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Parisi X, Bledsoe JR. Discerning clinicopathological features of congenital neutropenia syndromes: an approach to diagnostically challenging differential diagnoses. J Clin Pathol 2024; 77:586-604. [PMID: 38589208 DOI: 10.1136/jcp-2022-208686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Accepted: 03/28/2024] [Indexed: 04/10/2024]
Abstract
The congenital neutropenia syndromes are rare haematological conditions defined by impaired myeloid precursor differentiation or function. Patients are prone to severe infections with high mortality rates in early life. While some patients benefit from granulocyte colony-stimulating factor treatment, they may still face an increased risk of bone marrow failure, myelodysplastic syndrome and acute leukaemia. Accurate diagnosis is crucial for improved outcomes; however, diagnosis depends on familiarity with a heterogeneous group of rare disorders that remain incompletely characterised. The clinical and pathological overlap between reactive conditions, primary and congenital neutropenias, bone marrow failure, and myelodysplastic syndromes further clouds diagnostic clarity.We review the diagnostically useful clinicopathological and morphological features of reactive causes of neutropenia and the most common primary neutropenia disorders: constitutional/benign ethnic neutropenia, chronic idiopathic neutropenia, cyclic neutropenia, severe congenital neutropenia (due to mutations in ELANE, GFI1, HAX1, G6PC3, VPS45, JAGN1, CSF3R, SRP54, CLPB and WAS), GATA2 deficiency, Warts, hypogammaglobulinaemia, infections and myelokathexis syndrome, Shwachman-Diamond Syndrome, the lysosomal storage disorders with neutropenia: Chediak-Higashi, Hermansky-Pudlak, and Griscelli syndromes, Cohen, and Barth syndromes. We also detail characteristic cytogenetic and molecular factors at diagnosis and in progression to myelodysplastic syndrome/leukaemia.
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Affiliation(s)
- Xenia Parisi
- Department of Hematopathology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Jacob R Bledsoe
- Department of Pathology, Boston Children's Hospital, Boston, Massachusetts, USA
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Farruggia P, Fioredda F, Puccio G, Onofrillo D, Russo G, Barone A, Bonanomi S, Boscarol G, Finocchi A, Ghilardi R, Giordano P, Ladogana S, Lassandro G, Luti L, Lanza T, Mandaglio R, Marra N, Martire B, Mastrodicasa E, Motta M, Notarangelo LD, Pillon M, Porretti L, Serafinelli J, Trizzino A, Tucci F, Veltroni M, Verzegnassi F, Ramenghi U, Dufour C. Idiopathic neutropenia of infancy: Data from the Italian Neutropenia Registry. Am J Hematol 2019; 94:216-222. [PMID: 30456824 DOI: 10.1002/ajh.25353] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2018] [Revised: 10/27/2018] [Accepted: 11/12/2018] [Indexed: 01/13/2023]
Abstract
Autoimmune neutropenia of infancy (AIN) is characterized by low risk of severe infection, tendency to spontaneously resolve and typically onset at ≤4-5 years of age; it is due to auto-antibodies whose detection is often difficult. In case of negativity of 4 antineutrophils autoantibody tests, after having excluded ethnic, postinfection, drug induced, or congenital neutropenia, according to the Italian guidelines the patients will be defined as affected by "idiopathic neutropenia" (IN). We describe the characteristics of 85 IN patients enrolled in the Italian neutropenia registry: they were compared with 336 children affected by AIN. The 2 groups were clinically very similar and the main differences were detection age (later in IN), length of disease (longer in IN) and, among recovered patients, age of spontaneous recovery: the median age at resolution was 2.13 years in AINs and 3.03 years in INs (P = .00002). At bivariate analysis among AIN patients earlier detection age (P = .00013), male sex (P = .000748), absence of leucopenia (P = .0045), and absence of monocytosis (P = .0419) were significantly associated with earlier recovery; in the IN group only detection age (P = .013) and absence of monocytosis (P = .0333) were significant. At multivariate analysis detection age and absence of monocytosis were independently significant (P = 6.7e-05 and 4.4e-03, respectively) in the AIN group, whereas in the IN group only detection age stayed significant (P = .013).
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Affiliation(s)
- Piero Farruggia
- Pediatric Hematology and Oncology Unit; A.R.N.A.S. Ospedale Civico; Palermo Italy
| | - Francesca Fioredda
- Clinical and Experimental Unit G. Gaslini Children's Hospital; Genoa Italy
| | - Giuseppe Puccio
- Department of Sciences for Health Promotion; University of Palermo; Palermo Italy
| | - Daniela Onofrillo
- Pediatric Hematology and Oncology Unit, Department of Hematology; Spirito Santo Hospital; Pescara Italy
| | - Giovanna Russo
- Pediatric Hematology and Oncology Unit, Azienda Policlinico-Vittorio Emanuele; University of Catania; Catania Italy
| | - Angelica Barone
- Department of Pediatric Onco-Hematology; University Hospital; Parma Italy
| | - Sonia Bonanomi
- MBBM Foundation, Department of Pediatrics; University of Milano - Bicocca; Monza Italy
| | - Gianluca Boscarol
- Department of Pediatrics; Central Teaching Hospital Bolzano; Bolzano Italy
| | | | - Roberta Ghilardi
- Department of Pediatrics; Ospedale Maggiore Policlinico IRCCS; Milan Italy
| | - Paola Giordano
- Department of Biomedical Sciences and Human Oncology; Pediatric Section, University "A. Moro" of Bari; Bari Italy
| | - Saverio Ladogana
- Department of Hematology; IRCCS Casa Sollievo della Sofferenza; San Giovanni Rotondo Italy
| | - Giuseppe Lassandro
- Department of Biomedical Sciences and Human Oncology; Pediatric Section, University "A. Moro" of Bari; Bari Italy
| | - Laura Luti
- Pediatric Hematology Oncology; Bone Marrow Transplant, Azienda Ospedaliero Universitaria Pisana, S. Chiara Hospital; Pisa Italy
| | - Tiziana Lanza
- Clinical and Experimental Unit G. Gaslini Children's Hospital; Genoa Italy
| | | | | | - Baldassare Martire
- Pediatric Science and Surgery Department; Pediatric Onco-Hematology Unit, Hospital Policlinico- Giovanni XXIII; Bari Italy
| | - Elena Mastrodicasa
- Pediatric Oncology Hematology Unit; S. Maria Della Misericordia Hospital; Perugia Italy
| | - Milena Motta
- Pediatric Hematology and Oncology Unit, Azienda Policlinico-Vittorio Emanuele; University of Catania; Catania Italy
| | - Lucia Dora Notarangelo
- Onco-Haematology and Bone Marrow Transplantation Unit; Children's Hospital; Brescia Italy
| | - Marta Pillon
- Pediatric Onco-Hematology Department; University of Padova; Padova
| | - Laura Porretti
- Flow Cytometry Service; Laboratory of Clinical Chemistry and Microbiology, IRCCS “Ca‘ Granda” Foundation, Maggiore Hospital Policlinico; Milan Italy
| | | | - Angela Trizzino
- Pediatric Hematology and Oncology Unit; A.R.N.A.S. Ospedale Civico; Palermo Italy
| | - Fabio Tucci
- Department of Pediatric Onco-Hematology; Meyer Children's Hospital; Florence Italy
| | - Marinella Veltroni
- Department of Pediatric Onco-Hematology; Meyer Children's Hospital; Florence Italy
| | - Federico Verzegnassi
- Institute for Maternal and Child Health (I.R.C.C.S) Burlo Garofolo; Trieste Italy
| | - Ugo Ramenghi
- Department of Pediatric and Public Health Sciences; University of Torino; Italy
| | - Carlo Dufour
- Clinical and Experimental Unit G. Gaslini Children's Hospital; Genoa Italy
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Papadaki HA, Pontikoglou C. Pathophysiologic mechanisms, clinical features and treatment of idiopathic neutropenia. Expert Rev Hematol 2014; 1:217-29. [DOI: 10.1586/17474086.1.2.217] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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Genetic associations in acquired immune-mediated bone marrow failure syndromes: insights in aplastic anemia and chronic idiopathic neutropenia. Clin Dev Immunol 2012; 2012:123789. [PMID: 22956967 PMCID: PMC3432560 DOI: 10.1155/2012/123789] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2012] [Accepted: 08/06/2012] [Indexed: 01/10/2023]
Abstract
Increasing interest on the field of autoimmune diseases has unveiled a plethora of genetic factors that predispose to these diseases. However, in immune-mediated bone marrow failure syndromes, such as acquired aplastic anemia and chronic idiopathic neutropenia, in which the pathophysiology results from a myelosuppressive bone marrow microenvironment mainly due to the presence of activated T lymphocytes, leading to the accelerated apoptotic death of the hematopoietic stem and progenitor cells, such genetic associations have been very limited. Various alleles and haplotypes of human leucocyte antigen (HLA) molecules have been implicated in the predisposition of developing the above diseases, as well as polymorphisms of inhibitory cytokines such as interferon-γ, tumor necrosis factor-α, and transforming growth factor-β1 along with polymorphisms on molecules of the immune system including the T-bet transcription factor and signal transducers and activators of transcription. In some cases, specific polymorphisms have been implicated in the outcome of treatment on those patients.
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Spanoudakis M, Koutala H, Ximeri M, Pyrovolaki K, Stamatopoulos K, Papadaki HA. T-cell receptor Vβ repertoire analysis in patients with chronic idiopathic neutropenia demonstrates the presence of aberrant T-cell expansions. Clin Immunol 2010; 137:384-95. [DOI: 10.1016/j.clim.2010.08.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2010] [Revised: 08/19/2010] [Accepted: 08/20/2010] [Indexed: 01/09/2023]
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Eliopoulos DG, Mavroudi I, Pontikoglou C, Ximeri M, Stavroulaki E, Pyrovolaki K, Velegraki M, Spanoudakis M, Goulielmos G, Papadaki HA. The −509C/T polymorphism of transforming growth factor-β1 is associated with increased risk for development of chronic idiopathic neutropenia. Eur J Haematol 2009; 83:535-40. [DOI: 10.1111/j.1600-0609.2009.01319.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Pontikoglou C, Liapakis G, Pyrovolaki K, Papadakis M, Bux J, Eliopoulos GD, Papadaki HA. Evidence for downregulation of erythropoietin receptor in bone marrow erythroid cells of patients with chronic idiopathic neutropenia. Exp Hematol 2006; 34:1312-22. [PMID: 16982324 DOI: 10.1016/j.exphem.2006.05.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2005] [Revised: 05/12/2006] [Accepted: 05/12/2006] [Indexed: 01/06/2023]
Abstract
OBJECTIVE The aim of this study is to probe the mechanisms underlying anemia in patients with chronic idiopathic neutropenia (CIN) by evaluating parameters of bone marrow (BM) erythropoiesis. PATIENTS AND METHODS Ten CIN patients fulfilling the criteria of anemia of chronic disease, 27 nonanemic CIN patients, and 30 healthy volunteers were enrolled in the study. Reserves and survival characteristics of BM erythroid cells were evaluated using flow cytometry and clonogenic assays. Serum erythropoietin (EPO) was measured with ELISA. Expression of EPO receptors (EPORs) on BM erythroid cells was evaluated by flow cytometry and reverse-transcription polymerase chain reaction. RESULTS CIN patients display defective erythropoiesis in addition to previously reported impaired granulopoiesis. Patients have low number of CD34(+)/CD71(+) progenitor and CD36(-)/ Glycophorin A(+) (GlycoA(+)) precursor BM cells, and increased proportion of apoptotic cells within the CD34(+)/CD71(+) and CD36(+)/GlycoA(+) compartments. Burst-forming units erythroid (BFU-Es) in BM mononuclear or purified CD34(+) cells were significantly reduced in the patients. Patient BFU-Es increased significantly following in vitro treatment with tumor necrosis factor-alpha (TNF-alpha) and/or interferon gamma (IFN-gamma)-neutralizing antibodies. Local TNF-alpha and IFN-gamma production was higher in anemic than in nonanemic patients. EPO production was appropriate in the patients, but EPOR expression was significantly reduced in patient GlycoA(+) cells, especially in anemic patients. CONCLUSION Impaired BM erythropoiesis in CIN patients is probably the result of increased local production of TNF-alpha and IFN-gamma that induce apoptosis, cell growth inhibition, and downregulation of EPOR expression on erythroid cells. We suggest that anemia in CIN patients displays overlapping pathophysiologic features with anemia of chronic disease.
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Affiliation(s)
- Charalampos Pontikoglou
- Department of Hematology of the University of Crete School of Medicine, Heraklion, Crete, Greece
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Psyllaki M, Damianaki A, Gemetzi C, Pyrovolaki K, Eliopoulos GD, Papadaki HA. Impaired megakaryopoiesis in patients with chronic idiopathic neutropenia is associated with increased transforming growth factor β1 production in the bone marrow. Br J Haematol 2006; 134:624-31. [PMID: 16938119 DOI: 10.1111/j.1365-2141.2006.06242.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Patients with chronic idiopathic neutropenia (CIN) display relatively low peripheral blood platelet counts and hypo-lobulated megakaryocytes in the bone marrow (BM). The underlying pathogenetic mechanismswere probed by studying the reserves and clonogenic potential of BM megakaryocytic progenitor cells using flow-cytometry and a collagen-based clonogenic assay for the identification of megakaryocyte colony-forming units (CFU-Meg). Thrombopoietin (TPO) and transforming growth factor-beta1 (TGFbeta1) levels were also evaluated in long-term BM culture supernatants using an enzyme-linked immunosorbent assay. CIN patients (n = 39) showed a low proportion of BM CD34(+)/CD61(+) megakaryocytic progenitor cells and low frequency of early and mixed CFU-Meg in the BM mononuclear, but not CD34(+), cell fraction, compared with healthy controls (n = 20). TPO and TGFbeta1 levels were significantly higher in patients compared with controls. TPO levels inversely correlated with platelet counts whereas TGFbeta1 values correlated inversely with CD34(+)/CD61(+) and CFU-Meg megakaryocytic progenitor cell numbers and positively with TPO levels. The addition of an anti-TGFbeta1 neutralising antibody significantly increased the numbers of CFU-Meg in CIN patients but not in controls, compared with baseline. These data suggest that increased local production of TGFbeta1 probably affects the BM megakaryocytic progenitor cell growth in CIN whereas the compensatory production of TPO finally balances the TGFbeta1-induced inhibitory effect.
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Affiliation(s)
- Maria Psyllaki
- Department of Haematology of the University of Crete School of Medicine, University Hospital of Heraklion, Heraklion, Crete, Greece
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Papadaki HA, Stamatopoulos K, Damianaki A, Gemetzi C, Anagnostopoulos A, Papadaki T, Eliopoulos AG, Eliopoulos GD. Activated T-lymphocytes with myelosuppressive properties in patients with chronic idiopathic neutropenia. Br J Haematol 2005; 128:863-76. [PMID: 15755293 DOI: 10.1111/j.1365-2141.2005.05380.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
To characterize the cellular components responsible for the impaired granulopoiesis in chronic idiopathic neutropenia (CIN), we investigated the origin of the proapoptotic cytokine producing cells in the bone marrow (BM) microenvironment of CIN patients. We found that the interferon gamma (IFN gamma) and/or Fas-ligand expressing cells in patient BM mononuclear cells and long-term BM culture stroma cells were the CD3(+) T-lymphocytes but not the CD14(+) monocytes/macrophages. The percentage of activated T-lymphocytes was increased in patients' BM as indicated by the proportions of human leucocyte antigen (HLA)-DR(+), CD25(+), CD38(+), CD69(+) and Fas(+) cells within the CD3(+) fraction. Intracellular IFN gamma expression was higher in the BM than peripheral blood of the patients and was associated with increased BM T-lymphocyte numbers. In crossover experiments, patient CD3(+) T-lymphocytes conferred autologous and allogeneic haemopoietic progenitor cell colony inhibition. Patients' T-cell receptor repertoire and polymerase chain reaction analysis did not reveal any clonal T-lymphocyte expansion, suggesting the absence of a direct, antigen-driven recognition of CD34(+) myeloid progenitor cells by patient T-lymphocytes. We conclude that CIN patients have increased number of activated T-lymphocytes in the BM, probably in the setting of a localized polyclonal immune reaction and that these cells confer an inhibitory effect on myelopoiesis through myelosuppressive cytokines including Fas-ligand and IFN gamma.
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Affiliation(s)
- H A Papadaki
- Department of Haematology, University of Crete School of Medicine, Heraklion, Crete, Greece.
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Abstract
AbstractOur understanding of the pathogenesis of congenital and acquired neutropenia is rapidly evolving. New ground-breaking observations have identified the genes responsible for many of the congenital neutropenia syndromes and are also providing new insights into normal neutrophil commitment and differentiation. Acquired neutropenia remains a poorly understood syndrome, although new insights into its pathogenesis are also emerging, especially with regard to subsets of immune neutropenia.In Section I, Dr. Marshall Horwitz reviews the current understanding of the genetic basis, molecular pathology, and approaches to treatment of congenital neutropenia and cyclic hematopoiesis. Mutations in the ELA2 gene, which encodes for neutrophil elastase, cause cyclic hematopoiesis. ELA2 mutations are also the most common cause of congenital neutropenia, where their presence may equate with a more severe clinical course and higher frequency of leukemic progression. Emerging evidence indicates interrelatedness with Hermansky Pudlak syndrome and other disorders of neutrophil and platelet granules.In Section II, Dr. Nancy Berliner presents an overview of the clinical approach to the evaluation and treatment of acquired neutropenia. This includes a review of the pathogenesis of primary and secondary immune neutropenia, drug-induced neutropenia, and non-immune chronic idiopathic neutropenia of adults. Studies used to evaluate patients for potential immune neutropenia are reviewed. Management issues, especially the use of granulocyte colony-stimulating factor (G-CSF), are discussed.In Section III, Dr. Thomas Loughran, Jr., reviews the pathogenesis and clinical manifestations of large granular lymphocyte (LGL) leukemia. Possible mechanisms of neutropenia are discussed. In particular, discussion focuses on the relationship between LGL leukemia, rheumatoid disease, and Felty’s syndrome, and the complex interplay of defects in neutrophil production, distribution, destruction, and apoptosis that underly the development of neutropenia in those syndromes.
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Affiliation(s)
- Nancy Berliner
- Yale University School of Medicine, Section of Hematology, New Haven, CT 06510, USA
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Papadaki HA, Horwitz M, Coulocheri SA, Person RA, Benson KF, Eliopoulos GD. Low levels of serum elastase are not associated with mutations in ELA-2 elastase encoding gene in chronic idiopathic neutropenia. Blood 2003; 101:2898-9. [PMID: 12642348 DOI: 10.1182/blood-2003-01-0015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Papadaki HA, Eliopoulos AG, Kosteas T, Gemetzi C, Damianaki A, Koutala H, Bux J, Eliopoulos GD. Impaired granulocytopoiesis in patients with chronic idiopathic neutropenia is associated with increased apoptosis of bone marrow myeloid progenitor cells. Blood 2003; 101:2591-600. [PMID: 12517813 DOI: 10.1182/blood-2002-09-2898] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
To probe the pathophysiologic mechanisms underlying neutropenia in patients with chronic idiopathic neutropenia (CIN) with hypoplastic and left-shifted granulocytic series in the bone marrow (BM), we have studied granulocytopoiesis in 32 adults with CIN by evaluating the number and survival characteristics of cells in several stages of granulocyte differentiation using flow cytometry and BM culture assays. We found that patients with CIN displayed a low percentage of CD34(+)/CD33(+) cells, defective granulocyte colony-forming unit (CFU-G) growth potential of BM mononuclear or purified CD34(+) cells, and low CFU-G recovery in long-term BM cultures (LTBMCs), compared with controls (n = 46). A low percentage of CD34(+)/CD33(+) cells in patients was associated with accelerated apoptosis and Fas overexpression within this cell compartment compared with controls. No significant difference was documented in the percentage of apoptotic cells or the Fas(+) cells within the fractionated CD34(+)/CD33(-), CD34(-)/CD33(+), and CD34(-)/CD33(-)/CD15(+) BM subpopulations or the peripheral blood neutrophils, suggesting that the underlying cellular defect in CIN probably concerns the committed granulocyte progenitors. LTBMC stromal layers from patients produced abnormally high amounts of tumor necrosis factor alpha and cytokine levels in culture supernatants inversely correlated with the number of myeloid progenitor cells and positively with the proportion of apoptotic CD34(+) cells. Patient LTBMC stromal layers displayed pathologic interferon gamma and Fas-ligand mRNA expression and failed to support normal myelopoiesis. These data suggest that impaired granulocytopoiesis in CIN is probably due to overproduction of inflammatory cytokines by immune cells within the BM microenvironment that may exert an inhibitory effect on myelopoiesis by inducing Fas-mediated apoptosis in the granulocyte progenitors.
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Affiliation(s)
- Helen A Papadaki
- Department of Hematology of the University of Crete School of Medicine and Institute of Molecular Biology and Biotechnology, Heraklion, Crete, Greece.
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Papadaki HA, Palmblad J, Eliopoulos GD. Non-immune chronic idiopathic neutropenia of adult: an overview. Eur J Haematol 2001; 67:35-44. [PMID: 11553265 DOI: 10.1034/j.1600-0609.2001.00473.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
There is strong evidence that non-immune chronic idiopathic neutropenia of adult is a cytokine-mediated syndrome characterized by (a) neutropenia of varying degree associated with a low number of lineage-specific CD34+ cells and increased production of inhibitors of hematopoiesis, including transforming growth factor-beta1 and tumor necrosis factor-alpha; (b) lymphopenia due to selective loss of primed/memory T-cells and NK cells; (c) increased splenic volume on ultrasonography in 48.1% of patients; (d) osteopenia and/or osteoporosis in 60.0% of patients; (e) anemia, mostly of the type of anemia of chronic disease, in 15.6% of patients; (f) features of chronic antigenic stimulation, including increased proportion of bone marrow plasma cells, increased serum levels of IgG1 and/or IgA, increased frequency of monoclonal gammopathy of undetermined significance, increased frequency of antinuclear antibodies with specific reactivity, and increased serum levels of circulating immune complexes; and (g) increased concentrations of a variety of macrophage-derived pro-inflammatory cytokines and chemokines capable of affecting bone metabolism, bone marrow function, and leukocyte trafficking. All these findings are suggestive of the existence of an unrecognized low-grade chronic inflammatory process which may be involved in the pathogenesis of the disorder. Neutropenia in these patients is probably the result of a combination of at least three factors, reduced neutrophil production in bone marrow, enhanced neutrophil extravasation, and increased sequestration and/or extravasation of neutrophils into the spleen.
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Affiliation(s)
- H A Papadaki
- Department of Haematology, University of Crete School of Medicine, University Hospital of Heraklion, Crete, Greece.
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