Biomechanical and biochemical investigation of erythrocytes in late stage human leptospirosis.

J.A.X Silva,V.C.O Carvalho,E.V.L Costa,V.L.M Lima,A Fontes,A.V.P Albertini,R.A Nogueira,C.S.M Fonseca,D.C.N Silva

doi:10.1590/1414-431x20209268

Abstract

Leptospirosis is a zoonotic disease caused by bacteria of the genus Leptospira, which can cause lipid changes in the erythrocyte membrane. Optical tweezers were used to characterize rheological changes in erythrocytes from patients with leptospirosis in the late stage. Biochemical methods were also used for quantification of plasma lipid, erythrocyte membrane lipid, and evaluation of liver function. Our data showed that the mean elastic constant of erythrocytes from patients with leptospirosis was around 67% higher than the control (healthy individuals), indicating that patient’s erythrocytes were less elastic. In individuals with leptospirosis, several alterations in relation to control were observed in the plasma lipids, however, in the erythrocyte membrane, only phosphatidylcholine showed a significant difference compared to control, increasing around 41%. With respect to the evaluation of liver function of individuals with leptospirosis, there was a significant increase in levels of alanine transaminase (154%) and aspartate transaminase (150%), whereas albumin was 43.8% lower than control (P<0.01). The lecithin-cholesterol acyltransferase fractional activity was 3.6 times lower in individuals with leptospirosis than in the healthy individuals (P<0.01). The decrease of the erythrocyte elasticity may be related to the changes of erythrocyte membrane phospholipids composition caused by disturbances that occur during human leptospirosis, with phosphatidylcholine being a strong candidate in the erythrocyte rheological changes.

Highlights

Leptospirosis is a bacterial disease caused by Leptospira species that are transmitted to human beings and animals through contact with soils and water contaminated with the urine of infected animals, predominantly rodents [1]
Erythrocyte elasticity The images were taken from a pool of cells from controls (n=222) and patients with leptospirosis (n=73)
The optical tweezers experiments showed that the average values of erythrocyte elastic constant obtained from patients and healthy individuals were (6.5±2.5) Â 10–4 dyn/cm and (3.9±1.9) Â 10–4 dyn/cm, respectively

Summary

Introduction

Leptospirosis is a bacterial disease caused by Leptospira species that are transmitted to human beings and animals through contact with soils and water contaminated with the urine of infected animals, predominantly rodents [1]. This zoonosis occurs worldwide, but the incidence is highest in the tropical regions, being a disease with a great impact on the public health of the tropics [1,2,3,4]. Leptospirosis is an infection with a broad geographical distribution due to the large spectrum of mammalian hosts that house and excrete the leptospires from their renal tubules [5,6]. The causative microorganism is capable of infecting the mammalian hosts through abraded skin and mucous membranes, and disseminating through the bloodstream to several organs [2]

Methods

Results

Conclusion