from transplantation and with the autoimmune disease multiple sclerosis (MS), especially primary progressive MS (PPMS). We demonstrate that two CD127 haplotypes are highly associated with the proportion of the mRNA encoding the soluble isoform of CD127 (P<or=0.001). The soluble isoform is over-represented (P<or=0.002) in PPMS peripheral blood, irrespective of haplotype, and the MS susceptibility haplotype produces more of the soluble isoform. CD127 mRNA is underexpressed (P<or=0.001) in PPMS. Neutrophils, which produce very low levels of CD127 mRNA, were over-represented in our PPMS cohort (P<0.02). CD127 expression is lower in more differentiated cells, such as Th1s, which can be elevated in MS. A higher proportion of these two abundant cell types in peripheral blood could be the basis for the observed reduction in CD127 mRNA. CD127 expression may be a biomarker for these potentially pathologically significant leukocyte types. These significant haplotypic effects on expression are likely to modulate regulation, differentiation and function of T cell subsets in health and disease.

Immunosuppressive treatment in multiple sclerosis

Immunosuppressive therapy has been used to treat multiple sclerosis (MS) for over 30 years based on the hypothesis that MS is a T cell-mediated autoimmune disease. The most commonly used immunosuppressive agents in MS are azathioprine, cyclophosphamide, methotrexate, and mitoxantrone. Since the interferons and glatiramer acetate have become widely used in MS, immunosuppressive agents have found a role given as combination therapy or as monotherapy in instances where the interferons and glatiramer acetate are not effective in controlling the disease. Like the interferons and glatiramer acetate, immunosuppressive drugs are most efficacious in stages of MS that have an inflammatory component as evidenced by relapses and/or gadolinium-enhancing lesions on MRI or in patients in earlier stages of disease where inflammation predominates over degenerative processes in the CNS. There is no evidence of efficacy in primary progressive MS or later stages of secondary progressive MS. In our studies of cyclophosphamide, we have found that although it is a general immunosuppressant that affects both T cell and B cell functions, cyclophosphamide has selective immune effects in MS by suppressing IL-12- and Th1-type responses and enhancing Th2/Th3 responses (IL-4, IL-10, TGF-beta; eosinophils in peripheral blood). Cyclophosphamide and mitoxantrone are the most common immunosuppressive drugs used in patients with rapidly worsening MS whose disease is not controlled by beta-interferon or glatiramer acetate.

Treatment of multiple sclerosis with cyclophosphamide: critical review of clinical and immunologic effects

Cyclophosphamide is an alkylating agent used to treat malignancies and immune-mediated inflammatory non-malignant processes such as lupus nephritis and immune-mediated neuropathies. It has been studied as a treatment for multiple sclerosis (MS) for the past 30 years and is used by physicians in selected cases of progressive or worsening MS. Review of published reports suggests that it is efficacious in cases of worsening MS that have an inflammatory component as evidenced by relapses and/or gadolinium (Gd)-enhancing lesions on magnetic resonance imaging (MRI) or in patients in earlier stages of disease where inflammation predominates over degenerative processes in the central nervous system (CNS). There is no evidence of efficacy in primary progressive MS or later stages of secondary progressive MS. Although a general immunosuppressant that affects both T- and B-cell function, cyclophosphamide has selective immune effects in MS by suppressing IL-12 and Th1-type responses and enhancing Th2/Th3 responses (IL-4, IL-10, TGF-beta; eosinophils in peripheral blood). Side effects include nausea, alopecia, infertility, bladder toxicity and risk of malignancy. The most commonly used regimens involve every 4- to 8-week outpatient i.v. pulse therapy given with or without corticosteroids and are usually well-tolerated by patients. Cyclophosphamide is currently used in patients whose disease is not controlled by beta-interferon or glatiramer acetate and those with rapidly worsening MS.

Hematological effects of intermittent 2-hour infusions of cladribine in multiple sclerosis patients: a comparison of 2 dosage patterns

Cladribine is a lymphocytotoxic purine nucleoside with potential for treatment of autoimmune diseases. However, optimal administration regimens remain to be established. Twenty multiple sclerosis patients enrolled into this study were given 30 intermittent 2-hour cladribine infusions (0.07 mg/kg per infusion) each. Ten patients received cycles of 5 consecutive daily infusions at 5-week intervals (clustered dosage) on an inpatient basis; the other 10 patients received 1 infusion weekly (nonclustered dosage) on an outpatient basis. Red blood cell (RBC), platelet, and total white blood cell (WBC) counts were assessed at 5-week intervals during the treatment and at 13-week intervals during a 26-week follow-up period. Major WBC and lymphocyte subsets were assessed cytometrically at 15-week intervals during the treatment and at 13-week intervals thereafter. The clustered dosage produced a lasting decline in granulocyte count, a delayed decrease in monocyte count, and a transient decrease in RBC count. The nonclustered dosage caused a larger and persistent decline in RBC count, a smaller (P = .051. compared over the study period) decrease in monocyte count, and no change in granulocyte count. Both regimens transiently reduced natural killer and B-cell subsets (by 40%-60% and >80%, respectively) and caused lasting declines in CD4+ T-cell subsets (by >50%). No significant change was found in CD8+ T-cell subsets. These results show similar potency of these regimens with respect to major lymphocyte subsets, while suggesting that the nonclustered dosage is less toxic to myeloid precursors and more toxic to erythroid lineage precursors.

Flow cytometric differentiation of Asian and Western types of multiple sclerosis, HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and hyperIgEaemic myelitis by analyses of memory CD4 positive T cell subsets and NK cell subsets

We examined the alterations of memory CD4(+) T cell subsets bearing surface receptors linked to either Th1 or Th2 cytokine production as well as natural killer (NK) cell subsets by three color flow cytometry in the peripheral blood from 36 patients with clinically definite multiple sclerosis (MS), 27 patients with HAM/TSP, 13 patients with hyperIgEaemic myelitis who had mite antigen-specific IgE and 25 healthy controls (HC). The patients with MS were clinically classified into an optico-spinal form of MS (Asian type, MS-A) and the conventional form of MS (Western type, MS-W). MS-A showed a significant increase of CD4(+)CD45RA(-)CCR5(+) cells (Th1 cells) through the relapse and remission phases in comparison to HC, while MS-W showed a significant increase of CD4(+)CD45RO(+)CD62L(-) cells (Th1 cells) only at the relapse phase. HAM/TSP showed a significant increase of CCR5(+) and CD62L(-) memory CD4(+) T cells as well as CD30(+) memory CD4(+) T cells (Th2 cells) in comparison to HC. On the other hand, a selective increase of CD4(+)CD45RO(+)CD30(+) cells was found in hyperIgEaemic myelitis. The percentage of mature NK cells (CD3(-)CD16(+)CD56(+) cells) as well as double negative T cells (CD3(+)CD4(-)CD8(-) cells) decreased significantly in HAM/TSP in comparison to HC. Our findings therefore suggest a flow cytometric analysis of Th1/Th2-associated markers on memory CD4(+) T cells as well as NK cell subsets to be useful for differentiating various inflammatory neurologic conditions.

Inhibition of the progression of multiple sclerosis by linomide is associated with upregulation of CD4+/CD45RA+ cells and downregulation of CD4+/CD45RO+ cells

In a recent double-blind, phase II study, conducted in our department, we showed that Linomide-treated MS patients had significantly less active lesions (in serial monthly MRI tests) and a tendency for clinical stabilization. Here we present the immunological evaluation of the patients who participated in this study and propose a novel mechanism by which Linomide downregulates autoreactivity. Peripheral blood leukocytes (PBLs), serum, and CSF samples were obtained at two to four time points over the 6 months of the trial. Flow cytometric analysis (FACS) of the CD5/CD19, CD4/CD8, CD14/CD3, CD16/CD3, CD45RA/CD4, and CD45RO/CD4 surface markers on PBLs was performed and the levels of the IL-1beta, IL-2, IL-4, IL-6, IL-10, TNF-alpha, IFN-gamma, and IL-2R were also examined. White blood counts of Linomide-treated patients were consistently elevated throughout the treatment period (P = 0.002-0.04). Cytokines levels in serum and CSF were highly fluctuating and we could not detect any clear trend as a result of Linomide treatment. FACS analysis showed that Linomide treatment significantly increased the percentage of the CD4+/CD45RA+ cells (from 35.5% at baseline to 42.3% at week 24; P = 0.02), and decreased CD4+/CD45RO+ lymphocytes (62.6% at baseline vs 53.7% at week 24, P = 0.02). Linomide also induced a transient increase in the NK-cells, the NK 1.1 cells, and the CD5 B-cells (P = 0.02). Upregulation of naive CD45RA T-lymphocytes and parallel downregulation of memory CD45RO cells seems to be one of the main mechanisms by which Linomide inhibits MS activity and may represent an alternative immunomodulating approach for the treatment of MS and autoimmunity in general.