Serum glycolyl-sialylated mucin antigen 3EG5 in patients with interstitial lung diseases



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SERUM ALVEOMUCIN (GLYCOLYL-SIALYLATED MUCIN ANTIGEN) IN PATIENTS WITH INTERSTITIAL LUNG DISEASES

In collaboration with Research Institute of Pulmonology, Moscow

Polymorphic epithelial mucins are heavily glycosylated glycoproteins with MW exceeding 300 kDa, expressed on apical cell surface of glandular epithelia. Mucin is synthesized as a transmembrane molecule and its main function is cell-cell adhesive interaction. Detection of several mucins (CA 15-3, CA125, CA19-9) plays very important role in screening and monitoring of epithelial tumors. A new promising application of mucin in medical diagnostics is determination of serum mucin antigens (SSEA-1, KL-6, 3EG5) in patients with pulmonary fibrosis and other interstitial lung diseases.

Interstitial lung diseases (ILD) include a diverse group of acute and chronic disorders involving the lung parenchyma, characterized by damage to normal epithelium, its degeneration and necrosis. The main features of ILD are progressive dyspnea, bilateral interstitial shadows on chest radiograph and restrictive pulmonary dysfunction. Histologically the central feature of IPF (idiopathic pulmonary fibrosis) are the marked loss of type 1 cells in the lung tissue and re-epithelization of the epithelial surface with remaining type 2 alveolar cells, which are often hyperplastic and hypertrophic.. It was shown in vitro that epithelial mucins are produced by regenerating type 2 pneumocytes in the lower respiratory tract. Elevated levels of serum mucins may reflect the whole burden of proliferating type 2 alveolar cells in deranged and fibrotic lungs.

Serum Alveomicin test. A sandwich immunoassay for detection of original glycolyl-sialylated glycoprotein (mucin) antigen (previously designated as antigen 3EG5) was constructed using a monoclonal antibody 3E1.2 (developed in the University of Melbourne) and affinity-purified polyclonal antibody G5 against total mucin antigen family.

l. The role of serum Alveomucin as a screening marker of ILD

Serum levels of Alveomucin were examined in patients with the most common ILD forms - idiopathic pulmonary fibrosis (IPF) and chronic hypersensitivity pneumonitis (HP) – as well as in patients with other pulmonary (non-ILD) diseases.

The preliminary study (1) included 14 patients with IPF (mean age 67+ 12 years), 14 - with HP (mean age 44+ 13 years), 40 - with bronchial asthma (BA)( 46+ 9years), 18 - with chronic obstructive pulmonary disease (COPD)(66+ 8 years), 20 - with pneumonia (42 + 11 years) and 52 healthy volunteers (30 + 4 years).

ILD diagnosis was confirmed by histological examination of open-lung biopsy specimens and transbronchial specimens; for HP patients, there was a serologic evidence of precipitating antibodies against offending antigens.

An arbitrary cut-off value of 75 Units/ml (U/ml) was set as mean + 2SD (n=52) obtained for random population. Most of ILD patients have shown an elevation of serum Alveomucin up to 595 U/ml (mean 226 + 112 U/ml, n=24). Serum Alveomucin was not elevated in acute pneumonia (49 + 31 U/ml), COPD (78 +31 U/ml), BA (69 + 33 U/ml); a moderate elevation of serum Alveomucin levels (up to 169 U/ml) was observed in severe bronchial asthma, especially in children. Elevation of serum Alveomucin was found in all studied forms of ILD.



Figure 1. Serum levels of Alveomucin in different pulmonary diseases.

In all examined patients serum levels of Alveomucin exceeded 100 U/ml. A calculated clinical sensitivity, specificity and diagnostic accuracy of mucin levels for two cut-off points: 75 and 100 U/ml. Clinical specificity and diagnostic accuracy for cut-off level of 100 U/ml was higher without decrease of clinical sensitivity of the test (2).



Clinical sensitivity, specificity and diagnostic accuracy of Alveomucin for ILD.

 

Alveomucin > 75 U/ml

Alveomucin > 100 U/ml

Clinical sensitivity, %

100

100

Clinical specificity, %

76

91

Diagnostic accuracy, %

81

93

In conclusion, determination of serum Alveomucin may serve as a laboratory diagnostic marker of some forms of ILD.

ll. Serum Alveomucin as a marker of activity and severity of ILD

Usually, in all ILD forms, disease activity is assessed by examination of tissue obtained by open or transbronchial lung biopsy, but it is not practical to perform these invasive procedures frequently; moreover, due to a non-uniform distribution of histological changes throughout the lung small samples may be unrepresentative. Many attempts have been made so far to find disease markers in ILD which may define patients at risk for progressive and irreversible lung damage.

The degree of serum mucin elevation in ILD patients correlated with severity of clinical symptoms, degree of restrictive changes in pulmonary function tests, parameters of gas exchange and polymorphonuclear neutrophyls (PMN) count in bronchoalveolar lavage (BAL) fluid (the latter parameter only for IPF) (3).

Correlation between serum levels of Alveomucin and functional parameters in ILD patients (n= 28).


Parameter

R

P

DLCO % pred

- 0,64

< 0,001

DLCO/Va % pred.

- 0,52

0,005

FVC % pred.

- 0,46

0,014

FEV1 % pred

- 0,57

0,002

TLC % pred.

- 0,46

0,015

RV % pred

- 0,30

0,132

Neutrophils BAL, % (for IPF)

0,87

< 0,001

РаО2, mm Hg

- 0,65

< 0,001

Р(А-а)О2, mm Hg

- 0,59

< 0,001

 



Figure. Correlation between serum Alveomucin and a) DLCO and b) P(A-a)O2.

Thus it may be concluded that serum levels of Alveomucin may reflect severity and activity of ILD.



lll. The use of serial measurements of serum Alveomucin for monitoring of immunosuppressive therapy in patients with ILD

Serum Alveomucin is significantly elevated in chronic ILD and may reflect the severity of ILD: a degree of serum Alveomucin elevation in the patients was correlated with changes in pulmonary function tests (FVC, DLCO) and gas exchange abnormalities. As these variables are traditionally used for estimation of therapeutic response in ILD patients, the usefulness of Alveomucin in prediction of therapeutic response was evaluated.

We investigated the relationship between functional response to the anti-inflammatory therapy and changes in serum Alveomucin in ILD patients (4). Two patient groups were included in this part of the study: 9 - with idiopathic pulmonary fibrosis (IPF) (mean age 68 + 11 years) and 7 - with hypersensitivity pneumonitis (HP) (mean age 42 + 14 years). All patients received immunosuppressive therapy (prednisolone for all patients, azathioprine - 1, cycloposphamide - 1, penicillamine - 1), and their functional variables were assessed before and after 6 months of therapy.

According to the changes in pulmonary function tests during 6-months of steroid treatment, all patients were divided into groups of responders (15 % increase in FVC, 20 % increase in DLCO and reduction in the PA-aO2 of 5 mm Hg) and non-responders (worsening or insignificant changes in these variables).





Figure. Serum Alveomucin levels before and after 6 months of immunnosupressive therapy in responder and non-responder groups of ILD patients.

In responders (n= 7) serum levels of Alveomucin decreased substantially after treatment from 230 + 97 to 88 + 40 U/ml (p< 0,01). In non-responders serum Alveomucin levels did not differ significantly before and after therapy: 249 + 153 and 247 + 170 U/ml (p < 0,05). Two non-responding patients (both - with HP) showed significant decrease in Alveomucin, so the accuracy of changes in serum Alveomucin as a reflection of patient’s response to therapy was estimated as 88 %. There was a significant difference between the post-treatment levels of Alveomucin in these two groups of patients (p= 0,03).

The results obtained lead to the conclusion that serial measurements of serum mucin antigen Alveomucin may be used to predict clinical response to immunosuppressive therapy in ILD.

lV. Comparison of different commercially available serum mucin assays and Alveomucin as markers of severity and activity of IPF

Detection of certain mucins is traditionally used for screening and monitoring of epithelial tumors, but the same mucins may also be elevated in patients with ILD. We compared serum levels of commercially available mucins CA125, CA 15-3, MCA (Roche), MSA (Medical Innovations, Australia) and Alveomucin specially designed for ILD in IPF patients and evaluated the relationship between levels of serum mucins and markers of severity and activity of IPF.

Serum levels of mucin markers were examined in 17 patients with confirmed IPF (age: 57+ 10 years; FVC: 81+ 32 % pred.; DLCO: 65+ 26 % pred.; P(A-a)O2: 29+ 13 mm Hg) (5).

All examined mucins were elevated in IPF, also the positivity rates were different.



Mucin

Mean + SD

Range

Cut-off level

positivity (n/n)

positivity (%)

Alveomucin

217 + 129

108- 595

75

17/ 17

100

MSA

203 + 221

22- 600

30

16/ 17

94,1

CA-15.3

90 + 71

22- 210

28

15/ 17

88,2

MCA

21+ 13

6- 50

15

11/ 16

68,8

CA-125

69 + 136

3- 540

35

6/ 17

35,3

All mucin markers showed significant correlation with some of severity and activity markers of IPF. The best correlations were observed for Alveomucin.

 

Alveomucin

MSA

CA-15.3

MCA

CA-125

DLCO

-0,51 (p=0,03)

-0,55 (p=0,02)

-0,39 (p=0,12)

-0,33 (p=0,21)

-0,44 (p=0,08)

FVC

-0,52 (p=0,03)

-0,49 (p=0,07)

-0,58 (p=0,01)

-0,36 (p=0,17)

-0,38 (p=0,13)

BAL neut

0,79 (p<0,01)

0,61 (p=0,01)

0,46 (p=0,05)

0,52 (p=0,04)

0,50 (p=0,04)

These data show that although serum levels of different mucins (CA-15.3, CA-125, MSA, MCA) are elevated in IPF patients, Alveomucin is a most valuable marker for these patients.

References:

  1. Avdeeva O., Lebedin Y., Avdeev S., Chukanov S., Chuchalin A.G. Serum glycolyl-sialylated glycoprotein antigen 3EG5 as a laboratory marker for interstitial lung disease. Sarcoidosis 1997; 14: 37S.

  2. Avdeeva O., Lebedin Y., Avdeev S., Chukanov S., Chuchalin A.G., Cherniack A. Serum glycolyl-sialylated mucin antigen 3EG5 in patients with interstitial lung disease. Eur.Respir.J. 1997; 10: 262S.

  3. Chuchalin A.G., Avdeeva O., Lebedin Y., Avdeev S., Chukanov S. An elevated level of glycolyl-sialyated mucin antigen 3EG5 in patients with interstitial lung diseases. Am.J.Respir.Crit.Care Med. 1998; 157(Suppl.): A39.

  4. Avdeeva O., Lebedin Y., Avdeev S.N., Cherniack A., Chuchalin A. Successive measurements of serum mucin antigen 3EG5 before and after immunosuppressive therapy in patients with ILD. Eur.Respir.J. 1998; 11: 165S.

  5. Avdeeva, Y. Lebedin, S. Avdeev, A. Chuchalin. Role of serum mucins as markers of severity and activity of idiopathic pulmonary fibrosis (IPF). Eur.Respir.J. 1999; 12: (in press).

  6. Yokoyama A., Kohno N., Hamada H., Sakatani M., Ueda E., Kondo K., Hirasawa Y., Hiwada K. Circulating KL-6 predicts the outcome of rapidly progressive idiopathic pulmonary fibrosis. Am J Respir Crit Care Med 1998;158:1680- 1684.

  7. Yokoyama A., Kohno N., Kondo K., Ueda S., Hirasawa Y., Watanabe K., Takada Y., Hiwada K. Comparative evaluation of sialylated carbohydrate antigens, KL-6, CA19-9 and SLX as serum markers for interstitial pneumonia. Respirology 1998;3:199- 202.

  8. Satoh H., Kamma H., Ogata T., Yano H., Ohtsuka M., Hasegawa S. Clinical significance of serum levels of a carbohydrate antigen, syalyl SSEA-1, in patients with fibrosing lung disease. Am.Rev.Respir.Dis. 1991; 144: 1177- 1181.

  9. Norum L.F., Varaas T., Kierulf B., Nustad K. Carcinoma-associated MUC1 detected by immunoradiometric assays. Tumour Biol 1998; 19 Suppl 1: 134- 146

  10. Smart Y.C., Stewart J.F., Bartlett L.D., Brien J.H., Forbes J.F., Burton R.C. Mammary serum antigen (MSA) in advanced breast cancer. Breast Cancer Res Treat 1990; 16: 23- 28

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