Skip to main content

Table 2 Summary of the clinical characteristics of COPD patients identified as most relevant by clinical experts.

From: A diVIsive Shuffling Approach (VIStA) for gene expression analysis to identify subtypes in Chronic Obstructive Pulmonary Disease

Category

Continuous Variable for Quantitative Analysis

Discrete Variable

Bins

Characteristics

Differentially expressed genes at FDR < 0.05

Chronic Bronchitis

Not applicable

Cough with Phlegm for at least 3 mos/yr for at least 2 years

low extreme (Q1 = 64)

neither chronic cough nor chronic phlegm

0

   

high extreme (Q4 = 46)

both chronic cough and chronic phlegm

 

History of Exacerbations

Number of exacerbations per year

2 or more per year and less than 2 per year

low extreme (Q1 = 26)

0 - Never

0

   

high extreme (Q4 = 17)

3 - Always

 

Body Mass Index (Kg/m2)

BMI

BMI < 21, 21-30, > 30

low extreme (Q1 = 18)

BMI < 21

0

   

high extreme (Q4 = 35)

BMI > 30

 

Airflow Limitation severity

FEV1 (% predicted)

GOLD Stage

low extreme (Q1 = 69)

< 2-GOLD stage

6,049

   

high extreme (Q4 = 13)

>4 GOLD stage

 

6 Minute Walk Distance

Quantitative 6MWD

< 350 meters and > 350 meters

low extreme (Q1 = 38)

>350 meters

0

   

high extreme (Q4 = 101)

>350 meters

 

Radiologist

Emphysema

Emphysema severity category:

 

low extreme (Q1 = 40)

0-1.5 -No emphysema

0

assessment

Not affected (N): 0

Yes/No/Uncertain

high extreme (Q4 = 45)

4-5 - severe

 
 

Trivial (T): 1

    
 

Mild (M) 5-25%: 2

    
 

Moderate (O) 25-50%: 3

    
 

Severe (S) 50-75%: 4

    
 

Very Severe (V) > 75%: 5

    

Densitometric Emphysema

Emphysema at -950 HU

Emphysema >10% (Yes/No)

low extreme (Q1 = 37)

Emphysema >10% = No

0

   

high extreme (Q4 = 95)

Emphysema >10% = yes

 

CT Airway Disease

Pi10 (Square root of wall area of 10 mm internal perimeter airways)

GOLD Stages 2-4 with Emphysema < 5% (Yes) or > 5% (No)

low extreme (Q1 = 63)

Trivial (< %5)

0

   

high extreme (Q4 = 33)

Severe (50-75%, very severe (>75%))

 
  1. Columns 4-6 show the results of the differential gene expression analysis comparing the subjects of the defined bins or extremes for each characteristic. Q1/Q4 refer to the number of patients in the respective group (1st and 4th "quartile"). The only single characteristic yielding significantly differentially expressed genes is the degree of airflow limitation as given by GOLD stage (GOLDCD).