Mast Cell Diseases in Practice and Research: Issues and Perspectives Raised by Patients and Their Recommendations to the Scientific Community and Beyond.

BACKGROUND: Since 2010, patients and physicians have collaborated to understand unmet needs of patients with mast cell diseases, incorporating mastocytosis and mast cell activation disorders, which include mast cell activation syndromes. OBJECTIVE: This Open Innovation in Science project aims to expand understanding of the needs of patients affected by mast cell diseases, and encourage global communication among patient advocacy groups, physicians, researchers, industry, and government. A major aim is to support the scientific community's efforts to improve diagnosis, management, therapy, and patients' quality of life by addressing unmet needs. METHODS: In collaboration with mast cell disease specialists, 13 patient advocacy groups from 12 countries and regions developed lists of top patient needs. A core team of leaders from patient advocacy groups collected and analyzed the data and proposed possible actions to address patient needs. RESULTS: Findings identified similarities and differences among participating countries in unmet needs between patients with mastocytosis and those with mast cell activation syndromes. Issues emphasized struggles relating to the nature and rarity of mast cell diseases, their impact on quality of life, the diagnostic process, access to appropriate care, more effective treatment, and the need for research. CONCLUSIONS: Solutions vary across countries because situations differ, in particular regarding the existence of and access to centers of excellence and reference centers. Multifaceted mast cell activation syndrome barriers necessitate innovative approaches to improve access to appropriate care. The outcomes of this project should greatly support scientists and clinicians in their efforts to improve diagnosis, management, and treatment of patients with mastocytosis and mast cell activation disorders.

Prevalence of iron deficiency in pregnant women: A prospective cross-sectional Austrian study.

The aim of the study was to determine, for the first time, in a prospective cross-sectional multicenter study, the prevalence of iron deficiency (ID) in an Austrian pregnant population. A cohort of 425 pregnant women was classified into four groups of different weeks of gestation. Group 1 was monitored longitudinally, while groups 2-4, iron status, were sampled only once. Evaluation of the prevalence of ID was performed by comparing the diagnostic criteria of the WHO to the cutoff proposed by Achebe MM and Gafter-Gvili A (Achebe) and the Austrian Nutrition Report (ANR). In comparison with the ANR, the prevalence of ID was lower in group 1 and higher in groups 2-4 (17.2% vs. 12.17%, 25.84%, 35.29%, and 41.76%, respectively) (p-values < .01 except group 1). According to WHO, the prevalence in group 1 was 12.17% at inclusion, 2 months later 31.7%, and further 2 months later 65.71%, respectively. According to Achebe, the number of cases doubled; for group 1, the number of cases rose from 13 to 42 (115 patients total); for groups 2-4, we observed an increase from 112 to 230 (340 patients total). This study reported a prevalence of around 12% at the beginning of pregnancy, which increased during pregnancy up to 65%. ID can have a massive impact on quality of life, justifying screening, as iron deficiency would be easy to diagnose and treat.

Impact of HFE gene variants on iron overload, overall survival and leukemia-free survival in myelodysplastic syndromes.

Although iron overload is a clinical challenge, little is known about the clinical impact of HFE-variants in myelodysplastic syndromes (MDS) to date. We analyzed the HFE status in 167 MDS patients and 494 healthy controls. One or more of the 3 HFE-variants (H63D, C282Y, S65C) were found in 65/167 (38.9%) MDS patients and in 164/494 (33.2%) controls. At diagnosis, the median serum ferritin levels were higher in MDS patients with HFE-variants (409 µg/L; range: 23-7415) compared to those without HFE-variants (346.5 µg/L; range: 10-5450) (P=0.62). Moreover, 'HFE-mutated' patients had a slightly faster increase in serum ferritin in follow up examinations. The percentage of patients with HFE-variants was higher in refractory anemia (RA) (22/53=41.5%) or RA with ring sideroblasts (RARS) (17/39=43.6%) compared to RA with excess of blasts (RAEB) (16/46=34.8%) or RAEB in transformation (RAEB-T) (5/17=29.4%). Differences were also detectable when comparing low- and high-risk MDS variants defined by the World Health Organization classification. There was no significant correlation between HFE-variants and MDS-related somatic mutations. Progression-free survival was substantially longer in patients with HFE-variants compared to those without HFE-variants H63D and C282Y (P=0.089). Together, the HFE-variants H63D and C282Y are frequently detected in Austrian MDS patients. These patients have substantially higher ferritin levels at diagnosis, accumulate iron slightly faster and have a better progression-free survival than non-mutated patients.

Impact of frailty on the management of patients with gynecological cancer aged 80 years and older.

PURPOSE: To assess the impact of frailty on compliance of standard therapy, complication, rate and survival in patients with gynecological malignancy aged 80 years and older. METHODS: In total, 83 women with gynecological malignancy (vulva, endometrial, ovarian or cervical cancer) who underwent primary treatment between 2007 and 2017 were retrospectively analyzed. Frailty index was calculated and its association with compliance of standard treatment, peri- and postoperative mortality and morbidity, and survival was evaluated. RESULTS: Frailty was observed in 24.1% of cases. Both frail and non-frail patients were able to receive standard therapy in most cases - 75.0% and 85.7%, respectively (p = 0.27). Frail patients did not show an increased postoperative complication rate. Frail patients had shorter 3 years overall survival rates (28%) when compared to non-frail patients (55%) (p = 0.02). In multivariable analysis high frailty index (Hazard Ratio [HR] 12.15 [1.39-106.05], p = 0.02) and advanced tumor stage (HR 1.33 [1.00-1.76], p = 0.05) were associated with poor overall survival, but not age, histologic grading, performance status, and compliance of standard therapy. CONCLUSION: Majority of patients was able to receive standard therapy, as suggested by the tumor board, irrespective of age and frailty. Nonetheless, frailty is a common finding in patients with gynecological malignancy aged 80 years and older. Frail patients show shorter progression-free, and overall survival within this cohort.

Clustering of comorbidities is related to age and sex and impacts clinical outcome in myelodysplastic syndromes.

OBJECTIVES: Myelodysplastic syndromes (MDS) are typical diseases of the elderly. The clinical outcome of a well-characterized cohort of patients with MDS was analyzed for prevalence and impact of comorbidities to establish the basis for tailored treatment algorithms. Focus was on age- and sex-related differences. MATERIAL AND METHODS: The hematopoietic cell transplantation-comorbidity index (HCT-CI) was assessed in 616 well-defined patients from the Austrian MDS platform (median age: 71years). RESULTS: Most patients displayed one (24.5%) or more (23.7%) comorbidities. The highest frequencies were observed for cardiovascular disease (28.4%), diabetes (12.2%), and prior tumors (9.9%). Comorbidities were more frequent (mean number: 0.92 vs. 0.74 [male vs. female]; p=0.030) and more severe in men than in women (mean HCT-CI score: 1.41 vs. 1.09 [male vs. female]; p=0.016). Elderly patients (65+years) showed a higher prevalence of comorbidities than younger patients (HCT-CI score: 1.52, mean in 65+, vs. 0.24 and 0.76 in <45years and 46-65years, respectively) (p<0.001). These differences were most pronounced for cardiovascular disease, diabetes, and prior tumors (p<0.001). Presence of cardiac arrhythmia or prior solid tumor was significantly associated with shorter overall survival (p=0.023, 0.024, respectively). Moreover, HCT-CI risk grouping remained an independent prognostic parameter for survival in multivariate analysis. CONCLUSIONS: Comorbidities impact clinical outcome in elderly patients with MDS. Distinct diseases cluster in an age- and sex-related manner, which may have clinical implications when designing individualized therapies. Comorbidities should be evaluated with established scores and integrated in decision making.

Proposed score for survival of patients with myelodysplastic syndromes.

BACKGROUND: Patient selection for various therapies in myelodysplastic syndromes (MDS) is based on prognostic factors, scoring systems and the individual life expectancy. However, most established risk scores include mainly disease-related parameters and thus focus on leukaemia-transformation rather than survival. PATIENTS AND METHODS: To establish a risk score optimized for prediction of survival, we analysed international prognostic scoring system (IPSS)-related and IPSS-independent variables in 400 patients with primary MDS (median age: 71 years; range 18-91) of the Austrian MDS platform. Patients were randomly split into a learning sample (60%) and validation sample (40%). External validation was performed on 93 patients from the Heinrich Heine University (Duesseldorf/Germany). RESULTS: By multivariate analysis, IPSS, ferritin, age and comorbidities were found to be independent predictive variables concerning survival. Based on weighing these prognostic parameters against each other, we established a novel survival score employing IPSS, ferritin (< 900 ng/mL = 0; ≥ 900 ng/mL = 1), age (< 70 years = 0; 70-79 years = 1; ≥ 80 years = 1.5) and HCT-CI comorbidity (low/intermediate = 0; high = 0.5). Using this score, four prognostic risk groups could be discriminated in the validation sample, with highly significant differences in life expectancy [median survival: LowS (score 0), not reached; Int-1S (score 0.5-1.0), 3.84 years; Int-2S (score 1.5-2.0): 2.72 years; and HighS (score > 2.0): 0.80 years; P < 0.0001]. CONCLUSIONS: Our newly proposed score may be a useful tool for survival prediction in MDS and helpful in patient selection for various therapies in daily practice and clinical trials.

Guidelines and diagnostic algorithm for patients with suspected systemic mastocytosis: a proposal of the Austrian competence network (AUCNM).

Systemic mastocytosis (SM) is a hematopoietic neoplasm characterized by pathologic expansion of tissue mast cells in one or more extracutaneous organs. In most children and most adult patients, skin involvement is found. Childhood patients frequently suffer from cutaneous mastocytosis without systemic involvement, whereas most adult patients are diagnosed as suffering from SM. In a smaller subset of patients, SM without skin lesions develops which is a diagnostic challenge. In the current article, a diagnostic algorithm for patients with suspected SM is proposed. In adult patients with skin lesions and histologically confirmed mastocytosis in the skin (MIS), a bone marrow biopsy is recommended regardless of the serum tryptase level. In adult patients without skin lesions who are suffering from typical mediator-related symptoms, the basal serum tryptase level is an important diagnostic parameter. In those with slightly elevated tryptase (15-30 ng/ml), additional non-invasive investigations, including a KIT mutation analysis of peripheral blood cells and sonographic analysis, is performed. In adult patients in whom i) KIT D816V is detected or/and ii) the basal serum tryptase level is clearly elevated (> 30 ng/ml) or/and iii) other clinical or laboratory features are suggesting the presence of occult mastocytosis, a bone marrow biopsy should be performed. In the absence of KIT D816V and other indications of mastocytosis, no bone marrow investigation is required, but the patient's course and the serum tryptase levels are examined in the follow-up.

Idiopathic cytopenia of undetermined significance (ICUS) and idiopathic dysplasia of uncertain significance (IDUS), and their distinction from low risk MDS.

It is now generally appreciated that hematologic neoplasms can develop over many years if not decades, often being initially occult or showing minimal (subdiagnostic) abnormalities. However, whereas such early neoplastic conditions have been defined in some detail in lymphoproliferative neoplasms, little is known about minimal lesions preceding the manifestation of an overt myeloid neoplasm, about underlying mechanisms, the clinical course and outcome, and the prognostic significance of such conditions. Members of several groups have recently described two 'premalignant' myeloid conditions, namely idiopathic cytopenia of undetermined significance (ICUS) and idiopathic bone marrow dysplasia of uncertain significance (IDUS). At least in some patients these are neoplastic conditions. Both conditions may progress to an overt myelodysplastic syndrome (MDS), but may also progress to another myeloid neoplasm such as acute myeloid leukemia, a myeloproliferative neoplasm (MPN), or a mast cell disorder (mastocytosis). In ICUS the dysplasia is mild and does not fulfill the WHO criteria for MDS but cytopenias can be severe. In IDUS the dysplasia is prominent but cytopenias, if detectable, are mild. In both conditions it is possible that a neoplastic clone has already replaced most or all of normal bone marrow cells when ICUS or IDUS is detected, but evidence to support this possibility is not necessarily available. For both groups of patients we recommend a thorough hematologic follow up because of the potential of disease-manifestation and the unpredictable form and time of progression. In the present review, we discuss current concepts relating to ICUS and IDUS as well as diagnostic approaches and available criteria.

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 (SM(SY)). 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 SSM(SY) with uncontrolled symptoms (grade IV), therapy with 2CdA should be considered.

Idiopathic bone marrow dysplasia of unknown significance (IDUS): definition, pathogenesis, follow up, and prognosis.

Minimal diagnostic criteria for myelodysplastic syndromes (MDS) include constant cytopenia recorded for at least 6 months, dysplasia, and exclusion of other causes of cytopenia and dysplasia. However, there are patients with dysplastic bone marrow features with or without a karyotype, who have only mild if any cytopenia. This condition has been termed idiopathic dysplasia of unknown significance (IDUS). Out of a series of 1,363 patients with suspected MDS or mild cytopenia seen between 1997 and 2010, we have identified 10 patients with IDUS, and analyzed their clinical course and outcome as well as features potentially involved in disease-evolution. Follow-up ranged between 2 and 13 years. Progression to an overt myeloid neoplasm was observed in 4 patients: two progressed to frank MDS, one to chronic myelomonocytic leukemia, and one to a myelodysplastic/myeloproliferative neoplasm exhibiting 5q-and JAK2 V617F. Consecutive studies revealed that most IDUS patients have an adequate production of erythropoietin (EPO) and sufficient numbers of EPO-responsive erythroid progenitors, features rarely seen in MDS. The erythropoiesis-promoting JAK2 mutation V617F was only detectable in one case. We hypothesize that the dysplastic clone in IDUS cannot manifest as frank MDS because i) the clone retains responsiveness against EPO, and ii) an adequate EPO-production counteracts anemia. Evolution of IDUS to low risk MDS may thus depend on the biological properties of the clone as well as patient-related factors such as EPO production. The latter often decreases with age and may thus explain why MDS often manifests in the elderly.

Evaluation of the prognostic significance of eosinophilia and basophilia in a larger cohort of patients with myelodysplastic syndromes.

BACKGROUND: Lineage involvement and maturation arrest are considered to have prognostic significance in patients with myelodysplastic syndromes (MDS). However, although the prognostic value of neutropenia, thrombocytopenia, and monocytosis have been documented, little is known about the impact of eosinophils and basophils. METHODS: The authors examined the prognostic significance of eosinophils and basophils in 1008 patients with de novo MDS. Patients were enrolled from 3 centers of the Austrian-German MDS Working Group and were analyzed retrospectively. Blood eosinophils and basophils were quantified by light microscopy, and their impact on survival and leukemia-free survival was calculated by using Cox regression. RESULTS: Eosinophilia (eosinophils >350/microL) and basophilia (basophils >250/microL) predicted a significantly reduced survival (P < .05) without having a significant impact on leukemia-free survival. In multivariate analysis, eosinophilia and basophilia were identified as lactate dehydrogenase (LDH)-independent prognostic variables with International Prognostic Scoring System (IPSS)-specific impact. Although elevated LDH was identified as a major prognostic determinant in IPSS low-risk, intermediate-1 risk, and high-risk subgroups, the condition "eosinophilia and/or basophilia" was identified as a superior prognostic indicator in the IPSS intermediate-2 risk subgroup. CONCLUSIONS: The evaluation of eosinophils and basophils in patients with MDS was helpful and may complement the spectrum of variables to optimize prognostication in MDS.

Standards and impact of hematopathology in myelodysplastic syndromes (MDS).

The diagnosis, classification, and prognostication of patients with myelodysplastic syndromes (MDS) are usually based on clinical parameters, analysis of peripheral blood and bone marrow smears, and cytogenetic determinants. However, a thorough histologic and immunohistochemical examination of the bone marrow is often required for a final diagnosis and exact classification in these patients. Notably, histology and immunohistology may reveal dysplasia in megakaryocytes or other bone marrow lineages and/or the presence of clusters of CD34-positive precursor cells. In other cases, histology may reveal an unrelated or co-existing hematopoietic neoplasm, or may support the conclusion the patient is suffering from acute myeloid leukemia rather than MDS. Moreover, histologic investigations and immunohistology may reveal an increase in tryptase-positive cells, a coexisting systemic mastocytosis, or bone marrow fibrosis, which is of prognostic significance. To discuss diagnostic algorithms, terminologies, parameters, and specific issues in the hematopathologic evaluation of MDS, a Working Conference involving a consortium of US and EU experts, was organized in June 2010. The outcomes of the conference and resulting recommendations provided by the faculty, are reported in this article. These guidelines should assist in the diagnosis, classification, and prognostication in MDS in daily practice as well as in clinical trials.

Meeting report: Vienna 2008 Workshop of the German-Austrian Working Group for Studying Prognostic Factors in Myelodysplastic Syndromes.

Criteria, scoring systems, and treatment algorithms for myelodysplastic syndromes (MDS) have been updated repeatedly in recent years. This apparently results from increased awareness and early recognition of the disease, an increasing number of new diagnostic and prognostic markers and tools, and new therapeutic options that may change the course and thus prognosis in MDS. To address these challenges and to create useful new diagnostic and prognostic parameters and scores, the German-Austrian Working Group for Studying Prognostic Factors in MDS was established in 2003 and later was extended to centers in Switzerland (D-A-CH group). In addition, the group cooperates with the European LeukemiaNet, the MDS Foundation, and other national and international working groups in order to improve diagnosis and prognostication. The current article represents a meeting report from the latest workshop organized by the group in Vienna in October 2008.

[Individualized management and therapy of myelodysplastic syndromes]. / Die individualisierte Riskoeinschätzung und Therapieplanung bei myelodysplastischen Syndromen.

Myelodysplastic syndromes (MDS) are characterized by ineffective hematopoiesis and a tendency to transition to acute myeloid leukemia. Due to the increasing number of older patients in Austria and the high frequency of therapy-associated MDS following successful chemo- and/or radiotherapy of a primary tumor, the frequency and relevance of MDS are continuously increasing. While therapeutic options were until recently limited to best supportive care, AML-like induction chemotherapy and hematopoietic stem cell transplantation (HSCT) in younger patients, in recent years new therapeutic options have become available. Supportive care was improved through the introduction of effective iron chelation and the availability of hematopoietic growth factors like erythropoiesis-stimulating factors (ESF) and granulocyte colony-stimulating factors (G-CSF). In addition, immune-modulating drugs (IMiDs) like lenalidomide or epigenetically effective agents like the cytosine analogues or histone deacetylase (HDAC) inhibitors have become available and are highly effective in distinct subgroups of MDS patients. The development of state-of-the art recommendations is one of the major aims of the MDS Platform of the Austrian Society of Hematology and Oncology. This manuscript reviews recent developments in clinical scoring and targeted and individualized MDS therapy and discusses their relevance in and potential applicability to daily practice.

Impact of age and comorbidity in myelodysplastic syndromes.

Myelodysplastic syndromes (MDS) represent a heterogeneous group of myeloid neoplasms that are preferentially diagnosed in the elderly. With the increase in older patients with MDS in the Western world and the availability of more therapeutic options, new strategies and algorithms for optimal management and treatment of these patients must be developed. Although age is recognized as an important adverse variable affecting survival, most scoring systems have not included age in score risk calculations. Comorbidity is of particular importance and a frequent covariable in elderly patients with MDS. However, although comorbidity scores have been established and used for risk assessment in younger high-risk patients scheduled to undergo intensive therapy, these scores are only just being applied to elderly patients, with relevant results. Advanced age should not exclude a patient with MDS from appropriate treatment, and age alone should not be considered a surrogate marker for functional decline or comorbidities. This article discusses the need to improve scoring systems, individualized risk-assessment, and treatment algorithms for elderly patients with MDS by including age and comorbidities.

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.

Idiopathic cytopenia of undetermined significance (ICUS) versus low risk MDS: the diagnostic interface.

It may sometimes be difficult to diagnose low risk MDS in patients with mild cytopenia. We report on 10 patients with mild to marked, unexplained cytopenia without definitive signs of a myeloid neoplasm. In two patients, a karyotype-abnormality (trisomy 14; monosomy 7) was detected in a small subset of bone marrow cells. Progression to overt MDS was seen in two patients including the one with monosomy 7. In the remaining cases, no MDS developed in a follow-up of at least 6 months. The phrase "idiopathic cytopenia of undetermined significance (ICUS)", as also suggested by Mufti and co-workers, is proposed and long term follow-up is recommended to assess the evolution.

Eosinophilia in systemic mastocytosis: clinical and molecular correlates and prognostic significance.

BACKGROUND: In a group of patients with systemic mastocytosis (SM), marked and sustained eosinophilia is detectable (SM-eo). OBJECTIVE: Although the molecular defect has been defined in some cases, little is known about the impact and clinical correlates of eosinophilia. METHODS: In a cohort of 63 patients with SM, we identified 9 with permanent eosinophilia (>1500/microL). According to the World Health Organization classification, 2 had indolent SM, 1 had smoldering SM, 2 had SM with associated chronic eosinophilic leukemia (SM-CEL), and 4 had aggressive SM. RESULTS: SM-eo was found to be associated with a significantly reduced probability of overall and event-free survival compared with SM without eosinophilia (P < .05). In the 2 patients with SM-CEL, a CHIC2 deletion was found. By contrast, no KIT mutation at codon 816 was detectable in these patients. In the other patients with SM-eo, KIT D816V was demonstrable. The 2 patients with SM-CEL had cardiomyopathy, whereas other organ systems remained largely unaffected. By contrast, in all other patients with SM-eo, organopathy, if recorded, affected the bone marrow, liver, or/and skeletal system, but not the heart, even when eosinophilia persisted for many years. CONCLUSIONS: The biochemical basis of eosinophilia in SM is variable and predictive for the type of organopathy. CLINICAL IMPLICATIONS: In SM eosinophilia is of prognostic significance but is not a final diagnosis and is not invariably associated with cardiomyopathy. The latter might be restricted to cases with an associated primary eosinophilic disorder (SM-CEL).

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.

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.