Significance of fetal hemoglobin-containing erythroblasts (F blasts) and the F blast/F cell ratio in myelodysplastic syndromes

Fetal hemoglobin level predicts lower-risk myelodysplastic syndrome

The relationship between fetal hemoglobin (HbF) levels and disease prognosis in patients with myelodysplastic syndrome (MDS) is unclear. This study aimed to clarify the relationship between HbF level and the prognosis of MDS. To this end, data from 217 patients diagnosed with MDS between April 2006 and August 2020 at Ebina General Hospital were analyzed retrospectively. The primary endpoint was leukemia-free survival (LFS) for 5 years after diagnosis. HbF levels were significantly higher in patients with MDS than in control patients without MDS (n = 155), with a cut-off value of 0.4%. Higher-risk patients had a similar prognosis regardless of HbF level, but lower-risk patients had longer LFS at intermediate HbF levels. Although prognosis based on pre-treatment HbF levels did not differ significantly among azacitidine-treated patients, prognosis tended to be better in lower-risk patients with intermediate HbF levels. Multivariate analysis showed that the intermediate HbF category correlated with LFS, independently of MDS lower-risk prognostic scoring system (LR-PSS)-related factors. This study is the first to assess the association between HbF levels and the new World Health Organization 2016 criteria for MDS, demonstrating the significance of HbF levels in the prognosis of MDS.

Cyclosporine Monotherapy in Pediatric Patients With Non-severe Aplastic Anemia: A Retrospective Analysis

Objective

The management of children with non-severe aplastic anemia (NSAA) is undefined and the efficacies and benefits of immunosuppressive therapy remain inconsistent. The study aimed to investigate the efficacy of Cyclosporine (CsA) monotherapy for pediatric NSAA.

Methods

Clinical data of children with NSAA who had been treated with CsA monotherapy at the outpatient department of Beijing Children's Hospital, Capital Medical University, National Children's Medical Center from January 2017 to March 2021 was collected retrospectively. Patients who had been treated <1 years until the end of follow-up were excluded. Transfusion-independent NSAA was further divided into moderate NSAA and mild NSAA according to the degree of cytopenia. Progression was defined as the development of transfusion-dependent AA or SAA and relapse was considered when treatment failed after initial response.

Results

A total of 95 pediatric patients with NSAA were enrolled in this study with 49 (51.6%) patients confirmed as mild NSAA, 38 (40%) as moderate NSAA and 8 (8.4%) as transfusion-dependent NSAA. The median treatment time of CsA was 22 (12–44) months. The overall response rate (ORR) was 57.9%, with 30.5% CR and 27.4% PR. Unexpectedly, patients with mild NSAA acquired lowest ORR (46.9%), then patients with moderate NSAA (63.2%), while 8 patients who were transfusion-dependent all had an active response to CsA. The granulocyte and megakaryocyte response was 46.9 and 55.8% respectively, while the erythrocyte response rate was as low as 22.5%. Univariate analyses revealed that patients with lower platelet count and higher interleukin 10 level predict an active response to CsA while higher level of fetal hemoglobin (HbF) tended to be a negative factor. Data of Treg cells before and after 1 year's treatment was available in a total number of 40 patients. Paired comparison found that the percentage of Treg cells in CD4+ T cells was decreased after 1 year's treatment of CsA (6.78 ± 2.72 vs. 5.23 ± 2.06, P = 0.001),both in responders and non-responders. The degree of decline in Treg cells between two distinctive response groups had no significant difference (P>0.05). With a median follow-up time of 22 months, 10.9% of responders relapsed and maintained NSAA while 27.5% of non-responders progressed to SAA or became transfusion-dependent. The overall progression rate was 11.6%.

Conclusion

CsA monotherapy had heterogeneous effects in the treatment of children NSAA Treatment approaches should be hierarchical and individual in clinical. Patients with lower platelet count and higher interleukin 10 level predicted an active response to CsA. While higher level of fetal hemoglobin (HbF) tended to be a negative factor. The percentage of Treg cells in CD4+ T cells was decreased broadly after treatment.

Lessons From Pediatric MDS: Approaches to Germline Predisposition to Hematologic Malignancies

Pediatric myelodysplastic syndromes (MDS) often raise concern for an underlying germline predisposition to hematologic malignancies, referred to as germline predisposition herein. With the availability of genetic testing, it is now clear that syndromic features may be lacking in patients with germline predisposition. Many genetic lesions underlying germline predisposition may also be mutated somatically in de novo MDS and leukemias, making it critical to distinguish their germline origin. The verification of a suspected germline predisposition informs therapeutic considerations, guides monitoring pre- and post-treatment, and allows for family counseling. Presentation of MDS due to germline predisposition is not limited to children and spans a wide age range. In fact, the risk of MDS may increase with age in many germline predisposition conditions and can present in adults who lack classical stigmata in their childhood. Furthermore, germline predisposition associated with DDX41 mutations presents with older adult-onset MDS. Although a higher proportion of pediatric patients with MDS will have a germline predisposition, the greater number of MDS diagnoses in adult patients may result in a larger overall number of those with an underlying germline predisposition. In this review, we present a framework for the evaluation of germline predisposition to MDS across all ages. We discuss characteristics of personal and family history, clinical exam and laboratory findings, and integration of genetic sequencing results to assist in the diagnostic evaluation. We address the implications of a diagnosis of germline predisposition for the individual, for their care after MDS therapy, and for family members. Studies on MDS with germline predisposition have provided unique insights into the pathogenesis of hematologic malignancies and mechanisms of somatic genetic rescue vs. disease progression. Increasing recognition in adult patients will inform medical management and may provide potential opportunities for the prevention or interception of malignancy.

Fetal hemoglobin induction during decitabine treatment of elderly patients with high-risk myelodysplastic syndrome or acute myeloid leukemia: a potential dynamic biomarker of outcome

Hematologic responses to hypomethylating agents are often delayed in patients with myelodysplastic syndrome or acute myeloid leukemia. Fetal hemoglobin is a potential novel bio-marker of response: recently, we demonstrated that a high fetal hemoglobin level prior to decitabine treatment was associated with superior outcome. Here we investigated whether early fetal hemoglobin induction during decitabine treatment also had prognostic value, and studied the potential of decitabine to induce erythroid differentiation and fetal hemoglobin expression in vitro Fetal hemoglobin levels were measured by high-performance liquid chromatography in patients with higher-risk myelodysplastic syndrome (n=16) and acute myeloid leukemia (n=37) before treatment and after each course of decitabine. Levels above 1.0% were considered induced. Patients achieving complete or partial remission as best response had attained a median fetal hemoglobin of 1.9% after two courses of treatment, whereas the median value in patients who did not reach complete or partial remission was 0.8% (P=0.015). Fetal hemoglobin induction after two courses of decitabine treatment was associated with early platelet doubling (P=0.006), and its subsequent decrease with hematologic relapse. In patients with myelodysplastic syndrome, induction of fetal hemoglobin after course 2 of treatment was associated with longer overall survival: median of 22.9 versus 7.3 months in patients with or without induction of fetal hemoglobin, respectively [hazard ratio=0.2 (95% confidence interval: 0.1-0.9); P=0.03]. In vitro decitabine treatment of two bi-potential myeloid leukemia cell lines (K562 and HEL) resulted in induction of an erythroid (not megakaryocytic) differentiation program, and of fetal hemoglobin mRNA and protein, associated with GATA1 gene demethylation and upregulation. In conclusion, fetal hemoglobin may provide a useful dynamic biomarker during hypomethylating agent therapy in patients with myelodysplastic syndrome or acute myeloid leukemia.

A distinct expression of various gene subsets in CD34+ cells from patients with early and advanced myelodysplastic syndrome

Gene expression profiles of CD34+ cells were compared between 51 MDS patients and 7 controls. The most up-regulated genes in patients included HBG2, HBG1, CYBRD1, HSPA1B, ANGPT, and MYC, while 13 genes related to B-lymphopoiesis showed down-regulation. We observed in advanced MDS patients decreased expression of genes involved in cell cycle control, DNA repair and increased expression of proto-oncogenes, angiogenic and anti-apoptic genes. The results suggest that increased cell proliferation and resistance to apoptosis together with a loss of cell cycle control, damaged DNA repair and altered immune response may play an important role in malignant clone expansion in MDS.

Diagnostic challenges in the myelodysplastic syndromes: the current and future role of genetic and immunophenotypic studies

Myelodysplastic syndromes (MDS) comprise a clinically and pathologically diverse collection of hematopoietic neoplasms, most commonly presenting with peripheral cytopenias typically in the context of bone marrow hypercellularity. Mechanistically, at least in the early phases of the disease, this apparently paradoxical picture is primarily due to ineffective hematopoiesis, which is accompanied by a variety of morphologic abnormalities in hematopoietic cells. The identification of recurrent, clinically relevant cytogenetic defects in MDS has spurred the research of molecular mechanisms that contribute to its inception as well as to the development of heterogeneous subtypes. Although conventional cytogenetic analyses remain a diagnostic mainstay in MDS, the application of contemporary techniques including molecular cytogenetics, microarray technologies and multiparametric flow cytometry may ultimately reveal new diagnostic parameters that are theoretically more objective and sensitive than current morphologic approaches. This review aims to outline the role of genetic and immunophenotypic studies in the evaluation of MDS, including findings that may potentially influence future diagnostic classifications, which could refine prognostication and ultimately facilitate the growth of targeted therapies.

Development of fetal haemoglobin-blood cells (F cells) within colorectal tumour tissues

AIM

To evaluate the sources of fetal haemoglobin (HbF) as an indicator in cancer. An immunohistochemical study was carried out on some of the most common kinds of cancer. All of these cancers had serologically high levels of HbF as evaluated previously.

METHODS

Immunoaffinity-purified anti-HbF was immunohistochemically used to study F cell distribution in the following cancers: colorectal adenocarcinoma, urinary bladder transitional cell carcinoma, brain tumours, lung carcinoma, breast adenocarcinoma, leukaemia, Burkitt's lymphoma and endometrial carcinoma.

RESULTS

In colorectal adenocarcinoma, HbF-containing red blood cells (FRBC) were present within thin-walled vessels or were disposed in dense clusters within the tumour. Some of these cells were nucleated or binucleated HbF-erythroblasts or HbF-normoblasts (FNBS). In two cases, high levels of mitoses within HbF-erythroblasts were observed. In half of the cases with transitional cell carcinoma of the urinary bladder, regional intratumoral blood vessels were found to contain 5-50% FRBC. In the other tumours examined, F cells were not observed. FRBCs, however, were occasionally observed in the regional lymph nodes of some of these cancers.

CONCLUSIONS

The evaluation of HbF as a potential plasma marker is suggested by the high concentration of FRBCs in colorectal tumours. The apparent development of FRBCs in colorectal tumour tissues is an interesting observation, as these cells were previously thought to develop in medullary or lymphoid tissues. It is thus suggested that the colonic microenvironment may stimulate extramedullary fetal-type haematopoiesis.

Engraftment of NOD/SCID/gammacnull mice with multilineage neoplastic cells from patients with juvenile myelomonocytic leukaemia

Several lines of evidence indicate the clonal nature of juvenile myelomonocytic leukaemia (JMML), involving myeloid, erythroid, megakaryocyte and B-lymphoid lineages. However, it is unclear whether the T-lymphocyte lineage is involved. We demonstrated that cells from six patients with JMML repopulated in non-obese diabetic/severe combined immunodeficient/gammac(null) mice and differentiated into granulocytes, monocytes, erythrocytes, B lymphocytes, T lymphocytes and natural killer cells. The percentage of human CD45 antigen-positive cells ranged from 41% to 73% in the murine bone marrow 12 weeks after transplantation. To examine the involvement of lymphocyte subpopulations, we purified human CD3(+), CD19(+) and CD56(+) cells from murine bone marrow cells transplanted from a patient with monosomy 7. Fluorescence in situ hybridization (FISH) showed the clonal marker in 96-100% of purified CD3(+), CD19(+) and CD56(+) subpopulations. These findings support the concept that JMML originates in transplantable multilineage haematopoietic stem cells. This novel murine xenotransplant model should be useful for investigating the nature of stem cells and testing new therapies for patients with JMML.

The diagnosis from the pathological viewpoint of a blood disease

The histopathological viewpoints of a blood diseases are namely following the cytological examinations except for the viewpoint of organ pathology and has been required only the usefulness in case with the difficulty of cytological examination. If it looks at a blood disease as hematopoietic organ disease, histopathological diagnostic study might make the new paradigm of blood diseases. In this time, I would like to present the hematological diagnosis from the pathological viewpoint by using histological bone marrow sections. *How to examine the bone marrow histology *Hematopoietic microenvironment disorder *Differential diagnosis of hypoplastic marrow lesions *Clinicopathological characteristics of Hypoplastic leukemia *Hemophagocytosis in bone marrow *How to diagnose MDS by histopathology. Bone marrow histology is the valuable diagnostic tool of many kinds of marrow disorders especial cases. By using immunohistochemistry and Giemsa staining, further information might obtain than smear film cytology. Bone marrow clot section aspirated from sternum is enough for histological examination except bone marrow biopsy. Precise cytomorphology might demonstrate by smear film than section histology. However surface phenotype would define by flow cytometric analysis, immunostaining of sections could demonstrate which cells show which markers. Structural and architectural disorder could only be represent by histology. The histological examination of bone marrow might introduce a new aspects of blood disease.