1. Background

• disorder of cyclic neutropenia first described by Leale in 1910
• etiology unknown but episodes of neutropenia may be caused by a regulatory abnormality involving early hematopoietic precursor cells -> quantitative decreased entry of granulocyte progenitor cells into granulopoiesis -> decreased production of neutrophils - the entire stem cell pool may be involved since alterations in reticulocytes and platelet numbers parallel the alterations in neutrophils

1. Cyclic Neutropenia

• episodes occur in cycles with a mean of 21 days but can range from 14 day cycles to 28-36 day cycles
• episodes last from 3-10 days
• clinical features during episodes include
  • fever, malaise, headaches
  • oral ulcerations, stomatitis, peridontal disease
  • bacterial infections
  • pharyngitis, pneumonia, chronic cough
  • skin infections
  • others: lymphadenitis, arthritis
  • complications:
    • GI - peritonitis, clostridial sepsis, colonic necro-sis, recurrent ulcers of the vaginal or rectal mucosa
    • mastoiditis

1. Serum

• episodes characterized by:
  • neutropenia (granulocytes may fall to zero)
  • elevated monocyte count, eosinophilia
  • thrombocytopenia and decreased reticulocytes
  • increased erythropoietin

2. Bone Marrow

• granulocyte precursors may disappear before onset of neutropenia
• CFU-GM may be absent 1 week prior to neutropenic nadir
• intense myelopoiesis at beginning of episode
• may show cyclic oscillations of both lymphoid and myeloid lineage cells

1. Supportive

• treat bacterial infections with appropriate antibiotics
• G-CSF may shorten duration of episodes to 1 day and decrease the neutropenic nadir
• splenectomy and steroid therapy not consistently effective

2. Prognosis

• generally benign although death from infection in 10% of cases
  • death most commonly from pneumonia and peritonitis-sepsis (Clostridium perfringens)
• symptoms may improve as the patient grows older