Effect of IL-6 elevation in malignant pleural effusion on hyperfibrinogenemia in lung cancer patients.
BACKGROUND
The involvements of interleukin-6 (IL-6) and fibrinogen in cancer development were elucidated independently, irrespective of IL-6 activity to induce fibrinogen. This study was undertaken to clarify the clinicopathological association of these molecules in lung cancer patients with malignant pleurisy.


METHODS
IL-6, fibrinogen and the related molecules in blood and pleural effusion of 38 patients were assayed at 3-day intervals.


RESULTS
IL-6 levels were elevated in sera of 27 cases (71.1%) and in all the effusions with mean values of 20.5 and 9970.5 pg/ml, respectively. Their correlation in 22 cases who were examined on the same day was statistically strong (r = 0.902, p < 0.0001). Occasional elevations of tumor necrosis factor-alpha were independent of IL-6 elevation. Levels of plasma fibrinogen, fibrin(ogen) degradation products (FDP) and C-reactive protein (CRP) were more frequently elevated in the IL-6-elevated cases than those without IL-6 elevation. In all pleural effusions, fibrinogen levels were significantly decreased to <150 mg/dl with large elevations of FDP level. Immunocytologically, IL-6 was detected in cancer cells in 16 cases of adenocarcinoma in addition to host pleural cells, but its cellular positivity was not reflected in the IL-6 level in each pleural effusion.


CONCLUSIONS
Compared with lung cancer patients without malignant pleurisy, IL-6, fibrinogen, FDP and CRP levels in patients with malignant pleurisy were increased more frequently in their peripheral blood. These were basically attributed to systemic leakage of IL-6 from the affected pleural cavity, in which plasma fibrinogen induced in response to serum IL-6 was exudated and degraded predominantly to FDP.
Yamaguchi
T
T
Department of Internal Medicine, Toneyama National Hospital, Osaka, Japan.
Kimura
H
H
Yokota
S
S
Yamamoto
Y
Y
Hashimoto
T
T
Nakagawa
M
M
Ito
M
M
Ogura
T
T
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis*; D002097:C-Reactive Protein / Q000032:analysis; D002289:Carcinoma, Non-Small-Cell Lung / Q000150:complications* / Q000473:pathology; D018288:Carcinoma, Small Cell / Q000150:complications* / Q000473:pathology; D005260:Female; D005340:Fibrinogen / Q000378:metabolism*; D006801:Humans; D015850:Interleukin-6 / Q000032:analysis*; D008175:Lung Neoplasms / Q000150:complications* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D016066:Pleural Effusion, Malignant / Q000209:etiology* / Q000473:pathology
D014408:Biomarkers, Tumor; D015850:Interleukin-6; D005340:Fibrinogen; D002097:C-Reactive Protein