Thrombocytopenia and leptospirosis

• Published in: Revista do Instituto de Medicina Tropical de São Paulo Vol. 32; no. 4; pp. 252 - 259
• Main Authors: NICODEMO, A. C, DEL NEGRO, G, AMATO, V. NETO
• Format: Journal Article
• Language: English
• Published: São Paulo Instituto de Medicina Tropical de São Paulo 01.07.1990; Instituto de Medicina Tropical
• Subjects: Antibodies - analysis; Bacterial diseases; Biological and medical sciences; Blood Coagulation Tests; Blood Platelets - immunology; Disseminated Intravascular Coagulation - complications; Human bacterial diseases; Humans; Infectious diseases; Leptospirosis - blood; Leptospirosis - complications; Medical sciences; Miscellaneous; Platelet Count; Prospective Studies; Staphylococcal infections, streptococcal infections, pneumococcal infections; Thrombocytopenia - blood; Thrombocytopenia - etiology; TROPICAL MEDICINE; Urea - blood; Infection; South America; Human; Leptospirosis; Thrombocytopenia; America; Bacteriosis; Brazil; Hemopathy; Spirachaetosis; thrombocytopenia; hemorrhagic diathesis
• ISSN: 0036-4665; 1678-9946; 1678-9946; 0036-4665
• DOI: 10.1590/s0036-46651990000400004

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.