Hypereosinophilia

Hypereosinophilic syndrome with cardiac and cutaneous involvement: Missed treatment opportunity of a case from Ethiopia

Understand the importance of considering alternative diagnosis in patients presenting with atypical features. Understand the importance of considering common presentations of rare cases. Underscoring the critical importance of timely recognition and appropriate management of potentially life-threatening condition.

Hypereosinophilic vasculitis with Raynaud phenomenon presentation: a case report

BACKGROUND

Previous case series have reported idiopathic eosinophilic vasculitis as a potential manifestation of hypereosinophilic syndrome (HES). This condition is characterized by digital necrotizing, systemic vasculitis that affects varying-sized blood vessels. This report presents our experience in treating a patient with eosinophilic vasculitis.

CASE PRESENTATION

We describe the case of a 23-year-old man who presented with idiopathic HES, which manifested as digital ulcers and peripheral ischemia in both the upper and lower limbs, without the involvement of other organ systems. After ruling out primary and secondary causes of eosinophilia, a diagnosis of HES was established. Our patient has shown a positive response to corticosteroid therapy.

CONCLUSIONS

Our case contributes to the existing evidence about diagnosing idiopathic eosinophilic vasculitis in patients with HES. We observed a favorable response to corticosteroid treatment in our patient.

Emerging Role of Eosinophils in Resolution of Arthritis

Eosinophils are a minor component of circulating granulocytes, which are classically viewed as end-stage effector cells in host defense against helminth infection and promoting allergic responses. However, a growing body of evidence has emerged showing that eosinophils are versatile leukocytes acting as an orchestrator in the resolution of inflammation. Rheumatoid arthritis (RA) is the most common chronic inflammatory disease characterized by persistent synovitis that hardly resolves spontaneously. Noteworthy, a specific population of eosinophils, that is, regulatory eosinophils (rEos), was identified in the synovium of RA patients, especially in disease remission. Mechanistically, the rEos in the synovium display a unique pro-resolving signature that is distinct from their counterpart in the lung. Herein, we summarize the latest understanding of eosinophils and their emerging role in promoting the resolution of arthritis. This knowledge is crucial to the design of new approaches to rebalancing immune homeostasis in RA, considering that current therapies are centered on inhibiting pro-inflammatory cytokines and mediators rather than fostering the resolution of inflammation.

Gallbladder cancer accompanied by uncontrollable eosinophilia: report of a case

A 48-year-old male was referred to our hospital for evaluation of motor speech disorders and difficulty in the movement of both the hands. The clinical diagnosis was Trousseau's syndrome due to advanced gallbladder cancer (cT3aN1M0). The patient received anticoagulation therapy and systemic chemotherapy (gemcitabine and cisplatin). Motor speech disorders and difficulty in movement of both hands were recovered. After 2 courses of chemotherapy, the primary tumor developed a massive hepatic invasion and the peripheral blood eosinophils increased gradually. The patient was admitted to our hospital for abdominal distension, fever, right upper quadrant pain, systemic edema, loss of appetite, and general malaise. The peripheral blood eosinophil count was markedly elevated to 45,900/μl (90.3%). The serum level of GM-CSF was high and there was no evidence of leukemia, allergic status and other diseases. The patient was diagnosed as paraneoplastic eosinophilia with advanced gallbladder cancer, which was suspected to produce GM-CSF. The patient received palliative support and died of disseminated intravascular coagulation 15 days after admission. We herein reported a fatal case of gallbladder cancer suspected of producing GM-CSF.

What Are the Clinical Features and Etiology of Eosinophilic Liver Infiltration?

Background/Aims

Although eosinophilic liver infiltration (ELI) is not rare, few data exist regarding its clinical characteristics and etiology. Therefore, we evaluated these aspects to better understand the clinical implications of this lesion type, which is reasonably common in Korea.

Methods

Patients suspected of having ELI, based on abdominal computed tomography results obtained between January 2010 and September 2017, were enrolled in this retrospective study. The presumptive etiologies of ELI were categorized as parasite infections, hypereosinophilic syndrome (HES), eosinophilic granulomatosis with polyangiitis (EGPA), malignancies, and unidentified. Clinical courses and treatment responses were also evaluated.

Results

The mean age of the enrolled patients (male, 237/328) was 62 years. Most patients (63%) were diagnosed incidentally and had peripheral eosinophilia (90%). Only 38% of the enrolled patients (n=126) underwent further evaluations to elucidate the etiology of the suspected ELI; 82 (25%) had parasite infections, 31 (9%) had HES, five (2%) had EGPA, and five (2%) had drug reactions in conjunction with eosinophilia and systemic symptoms. Almost half of the other enrolled patients had cancer. Radiologic resolution was achieved in 191 patients (61%; median time to radiologic resolution, 185 days). Resolution of peripheral eosinophilia was achieved in 220 patients (79%). In most cases, the course of ELI was benign.

Conclusions

This large ELI study is unique in that the incidence rate, underlying diseases, and clinical courses were comprehensively evaluated. Clinicians should investigate the etiology of ELI, as several of the underlying diseases require intervention rather than observation.

Response to corticosteroids and cytotoxic drugs in a case of idiopathic hypereosinophilic syndrome with predominantly elevated eosinophils and multiple clinical manifestations

In the present case study, a 42-year-old Chinese woman fulfilling the WHO criteria for idiopathic hypereosinophilic syndrome (IHES) who exhibited clinical manifestations of eosinophilic infiltration of multiple tissues including the lungs, heart, central and peripheral nervous system, gastrointestinal tract, spleen, liver and unexplained clinical findings is described. Laboratory investigations revealed the topmost white blood cell and eosinophil that were 150 × 10(9)/L and 136 × 10(9)/L (90.6 %), respectively. To our knowledge, such a large number of eosinophils has rarely been reported, and all reactive causes of hypereosinophilia were excluded. Treatment with cytotoxic chemotherapy, prednisone and dexamethasone was not beneficial. The patient showed a remarkable hematological response when methylprednisolone pulse therapy was initiated when progression of respiratory symptoms occurred, but without clinical remission. The patient subsequently died. We consider that her critical organ damage and poor prognosis were related to the large number of eosinophils and delayed effective anti-eosinophilic therapy after severe organ damage occurred. This case highlights the clinical importance of methylprednisolone pulse therapy which should be initiated without delay once the diagnosis of IHES is made.

The coincidence of familial mediterranean Fever and hypereosinophilia in a patient with hereditary elliptocytosis

Familial Mediterranean fever (FMF) is a genetic disease with autosomal inheritance characterized by recurrent fever, abdominal pain, and serositis attacks. It is relatively common in the races and ethnical groups around Mediterranean Sea (Sephardic Jews, Armenians, Turks and Arabians). Hereditary elliptocytosis (HE) is common genetic defect of the red blood cell membrane skeleton. Spectrin mutations are the predominant causes of HE. Hypereosinophilia is defined as a number of eosinophil granulocytes equal or greater than 0.5 × 10(9)/L of circulating blood. The main causes are allergies and parasitic infections. This case report describes a Turkish female HE patient who presented with FMF and hypereosinophilia. Genetic analysis revealed heterozygous mutation in exon 10 of the MEFV gene (V726A). The patient was successfully treated with colchicine and steroid treatment at 3-month follow-up. To the best of our knowledge, this is the first report of association between FMF, HE, and hypereosinophilia.

Prominent hypereosinophilia with disseminated intravascular coagulation as an unusual presentation of advanced gastric cancer

A 78-year-old woman was admitted to our hospital complaining of anorexia and purpura of the extremities. She presented with prominent peripheral eosinophilia and disseminated intravascular coagulation (DIC). Despite receiving intensive therapy for DIC, her illness worsened. Esophagogastroduodenoscopy revealed advanced gastric cancer (AGC), and a bone marrow biopsy led to a diagnosis of disseminated carcinomatosis of the bone marrow caused by AGC. We initiated combination chemotherapy with S-1 and cisplatin, which lead to a significant improvement of the DIC and eosinophilia, and the patient was finally discharged. The primary symptoms of DIC and eosinophilia were both considered to be caused by AGC, and we successfully treated the patient's critical condition.

Clonal hypereosinophilic syndrome: two cases report in black men from sub-saharan Africa and literature reviews

The first case is about a man of 60 years old suffering of hypereosinophilic syndrome (HES) developed since 1998. He presented chronic cough, insomnia, and negative parasitical test. We observed hypereosinophilia and fibroblastic hyperplasia at the bone marrow biopsy. Initially, hydroxyurea and α-interferon treatment failed. We proposed to him imatinib mesylate in May 2003. The FIP1L1-PDGFRA gene was detected. The second case is about a man of 34 years old seen in March 2002. First investigation concluded to CML. Progressively, eosinophil cells increased, and complications occurred as oedema syndrome, dyspnoea, and parietal chronic endocarditic fibrosis associated with pericarditis. In addition, a bowel obstruction happened and was cured by surgery. Bcr-abl fusion was negative, and FIP1L1-PDGFRA gene was detected after and imatinib mesylate was given. Actually, endocarditic fibrosis decreased. The two patients are in haematological and cytogenetic remission. We concluded that clonal HES is present in Africa, and imatinib mesylate is effective.

Advances in diagnosis and treatment of eosinophilia

PURPOSE OF REVIEW

Hypereosinophilic syndromes (HESs) are disorders characterized by sustained blood or tissue hypereosinophilia or both with subsequent damage to various organs due to eosinophilic infiltration and release of mediators. HES are now recognized to include varied eosinophilic disorders for some of which there are recent insights into their pathogenesis and targeted treatment.

RECENT FINDINGS

Studies have helped delineate two subtypes of HES: the myeloproliferative variants of HES and the lymphocytic variants of HES. Many, but not all, myeloproliferative-HES patients have interstitial deletions on chromosome 4q12 that lead to fusion of the FIP1-like 1 and platelet-derived growth factor receptor alpha genes, with the fusion product encoding a protein that has constitutive tyrosine kinase activity. Lymphocytic-HES is a primary lymphoid disorder characterized by nonmalignant expansion of a T-cell population able to produce eosinophilopoietic cytokines, with the T-cell population being identified by flow cytometry or reverse transcriptase-PCR for T-cell receptor usage or both. Other HES subtypes are of uncertain causes and are included in recent diagnostic algorithms for the spectrum of HES.

SUMMARY

The contemporary definition of the hypereosinophilic syndromes encompasses a range of eosinophilic disorders characterized by chronic blood hypereosinophilia often with eosinophil-mediated damage to various organs.

Oral mucosa lesions in hypereosinophilic syndrome--an update

Hypereosinophilic syndrome (HES) is a rare disorder characterized by persistent and marked eosinophilia. Some HES forms have a poor prognosis, either because of end-organ damage (particularly endomyocardial fibrosis), or because of associated myeloid leukemia or malignant T-cell lymphoma. Oral mucosa ulcerations can be early clinical signs in severe forms. They are discrete, round or oval, sometimes confluent ulcers or erosions, located on non-keratinized, unattached oral mucosa. In the last 15 years a better understanding of eosinophil biology has led to a new clinical classification of HES. The lymphocytic form is characterized by T-lymphocyte clonality, IL-5 production, and a possible progression to T-cell lymphoma. Oral lesions are more frequently associated with the myeloproliferative form, characterized by an increased risk of developing myeloid malignancies and a good response to a recent anti-tyrosine kinase therapy (imatinib mesylate). The target of imatinib is a novel kinase resulting from an 800-kb deletion on chromosome 4. Recently, the resulting FIP1L1-PDGFRalpha fusion gene was characterized as a marker of response to imatinib. Exclusion of other erosive ulcerative oral disease and early recognition of HES in patients with oral ulcerations, and precise characterization of the lymphocytic or myeloproliferative form are therefore important to rapidly initiate an effective therapy.

Clinical overview of hypereosinophilic syndromes

Hypereosinophilic syndrome (HES) or syndromes are disorders characterized by chronic peripheral blood hypereosinophilia with damage to various organs due toeosinophilic infiltration and release of mediators. HES is most accurately described as a collection of heterogeneous disorders, with some similarities in clinical features, but many differences. Based on recent advances in molecular and genetic diagnostic techniques and increasing experience with differences in clinical features and prognosis, some subtypes of HES have been defined, such as myeloproliferative variants, including chronic eosinophilic leukemia, and lymphocytic variants, but other subtypes remain undefined. Recent evidence suggests that, in addition to differences in clinical features, the range of complications, treatment options, and prognoses differs significantly among the myeloproliferative, lymphocytic, and undefined variants of HES.

Evaluation and differential diagnosis of marked, persistent eosinophilia

Hypereosinophilic syndromes (HES) are a group of heterogeneous disorders many of which remain ill-defined. By definition, the HES must be distinguished from other disorders with persistently elevated eosinophilia with a defined cause. Although marked eosinophilia worldwide is most commonly caused by helminth (worm) infections, the diagnostic approach must include noninfectious (nonparasitic) causes of marked eosinophilia as well.

WT1 transcript amount discriminates secondary or reactive eosinophilia from idiopathic hypereosinophilic syndrome or chronic eosinophilic leukemia

Idiopathic hypereosinophilic syndromes (HES) comprise a spectrum of indolent to aggressive diseases characterized by persistent hypereosinophilia. Hypereosinophilia can result from the presence of a defect in the hematopoietic stem cell giving rise to eosinophilia, it can be present in many myeloproliferative disorders or alternatively it may be a reactive form, secondary to many clinical conditions. The hybrid gene FIP1L1-PDGRFalpha was identified in a subset of patients presenting with HES or chronic eosinophilic leukemia (CEL). In spite of this, the majority of HES patients do not present detectable molecular lesions and for many of them the diagnosis is based on exclusion criteria and sometimes it remains doubt. In this study we explored the possibility to distinguish between HES/CEL and reactive hypereosinophilia based on WT1 transcript amount. For this purpose, 312 patients with hypereosinophilia were characterized at the molecular and cytogenetic level and analyzed for WT1 expression at diagnosis and during follow-up. This study clearly demonstrates that WT1 quantitative assessment allows to discriminate between HES/CEL and reactive eosinophilia and represents a useful tool for disease monitoring especially in the patients lacking a marker of clonality.

The hypereosinophilic syndromes: still more heterogeneity

In 1968, the term hypereosinophilic syndromes (HES) was coined to refer to a spectrum of eosinophil-associated diseases presumed to be caused by an underlying immunological pathology. In the 1990s, the identification of an HES subset with T lymphocyte clonality and production of cytokines, particularly IL-5, validated this concept. Then, in 2002, imatinib mesylate, which was introduced for the treatment of chronic myelogenous leukemia, effectively controlled another subgroup of HES patients. Imatinib's target is a novel constitutively-active kinase. Most imatinib-responsive HES patients show an increased number of bone marrow mast cells and elevated serum tryptase; mast cells, lymphocytes and neutrophils express the novel kinase. This new information critically modifies our view of HES and indicates that several cell lines are altered and likely to contribute to HES pathophysiology.

Hypereosinophilic syndrome: an update

Hypereosinophilic syndrome (HES) is a rare disorder that is characterized by persistent and marked eosinophilia combined with organ system dysfunction. HES has substantial clinical heterogeneity but can be fatal without treatment, especially in patients who present with a myelodysplastic variant of the disorder. Although the pathophysiology of HES is poorly defined, dysregulation of cytokines (interleukin 5 [IL-5], IL-3, granulocyte-macrophage colony-stimulating factor [GM-CSF]) responsible for the maturation of eosinophils is a primary feature. Of these cytokines, IL-5 appears to have the greatest role in the regulation of eosinophil maturation. There is no Food and Drug Administration-approved treatment for HES as yet; current strategies are designed to lower blood eosinophils and attempt to limit end-organ damage. Historically, corticosteroids and cytotoxic agents have been the mainstays of therapy, with biological response modifiers such as interferon-alpha also effective in some patients. However, despite improvements in survival, available agents have significant limitations in terms of efficacy, tolerability, and long-term toxicity. More recently, new agents directed at specific targets in the pathogenesis of HES have been developed. These include imatinib mesylate, a tyrosine kinase inhibitor, and more recently, mepolizumab, an anti-IL-5 monoclonal antibody. In a small case series of patients, these agents have been shown to produce hematological and clinical responses in patients with HES, although they may be effective in different subsets of patients. These targeted therapies have the potential to improve clinical outcomes and to further the understanding the pathophysiology of this difficult-to-treat condition.

Atypical presentation of eosinophilic endomyocardial disease

Idiopathic hypereosinophllic syndrome is classically defined as prolonged, unexplained peripheral eosinophilia in a patient presenting with evidence of end-organ damage. The heart is frequently Involved, resulting In eosinophilic endomyocardial disease and eventually restrictive cardlomyopathy. The mortality rate is high because of progressive heart failure or ventricular arrhythmias. We describe a patient who presented with a left ventricular apical thrombus without notable peripheral eosinophilia. Findings from clinical evaluation and extensive diagnostic testing, including right ventricular biopsy, were Inconclusive. Resection of the thrombus and subjacent endomyocardium revealed eosinophilic Infiltration of the endomyocardium, which led to the diagnosis of eosinophilic endomyocardial disease. Clinicians should be aware of the variable presentation of patients with eosinophil-associated endomyocardial disease so that affected patients may benefit from early diagnosis and treatment.

Hypereosinophilia presenting as eosinophilic vasculitis and multiple peripheral artery occlusions without organ involvement

We report here a case with hypereosinophilia and peripheral artery occlusion. A 32-yr-old Korean woman presented to us with lower extremity swelling and pain. Angiography revealed that multiple lower extremity arteries were occlusive. The biopsy specimen showed perivascular and periadnexal dense eosinophilic infiltration in dermis and subcutaneous adipose tissue. Laboratory investigations revealed a persistent hypereosinophilia. She was prescribed prednisolone 60 mg daily. Her skin lesion and pain were improved and the eosinophil count was dramatically decreased. After discharge, eosinophil count gradually increased again. Cyanosis and pain of her fingers recurred. She had been treated with cyclophosphamide pulse therapy. Her eosinophilia was decreased, but the cyanosis and tingling sense were progressive. The extremity arterial stenoses were slightly progressed. Skin biopsy showed perivascular eosinophilic infiltration in the dermis and CD40 ligand (CD40L) positive eosinophilic infiltration. The serum TNF-alpah was markedly increased. These results suggest that CD40L (a member of TNF-alpah superfamily) could play a role in the inflammatory processes when eosinophil infiltration and activation are observed. We prescribed prednisolone, cyclophosphamide, clopidogrel, cilostazol, beraprost and nifedipine, and she was discharged.

Manifestations cardiaques du syndrome hyperéosinophilique essentiel

BACKGROUND

The aim of our study is to describe the more common cardiac manifestations of idiopathic hypereosinophilic syndrome representing the major cause of mortality.

MAIN POINTS

Current therapy consists of corticosteroid, hydroxyurea and interferon alpha. Recent publications confirm the activity of imatinib mesylate, a selective tyrosine kinase inhibitor, in patients with idiopathic hypereosinophilic syndrome. In cases with marked valvular compromise or with endomyocardial thrombosis or fibrosis, cardiac surgery can provide substantial benefits.

PERSPECTIVES

A better understanding of the pathophysiology of this syndrome could lead to the development of new therapeutic agents.

Evaluation of eosinophilia in hospitalized preterm infants

OBJECTIVE

To characterize changes in eosinophil counts over time, and to draw comparisons across four gestational age groups with respect to the incidence of, and clinical conditions associated with eosinophilia over the first months of life in a single neonatal intensive care unit (NICU).

STUDY DESIGN

Weekly complete blood counts (CBCs) were collected from all NICU patients. Eosinophilia was classified as mild, moderate, or severe. Changes in eosinophil counts were examined over time, the incidence of eosinophilia was determined by gestational age group, and clinical correlations sought.

RESULTS

Eosinophil data from 1652 CBCs were analyzed from 332 infants. Eosinophilia occurred in 148 infants (45%) during their hospitalization. The prevalence, severity, and timing of eosinophilia varied by gestational age, infection, and red blood cell transfusions.

CONCLUSIONS

The incidence and severity of eosinophilia increased with immaturity, and was temporally associated with infection, necrotizing enterocolitis, and packed red blood cell transfusion.

Interferon treatment for hypereosinophilic syndromes and systemic mastocytosis

Hypereosinophilic syndromes (HES) and systemic mastocytosis (SMCD) are heterogeneous disorders with clinical symptoms from local and remote effects of excessive proliferation of eosinophils and mast cells, respectively. Interferon alpha (IFN-alpha), alone or in combination with other medications, can be a useful, and at times life-saving, treatment for patients with HES. Receptors for IFN-alpha are present on eosinophils, and clinical benefits are due to its effect on eosinophil proliferation, migration, activation, and survival. These effects are likely mediated through multiple pathways including, but not limited to, inhibition of eosinophil colony-forming cells, upregulation of IFN-gamma synthesis, and inhibition of production of eosinophil-active cytokines by T cells, mast cells, and mononuclear cells. IFN-alpha has been life-saving for patients with intractable HES that were resistant to prednisone, hydroxyurea, and other agents. Resistance to the eosinopenic effect of IFN-alpha does not develop and the dose of IFN-alpha necessary to maintain control of eosinophilia often decreases with time. The combination of IFN-alpha and hydroxyurea is very useful and allows dosage reduction of IFN-alpha and better control of hypereosinophilia than with either agent alone. The efficacy of IFN-alpha for treatment of SMCD has been more difficult to establish, with both favorable and unfavorable results reported. The disparate results may have resulted from the small number of patients with SMCD treated with IFN-alpha, the use of various criteria for a "successful" treatment outcome, short duration of treatment and follow-up, and the use of modest dosages. In reported series, side effects from IFN-alpha have frequently been dose-limiting. IFN-alpha improves many of the clinical symptoms of SMCD including dermatological, hematological, gastrointestinal, and systemic symptoms associated with histamine release. IFN-alpha has a beneficial effect on skeletal symptoms because of its ability to increase bone density and reduce painful episodes from vertebral fractures. No consistent improvement in bone marrow infiltration by mast cells has been demonstrated except in a recent study employing high dosages of IFN-alpha. A beneficial effect from the combination of IFN-alpha and prednisone has been reported for several patients, suggesting that combined use of these two medications may provide synergism in treatment outcomes.

In situ eosinophil activation in 26 primary cutaneous T-cell lymphomas with blood eosinophilia

Blood and tissue eosinophils can be associated with Hodgkin and non-Hodgkin lymphomas in that they have prognostic value. Tissue eosinophils in T-cell lymphoma patients with blood eosinophilia have not been systematically assessed. The objective of this research was to study the presence, density, and activation of tissue eosinophils in patients with primary cutaneous T-cell lymphomas (CTCLs) with blood eosinophilia and a possible relationship between features of the disease and prognosis. With skin biopsy specimens from 26 CTCL patients with blood eosinophilia, tissue eosinophils were studied with electron microscopy, extracellular eosinophil peroxidase deposits, and interleukin-5 expression. Tissue eosinophils, found in 22 of 26 cases, were constantly activated. Both density and activation of tissue eosinophils were significantly related to disease progression. The state of activation of tissue eosinophils in CTCL might reflect inflammatory flare-ups associated with aggressive lymphomas. Further studies are needed to confirm the value of eosinophil density as a simple and reliable marker of CTCL progression.

Hypereosinophilic syndrome: long-term remission following allogeneic stem cell transplant in spite of transient eosinophilia post-transplant

A 38-year-old male with progressive myeloproliferative variant of hypereosinophilic syndrome (HES) underwent allogeneic bone marrow transplantation from a matched unrelated donor. The preparative regimen consisted of TBI, cytarabine, and cyclophosphamide. The graft was T-cell-depleted. The patient had slow, but complete, hematologic recovery, and all cells were shown by VNTR analysis to be of donor origin. Five months after transplant, the patient developed prominent eosinophilia (peak 4.1 x 10(9)/L) with dermatographism and very high IL-5 levels. Eosinophils isolated to purity by cell sorting were all of donor origin. Mild increase in immunosuppression led to a normalization of eosinophil count after about 6 months. The patient is now 6 years after transplant, off all medications, and without evidence of disease. Allogeneic stem-cell transplantation is a potentially curative therapy for HES.

Recent advances in pathogenesis and management of hypereosinophilic syndromes

Idiopathic hypereosinophilic syndrome is a largely heterogeneous disorder defined until now as persistent marked hypereosinophilia of unknown origin generally complicated by end-organ damage. Recent studies clearly indicate that many patients fulfilling the diagnostic criteria of this syndrome can now be classified as presenting one of two major disease variants: the myeloproliferative or the lymphocytic variant. Research in cellular and molecular biology has provided firm evidence for the existence of discrete hematological disorders underlying these variants, questioning the pertinence of continued reference to 'idiopathic' hypereosinophilic syndrome in such patients. Furthermore, identification of these variants has a number of prognostic and therapeutic implications that must be taken into consideration for adequate management of these patients.

Clinical and molecular features of FIP1L1-PDFGRA (+) chronic eosinophilic leukemias

Detection of the FIP1L1-PDGFRA fusion gene or the corresponding cryptic 4q12 deletion supports the diagnosis of chronic eosinophilic leukemia (CEL) in patients with chronic hypereosinophilia. We retrospectively characterized 17 patients fulfilling WHO criteria for idiopathic hypereosinophilic syndrome (IHES) or CEL, using nested RT-PCR and interphase fluorescence in situ hybridization (FISH). Eight had FIP1L1-PDGFRA (+) CEL, three had FIP1L1-PDGFRA (-) CEL and six had IHES. FIP1L1-PDGFRA (+) CEL responded poorly to steroids, hydroxyurea or interferon-alpha, and had a high probability of eosinophilic endomyocarditis (n=4) and disease-related death (n=4). In FIP1L1-PDGFRA (+) CEL, palpable splenomegaly was present in 5/8 cases, serum vitamin B(12) was always markedly increased, and marrow biopsies revealed a distinctively myeloproliferative aspect. Imatinib induced rapid complete hematological responses in 4/4 treated FIP1L1-PDGFRA (+) cases, including one female, and complete molecular remission in 2/3 evaluable cases. In the female patient, 1 log reduction of FIP1L1-PDGFRA copy number was reached as by real-time quantitative PCR (RQ-PCR). Thus, correlating IHES/CEL genotype with phenotype, FIP1L1-PDGFRA (+) CEL emerges as a homogeneous clinicobiological entity, where imatinib can induce molecular remission. While RT-PCR and interphase FISH are equally valid diagnostic tools, the role of marrow biopsy in diagnosis and of RQ-PCR in disease and therapy monitoring needs further evaluation.

Imatinib therapy for hypereosinophilic syndrome and eosinophilia-associated myeloproliferative disorders

A pathogenetic mutation, FIP1L1-PDGFRA, that results from an interstitial chromosome 4q12 deletion, leads to a constitutive activation of the platelet-derived growth factor receptor-alpha (PDGFRA) tyrosine kinase as well as a disease phenotype that mimics both the hypereosinophilic syndrome (HES) and systemic mast cell disease associated with eosinophilia (SMCD-eos). Complete remissions, in response to treatment with low-dose imatinib mesylate (100 mg/day or less) have now been documented in all cases of FIP1L1-PDGFRA(+) eosinophilic disorder as well as other eosinophilic disorders that carry activation mutations of the PDGFRB gene that is located on chromosome 5q33. Furthermore, response to therapy has been rapid (within days) and durable. Interestingly, imatinib mesylate treatment, at a higher dose level (400 mg/day), might induce either partial or short-lived complete remissions in HES that is not associated with the aforementioned PDGFR mutations. These observations make it necessary to re-examine current disease classification and treatment algorithms in eosinophilic disorders.

Pathology of the myeloproliferative diseases

The classification of myeloid neoplasms now includes CMPD, mixed CMPD/ MDS, MDS, and acute myeloid leukemias. CMPD and CMPD/MDS, both clonal stem cell diseases, share myeloproliferative features, including typical hypercellular marrows, organomegaly, and cell lineage maturation. The CMPD generally differ by which myeloid cell lineage dominates hematopoiesis, and the main diseases include CML, PV, ET, and CIM. The mixed CMPD/MDS disorders also show dysplastic features and variable amounts of effective hematopoiesis; these disorders include CMML, JMML, and atypical CML. Given the overlap in morphology among these diseases, correlation with clinical, hematologic, and cytogenetic/molecular genetic findings is imperative for precise classification.

The FIP1L1-PDGFRalpha fusion tyrosine kinase in hypereosinophilic syndrome and chronic eosinophilic leukemia: implications for diagnosis, classification, and management

Idiopathic hypereosinophilic syndrome (HES) and chronic eosinophilic leukemia (CEL) comprise a spectrum of indolent to aggressive diseases characterized by unexplained, persistent hypereosinophilia. These disorders have eluded a unique molecular explanation, and therapy has primarily been oriented toward palliation of symptoms related to organ involvement. Recent reports indicate that HES and CEL are imatinib-responsive malignancies, with rapid and complete hematologic remissions observed at lower doses than used in chronic myelogenous leukemia (CML). These BCR-ABL-negative cases lack activating mutations or abnormal fusions involving other known target genes of imatinib, implicating a novel tyrosine kinase in their pathogenesis. A bedside-to-benchtop translational research effort led to the identification of a constitutively activated fusion tyrosine kinase on chromosome 4q12, derived from an interstitial deletion, that fuses the platelet-derived growth factor receptor-alpha gene (PDGFRA) to an uncharacterized human gene FIP1-like-1 (FIP1L1). However, not all HES and CEL patients respond to imatinib, suggesting disease heterogeneity. Furthermore, approximately 40% of responding patients lack the FIP1L1-PDGFRA fusion, suggesting genetic heterogeneity. This review examines the current state of knowledge of HES and CEL and the implications of the FIP1L1-PDGFRA discovery on their diagnosis, classification, and management.

Discovery of a fusion kinase in EOL-1 cells and idiopathic hypereosinophilic syndrome

Idiopathic hypereosinophilic syndrome (HES) is a myeloproliferative disease of unknown etiology. Recently, it has been reported that imatinib mesylate (Gleevec), an inhibitor of Bcr-Abl kinase useful in the treatment of chronic myeloid leukemia, is also effective in treating HES; however, the molecular target of imatinib in HES is unknown. This report identifies a genetic rearrangement in the eosinophilic cell line EOL-1 that results in the expression of a fusion protein comprising an N-terminal region encoded by a gene of unknown function with the GenBank accession number NM_030917 and a C-terminal region derived from the intracellular domain of the platelet-derived growth factor receptor alpha (PDGFRalpha). The fusion gene was also detected in blood cells from two patients with HES. We propose naming NM_030917 Rhe for Rearranged in hypereosinophilia. Rhe-PDGFRalpha fusions result from an apparent interstitial deletion that links Rhe to exon 12 of PDGFRalpha on chromosome 4q12. The fusion kinase Rhe-PDGFRalpha is constitutively phosphorylated and supports IL-3-independent growth when expressed in BaF3 cells. Proliferation and viability of EOL-1 and BaF3 cells expressing Rhe-PDGFRalpha are ablated by the PDGFRalpha inhibitors imatinib, vatalanib, and THRX-165724.

The hypereosinophilic syndrome revisited

Clinical and biological features of patients with the idiopathic hypereosinophilic syndrome (HES) are heterogeneous. Recent evidence suggests at least two distinct underlying hematological disorders involving myeloid and lymphoid cells, respectively. We therefore suggest that the term idiopathic should be abandoned in the classification of HES. This review defines the "myeloproliferative" and "lymphocytic" variants of the HES and addresses the management of each variant, focusing on diagnosis and treatment of the newly identified lymphocytic variant.

Imatinib therapy for hypereosinophilic syndrome and other eosinophilic disorders

Imatinib mesylate (Gleevec), a small molecule inhibitor of abl, kit, and platelet-derived growth factor receptor (PDGFR) tyrosine kinases, has been reported to be effective in the treatment of hypereosinophilic syndrome (HES) and a rare eosinophilia-associated chronic myeloid disorder (eos-CMD) characterized by the t(5;12)(q33;p13) cytogenetic abnormality. In the current study, we sought to confirm the preliminary observations in HES as well as evaluate the therapeutic value of imatinib in eos-CMD that is not associated with t(5;12)(q33;p13). Five patients with HES (all men, median age = 46 years) and 2 with eos-CMD (both men, aged 45 and 58 years) were treated with imatinib at a starting dose of 100 to 400 mg/day. Cytogenetic studies showed no evidence of either the bcr-abl translocation or t(5;12)(q33;p13) in any patient. Screening of exons encoding the intracellular catalytic domains and extracellular ligand binding domains of PDGFR beta (exons 2-23) and c-kit (exons 1-21) in 6 patients demonstrated mostly previously known polymorphisms. At a median follow-up of 17 weeks (range, 10-33 weeks), 2 patients with HES and 1 with eos-CMD have achieved complete clinical remission and 1 additional patient with HES has achieved a partial remission. In contrast to previous observations, all 4 responding patients had elevated serum interleukin-5 levels. Although the drug was well tolerated in most patients, a previously unrecognized treatment toxicity of acute left ventricular dysfunction occurred in a responding patient with HES within the first week of treatment. Myocardial biopsy revealed eosinophilic infiltration and degranulation, and the cardiogenic shock was reversed with the prompt institution of corticosteroid therapy.

Multilineage involvement in hypereosinophilic syndrome terminating in granulocytic sarcoma and leukaemic transformation with trisomy 8

We report a patient with hypereosinophilic syndrome (HES), which, 8 years later, transformed into granulocytic sarcoma in the brain and, subsequently, into acute myelocytic leukaemia. Repeated chromosome analyses showed a normal karyotype, until the time of leukaemic transformation when trisomy 8 was confirmed in cells from the bone marrow and cerebrospinal fluid. The combined techniques of May-Grunwald-Giemsa staining and fluorescence in situ hybridization identified trisomy 8 not only in blasts and eosinophils but also in neutrophils and erythroblasts. Our observation suggests that HES is a multilineage myeloproliferative disorder involving precursors of at least the eosinophil, neutrophil and erythroid lineages.

Late appearance of t(1;19)(q11;q11) in myelodysplastic syndrome associated with dysplastic eosinophilia and pulmonary alveolar proteinosis

We report a case of myelodysplastic syndrome (MDS), which developed marked eosinophilia and pulmonary alveolar proteinosis after the appearance of t(1;19)(q11;q11). Chromosomal analysis of the peripheral eosinophils identified the same chromosome abnormality in all metaphases to that of bone marrow blast cells. Review of the literature revealed three reported cases of concurrent MDS and pulmonary alveolar proteinosis. We reviewed four cases of concurrent MDS and pulmonary alveolar proteinosis, including the present case. Interestingly, all but one of these patients also had evidence of eosinophilia and abnormality of chromosome 1p. These findings, together with morphologic abnormalities of eosinophils observed in this case, indicate clonal involvement of eosinophils in the MDS clone, and that the eosinophilia was derived from the neoplastic clone with the translocation. We postulate that this chromosomal rearrangement is involved in the development of eosinophilia and pulmonary alveolar proteinosis in MDS.

Chronic eosinophilic leukaemia presenting with erythroderma, mild eosinophilia and hyper-IgE: clinical, immunological and cytogenetic features and therapeutic approach. A case report

A 23-year-old, white male metallurgist presented with pruritic erythematous maculo-papules over the trunk and upper limbs and 6 months later developed erythroderma, eosinophilia and multi-organ dysfunction. A diagnosis of chronic eosinophilic leukaemia was made on the basis of myeloproliferative involvement of both peripheral blood and bone marrow, associated with eosinophilic differentiation and a t(5;12)(q33;p13) translocation. The initial therapeutic approach was interferon alfa-2b plus cytosine arabinoside, for 13 months, followed by hydroxyurea plus vincristine. There was improvement of skin lesions, disappearance of eosinophilia and decrease of serum immunoglobulin E, towards normal values.

New diagnostic tool for differentiation of idiopathic hypereosinophilic syndrome (HES) and secondary eosinophilic states

The hypereosinophilic syndrome (HES) is a very rare disease, characterized by persistent eosinophilia with tissue involvement and organ dysfunction which often precedes a subsequent T cell lymphoma. Interleukin-5 secreted by a T lymphocyte subpopulation has been described in previous reports as the most important factor responsible for the prolonged lifespan of the eosinophils. The goal of the present study was to describe a fast, simple diagnostic method for the differentiation of HES and secondary eosinophilic states. Beside the surface marker analysis of peripheral blood mononuclear cells (PBMC) we measured surface bound IgE molecules on lymphocytes and eosinophil cells, intracellular cytokines (IL-5, INFgamma) in CD4+ lymphocytes and eosinophil major basic protein (MBP) in eosinophils using flow cytometric detection method. The appearance of an IL-5 producing cell population with a decreased number of INFgamma positive lymphocytes was characteristic for the blood samples of HES patients. Predominance of Th2 cells with the appearance of a CD8+/CD3 /CD56+ cell population was restricted for the HES cases and could not be detected in secondary eosinophilic individuals. Our flow cytometric cytokine detection method (with parallel cell surface marker analysis) does not require cell separation or long term cell culture steps previously described for the detection of IL-5 producing cells. Therefore it seems to be a more appropriate approach for the differential diagnosis of primary and secondary eosinophilic states.