Anti-Myxovirus Resistance Protein-1 Immunoglobulin A Autoantibody in Idiopathic Pulmonary Fibrosis

Table 7

Cox proportional hazard regression analysis to predict acute exacerbation in IPF.

Parameters	HR	95% CI	value
Univariate analysis
Gender, male vs. female	1.074	0.364–3.166	0.897
Age	1.042	0.983–1.104	0.165
Smoking, y/n	0.783	0.249–2.182	0.583
Diagnosis of IPF, clinical vs. SLB	1.583	0.689–3.633	0.279
BMI	1.011	0.884–1.156	0.870
mMRC, 2≤ vs. <2	4.786	2.024–11.316	<0.001
%FVC	0.955	0.932–0.978	<0.001
%DLco	0.971	0.946–0.996	0.025
Neutrophils in BAL, %	1.086	1.009–1.168	0.028
Lymphocytes in BAL, %	0.997	0.949–1.047	0.901
GAP stage, II vs. I	7.671	2.750–21.399	<0.001
GAP stage, III vs. I	5.928	0.642–57.744	0.117
KL-6, x100 U/mL	1.064	1.024–1.106	0.002
SP-D, x10 ng/mL	1.017	1.001–1.034	0.043
HRCT pattern
Possible UIP vs. UIP	0.972	0.385–2.453	0.951
Inconsistent with UIP vs. UIP	2.500	0.559–11.179	0.231
Multivariate analysis
mMRC, 2≤ vs. <2	3.076	1.202–7.870	0.019
%FVC	0.965	0.939–0.992	0.012

HR, hazard ratio; CI, confidence interval; IPF, idiopathic pulmonary fibrosis; BMI, body mass index; mMRC, modified Medical Research Council score for shortness of breath; %FVC, percent predicted value of forced vital capacity; %DLco, percent predicted value of diffusing capacity of carbon monoxide; GAP stage, gender, age, and physiology stage; KL-6, Krebs von den Lungen-6; SP-D, surfactant protein; HRCT, high-resolution computed tomography; UIP, usual interstitial pneumonia. Significance of each parameter to predict occurrence of acute exacerbation in IPF was evaluated by univariate Cox proportional hazard regression analysis. Multivariate analysis with the stepwise method was performed using all significant parameters except for GAP stage, KL-6, and SP-D to clarify predictive factors specific for our cases other than GAP stage. HRs of %FVC and %DLco less than 1 suggests patients with higher %FVC and higher %DLco experience less occurrence of acute exacerbation.