The review article by Mauland et al. provided evidence that the DNA content assessment may be of clinical value in endometrial cancer (EC) . As many of us may recall, DNA ploidy in EC was introduced as a prognostic marker 30 years ago . Despite the accumulating evidence that tumor aneuploidy is associated with poorer clinical outcome, this parameter was not incorporated into daily clinical practice for a number of reasons, mainly due to the lack of a routine diagnostic test validating its clinical applicability in EC. Looking at literature data in this field, the majority of the studies demonstrated highly significant correlation between DNA aneuploidy and survival in both univariate and multivariate analysis. Unfortunately, few studies have focused on DNA ploidy as a prognostic marker in a prospective setting. In conclusion, based on the reviewed literature, authors concluded that DNA ploidy analysis in hysterectomy specimen is superior to analysis in curettage material and may predict lymph node metastasis. However, the clinical significance of tumor aneuploidy in this setting may be hampered by the methodology used (flow cytometry, image cytometry, and laser scanning cytometry), thus limiting the clinical applicability of this analysis.
Paroxysmal nocturnal hemoglobinuria (PNH) is caused by somatic mutations in the PIG-A gene in hematopoietic stem cells and is characterized by the triad of intravascular hemolysis, severe acquired thrombophilia, and multiple cytopenias. The occurrence of cytopenias is thought to be an expression of bone marrow failure (BMF), and due to this consideration, a number of authors have recently investigated the presence of PNH clones in aplastic anemias (AA) and related disorders. Practical guidelines for the high sensitivity detection and monitoring of PNH clones by flow cytometry have been recently published in Cytometry B .
In this issue of Cytometry B, a prospective multicenter study of PNH cells in patients with BMF has been published, with the primary objective of determining the prevalence of PNH clones in patients diagnosed with BMF. A significant number (>1%) of granulocyte PNH cells was detected in 18% of AA patients, and 1% of myelodysplastic syndromes (MDS), confirming the presence of glyco-phosphatidyl-inositol-deficient cells in several hematological disorders characterized by peripheral cytopenias and BMF. On the whole, these data suggest that screening such patients may facilitate patient management and care . The association between PNH and BMF syndromes suggests that the selection pressure for PNH clonal expansion is mediated through the patient's immune system . Interestingly, the presence of minor populations of PNH cells in patients with BMF proved to be an important indicator of a higher rate of response to immune-suppressive therapy. The major limitation of this investigational study called EXPLORE is that it did not include a longitudinal assessment of clone sizes; it is known, in fact, that PNH clone size in single patients is dynamic, with longitudinal studies reporting significant variation in PNH clone size.
In the manuscript by Alhan et al., the absence of aberrant myeloid progenitors by flow cytometry was found to be associated with a favorable response to azacitidine therapy in higher risk MDS. This is a very interesting finding, emphasizing the role played by the flow cytometry for the identification of MDS patients possibly responding to novel cytostatic drugs. Since, it is well known that in high risk MDS patients treatment with azacitidine is associated with prolonged overall survival in patients who respond to therapy, the use of multiparametric flow cytometry may represent a new tool for refining treatment modality in MDS patients [6-11]. In particular, using the flow cytometric scoring system (FCSS), the presence of myeloid progenitors having an aberrant immunophenotype was significantly associated with lack of response to azacytidine therapy. FCSS score was generated by weighed scoring for the number of abnormalities in the myelomonocytic compartment and for the percentage of progenitor cells, as previously outlined in the review article by Della Porta et al. .
In the paper by Boldt et al., polychromatic flow cytometry was used to characterize T-B and NK cell subpopulations in chronic immunodeficiencies. Since primary and secondary immunodeficient states are quite heterogeneous, a standardized approach to enumerate the various lymphocyte subpopulations is highly demanding. This study represents a practical approach to standardize the immunophenotyping of most B, T, and NK cell subsets that allows a careful assessment of the various phenotypic abnormalities in primary and secondary deficits, and their discrimination with other immunological aspects such as infections .
The remaining two articles published in this issue of cytometry dealt with the stability in cocktails and compensation considerations of Tandem Dyes, and on the Basophil Activation Test in the diagnosis and monitoring of mastocytosis patients with wasp venom allergy [13-15]. I am sure that both of them will be of great interest for readers who are familiar with these areas of investigation, and will consider them as a valuable support for their daily activity.