Thrombocytopenia and leptospirosis

Abstract

The present study has intended to contribute to the elucidation of the pathogenic mechanisms, involved in the thrombocytopenia and in the bleeding diathesis seen in the course of Leptospirosis. The group of cases included in the present prospective study consisted of 30 patients with Leptospirosis, admitted to the Infectious and Parasitic Diseases Ward, Hospital das Clínicas, Faculty of Medicine, University of São Paulo. The following possible mechanisms of thrombocytopenia have been considered and therefore investigated: platelet consumption, due to disseminated intravascular coagulation; immune-mediated platelet destruction, due to platelet-associated antibodies and an inhibited platelet production in the bone marrow. Thrombocytopenia occurred in 86.6% of 30 patients and did not seem to be immune-mediated by platelet-associated antibodies. Furthermore it did not seem to be due to a disseminated intravascular coagulation consumption. Although there was a statistically-significant correlation between bone marrow platelet production and platelet counts we think that the static microscopic examination of a bone marrow aspirate cannot accurately depict the dynamic mechanisms of platelet production when these cells are being consumed in peripheral blood. Vasculitis should be considered as the most important factor for the pathogenesis of the bleeding disturbances in Leptospirosis. However, we believe that thrombocytopenia, uremia and coagulation disorders, individually or as a group, should be included among the contributing factors that lead to and worsen bleeding episodes, which represent the leading cause of death in this disease.

Evaluation of hemostasis disorders and anticardiolipin antibody in patients with severe leptospirosis

“…This seems to be the part of coagulation most affected in the severe forms of leptospirosis. Such findings are in accordance with those observed by several authors 7,15,[19][20][21][22][23] . NICODEMO et al 22 observed that thrombocytopenia in leptospirosis seems to be determined by activation, adhesion and aggregation of platelets to the stimulated vascular endothelium by the action of endotoxin or other bacterial products.…”

“…The hemorrhagic phenomena present in our environment have been described by several authors 2,3,15,[19][20][21][22][23][24] . PEREIRA DA SILVA et al 24 have described hemorrhagic manifestations in 95% of cases of severe clinical forms of leptospirosis.…”

“…Various systematic studies of the alterations in hemostasis have been published 7,8,14,[19][20][21][22][23][24][25] .…”

Pathology and pathophysiology of pulmonary manifestations in leptospirosis

“…Autopsy showed extensive areas of pleuropulmonary hemorrhage, with a microscopic picture of hemorrhagic infiltrates involving alveoli and septa. The three patients also presented thrombocytopenia, a common finding in patients with severe leptospirosis [23][24][25].…”

Aspectos anatomopatológicos da leptospirose em cães: 53 casos (1965-2011)

“…Esses achados, em conjunto com edema, foram as lesões mais frequentemente encontradas por nós. Além disso, e ao contrário do que aϐirmam alguns autores (Greene et al 2006), observamos com frequência um leve a moderado inϐiltrado inϐla-matório nos espaços alveolares, constituído principalmente por macrófagos e neutróϐilos, um aspecto semelhante ao que foi descrito na doença humana (Ramachandran & Perera 1977, Nicodemo et al 1990.…”