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Query: UMLS:C0026986 (myelodysplastic syndrome)
 14,926 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

There is a growing interest in the use of granulocytic surface markers for the diagnosis of some inherited and acquired disorders, such as Shwachman-Diamond syndrome and myelodysplastic syndromes. Understanding the impact of physiologic factors, such as age, gender, pregnancy, race, and stress on granulocytic surface markers is essential for appropriate interpretation of results. Some surface markers show marked variations at the very early and the very late stages in life. Fetal granulocytes tend to have a lower expression of CD11b, CD11c, CD18, and CD32. Term neonatal granulocytes are frequently associated with a lower expression of CD10, CD11b, CD13, CD33, and CD62L and a higher expression of CD55 and CD64. Elderly individuals have shown a higher expression of CD64. Pregnancy is associated with temporary changes in granulocytic surface markers, such as a lower expression of CD16 and a higher CD64, partially mimicking an inflammatory response. Stress also has an impact on some surface markers, particularly adhesion molecules, such as CD62L and CD54. These factors need to be taken in consideration for the optimal interpretation of granulocytic surface marker studies.
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PMID:Physiologic variations in granulocytic surface antigen expression: impact of age, gender, pregnancy, race, and stress. 1455 86

Selected patients with Myelodysplastic Syndromes (MDS) are responsive to immunosuppressive therapy, suggesting that hematopoietic suppressive T cells have a pathogenic role in ineffective hematopoiesis. We assessed T-cell receptor (TCR) clonality through combined flow cytometry and molecular analysis of the complementarity determining region (CDR)-3 of the T-cell receptor-Vbeta gene. We identified clonal T cells in 50% of MDS patients (n=52) compared to 5% of age-matched normal controls (n=20). The presence of T-cell clones was not associated with features linked previously to immunosuppression response, including WHO diagnostic category, karyotype, marrow cellularity, IPSS category, sex or age <or=60. Using flow cytometry to identify expanded Vbeta-families, we found that T cells showed greater expansion in the bone marrow compared with peripheral blood, and were characterized as CD8(+)/CD57(+)/CD28(-) effector T cells. Expanded effector T cell were CD62L negative and expressed the natural killer C-lectin-family receptor NKG2D and CD244 (2B4). We conclude that clonal T-cell expansion is common among all MDS prognostic subgroups.
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PMID:Prevalence and clinical association of clonal T-cell expansions in Myelodysplastic Syndrome. 1730 13

We studied the immune compartment in patients with myelodysplastic syndromes. We show increased surface expression of activation markers (HLA-DR(+), CD57(+), CD28(-), CD62L(-)) on T lymphocytes in blood and bone marrow (n=131). T cell activation was not restricted to any relevant clinical subgroup (FAB, IPSS, cytogenetics) and did not correlate with blood counts or need for treatment. In vitro clonogenic growth of marrow mononuclear cells (n=18) was not influenced by T cells expressing these markers. In addition, using X-chromosome inactivation analysis (n=12) we demonstrate clonal involvement of NK and B cells in half of these patients. We conclude that although activated T lymphocytes can be found in MDS, their role in disease pathogenesis remains unclear in the majority of patients.
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PMID:The clinical significance of activated lymphocytes in patients with myelodysplastic syndromes: a single centre study of 131 patients. 1800 57

Response to immunosuppressive therapy (IST) in younger patients with myelodysplastic syndrome (MDS) has been linked to a T-cell-dominant autoimmune process that impairs hematopoiesis. Analysis of the age-adjusted CD4:CD8 ratio in 76 MDS patients compared with 54 healthy controls showed that inadequate CD4+, rather than expansion of CD8+ T cells, was associated with a lower ratio in a group that included both lower and higher risk MDS patients defined by the International Prognostic Scoring System. In younger MDS patients, naive and memory phenotypes defined by CD45RA and CD62L display showed depletion of naive CD4+ and CD8+ T cells, suggesting a possible relationship to IST responsiveness. To determine the correlation between T-cell subset distribution, T-cell turnover and autoimmunity, a cohort of 20 patients were studied before and after IST. The CD4:CD8 ratio correlated inversely with the proliferative T-cell index before treatment in IST-responsive patients, suggesting that proliferation may be linked to accelerated CD4+ T-cell turnover and hematopoietic failure. Our data show seminal findings that both CD4+ and CD8+ T-cell subsets are dysregulated in MDS. Association between these T-cell defects and response to IST suggests that aberrant T-cell homeostasis and chronic activation are critical determinants influencing autoimmune hematopoietic suppression in younger patients.
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PMID:Altered naive and memory CD4+ T-cell homeostasis and immunosenescence characterize younger patients with myelodysplastic syndrome. 1928 34

Myelodysplastic syndrome (MDS) is a clonal stem cell disorder frequently associated with inefficient granulopoiesis showing dysplastic polymorphonuclear neutrophils (PMNs). To assess PMN functionality in MDS in a clinical routine setting, 30 MDS patients and ten healthy volunteers were analyzed for PMN and monocyte phenotype and function (degranulation, CD62L shedding, oxidative burst and phagocytosis) upon stimulation with lipopolysaccharide by multi-color flow cytometry (MCFC). Our data show a heterogeneous pattern for CD66, CD16 and CD64 expression on PMNs of MDS patients. CD62L shedding rate and CD66 degranulation were reduced. Interestingly, we detected correlations between the WHO adapted prognostic scoring system (WPSS) and CD16 expression on PMNs as well as the international prognostic scoring system (IPSS) and CD11b degranulation by MCFC, suggesting clinical relevance of MCFC based function testing. In conclusion, MCFC of myelodysplastic immunophenotypes and PMN functionality are applicable in clinical settings, but further prospective studies are needed to assess the practical clinical value of such analyses.
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PMID:Phenotypic and functional characterization of neutrophils and monocytes from patients with myelodysplastic syndrome by flow cytometry. 2741 53