title: Increased circulating CD16+ CD14dim monocytes in a patient with pulmonary alveolar proteinosis.
abstract: Pulmonary alveolar proteinosis (PAP) is characterized by filling of the alveoli with a periodic acid-Schiff-positive proteinaceous material. Although the pathogenesis of primary or idiopathic PAP remains unknown, it has been proposed that a deficiency or loss of responsiveness of the monocyte/macrophage lineage to granulocyte-macrophage colony stimulating factor (GM-CSF) is involved in PAP. Secondary PAP is associated with haematological malignancies, especially in myeloid disorders. Herein, we report on an adult with PAP associated with myelodysplastic syndrome (MDS). The CD16+ CD14dim monocytes comprise 5-10% of circulating monocytes in healthy volunteers. Flow cytometric analysis of the patient in the present study revealed increased CD16+ CD14dim monocytes in the peripheral blood. It has been demonstrated that the expression of CD16 and CD14 is regulated by macrophage colony stimulating factor (M-CSF) and GM-CSF. Hence, serum cytokines were analysed in our patient and the concentration of serum GM-CSF was found to be less than the lower limit of the assay. In addition, serum M-CSF and granulocyte colony stimulating factor levels were only slightly increased above the normal range. These results suggest that the increase in the CD16+ CD14dim subpopulation in the circulation of our patient indicates another pathogenetic mechanism for secondary PAP, such as hyperresponsiveness of the monocyte/macrophage lineage to these cytokines.
authors.affiliation: Department of Respiratory Medicine, Juntendo University, School of Medicine, Yokyo, Japan. yoshioka@med.juntendo.ac.jp
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Yoshioka
authors.forename: Akihiko
authors.initials: A
authors.lastname: Ohwada
authors.forename: Norihiro
authors.initials: N
authors.lastname: Harada
authors.forename: Naotake
authors.initials: N
authors.lastname: Satoh
authors.forename: Shoko
authors.initials: S
authors.lastname: Sakuraba
authors.forename: Takashi
authors.initials: T
authors.lastname: Dambara
authors.forename: Yoshinosuke
authors.initials: Y
authors.lastname: Fukuchi
mesh_terms: D000368:Aged; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology; D016207:Cytokines / Q000097:blood; D006801:Humans; D018950:Lipopolysaccharide Receptors / Q000097:blood*; D016676:Macrophages, Alveolar / Q000378:metabolism; D008297:Male; D009190:Myelodysplastic Syndromes / Q000150:complications*; D011649:Pulmonary Alveolar Proteinosis / Q000209:etiology* / Q000276:immunology*; D017452:Receptors, IgG / Q000097:blood*
chemical_list: D016207:Cytokines; D018950:Lipopolysaccharide Receptors; D017452:Receptors, IgG