Friedrich Wimazal

New insights into the prognostic impact of the karyotype in MDS and correlation with subtypes: evidence from a core dataset of 2124 patients

We have generated a large, unique database that includes morphologic, clinical, cytogenetic, and follow-up data from 2124 patients with myelodysplastic syndromes (MDSs) at 4 institutions in Austria and 4 in Germany. Cytogenetic analyses were successfully performed in 2072 (97.6%) patients, revealing clonal abnormalities in 1084 (52.3%) patients. Numeric and structural chromosomal abnormalities were documented for each patient and subdivided further according to the number of additional abnormalities. Thus, 684 different cytogenetic categories were identified. The impact of the karyotype on the natural course of the disease was studied in 1286 patients treated with supportive care only. Median survival was 53.4 months for patients with normal karyotypes (n = 612) and 8.7 months for those with complex anomalies (n = 166). A total of 13 rare abnormalities were identified with good (+1/+1q, t(1q), t(7q), del(9q), del(12p), chromosome 15 anomalies, t(17q), monosomy 21, trisomy 21, and -X), intermediate (del(11q), chromosome 19 anomalies), or poor (t(5q)) prognostic impact, respectively. The prognostic relevance of additional abnormalities varied considerably depending on the chromosomes affected. For all World Health Organization (WHO) and French-American-British (FAB) classification system subtypes, the karyotype provided additional prognostic information. Our analyses offer new insights into the prognostic significance of rare chromosomal abnormalities and specific karyotypic combinations in MDS.

Comorbidity as prognostic variable in MDS: comparative evaluation of the HCT-CI and CCI in a core dataset of 419 patients of the Austrian MDS Study Group

BACKGROUND The evaluation of comorbidity is of increasing importance in patients with hematologic disorders. PATIENTS AND METHODS In the present study, the influence of comorbidity on survival and acute myeloid leukemia (AML) evolution was analyzed retrospectively in 419 patients with de novo myelodysplastic syndromes (MDS) (observation period: 1985-2007). The median age was 71 years (range 24-91 years). Two different scoring systems, the hematopoietic stem-cell transplantation-specific comorbidity index (HCT-CI) and the Charlson comorbidity index (CCI) were applied. RESULTS The HCT-CI was found to be a significant prognostic factor for overall survival (OS, P < 0.05) as well as event-free survival (EFS, P < 0.05) in our patients, whereas the CCI was of prognostic significance for OS (P < 0.05), but not for EFS. For AML-free survival, neither the HCT-CI nor the CCI were of predictive value. A multivariate analysis including age, lactate dehydrogenase, ferritin, karyotype, number of cytopenias, French-American-British groups, and comorbidity was applied. Comorbidity was found to be an independent prognostic factor in patients with low- or int-1-risk MDS (P < 0.05) regarding OS and EFS. CONCLUSIONS Together, our data show that comorbidity is an important risk factor for OS and EFS in patients with MDS.

Diagnostic and Subdiagnostic Accumulation of Mast Cells in the Bone Marrow of Patients with Anaphylaxis: Monoclonal Mast Cell Activation Syndrome

Background: Patients with mastocytosis may suffer from severe hypotension after wasp or bee stings. In these patients, no specific IgE is detectable, but they usually have skin lesions and an elevated serum tryptase level. Methods: We report on 6 patients who were referred to our department because of severe hypotension following bee or wasp stings without cutaneous lesions. Results: In 3 patients, the baseline serum tryptase level was elevated (26, 36, and 67 ng/ml, respectively), and investigation of their bone marrow revealed systemic mastocytosis (SM). In the remaining 3 patients, serum tryptase levels were <20 ng/ml, and bone marrow histology and tryptase immunohistochemistry did not reveal diagnostic mast cell infiltrates. However, in 1 patient, three minor SM criteria were demonstrable leading to the diagnosis SM, and in the 2nd patient, two minor SM criteria, including an aberrant mast cell phenotype, were found. In the 3rd patient, no minor SM criteria were detected. Conclusions: All patients with unexplained hypotension after hymenoptera stings should undergo a thorough investigation for major and minor SM criteria regardless of the tryptase level or presence of skin lesions, in order to diagnose or exclude SM or a related subdiagnostic condition (1 or 2 minor SM criteria) tentatively termed monoclonal mast cell activation syndrome.

Indolent Systemic Mastocytosis with Elevated Serum Tryptase, Absence of Skin Lesions, and Recurrent Severe Anaphylactoid Episodes

Background: In contrast to aggressive mastocytosis, patients with indolent systemic mastocytosis (ISM) usually present with urticaria pigmentosa-like skin lesions. In those who lack skin lesions, mastocytosis is often overlooked or confused with endocrinologic, allergic, or other internal disorders. Case Report and Results: We report on a 33-year-old male patient in whom severe hypotensive episodes occurred after contact with ants or yellow jackets. Since no specific IgE was detected, the serum tryptase concentration was measured and found to be clearly elevated (70 ng/ml). Consecutive staging and examination of the bone marrow revealed ISM. The patient was advised to circumvent insect contact, to take antihistamines on demand, and to carry an epinephrine self-injector for emergency events. In a retrospective analysis of 40 patients seen between 1988 and 2003, only 2 had a life-threatening mediator-related episode before ISM was diagnosed. Conclusions: Our report confirms the diagnostic value of tryptase in patients with suspected mastocytosis. In addition, the report suggests that the lack of typical skin lesions does not exclude an indolent form of mastocytosis even if the serum tryptase is clearly elevated. Finally, our case further shows that mastocytosis can be an important differential diagnosis to be considered in patients with unexplained anaphylactoid or other mediator-related symptoms.

Serum tryptase measurements in patients with myelodysplastic syndromes.

Abnormal differentiation and maturation of hemopoietic cells are characteristic features of myelodysplastic syndromes (MDS). Tryptases (α- and β-type) are lineage-restricted serine proteases primarily expressed in mast cells (MC). We have analyzed expression of tryptase in 89 de novo MDS patients (refractory anemia (RA), n = 30; RA with ringed sideroblasts (RARS), n = 21; RA with excess of blasts (RAEB/RAEB-t), n = 27; chronic myelomonocytic leukemia (CMML), n = 11). Serum levels of total tryptase (α – protryptase + β – tryptase) were measured by FIA. The numbers of tryptase+ cells were determined in paraffin-embedded bone marrow (bm) sections by immunohistochemistry and morphometry. In healthy individuals, serum total tryptase levels ranged between < 1 and 15 ng/ml (5.6 ± 2.8 ng/ml). Tryptase levels of > 20 ng/ml were detected in 5/22 patients with RA (22.7%), 4/17 with RARS (23.5%), 0/16 with RAEB/RAEB-t, and 3/8 with CMML (37.5%). Thus, serum tryptase concentrations were higher in RA (16.6 ± 14.3 ng/ml), RARS (12.9 ± 8.2), and CMML (16.5 ± 7.6) compared to RAEB/-t (8.7 ± 3.8). By morphometry, elevated numbers of tryptase+ bm cells were detected in all MDS groups (RA: 139 ± 131; RARS: 118 ± 98; RAEB/RAEB-t: 80 ± 79; CMML: 105 ± 114 cells/mm2) compared to controls (54 ± 51 cells/mm2). As assessed by Northern blotting and protein analysis, bm cells in MDS primarily produced α-(pro)tryptase, but little or no β-tryptase. Together, our data show that elevated levels of tryptase are detectable in a group of patients with MDS probably because of an increase in neoplastic (mast) cells producing the enzyme(s). In addition, serum tryptase levels appear to correlate with MDS variants. Follow up studies should clarify whether an elevated tryptase concentration in MDS is of prognostic significance.

Severe Life-Threatening or Disabling Anaphylaxis in Patients with Systemic Mastocytosis: A Single-Center Experience

Background: Mediator-related symptoms in patients with systemic mastocytosis (SM) range from mild episodic to severe life-threatening events. Methods: We examined a series of 137 consecutive patients with mastocytosis (63 females and 74 males) referred to our center between 1988 and 2010. Almost all patients received prophylactic histamine receptor (HR1 and HR2) antagonists. Results: Forty-two patients suffered from one or more mediator-related symptoms (hypotension, headache, flush, abdominal cramping, diarrhea) requiring therapy (SMSY). Severe life-threatening events (grade IV) occurred in 17 patients (12%). In 4 of these 17 patients, a deteriorating clinical course was recorded. One patient died of an apallic syndrome 1.5 years after an hymenoptera sting and cerebral hypoxia. One patient was disabled for months after an insect sting and cerebral hypoxia. Two patients with smoldering SM (SSM) suffered from severe recurrent hypotension requiring hospitalization and repeated resuscitation. Symptoms in these SSM patients did not respond to any of the antimediator-type drugs applied. However, after therapy with cladribine (2CdA), a major durable response was obtained in both cases. In patients with aggressive SM and mast cell leukemia (n = 6), life-threatening mediator-related events (grade IV) were not recorded. Conclusions: SM may be accompanied by life-threatening mediator-related symptoms. Most of these patients have indolent SM or SSM. In patients with SSMSY with uncontrolled symptoms (grade IV), therapy with 2CdA should be considered.

Immunohistochemical detection of vascular endothelial growth factor (VEGF) in the bone marrow in patients with myelodysplastic syndromes: correlation between VEGF expression and the FAB category.

Recent data suggest that vascular endothelial growth factor (VEGF) is produced in neoplastic cells in various myeloid neoplasms and plays a key role as an autocrine regulator and mediator of angiogenesis. We examined the expression of VEGF in paraffin-embedded bone marrow sections obtained from normal donors (n = 5) and 46 patients with myelodysplastic syndromes [MDS, French–American–British (FAB)-type refractory anemia (RA), n = 10; refractory anemia with ringed sideroblasts (RARS), n = 10; refractory anemia with excess blasts (RAEB), n = 10; RAEB in transformation (RAEB-T), n = 8; chronic myelomonocytic leukemia (CMML), n = 8] by immunohistochemistry using an anti-VEGF antibody. In normal bone marrow, the anti-VEGF antibody was found to react with myeloid progenitor cells, immature monocytic cells, plasma cells and megakaryocytes, but not with erythroid cells or mature granulocytic cells. Higher levels of VEGF were found in patients with MDS, subtypes RAEB, RAEB-T and CMML, compared to patients with RA or RARS, or the normal bone marrow. These differences were found to result from expression of VEGF in immature myeloid cells in RAEB, RAEB-T and CMML. The microvessel density was also higher in patients with RAEB-T and CMML compared to RA and RARS or the normal bone marrow. Expression of VEGF mRNA was demonstrable in isolated neoplastic cells by reverse transcriptase-polymerase chain reaction in all patients examined. In aggregate, these data show that VEGF is expressed in bone marrow cells in patients with MDS. The amount of expressed VEGF is related to the percentage of immature myeloid cells (blasts and monocytic progenitors) and correlates with the FAB category.

The KIT D816V allele burden predicts survival in patients with mastocytosis and correlates with the WHO type of the disease

KIT D816V is present in a majority of patients with systemic mastocytosis (SM). We determined the KIT D816V allele burden by quantitative real‐time PCR in bone marrow and peripheral blood of 105 patients with mastocytosis. KIT D816V was detected in 92/105 patients (88%). Significant differences in the median allele burden were observed between disease subgroups: cutaneous mastocytosis (0.042%), indolent SM (0.285%), smoldering SM (5.991%), aggressive SM (9.346%), and SM with associated hematologic non‐mast cell lineage disease (3.761%) (P < 0.001). The KIT D816V burden also correlated with serum tryptase (R = 0.5, P < 0.005) but not with mast cell infiltration in bone marrow or mediator symptoms. Moreover, the allele burden was of prognostic significance regarding survival (P < 0.01). Patients responding to cytoreductive therapy showed a significant decrease in KIT D816V (P < 0.05). To conclude, the KIT D816V burden correlates with the variant of mastocytosis, predicts survival, and is a valuable follow‐up parameter in SM.

Increased Angiogenesis in the Bone Marrow of Patients with Systemic Mastocytosis

Recent data suggest that angiogenesis in the bone marrow (BM) is augmented and associated with growth of neoplastic cells in various hematological malignancies. Systemic mastocytosis (SM) is a neoplasm affecting multilineage and mast cell (MC)-committed hemopoietic progenitors. In the present study, we have assessed the BM microvessel density (MVD) by CD34 immunohistochemistry in 21 patients with SM, 5 with cutaneous mastocytosis (no BM infiltrates), and 5 control cases (normal BM). The median BM MVD was significantly higher in SM compared to cutaneous mastocytosis or controls (P < 0.05). In addition, a significant correlation (r = 0.74) between the BM MVD and grade of MC infiltration (percent tryptase(+) BM infiltrates) was found in SM. Moreover, the MVD was higher in MC infiltrates compared to the nonaffected adjacent marrow (P < 0.05). Immunohistochemical staining revealed expression of vascular endothelial growth factor in MC infiltrates. The notion that SM is associated with increased BM angiogenesis and vascular endothelial growth factor expression may have implications for the biology of disease and development of new treatment strategies.

Prognostic value of lactate dehydrogenase activity in myelodysplastic syndromes

Several prognostic factors for patients with myelodysplastic syndromes (MDS) have been defined in the past. One of these factors appears to be the serum lactate dehydrogenase (LDH) activity. However, the precise predictive value of an elevated LDH level with regard to AML transformation remains uncertain. In this study, the prognostic value of the LDH activity was examined in a cohort of 180 patients with de novo MDS (median age 71 years [27-93]; f/m-ratio 1:1.2; RA: n=53; RARS: n=37; RAEB: n=50; RAEBT: n=19; CMML: n=21). Significant differences in LDH activities were found among FAB groups (P<0.05), and especially among IPSS groups (HIGH: 411+/-574; INT-2: 221+/-90; INT-1: 254+/-145; LOW: 192+/-47 U/l; P<0.05). An LDH level of >/=300 U/l was found to be associated with a significantly shorter median survival (10.3 months) when compared to <300 U/l (33.7 months; P<0.01). Moreover, an LDH activity of >/=300 U/l indicated a reduced AML-free survival in our MDS patients (P<0.01). As assessed by Cox regression, the inclusion of LDH as additional variable into the IPSS system resulted in an improved prediction concerning survival, but not with regard to AML evolution. Together, our data show that a serum LDH activity of >/=300 U/l in MDS is associated with a significantly shorter survival and higher risk to transform to AML. The LDH activity should be considered as an important prognostic factor in MDS.