Hemosiderin-laden macrophages are an independent factor correlated with pulmonary vascular resistance in idiopathic pulmonary fibrosis: a case control study.
BACKGROUND
Increases in hemosiderin-laden macrophages (HLM) are reported to be observed in idiopathic pulmonary fibrosis (IPF). According to a recent study, significant correlation between hemosiderin deposition in the lung tissue of IPF and pulmonary hypertension evaluated by echocardiography has been suspected. In this study, we aimed to evaluate whether HLM in bronchoalveolar lavage fluid (BALF) is a factor correlated with pulmonary hemodynamic parameters evaluated by right heart catheterization in patients with IPF.


METHODS
Initial data from 103 consecutive patients with IPF who underwent surgical lung biopsy between November 2007 and March 2014 were retrospectively analyzed. The "HLM score" of BALF was established by dividing the number of Perls' Prussian blue stain positive macrophages by the total number of macrophages counted.


RESULTS
BALF showed an elevated HLM score (38.2%). Right heart catheterization revealed mean pulmonary arterial pressure (mPAP) of 16.3 mmHg and pulmonary vascular resistance (PVR) of 1.55 Wood units. HLM score was positively correlated with mPAP (ρ = 0.204; p = 0.038) and PVR (ρ = 0.349, p < 0.001). In multivariate analysis, 6-min walk distance (standardized partial regression coefficient [β], -0.391; p < 0.001), minimum oxygen saturation during 6-min walk distance (β, -0.294; p = 0.001) and HLM score (β, 0.265; p = 0.002) were independently correlated with PVR.


CONCLUSIONS
HLM score in BALF is an independent factor correlated with PVR in patients with IPF.
Department of Respiratory Medicine and Allergy, Tosei General Hospital, 160 Nishioiwake-cho, Seto-shi, Aichi, 489-8642, Japan.
Jun
J
Fukihara
Department of Respiratory Medicine and Allergy, Tosei General Hospital, 160 Nishioiwake-cho, Seto-shi, Aichi, 489-8642, Japan. taniguchi@tosei.or.jp.
Hiroyuki
H
Taniguchi
Center of Advanced Medicine and Clinical Research, Nagoya University Hospital, 65 Tsurumai-cho, Showa-ku, Nagoya-shi, Aichi, 466-0065, Japan.
Masahiko
M
Ando
Department of Respiratory Medicine and Allergy, Tosei General Hospital, 160 Nishioiwake-cho, Seto-shi, Aichi, 489-8642, Japan.
Yasuhiro
Y
Kondoh
Department of Respiratory Medicine and Allergy, Tosei General Hospital, 160 Nishioiwake-cho, Seto-shi, Aichi, 489-8642, Japan.
Tomoki
T
Kimura
Department of Respiratory Medicine and Allergy, Tosei General Hospital, 160 Nishioiwake-cho, Seto-shi, Aichi, 489-8642, Japan.
Kensuke
K
Kataoka
Department of Respiratory Medicine and Allergy, Tosei General Hospital, 160 Nishioiwake-cho, Seto-shi, Aichi, 489-8642, Japan.
Taiki
T
Furukawa
Department of Radiology, Kinki Central Hospital of Mutual Aid Association of Public School Teachers, 3-1 Kurumazuka, Itami-shi, Hyogo, 664-8533, Japan.
Takeshi
T
Johkoh
Department of Pathology, Nagasaki University Graduate School of Biomedical Sciences, 1-12-4 Sakamoto, Nagasaki-shi, Nagasaki, Japan.
Junya
J
Fukuoka
Department of Respiratory Medicine, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya-shi, Aichi, 466-0065, Japan.
Koji
K
Sakamoto
Department of Respiratory Medicine, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya-shi, Aichi, 466-0065, Japan.
Yoshinori
Y
Hasegawa
D000368:Aged; D062186:Arterial Pressure; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry / Q000166:cytology; D006328:Cardiac Catheterization; D016022:Case-Control Studies; D004452:Echocardiography; D005260:Female; D006485:Hemosiderin / Q000378:metabolism*; D006801:Humans; D054990:Idiopathic Pulmonary Fibrosis / Q000503:physiopathology* / Q000628:therapy*; D007564:Japan; D016014:Linear Models; D008168:Lung / Q000473:pathology / Q000503:physiopathology*; D008264:Macrophages / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D012129:Respiratory Function Tests; D012189:Retrospective Studies; D012720:Severity of Illness Index; D014655:Vascular Resistance; D000070857:Walk Test
D006485:Hemosiderin
Bronchoalveolar-lavage; Hemosiderin-laden macrophages; Idiopathic pulmonary fibrosis; Mean pulmonary arterial pressure; Pulmonary vascular resistance; Right heart catheterization