title: Is chronic neutropenia always a benign disease? Evidences from a 5-year prospective study.
abstract: OBJECTIVE
  To evaluate infections and oncohematologic evolution in adult patients with chronic idiopathic and autoimmune neutropenia in a prospective study.
  
  
  METHODS
  76 consecutive patients were enrolled from September 2008 to April 2012. Complete blood counts and clinical evaluation were performed at enrolment, at month 3, 6, and then every 6 months. Anti-neutrophil antibodies were tested by GIFT method.
  
  
  RESULTS
  Patients (49 chronic idiopathic- and 27 autoimmune neutropenia) were followed for a median of 5 years (range 24-84 months). At enrolment, neutropenia was mild in 44 patients (median neutrophils 1.27×10(3)/μL), moderate in 23 (median 0.8×10(3)/μL), and severe in 9 (median 0.4×10(3)/μL). Neutrophil counts showed a great inter-subject but no intra-subject variability, with lower values in autoimmune neutropenia, in males, and in MGUS cases. Over time, no grade >3 infections occurred; 13/49 chronic idiopathic and 6/27 autoimmune neutropenia patients experienced a grade 2 event, irrespective of mean and nadir neutrophil values. Bone marrow evaluation at enrolment showed reduced cellularity in 23% of cases, and dyserythropoietic features in 55%, with no definite hematologic diagnosis. During the follow-up, 5 cases were diagnosed with NK expansion, 4 with hairy cell leukemia, and 3 with myelodysplasia (1 myelomonocytic leukemia, 1 refractory cytopenia with unilineage dysplasia, and 1 multilineage dysplasia), with a median time to evolution of 30 months.
  
  
  CONCLUSIONS
  Chronic idiopathic and autoimmune neutropenia, although usually benign, deserve hematological follow-up with a bone marrow evaluation at diagnosis and a re-evaluation in the presence of worsening neutropenia, appearance of additional cytopenias, and lymphocytosis.
authors.affiliation: U.O. Oncoematologia, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milano, Italy.
authors.forename: Bruno
authors.initials: B
authors.lastname: Fattizzo
authors.affiliation: U.O. Oncoematologia, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milano, Italy.
authors.forename: Anna
authors.initials: A
authors.lastname: Zaninoni
authors.affiliation: U.O. Epidemiologia, Dipartimento della Medicina Preventiva, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milano, Italy.
authors.forename: Dario
authors.initials: D
authors.lastname: Consonni
authors.affiliation: U.O. Oncoematologia, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milano, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Zanella
authors.affiliation: Servizio di Ematopatologia, U.O. di Patologia, Dipartimento di Fisiopatologia e Trapianti, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milano e Università degli Studi di Milano, Italy.
authors.forename: Umberto
authors.initials: U
authors.lastname: Gianelli
authors.affiliation: U.O. Oncoematologia, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milano e Università degli Studi di Milano, Italy.
authors.forename: Agostino
authors.initials: A
authors.lastname: Cortelezzi
authors.affiliation: U.O. Oncoematologia, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milano, Italy. Electronic address: wbarcel@policlinico.mi.it.
authors.forename: Wilma
authors.initials: W
authors.lastname: Barcellini
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002908:Chronic Disease; D018450:Disease Progression; D005260:Female; D006801:Humans; D007239:Infections / Q000453:epidemiology / Q000209:etiology; D007958:Leukocyte Count; D008297:Male; D008875:Middle Aged; D009503:Neutropenia / Q000139:chemically induced / Q000150:complications* / Q000209:etiology / Q000503:physiopathology; D009504:Neutrophils; D011446:Prospective Studies; D012720:Severity of Illness Index; D055815:Young Adult
keywords: Autoimmune neutropenia; Chronic NK expansion; Chronic idiopathic neutropenia; Hairy cell leukemia; Myelodysplasia