Detection Of Lung Surfactant In Pleural Effusions

ObjectiveLung surfactant protein-A(SP-A)is a useful immunohistochemical marker for lung adenocarcinoma.To measure surfactant-associated protein-A,D(SP-A,SP-D)and phospholipids in pleural effusions,by analyzing the differences to investigate the diagnostic values in pleural effusion,especially in diagnosis primary lung adenocarcinoma from tuberculous pleurisy.The degree of adhesions of pleura was valued by thoracoscope,to study whether the adhesion of pleura is related to pulmonary surfactant in pleural effusion.Methods and materialsFrom among the 82 assessable patients with pleural effusions enrolled in this study,50 had pleural effusions caused by malignant tumors,44 of whom had primary lung cancer:36 with lung adenocarcinoma,6 with lung squamous carcinoma and 2 with small cell lung carcinoma.The other 6 patients had extrapulmonary malignant tumors,consisting of 2 malignant mesotheliomas of pleura and 4 mammary adenocarcinomas.The remaining 32 patients had non-neoplastic pleural effusion, consisting of 28 tuberculous pleurisies and 4 pneumonia.All cases were diagnosed by histological findings and anti-tuberculosis or anti-inflammatory therapy.Total proteins in pleural effusion were measured by micro-BCA and SP-A and SP-D were measured by western-blotting of sodium dodecylsulfate gels.The pictures of SP-A and SP-D were analyzed by AlphaImager 2000.Total phospholipids were determined by analysis of phospholipids phosphorus following digestion of lipids in perchloric acid.The degree of adhesions of pleura was graded from 1(no adhesions)to 8 (complete symphysis＞50%of chest wall)under thoracoscope.The degree of pleurodesis was graded on the following scale of 1 to 8.1＝no adhesions between the visceral and parietal pleura;2= rare adhesions between the visceral and parietal pleura;3=a few scattered adhesions between the visceral and parietal pleura;4=many adhesions between the visceral and parietal pleura;5= many adhesions between the visceral and parietal pleura with symphysis involving less than 5%of the hemithorax;6=many adhesions between the visceral and parietal pleura with symphysis involving 5-25%of the hemithorax;7=many adhesions between the visceral and parietal pleura with symphysis involving 25-50%of the hemithorax;8=many adhesions between the visceral and parietal pleura with symphysis involving more than 50%of the hemithorax.Results1.Total protein concentration in pleural effusion(1)Total protein concentrations in pleural effusions due to lung adenocarcinoma and tuberculous pleurisy were 32.2±12.31ug/uL and 29.4±8.97ug/uL(mean±S.D.), respectively.The determinations showed no change in amounts of total proteins between patients with tuberculous pleurisy and patients with primary lung adenocarcinoma(P＞0.05).(2)Total protein concentration in pleural effusion due to lung squamous carcinoma was 33.5±10.27 ug/uL;29.6ug/uL and 34.8ug/uL in 2 small cell lung carcinoma;2 malignant mesothelioma of pleura were 35.3ug/uL and 32.8ug /uL; 30.5±3.37ug/uL and 29.5±4.36ug/uL due to mammary adenocarcinoma and pneumonia,respectively.2.SP-A and SP-D concentrations in pleural effusion(1)SP-A concentrations in pleural effusions due to lung adenocarcinoma and tuberculous pleurisy were 265.1±141.1 and 180.0±64.1(mean±S.D.),respectively. The samples from primary lung adenocarcinoma showed significant increase in SP-A compared with those of the tuberculous pleurisy(P＜0.05).(2)SP-D concentrations in pleural effusions due to lung adenocarcinoma and tuberculous pleurisy were 299.9±140.6 and 206.8±86.8(mean±S.D.),respectively. The samples from primary lung adenocarcinoma showed significant increase in SP-D compared with those of the tuberculous pleurisy(P＜0.05).(3)SP-A＞250 was found in 23 of 36 lung adenocarcinomas,and SP-D＞250 in 16 of 36 lung adenocarcinomas,while increased values of SP-A and/or SP-D were found in pleural effusions from 29 of 36 lung adenocarcinomas.SP-A and-D values did not exceed 250 in any of 28 tuberculous pleurisy.(4)The detections of SP-A and SP-D in pleural effusions due to lung squamous carcinoma,small cell lung carcinoma,malignant mesothelioma of pleura,mammary adenocarcinoma and pneumonia were different,but the samples were too few to analyse the statistics value.3.Total phospholipids in pleural effusions(1)Total phospholipids concentrations in pleural effusions due to lung adenocarcinoma and tuberculous pleurisy were 0.9156±0.4380mmol/L and 0.9148±0.2870 mmol/L(mean±S.D.),respectively.The determinations of primary lung adenocarcinoma showed no significant increase in phospholipid phosphorus compared with those of the tuberculous pleurisy(P＞0.05).(2)Total phospholipids concentrations in pleural effusion due to lung squamous carcinoma was 0.8257±0.2005mmol/L;0.8756mmol/L and 0.7120mmol/L in 2 small cell lung carcinoma;0.7153mmol/L and 0.7589mmol/L in 2 malignant mesothelioma of pleura;0.7257±0.1235mmol/L and 0.8356±0.1587mmol/L due to mammary adenocarcinoma and pneumonia,respectively,but the samples were too few to analyse the statistics value.4.The relation of pulmonary surfactant with pleural adhesion:The degree of adhesions of pleura was evaluated by the method of Lee YC.(1)The pleural adhesion of tuberculous pleurisy was hackneyed.The scores of pleural adhesion due to lung adenocarcinoma and tuberculous pleurisy were 2.2±1.0 and 4.3±1.3(mean±S.D.),respectively.The scores from tuberculous pleurisy showed significant increase compared with those of the primary lung adenocarcinoma(P＜0.05).(2)The patients of tuberculous pleurisy were divided into three subgroups by surfactant associated protein-A and D,respectively.A1:250＞SP-A＞200,A2: 200＞SP-A＞100,A3:SP-A＜100;D1:250＞SP-D＞200,D2:200＞SP-D＞100,D3: SP-D＜100.The scores of pleural adhesion in A1 and A2 were 3.3±0.5 and 3.8±0.8 (mean±S.D.),respectively.The scores have no significant difference in A1 and A2 (P＞0.05).The scores of pleural adhesion A1 and A3 were 3.3±0.5 and 5.3±0.3 (mean±S.D.),respectively.The scores from A3 showed significant increase compared with those of A1(P＜0.05).The scores of pleural adhesion A2 and A3 were 3.8±0.8 and 5.3±0.3(mean±S.D.),respectively.The scores from A3 showed significant increase compared with those of A2(P＜0.05).The scores of pleural adhesion in D1 and D2 were 3.0±0.4 and 3.6±1.1 (mean±S.D.),respectively.The scores have no significant difference in D1 and D2 (P＞0.05).The scores of pleural adhesion D1 and D3 were 3.0±0.4 and 5.0±0.7 (mean±S.D.),respectively.The scores from D3 showed significant increase compared with those of D1(P＜0.05).The scores of pleural adhesion D2 and D3 were 3.6±1.1 and 5.0±0.7(mean±S.D.),respectively.The scores from D3 showed significant increase compared with those of D2(P＜0.05).(3)The pleural adhesion of lung adenocarcinoma and other tumors were rare.Conclusions1.SP-A in pleural effusion had applied value in diagnosis of primary lung adenocarcinoma and tuberculous pleurisy,however,a combination of SP-D and A assays in pleural effusions will be better for discriminating lung adenocarcinoma from tuberculous pleurisy.2.Total phospholipids concentrations in pleural effusions due to lung adenocarcinoma showed no significant increase compared with those of the tuberculous pleurisy.3.The pleural adhesion is a complicated procedure and the mechanism is not understand at present,and many factors take part in it,probably including of transforming growth factor beta,vascular endothelial growth factors,basic fibroblast growth facto,tumor necrosis factor-alpha,plasminogen activator inhibitor type-1 and fibrinogen.Pleural thickness and the incidence rate of pleural adhesion were probably effected by the content of SP-A and SP-D in pleural effusion.