Table 2 Proteins differing between participants with non-productive cough and participants without cough (with p-value < 0.05)

Adhesion G protein-coupled receptor E2

ADGRE2

2.70E−05

0.005

0.64

Endothelial cell-selective adhesion molecule

ESAM

1.90E−04

0.015

0.79

Complement factor H

CFH

2.28E−04

0.015

2.35

Polymeric immunoglobulin receptor

PIGR

7.60E−04

0.028

0.51

Complement factor B

CFB

7.82E−04

0.028

1.64

Inhibin beta A chain:Inhibin beta B chain heterodimer

INHBA, INHBB

8.19E−04

0.028

0.84

Inter-alpha-trypsin inhibitor heavy chain H4

ITIH4

1.36E−03

0.036

1.80

Inhibin beta A chain

INHBA

1.42E−03

0.036

0.76

Hepatocyte growth factor receptor

MET

1.72E−03

0.039

0.85

Plasma kallikrein

KLKB1

2.25E−03

0.040

1.81

Prothrombin

F2

2.29E−03

0.040

1.81

Granulins

GRN

2.46E−03

0.040

0.63

Immunoglobulin A

IGHA1, IGHA2

2.54E−03

0.040

1.68

Contactin-1

CNTN1

2.79E−03

0.040

0.70

Fatty acid-binding protein, heart

FABP3

3.11E−03

0.041

0.62

Complement component C6

C6

3.51E−03

0.041

1.56

Interleukin-6 receptor subunit beta

IL6ST

3.63E−03

0.041

0.80

Fibrinogen

FGA, FGB, FGG

3.67E−03

0.041

1.75

Complement C2

C2

4.16E−03

0.043

0.80

Vitamin K-dependent protein C

PROC

4.46E−03

0.043

1.45

kininogen-1

FSTL3

4.48E−03

0.043

0.81

Macrophage mannose receptor 1

MRC1

6.13E−03

0.057

0.71

Collectin-12

COLEC12

6.87E−03

0.061

0.81

Complement C1q subcomponent

C1QA, C1QB, C1QC

8.02E−03

0.065

1.64

Lumican

LUM

8.53E−03

0.065

1.33

Alpha-2-macroglobulin

A2M

8.76E−03

0.065

1.26

14–3-3 protein zeta/delta

YWHAZ

8.85E−03

0.065

0.78

Coagulation factor IX

F9

8.94E−03

0.065

1.71

Plasminogen

PLG

9.96E−03

0.070

1.79

Tumor necrosis factor receptor superfamily member 1A

TNFRSF1A

0.011

0.072

0.87

C-X-C motif chemokine 16

CXCL16

0.011

0.072

0.66

Beta-2-microglobulin

B2M

0.012

0.072

0.77

Small ubiquitin-related modifier 3

SUMO3

0.012

0.072

0.84

Serum amyloid P-component

APCS

0.012

0.072

1.76

Hepatocyte growth factor activator

HGFAC

0.014

0.082

1.52

Immunoglobulin G

IGHG

0.016

0.082

1.57

Resistin

RETN

0.016

0.082

0.78

Hemopexin

HPX

0.017

0.082

1.53

Immunoglobulin G (2)

IGHG

0.017

0.082

1.47

Fibronectin Fragment 3

FN1

0.017

0.082

1.42

Complement decay-accelerating factor

CD55

0.017

0.082

0.74

C3a anaphylatoxin des Arginine

C3

0.017

0.082

1.45

Carboxypeptidase B2

CPB2

0.018

0.082

1.46

Histidine-rich glycoprotein

HRG

0.018

0.082

1.29

Coagulation factor IXab

F9

0.019

0.084

1.48

Protein FAM3B

FAM3B

0.019

0.084

0.80

Transgelin-2

TAGLN2

0.020

0.084

0.76

Angiogenin

ANG

0.020

0.084

1.35

Complement component C9

C9

0.020

0.084

1.32

Afamin

AFM

0.021

0.085

1.33

Complement factor I

CFI

0.023

0.092

1.24

Transforming growth factor beta receptor type 3

TGFBR3

0.025

0.096

0.87

Fibronectin Fragment 4

FN1

0.025

0.096

1.29

Properdin

CFP

0.025

0.096

1.40

Coagulation factor Xa

F10

0.027

0.099

1.76

Kininogen-1

KNG1

0.030

0.107

1.55

Fibronectin

FN1

0.030

0.107

1.56

14–3-3 protein beta/alpha

YWHAB

0.032

0.112

0.82

Complement C3d fragment

C3

0.033

0.114

1.24

Translationally-controlled tumor protein

TPT1

0.034

0.115

0.83

Complement C3

C3

0.035

0.117

1.28

Follistatin-related protein 1

FSTL1

0.036

0.118

0.84

C–C motif chemokine 18

CCL18

0.037

0.118

1.41

Haptoglobin

HP

0.039

0.122

1.70

Alpha-1-antichymotrypsin

SERPINA3

0.039

0.122

1.29

Malate dehydrogenase, cytoplasmic

MDH1

0.042

0.126

0.77

Scavenger receptor class F member 1

SCARF1

0.042

0.126

0.86

Adiponectin

ADIPOQ

0.044

0.126

1.40

Testican-2

SPOCK2

0.044

0.126

0.83

Complement component C7

C7

0.044

0.126

1.21

Neurexin-3-beta

NRXN3

0.045

0.126

0.83

Immunoglobulin D

IGHD

0.046

0.126

1.25

Extracellular matrix protein 1

ECM1

0.046

0.126

1.37

Insulin-like growth factor-binding protein 4

IGFBP4

0.047

0.126

1.24

L-lactate dehydrogenase B chain

LDHB

0.047

0.126

0.78