Myelodysplastic Syndromes (MDS) Presenting with Isolated Thrombocytopenia: Characteristics, Outcomes, and Clinical Presentation Differences from Immune Thrombocytopenic Purpura (ITP)

Introduction: Less than 5% of patients with MDS present with thrombocytopenia as an isolated abnormality (MDS-IT). There have been few systematic studies on MDS-IT and data regarding its course and prognosis are conflicting. Previous studies have defined MDS-IT based on the IPSS thresholds (Hb ≥10 g/dL; ANC ≥1.8×10 9/L; PLT <100×10 9/L). However, these were developed for prognostic, not diagnostic purposes which means that mild anemia and/or neutropenia might be present concomitantly with "isolated" thrombocytopenia. We aimed to investigate the characteristics, overall survival (OS), and leukemia-free survival (LFS) of patients with MDS-IT.

Methods: We identified patients who had PLT <150 ×10 9/L, Hb >13 g/dL (men) or >12 g/dL (women), and ANC ≥1.8 ×10 9/L, registered in the Hellenic National Registry of Myelodysplastic and Hypoplastic Syndromes which includes 2792 patients (analysis cut-off date; July 7, 2016). Patients were divided into 4 groups: group 1 had PLT 149-100 ×10 9/L; group 2, 99-50 ×10 9/L; group 3, <50 ×10 9/L; and group 4, <25 ×10 9/L. We also collected data from the Hellenic National ITP Registry which includes 1317 adult patients with ITP.

Results: A total of 77 patients (45 men; 32 women) with MDS-IT were identified (2.9% of total MDS cohort). Of these, 28.6% were classified in group 1; 49.4% in group 2; 14.3% in group 3; and 7.8% in group 4. Median PLT count was 87 ×10 9/L (12-139 ×10 9/L), WBC count 4.6 ×10 9/L, and Hb 13.6 g/dL. Bone marrow (BM) blasts ranged from 0-9% (median, 2%). Median follow-up was 51.0 months (41.6-60.4), during which 15 (19.5%) patients died. AML developed in 9 patients (11.7%). Histologically, MDS with multilineage dysplasia (MLD) was seen in 77.6% whereas MDS with excess blasts (EB) and MDS with single lineage dysplasia (SLD) comprised 10.7% and 11.9% of cases, respectively. Most patients (73.5%) had lower-risk MDS on the IPSS-R (i.e. IPSS-R ≤3.5). Of the 59 patients with cytogenetic data, 83.1% had favorable, 13.5% intermediate, and 3.4% poor risk cytogenetics. Most (40) had a normal karyotype followed by isolated del(20q) (6). All patients with del(20q) showed a characteristic set of clinical features: age >60 years, blasts 0-3%, bilineage (erythroid/megakaryocytic) dysplasia, and increased reticulin fibrosis. There were no significant differences between any of the 4 PLT groups regarding age, sex, IPSS-R, cytogenetics, BM blasts, and histology.

Median OS was 109 months (95% CI 103-115) and LFS 108 months (101-115). Our results showed no significant difference in OS (P=0.891) and LFS (P=0.871) between the 4 PLT groups. As compared with total MDS cohort, MDS-IT occurred at younger age (64.7 vs. 72.4 years, P<0.001). In a Kaplan-Meier analysis, patients with MDS-IT had markedly longer OS and LFS than patients in the total MDS cohort, even after adjustment for age, sex, IPSS-R, blasts, and PLT (P=0.013 for OS; P=0.017 for LFS) (Figure 1A). There were no differences in the top causes of death: infection was the commonest cause followed by disease progression and cardiovascular disease. Major bleeding comprised 10.3% of deaths in MDS-IT vs. 12.7% in total MDS cohort (P=0.217).

In comparing MDS-IT with ITP, the median age at diagnosis was 66.0 years for MDS-IT and 49.0 years for ITP (P<0.001).MDS-IT was uncommon in patients <50 or >80 years. Its incidence reached a peak between the ages of 70-79 years, whereas ITP occurred at a more constant level over time (Figure 1B). Women predominated in ITP and men in MDS-IT (P=0.007). Overall, ITP was associated with more marked thrombocytopenia than MDS-IT (15.0 ×10 9/L vs. 87.0 ×10 9/L) (P<0.001). Median WBC count was higher in ITP (7.6 ×10 9/L vs. 4.6 ×10 9/L; P<0.001). Median Hb was similar in the 2 groups. Patients with ITP had longer OS than MDS-IT (P<0.001).

Conclusions: In one of the largest reported series, we conclude that MDS-IT is associated with MDS-MLD, favorable cytogenetics, lower-risk IPSS-R, high survival rate, and a low risk of AML evolution. Our data suggest that the superior prognosis in MDS-IT than general MDS may have intrinsic genomic underpinnings as survival curves remained unchanged after correcting for age, sex, blasts and IPSS-R. Importantly, no significant differences in OS and LFS were noted between the 4 PLT subgroups, suggesting that the degree of thrombocytopenia does not correlate with mortality in MDS-IT. From the diagnostic standpoint, age <50 or >80 years and PLT <25 ×10 9/L favored a diagnosis of ITP over MDS-IT.

Figure 1 Figure 1.

Myelodysplastic Syndromes (MDS) Presenting with Isolated Thrombocytopenia: Characteristics, Outcomes, and Clinical Presentation Differences from Immune Thrombocytopenic Purpura (ITP)

Introduction: Less than 5% of patients with MDS present with thrombocytopenia as an isolated abnormality (MDS-IT). There have been few systematic studies on MDS-IT and data regarding its course and prognosis are conflicting. Previous studies have defined MDS-IT based on the IPSS thresholds (Hb ≥10 g/dL; ANC ≥1.8×10 9/L; PLT <100×10 9/L). However, these were developed for prognostic, not diagnostic purposes which means that mild anemia and/or neutropenia might be present concomitantly with "isolated" thrombocytopenia. We aimed to investigate the characteristics, overall survival (OS), and leukemia-free survival (LFS) of patients with MDS-IT.

Methods: We identified patients who had PLT <150 ×10 9/L, Hb >13 g/dL (men) or >12 g/dL (women), and ANC ≥1.8 ×10 9/L, registered in the Hellenic National Registry of Myelodysplastic and Hypoplastic Syndromes which includes 2792 patients (analysis cut-off date; July 7, 2016). Patients were divided into 4 groups: group 1 had PLT 149-100 ×10 9/L; group 2, 99-50 ×10 9/L; group 3, <50 ×10 9/L; and group 4, <25 ×10 9/L. We also collected data from the Hellenic National ITP Registry which includes 1317 adult patients with ITP.

Results: A total of 77 patients (45 men; 32 women) with MDS-IT were identified (2.9% of total MDS cohort). Of these, 28.6% were classified in group 1; 49.4% in group 2; 14.3% in group 3; and 7.8% in group 4. Median PLT count was 87 ×10 9/L (12-139 ×10 9/L), WBC count 4.6 ×10 9/L, and Hb 13.6 g/dL. Bone marrow (BM) blasts ranged from 0-9% (median, 2%). Median follow-up was 51.0 months (41.6-60.4), during which 15 (19.5%) patients died. AML developed in 9 patients (11.7%). Histologically, MDS with multilineage dysplasia (MLD) was seen in 77.6% whereas MDS with excess blasts (EB) and MDS with single lineage dysplasia (SLD) comprised 10.7% and 11.9% of cases, respectively. Most patients (73.5%) had lower-risk MDS on the IPSS-R (i.e. IPSS-R ≤3.5). Of the 59 patients with cytogenetic data, 83.1% had favorable, 13.5% intermediate, and 3.4% poor risk cytogenetics. Most (40) had a normal karyotype followed by isolated del(20q) (6). All patients with del(20q) showed a characteristic set of clinical features: age >60 years, blasts 0-3%, bilineage (erythroid/megakaryocytic) dysplasia, and increased reticulin fibrosis. There were no significant differences between any of the 4 PLT groups regarding age, sex, IPSS-R, cytogenetics, BM blasts, and histology.

Median OS was 109 months (95% CI 103-115) and LFS 108 months (101-115). Our results showed no significant difference in OS (P=0.891) and LFS (P=0.871) between the 4 PLT groups. As compared with total MDS cohort, MDS-IT occurred at younger age (64.7 vs. 72.4 years, P<0.001). In a Kaplan-Meier analysis, patients with MDS-IT had markedly longer OS and LFS than patients in the total MDS cohort, even after adjustment for age, sex, IPSS-R, blasts, and PLT (P=0.013 for OS; P=0.017 for LFS) (Figure 1A). There were no differences in the top causes of death: infection was the commonest cause followed by disease progression and cardiovascular disease. Major bleeding comprised 10.3% of deaths in MDS-IT vs. 12.7% in total MDS cohort (P=0.217).

In comparing MDS-IT with ITP, the median age at diagnosis was 66.0 years for MDS-IT and 49.0 years for ITP (P<0.001).MDS-IT was uncommon in patients <50 or >80 years. Its incidence reached a peak between the ages of 70-79 years, whereas ITP occurred at a more constant level over time (Figure 1B). Women predominated in ITP and men in MDS-IT (P=0.007). Overall, ITP was associated with more marked thrombocytopenia than MDS-IT (15.0 ×10 9/L vs. 87.0 ×10 9/L) (P<0.001). Median WBC count was higher in ITP (7.6 ×10 9/L vs. 4.6 ×10 9/L; P<0.001). Median Hb was similar in the 2 groups. Patients with ITP had longer OS than MDS-IT (P<0.001).

Conclusions: In one of the largest reported series, we conclude that MDS-IT is associated with MDS-MLD, favorable cytogenetics, lower-risk IPSS-R, high survival rate, and a low risk of AML evolution. Our data suggest that the superior prognosis in MDS-IT than general MDS may have intrinsic genomic underpinnings as survival curves remained unchanged after correcting for age, sex, blasts and IPSS-R. Importantly, no significant differences in OS and LFS were noted between the 4 PLT subgroups, suggesting that the degree of thrombocytopenia does not correlate with mortality in MDS-IT. From the diagnostic standpoint, age <50 or >80 years and PLT <25 ×10 9/L favored a diagnosis of ITP over MDS-IT.

Figure 1 Figure 1.

Emerging roles of endoglin/CD105 and angiogenic cytokines for disease development and progression in multiple myeloma patients

Angiogenesis is an essential process for the expansion of multiple myeloma (MM), in which many angiogenic factors participate. Endoglin (CD105) is a transforming growth factor-β co-receptor, being mainly expressed in angiogenic endothelial cells and has been used as a marker of tumor angiogenesis, having prognostic potential. The aim of the study was to evaluate serum levels of soluble CD105 (sCD105) in MM patients, both during diagnosis and after effective conventional chemotherapy, in the plateau phase, and to correlate them with the clinical stage of the disease, as well as with the known angiogenic factors vascular endothelial growth factor, angiogenin and interleukin-18 (IL-18). Serum levels of the aforementioned factors were measured, by enzyme-linked immunosorbent assay, in 56 newly diagnosed MM patients, in 35 of them who entered plateau phase and in 24 healthy controls. Bone marrow aspirations were also performed in all patients to determine plasma cell infiltration. All measured cytokines were higher in MM patients compared with controls and with advancing disease stage (p < 0.001 for all cases). Furthermore, the values of all factors decreased significantly in the plateau phase (p < 0.001 for all cases). Serum levels of sCD105 correlated with the other angiogenic cytokines, whereas only serum levels of angiogenin had prognostic value for the survival. In conclusion, CD105 and the angiogenic cytokines vascular endothelial growth factor, angiogenin and IL-18, seem to have emerging roles both in angiogenesis and tumor growth in MM.

Serum concentrations and clinical significance of soluble CD40 ligand in patients with multiple myeloma

Multiple myeloma (MM) is a disease of plasma cells that express the CD40 receptor. Binding of the CD40 by its natural ligand, CD40 ligand (CD40L), produces growth arrest and/or apoptosis in MM. To evaluate serum levels of soluble CD40L (sCD40L) in MM patients and to correlate them with markers of disease activity and angiogenesis, such as vascular endothelial growth factor (VEGF), hepatocyte growth factor (HGF), interleukin-6 (IL-6), proliferation marker Ki-67 proliferation index (Ki-67 PI) and bone marrow plasma cell infiltration, fifty-eight MM patients were studied in diagnosis and 43 of them after completion of treatment. Serum levels of sCD40L, VEGF, HGF and IL-6 were measured by ELISA, whereas Ki-67 PI and bone marrow plasma cell infiltration were measured by immunohistochemistry. Pre-treatment levels of sCD40L in MM patients were higher compared to controls and to their levels after effective treatment. Treatment regimen did not affect the degree of reduction of sCD40L levels, whereas patient in partial remission had increased levels compared to those with better response. Significant differences were found among disease stages. There were also positive correlations between CD40L with HGF, VEGF, IL-6 and Ki-67 PI. Elevated serum sCD40L is found in patients with advanced MM stage and can be reduced after effective treatment. Increased levels of this mediator are correlated with angiogenic cytokines, providing evidences that CD40L/CD40 interactions play a significant role in the mechanisms of angiogenesis in MM patients.

Mesenchymal stem cells contribute to the abnormal bone marrow microenvironment in patients with chronic idiopathic neutropenia by overproduction of transforming growth factor-β1

Chronic idiopathic neutropenia (CIN) is a granulopoiesis disorder associated with an inhibitory bone marrow (BM) microenvironment consisting of activated T-lymphocytes and pro-inflammatory mediators. In this study, we investigated the possible involvement of BM mesenchymal stem cells (MSCs) in the pathophysiology of CIN by assessing the frequency and function of BM MSCs in terms of the proliferative/clonogenic characteristics, the differentiation capacity, the potential to produce pro-inflammatory cytokines, and the ability to suppress T-cell proliferation. The frequency, differentiation capacity toward adipocytes, chondrocytes, or osteoblasts, and immunosuppressive potential to inhibit mitogen-induced T-cell proliferation did not differ significantly between patient (n = 14) and normal (n = 21) MSCs. Tumor necrosis factor-α, interleukin-1β, and interleukin-6 levels in MSC supernatants did not differ significantly between patients and controls; however, transforming growth factor (TGF)-β1 levels were significantly elevated in patients, particularly in those displaying the -509C/T TGF-β1 polymorphism. Patient MSCs displayed defective proliferative/clonogenic potential, which could not be attributed to altered cellular survival characteristics or to increased TGF-β1 production as TGF-β1 neutralization did not restore the impaired colony formation by patient MSCs. We conclude that although BM MSCs do not exert a significant role in the immune deregulation associated with CIN, they contribute to the inhibitory microenvironment by overproducing TGF-β1, at least in patients displaying the -509C/T polymorphism.

Increased levels of soluble flt-3 ligand in serum and long-term bone marrow culture supernatants in patients with chronic idiopathic neutropenia

The levels of serum and long-term bone marrow culture supernatant soluble flt-3 ligand (sFL) were determined in 54 patients with chronic idiopathic neutropenia (CIN) and 16 normal controls. Both serum and supernatant sFL levels were significantly increased in the patients compared with controls. Individual sFL values inversely correlated with the number of circulating neutrophils and the proportion of bone marrow CD34+ cells. Supernatant sFL values positively correlated with the levels of supernatant G-CSF. These findings suggest that the impaired myelopoiesis in CIN patients is accompanied by a compensatory mechanism attempting to increase the neutrophil production at the myeloid progenitor cell level.

Soluble c-kit ligand production by bone marrow stromal cells is independent of the degree of neutropenia in patients with chronic idiopathic neutropenia

The levels of soluble c-kit ligand (sKL), also known as Steel factor or stem cell factor, were measured in blood serum and long-term bone marrow culture supernatants of 81 patients with chronic idiopathic neutropenia (CIN) and 22 normal controls using a commercially available enzyme-linked immunosorbent assay (ELISA). We found that the levels of serum and culture supernatant sKL did not differ significantly between patients and control subjects and that both serum and supernatant values of the cytokine did not correlate with the number of circulating neutrophils. Furthermore, we found that the levels of the culture supernatant granulocyte colony-stimulating factor (G-CSF), also measured by ELISA, were significantly increased in the patients compared to controls but individual G-CSF values did not correlate with the values of supernatant sKL. These findings suggest that sKL-producing cells continuously secrete sKL and that cytokine secretion is independent of the degree of neutropenia or the levels of supernatant G-CSF in patients with CIN.

High prevalence of Helicobacter pylori infection and monoclonal gammopathy of undetermined significance in patients with chronic idiopathic neutropenia

The prevalence of Helicobacter pylori infection was evaluated in 120 patients with chronic idiopathic neutropenia (CIN), 8 patients with monoclonal gammopathy of undetermined significance (MGUS) associated with CIN, and 74 age- and sex-matched normal volunteers, all derived from the same geographical area. The purpose of the study was to investigate the possible causal relationships of H. pylori infection with the development of MGUS in CIN patients. We found that the prevalence of H. pylori infection was elevated to 69.2% in the group of CIN patients, 100% in the group of patients with CIN-associated MGUS, and 32.4% in the group of control subjects. No statistically significant difference, however, was found in the prevalence of H. pylori infection between CIN patients with concomitant MGUS and CIN patients without MGUS, no resolution of the gammopathy after eradication of the bacterium, no significant rise in the titers of serum anti-H. pylori antibodies, and no formation of an abnormal precipitation line in immunoelectrophoresis using a saline extract of NCTC11367 H. pylori reference strain as antigen. We concluded that there is no evidence that H. pylori infection is the cause of MGUS in CIN patients.