Clinical history, morphological appearance and cytogenetic data are required in identifying cases of MyelodysplasticSyndrome (MDS). However, this clonal stem cell disorder is still widely heterogenous and multiple tools are utilized in determining the diagnosis and prognosis. The current approaches in diagnosis are inherently subjective and lack of sensitivity. Over the years, altered maturation patterns using flow cytometry analysis have been reported to be useful for identification of MDS. This systematic review aims to assess the sensitivity of maturation pattern in obtaining MDS diagnosis. Electronic databases (MEDLINE, PROQUEST, OVID, Scopus, Web of Science) searched were yielded 677 articles. Snowballing was also employed. Two reviewers assessed each article independently using the following inclusion criteria: all types of MDS; WHO or FAB classification; diagnosis; immunophenotyping. Nineteen papers that met our inclusion criteria were analysed on the maturation pattern using flow cytometry. Samples used were bone marrow aspiration and prepared using either whole blood lysis or Ficoll-density gradient centrifugation. The most studied lineage in diagnosing MDS using maturation pattern is myeloid mainly looking on the CD34+, CD11b/CD16, CD13/CD16 and CD235a/CD71 expression pattern. Five studies showed sensitivity between 70 to 98 percent. Maturation pattern has shown high sensitivity and may be used as an ancillary technique for the diagnosis of MDS. However, flow cytometry strategies employed lack of standardization in assay, scoring system, and on how flow cytometry data have been analysed. Thus, more study need to be done within laboratory and multi-centre study to ensure validity and reliability of maturation pattern as an adjunct test.

Introduction: Myelodysplastic syndrome (MDS) is clonal haematopoietic stem cell disorder characterized by peripheral pancytopenia, despite the normo- or hypercellularity appearance of bone marrow. Accelerated apoptosis has been postulated to be involved in the pathogenesis of MDS, leading to ineffective hematopoiesis. The aim of this systematic review was to study the role of apoptosis in the pathogenesis of MDS. Methodology: We searched Proquest and Ebscohost databases up to March 2015. The search yielded 966 articles using keywords; Myelodysplastic Syndrome or MDS or Myelodysplasia and apopto* or cell death. Results/Discussion: A total of 18 experimental papers have been found to meet the inclusion criteria. Apoptosis has been found to occur in CD34 positive, mononuclear cells as well as stromal cells of the bone marrow microenvironment with high expressions of pro-apoptotic mediators such as Fas/Fas L, TNF-α, caspase family proteins and Granzyme-B. Bcl-2, p53 mediators and mc11 and bfl1 genes are highly expressed to compensate the apoptosis process while allowing the accumulation of blast cells within the bone marrow. Mitocondrial membrane potential, phosphatidylserine expression and DNA fragmentation act as a marker to quantify the level of apoptosis. Clonogenic assay with appropriate apoptosis inhibitors resulted in significant growth of progenitor cells. In conclusion, apoptosis is involved in various stages of MDS development. Apoptosis is up-regulated at the early stage of MDS and is diminished with disease progression.