Does the evaluation of coagulation factors contribute to etiological diagnosis of pleural effusions?
OBJECTIVE
The aim of this study was to identify the participation of the coagulation system in the differential diagnosis of pleural effusions.


BACKGROUND
Imbalance between immunologic and metabolic factors triggers a sequence of events resulting in pleural reactions and accumulation of fluid. The coagulation system, which is fundamental for the maintenance of homeostasis, contributes to the inflammatory process responsible for pleural effusions, and participates in cellular proliferation and migration as well as in the synthesis of inflammatory mediators.


METHODS
We evaluated the laboratory profile of coagulation and fibrinolysis in 54 pleural fluids (15 transudates and 39 exudates).


RESULTS
The coagulation system acts according to the pathophysiologic mechanisms involved in the development of pleural effusions. In inflammatory effusions (exudates), there is activation of coagulation with increased levels of fragment 1+2 and thrombin-antithrombin complex in addition to reduction of fibrinogen levels due to fibrinolysis and fibrin tissue incorporation. As a consequence, there is activation of the fibrinolytic system with increased levels of fibrin degradation products, including the D-dimer. These changes are not sufficient for differentiation of different subgroups of exudates. In transudates, these events were observed to a lesser degree.


CONCLUSIONS
The coagulation system plays an important role in the development of pleural diseases. Coagulation tests show differences between transudates and exudates but not among exudate subgroups. Understanding the physiopathological mechanisms of pleural disorders may help to define new diagnostic and therapeutic approaches.
Vaz
Marcelo Alexandre Costa
MA
Pleural Laboratory, Pulmonary Division, Heart Institute (InCor), Hospital das Clinicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo/SP, Brazil.
Vargas
Francisco Suso
FS
Marinho
Felipe Costa de Andrade
FC
D'Amico
Elbio Antonio
EA
Rocha
Tânia Rubia Flores
TR
Teixeira
Lisete Ribeiro
LR
D001777:Blood Coagulation / Q000502:physiology*; D003937:Diagnosis, Differential; D005122:Exudates and Transudates / Q000737:chemistry*; D005341:Fibrinolysin / Q000032:analysis*; D006801:Humans; D010996:Pleural Effusion / Q000097:blood / Q000175:diagnosis* / Q000209:etiology
D005341:Fibrinolysin