Background and Purpose-In a murine model of stroke, we identified a population of very small embryonic-like (VSEL) stem cells (SCs) in adult murine bone marrow that could be mobilized into peripheral blood (PB). This raised the question of whether a similar population of cells is mobilized in human stroke patients. Methods-We evaluated a number of cells that corresponded to VSEL SCs in the PB of 44 stroke patients and 22age-matched controls. After each patient's stroke, PB samples were harvested during the first 24 hours, on day ϩ3, and on day ϩ7 and then compared with normal controls. The circulating human cells with the phenotype of VSEL SCs were evaluated in PB by real-time quantitative polymerase chain reaction, fluorescence-activated cell sorting analysis, and direct immunofluorescence staining. In parallel, we also measured the serum concentration of stromal derived factor-1 by ELISA. Results-In stroke patients, we found an increase in the number of circulating cells expressing SC-associated antigens, such as CD133, CD34, and CXCR4. More important, we found an increase in the number of circulating primitive cells expressing the VSEL phenotype (CXCR4

The hematopoietic and non-hematopoietic stem/progenitor cells harvested directly from the bone marrow (BM) or G-CSF mobilized peripheral blood were demonstrated to play an important role in regeneration of damaged organs (1, 2). Here, we asked if the stroke- or acute heart infarct-related stress triggers mobilization of stem/progenitor-enriched CD34(+)cells from the BM into the peripheral blood, which subsequently could contribute to regeneration of damaged tissues. To address this question the peripheral blood samples were harvested from patients with ischemic stroke during the first 24 h of manifestation of symptoms and on the second and sixth day afterwards or during the first 24 h of acute cardiac pain as well as on the second and sixth day of infarct. We measured in these patients (i) percentage of circulating hematopoietic stem/progenitor-enriched CD34(+) cells in peripheral blood by employing fluorescence activated cell sorter (FACS) and (ii) number of hematopoietic progenitor cells for the granulocyte-monocytic colony-forming unit (CFU-GM) and erythoid burst-forming unit (BFU-E) lineages circulating in peripheral blood. We concluded that stress related to ischemic stroke or acute myocardial infarction triggers the mobilization of hematopoietic stem/progenitor-enriched CD34(+) cells from the BM into peripheral blood. These circulating stem/progenitor-enriched CD34(+) cells may contribute to the regeneration of ischemic tissues, however, this possibility requires further studies.

Background: Reliable markers of disease outcomes in multiple sclerosis (MS) would help to predict the response to treatment in patients treated with high efficacy drugs. No evidence of disease activity (NEDA) has become a treatment goal whereas the modified Rio score (MRS) predicts future suboptimal responders to treatment. The aim of our study was to identify factors that would predict poor response to treatment with natalizumab and fingolimod. Methods: In the multicenter prospective trial, 336 subjects were enrolled, initiating therapy with natalizumab (n = 135) or fingolimod (n = 201). Data on relapse rate, the expanded disability status scale, and MRI results were collected, and MRS was estimated. Results: NEDA-3 after the first year of therapy was 73.9% for natalizumab and 54.8% for fingolimod (p < 0.0001). Patients with MRS = 0 in the last year on platform therapy had the best NEDA-3 (71%) and patients with MRS = 3 had the worst NEDA-3 (41%) in the first year of treatment with the second-line therapy. Conclusion: We conclude that switching to the second-line therapy should occur earlier to enable better results for patients treated with natalizumab or fingolimod. The outcome on both drugs is better with better neurological conditions and lower MRS of the patient on the platform therapy.

Multiple sclerosis (MS) treatment with new agents is associated with the risk of the development of progressive multifocal leukoencephalopathy (PML). The seropositivity and a high index of anti-John Cunningham virus (JCV) antibodies are some of the risk factors for PML development. The aim of this study was to assess the seroprevalence of anti-JCVAb and JCVAb index (AI), as well as its correlations with demographic and clinical characteristics in treatment-naïve Polish MS patients. This is a multicenter, prospective, and cross-sectional study involving 665 MS patients. The overall prevalence of anti-JCVAb was 65.3%, while 63.1% of seropositive patients had an index level of >1.5. The seroprevalence was shown to increase along with the patient’s age. Except for age, the prevalence of anti-JCVAb was not associated with demographic or clinical data. No correlations between the index levels and the demographic or clinical data were observed. In Poland, the seroprevalence of anti-JCVAb in treatment-naïve MS patients is one of the highest in Europe. The majority of seropositive patients had an anti-JCV antibody level denoting a high-risk category. This means that we need further studies to be conducted on the individualization of MS treatment in order to provide patients with an appropriate therapeutic safety level.