The lectin pathway and coagulation in lung cancer patients undergoing lobectomy - A randomised controlled trial

Background: Lectin pathway proteases activate coagulation and may theoretically play a role in the increased thrombosis risk in cancer, which is especially high during surgery. Aims: To investigate lectin pathway proteins during lung cancer surgery, the influence of low molecular weight heparin (LMWH) on lectin pathway proteins, and correlations between lectin pathway proteins and coagulation. Methods: Fifty lung cancer patients undergoing video-assisted thoracoscopic surgery lobectomy were randomised to LMWH, n= 26, or no anticoagulant (control), n= 24. Pre-, intra-and postoperative lectin pathway protein concentrations (mannose-binding lectin (MBL), H-and M-ficolin, collectin liver-1, MBL-associated serine protease (MASP)-1, -2 and -3, MBL-associated proteins MAp44 and MAp19) were assessed using a time-resolved immunofluorometric assay, and fibrinogen, fibrin d-dimer, and thrombin generation were analysed. Results: For all proteins except MASP-1, concentrations decreased during surgery in both groups; most markedly M-ficolin which decreased 49% (median: 2836 [quartiles: 2297-3505] to 1424 [1187-2199] ng/ml) (LMWH group) and 43% (2974 [2539-3510] to 1685 [1391-2076] ng/ml) (control group), while MBL decreased 12% (1936 [823-2801] to 1702 [676-2830] ng/ml) (LMWH) and 23% (1526 [250-2412] to 1175 [229-1947]) (controls). No differences in postoperative change were observed between groups except for MAp19 (p= 0.03) which decreased 9% (401 [337-467] to 364 [288-416] ng/ml) (LMWH) vs 28% (370 [272-468] to 268 [212-379] ng/ml) (controls). No correlation was found between lectin pathway proteins and coagulation (r=-0.23-0.28, p > 0.06) except for M-ficolin and fibrinogen (r= 0.29-0.36, p= 0.01-0.04). Conclusion: Lectin pathway proteins were influenced by surgery but not by LMWH. No consistent correlation was found between lectin pathway proteins and coagulation.