Hemosiderin-Laden Macrophages in Bronchoalveolar Lavage: Predictive Role for Acute Exacerbation of Idiopathic Interstitial Pneumonias

Table 1

Patient demographics.

Parameters	Lower HS (n = 214)	Higher HS (n = 7)	value
Sex, male/female	150/64	6/1	0.677
Age, yrs	69 (62–74)	62 (56–74)	0.185
BMI, kg/m^2	24.0 (21.5–26.3)	28.0 (24.5–31.6)	0.024
Smoking, CS or ES/NS	159/55	7/0	0.197
Smoking CS/ES/NS	39/120/55	1/6/0	0.319
Iron dust exposure, yes/no	10/204	2/5	0.807
Autoantibody, yes/no	26/188	0/7	1.000
Diagnosis, IPF/non-IPF	84/130	3/4	1.000
HRCT, UIP/possible/inconsistent	56/96/62	3/1/3	0.291
SLB, yes/no	51/163	2/5	0.674
SLB-diagnosed cases			0.345
IPF	43	1
NSIP	7	1
LIP	1	0
mMRC, < 2/≥ 2	137/77	6/1	0.426
%FVC, %	78.7 (64.6–93.9)	103.5 (70.5–115.2)	0.115
%DLco, %	52.3 (35.6–67.2)	50.9 (39.6–78.9)	0.766
KL-6, ×100 U/mL	8.95 (5.47–15.03)	7.90 (3.81–9.52)	0.271
SP-D, ×10 ng/mL	17.3 (9.8–26.6)	18.8 (14.6–24.9)	0.643
Neu in BAL, %	2.2 (0.8–7.2)	2.40 (0.5–4.6)	0.835
PT	1.01 (0.97–1.06)^†	0.98 (0.95–1.84)^¶	0.771
APTT	28.0 (25.6–30.4) ^‡	27.8 (25.0–36.6)^¶	0.478
Fibrinogen	308.3 (270.0–382.4) ^§	286.0 (267.5–383.7)^¶	0.845
Prednisolone use before AE, yes/no	55/159	0/7	0.197
Immunosuppressant before AE, yes/no	24/190	2/5	0.193
Observation period^#, days	1214 (363-2028)	1284 (346-2144)	0.990
Occurrence of AE, yes/no	41/173	4/3	0.033
PaO2/FiO2 ratio at AE, ≤200/>200	25/16	2/2	1.000
AE-occurred cases/IIP diagnosis
IPF	26/84	2/3
NSIP	0/7	1/1
LIP	0/1	0/0
Non-IPF w.o. SLB	15/122	1/3
Median survival days after AE	34	549	0.121

Abbreviations: AE, acute exacerbation; APTT, activated partial thromboplastin time; BAL, bronchoalveolar lavage; BMI, body mass index; CS, current smoker; DLco, diffusing capacity of carbon monoxide; ES, ex-smoker; FVC, forced vital capacity; HRCT, high-resolution computed tomography; HS, hemosiderin score; IIPs, idiopathic interstitial pneumonias; IPF, idiopathic pulmonary fibrosis; KL-6, Krebs von den Lungen-6; LIP, lymphocytic interstitial pneumonia; Neu, neutrophils; NS, nonsmoker; mMRC, modified Medical Research Council Score for shortness of breath; NSIP, nonspecific interstitial pneumonia; PT, prothrombin time; SLB, surgical lung biopsy; SP-D, surfactant protein-D; UIP, usual interstitial pneumonia. Data are presented as median (IQR) for continuous variables or as the number for categorical variables. Continuous variables were compared with Wilcoxon rank sum test and categorical variables were Fisher’s exact test. Antinuclear antibody (n = 5), rheumatoid factor (n = 5), anticyclic citrullinated peptide antibody (n = 4), myeloperoxidase-antineutrophil cytoplasmic antibody (n = 3), anticentromere antibody (n = 3), antiU1-ribonucleoprotein antibody (n = 3), antiRo/SSA antibody (n = 3), antiaminoacyl-tRNA synthetases antibody (n = 2), antidouble-strand deoxy nucleic acid antibody (n = 1), anti-La/SSB antibody (n = 1). Coagulation-related tests were performed: ^†n = 220, ^‡n = 219, ^§n = 175, ^¶n = 7. ^#From diagnosis to onset of AE in AE-occurred cases or last follow-up in the other cases. Survival of higher and lower HS groups were similar by log-rank test.