1
|
Niroomandi E, Maleki S, Abdollahpour G, Zakian A, Ahmadvand H. The effect of natural infection with different Leptospira interrogans serovars on oxidative stress biomarkers and acute-phase responses in horses and cattle. Vet Clin Pathol 2022; 51:84-92. [PMID: 35179227 DOI: 10.1111/vcp.13042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 05/06/2021] [Accepted: 05/11/2021] [Indexed: 11/29/2022]
Abstract
Leptospirosis is one of the important zoonotic bacterial diseases with a worldwide distribution that is often subclinical. We aimed to investigate the oxidant/antioxidant balance and acute-phase response in naturally infected horses and cattle with Leptospira interrogans. A total of 600 serum samples from horses and cattle were examined for L. interrogans antibodies using the microscopic agglutination test to determine anti-Leptospira IgG antibodies against a panel of eight important Leptospira antigens in Iran. Then, serum total antioxidant capacity, catalase, glutathione peroxidase, and malondialdehyde activities, and nitric oxide, total protein, serum amyloid A, haptoglobin, and albumin concentrations were measured in seropositive and seronegative samples. Serum catalase activities and malondialdehyde, serum amyloid A, and haptoglobin concentrations in seropositive cattle and horses were significantly higher (P < .05) than in those that were seronegative. Antibody titers increased from 1:100 to ≥ 1:200 in cattle with L. interrogans infection, resulting in a decrease in the serum total antioxidant capacity (P < .05), an increase in serum glutathione peroxidase (P < .01) activity and nitric oxide (P < .05) , serum amyloid A (P < .01), and haptoglobin (P < .05) concentrations. Following the increase in the agglutinating antibody titers in horses infected with L. interrogans, the serum total antioxidant capacity (P < .01) decreased, and serum nitric oxide (P < .05), malondialdehyde (P < .05), and serum amyloid A (P < .01) concentrations were increased. In this study, horses and cattle had extensive changes in oxidant/antioxidant equilibrium and acute-phase protein concentrations when infected with L. interrogans. We also demonstrated a direct link between antibody titers and the type of leptospiral serovar using serum oxidative and inflammatory markers.
Collapse
Affiliation(s)
- Ehsan Niroomandi
- School of Veterinary Medicine, Lorestan University, Khorramabad, Iran
| | - Shahram Maleki
- Department of Clinical Sciences, School of Veterinary Medicine, Lorestan University, Khorramabad, Iran
| | - Gholamreza Abdollahpour
- Department of Internal Medicine, School of Veterinary Medicine, University of Tehran, Tehran, Iran
| | - Amir Zakian
- Department of Clinical Sciences, School of Veterinary Medicine, Lorestan University, Khorramabad, Iran
| | - Hasan Ahmadvand
- Department of Biochemistry and Genetics, Lorestan University of Medical Sciences, Khorramabad, Iran
| |
Collapse
|
2
|
Niloofa R, Karunanayake L, de Silva HJ, Premawansa S, Rajapakse S, Handunnetti S. Development of in-house ELISAs as an alternative method for the serodiagnosis of leptospirosis. Int J Infect Dis 2021; 105:135-140. [PMID: 33556609 DOI: 10.1016/j.ijid.2021.01.074] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 01/23/2021] [Accepted: 01/25/2021] [Indexed: 10/22/2022] Open
Abstract
BACKGROUND Leptospirosis is most often diagnosed clinically, and a laboratory test with high diagnostic accuracy is required. METHODS IgM and IgG ELISAs using Leptospira antigens were established and evaluated in relation to the microscopic agglutination test (MAT). Antigen preparation consisted of saprophytic Leptospira biflexa to detect genus-specific antibodies (genus-specific ELISA) and a pool of the five most prevalent Leptospira interrogans serovars in Sri Lanka to detect serovar-specific antibodies (serovar-specific ELISA). IgM and IgG immune responses were studied in severe and mild leptospirosis patients (n = 100 in each group). RESULTS The ELISAs showed high repeatability and reproducibility. The serovar-specific IgM-ELISA showed a sensitivity of 80.2% and specificity of 89%; the genus-specific IgM-ELISA showed a sensitivity of 83.3% and specificity of 91%. The serovar- and genus-specific IgG-ELISAs showed sensitivities of 73.3% and 81.7%, respectively, and specificities of 83.3% and 83.3%, respectively. The commercial IgM-ELISA showed a sensitivity of 79.2% and specificity of 93%. The commercial IgG-ELISA showed a sensitivity of 50% and specificity of 96.7%. IgM levels observed in mild and severe leptospirosis patients were significantly higher than in the healthy control group, with mean absorbance values of 0.770, 0.778, and 0.163, respectively. Severe leptospirosis patients had significantly higher mean anti-leptospiral IgG levels compared to both mild leptospirosis patients and healthy control group subjects (0.643, 0.358, and 0.116, respectively; ANOVA, p < 0.001). The presence of anti-leptospiral IgG above an optical density of 0.643 at 1:100 could predict a high risk of severe disease. CONCLUSION The serovar-specific in-house ELISA could be used for the laboratory diagnosis of leptospirosis in endemic settings. The high levels of anti-leptospiral IgG observed suggest its value as a predictor of disease severity.
Collapse
Affiliation(s)
- Roshan Niloofa
- Institute of Biochemistry, Molecular Biology and Biotechnology, University of Colombo, Colombo, Sri Lanka.
| | | | | | | | - Senaka Rajapakse
- Tropical Medicine Research Unit, Faculty of Medicine, University of Colombo, Colombo, Sri Lanka
| | - Shiroma Handunnetti
- Institute of Biochemistry, Molecular Biology and Biotechnology, University of Colombo, Colombo, Sri Lanka
| |
Collapse
|
3
|
Fernando Y, Wickramasinghe P, De Silva U, Alahakoon M, Anuradha KWDA, Handunnetti S. Differences in serum markers of oxidative stress in well controlled and poorly controlled asthma in Sri Lankan children: a pilot study. Allergy Asthma Clin Immunol 2020; 16:66. [PMID: 32944026 PMCID: PMC7491346 DOI: 10.1186/s13223-020-00463-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Accepted: 07/10/2020] [Indexed: 12/22/2022] Open
Abstract
Background Asthma is a disease characterised by hyper responsiveness and bronchoconstriction of airways, and is a major health burden globally. A dysfunction of the oxidant-antioxidant balance, termed oxidative stress, has been implicated in the pathophysiology of asthma. The present study aims to assess the changes in oxidative stress markers, namely nitric oxide metabolites and antioxidant capacity, in children with poorly controlled and well controlled asthma, in comparison to healthy controls. Methods The present study enrolled 72 children (ages 5-15 years) classified into three groups: (1) poorly controlled asthma (n = 20), (2) well controlled asthma (n = 24) and (3) healthy controls (n = 27). An interviewer-administered questionnaire was used to record socio-demographic data of the participants. The serum concentrations of the oxidant markers (nitrite, nitrate and total nitric oxide metabolites [NOx]) were determined using the Griess test, and the total antioxidant capacity (TAOC) was determined using the ABTS decolorisation method. The concentrations of these markers were compared across the three groups. Results The three study groups were similar in terms of socio-demographic data. The differences across the three groups were statistically significant for serum concentrations of nitrate and NOx (but not nitrite) and serum TAOC. Further analyses showed that the disparity for nitrate and NOx concentrations was greatest between poorly controlled asthma and healthy controls (p = 0.001 and p < 0.001) compared to the well-controlled asthmatics and healthy controls (p = 0.036 and p = 0.049). A significant difference in serum nitrate and NOx concentrations was not observed between the two asthma groups (p = 0.311 and 0.203). The TAOC were significantly lower in poorly controlled asthmatics as compared to well-controlled asthmatics (p = 0.003) and healthy controls (p < 0.001). However, there was no significant difference in the serum TAOC between healthy controls and well-controlled asthmatics (p = 0.496). These findings may indicate that it is perhaps the higher TAOC that contributes to the well controlled state of asthma. Conclusions The present study indicated that an imbalance of oxidants and antioxidants in the serum may have an underlying role in asthma pathophysiology, and how these markers may be effective in asthma management.
Collapse
Affiliation(s)
- Yenuli Fernando
- Institute of Biochemistry, Molecular Biology and Biotechnology, University of Colombo, Colombo, Sri Lanka.,Colombo International School, Colombo, 7 Sri Lanka
| | - Pujitha Wickramasinghe
- Department of Paediatrics, Faculty of Medicine, University of Colombo, Colombo, Sri Lanka
| | - Udani De Silva
- Institute of Biochemistry, Molecular Biology and Biotechnology, University of Colombo, Colombo, Sri Lanka
| | | | - K W D A Anuradha
- Department of Paediatrics, Faculty of Medicine, University of Colombo, Colombo, Sri Lanka
| | - Shiroma Handunnetti
- Institute of Biochemistry, Molecular Biology and Biotechnology, University of Colombo, Colombo, Sri Lanka
| |
Collapse
|
4
|
Warnasekara J, Koralegedara I, Agampodi S. Estimating the burden of leptospirosis in Sri Lanka; a systematic review. BMC Infect Dis 2019; 19:119. [PMID: 30727968 PMCID: PMC6364467 DOI: 10.1186/s12879-018-3655-y] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 12/21/2018] [Indexed: 12/18/2022] Open
Abstract
Background Although the assessment of disease burden should be a priority for allocating resources, leptospirosis is grossly underestimated despite its true burden in Sri Lanka. This study aimed to assess the morbidity and mortality of leptospirosis based on routine surveillance data, hospital reported data and scientific publications from Sri Lanka. Method A systematic review was carried out, and Pub Med, MEDLINE®, BIOSIS Previews, Zoological Record, Web of Science Core Collection, Current Contents Connect, KCI-Korean Journal Database, BIOSIS Citation Index, Data Citation Index, SciELO Citation Index and Google Scholar databases were searched. Quarterly epidemiological bulletin (QEB), indoor morbidity & mortality returns (IMMR) and hand searches of local literature were performed in local libraries. Forty-two relevant full texts, 32 QEBs, and 8 IMMR were included in the full text review. Adjustments were made for under diagnosis, underreporting and chance variability. Results The estimated annual caseload of leptospirosis in Sri Lanka from 2008 to 2015, was 10,423, and the cumulative annual incidence of leptospirosis that required hospitalization was 52.1 (95% CI 51.7–52.6) per 100,000 people. The estimated number of annual deaths due to leptospirosis was approximately 730 (95% CI 542–980), with an estimated pooled case fatality ratio of 7.0% (95% CI 5.2–9.4). The most common organs involved were the kidney, liver and heart, with median rates of 48.7, 30, and 14.2%, respectively. Conclusion Our systematic review shows gross underestimation of the true leptospirosis burden in the national statistics of Sri Lanka, and the hospitalization rates estimated in our study were compatible with the total burden estimate of 300·6 (95% CI 96·54–604·23) per 100,000 people published previously. Electronic supplementary material The online version of this article (10.1186/s12879-018-3655-y) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Janith Warnasekara
- Department of Community Medicine, Faculty of Medicine and Allied Sciences, Rajarata University of Sri Lanka, Saliyapura, 50008, Sri Lanka.
| | - Iresha Koralegedara
- Department of Community Medicine, Faculty of Medicine and Allied Sciences, Rajarata University of Sri Lanka, Saliyapura, 50008, Sri Lanka
| | - Suneth Agampodi
- Department of Community Medicine, Faculty of Medicine and Allied Sciences, Rajarata University of Sri Lanka, Saliyapura, 50008, Sri Lanka
| |
Collapse
|
5
|
Is Total Serum Nitrite and Nitrate (NOx) Level in Dengue Patients a Potential Prognostic Marker of Dengue Hemorrhagic Fever? DISEASE MARKERS 2018; 2018:5328681. [PMID: 30069272 PMCID: PMC6057279 DOI: 10.1155/2018/5328681] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/14/2018] [Revised: 03/19/2018] [Accepted: 04/26/2018] [Indexed: 11/17/2022]
Abstract
Potential use of total nitrite plus nitrate (NOx) and nitrite (NO2-) separately as surrogate markers for serum nitric oxide in severe dengue and their longitudinal changes along with the progression of infection was studied. Deproteinized sera from confirmed dengue fever (DF, n = 145) and dengue hemorrhagic fever (DHF, n = 74) patients on admission-A, critical-C, discharge-D, and convalescence-CON stages and from age-gender matched healthy individuals (HC, n = 77) were taken to assess NO2- and NOx levels using Griess and modified Griess assays. Serum NOx in DHFA was significantly lower compared to DFA (p < 0.001). HC had the lowest NOx and NO2- compared to all patient categories (p < 0.001) except NO2- in DF-CON and DHF-CON and NOx in DHF-CON. Serum NOx and NO2- in DHF patients admitted on fever day 3 (DHFA-3) was significantly lower compared to DFA-3 (p < 0.05). Cut-off values of 4.46 μM for NOx (91.3% sensitivity and 80.1% specificity) and 1.25 μM for NO2- (75.0% sensitivity and 73.3% specificity) were obtained for day 3 of fever. Serum NOx may be used as potential prognostic marker of DHF in patients presenting with DF in the early stage (on day 3 of fever) of the disease.
Collapse
|
6
|
Abstract
The search for the bactericidal activity of macrophage (Mϕ) is crucial not only during infection, but also to explore its functional activities in normal and pathological conditions, such as autoimmune and inflammatory disorders, allergic inflammation, and cancer. There are several methods exploring the phagocytic and bactericidal activities of Mϕ. This chapter focuses specifically on the technique called antibiotic protection assay and on the methods for the determination of Mϕ production of nitric oxide and hydrogen peroxide as antimicrobial agents and biomarkers of respiratory burst. The protocols presented herein are valid for both Mϕ cell lines and monocyte-derived Mϕs (MDMs).
Collapse
Affiliation(s)
- Mourad Aribi
- Laboratory of Applied Molecular Biology and Immunology (BIOMOLIM, W0414100), Department of Biology, University of Tlemcen, Tlemcen, Algeria.
| |
Collapse
|
7
|
Vk C, Ty L, Wf L, Ywy WS, An S, S Z, A M. Leptospirosis in human: Biomarkers in host immune responses. Microbiol Res 2017; 207:108-115. [PMID: 29458845 DOI: 10.1016/j.micres.2017.11.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Revised: 11/23/2017] [Accepted: 11/25/2017] [Indexed: 02/07/2023]
Abstract
Leptospirosis remains one of the most widespread zoonotic diseases caused by spirochetes of the genus Leptospira, which accounts for high morbidity and mortality globally. Leptospiral infections are often found in tropical and subtropical regions, with people exposed to contaminated environments or animal reservoirs are at high risk of getting the infection. Leptospirosis has a wide range of clinical manifestations with non-specific signs and symptoms and often misdiagnosed with other acute febrile illnesses at early stage of infection. Despite being one of the leading causes of zoonotic morbidity worldwide, there is still a gap between pathogenesis and human immune responses during leptospiral infection. It still remains obscure whether the severity of the infection is caused by the pathogenic properties of the Leptospira itself, or it is a consequence of imbalance host immune factors. Hence, in this review, we seek to summarize the past and present milestone findings on the biomarkers of host immune response aspects during human leptospiral infection, including cytokine and other immune mediators. A profound understanding of the interlink between virulence factors and host immune responses during human leptospirosis is imperative to identify potential biomarkers for diagnostic and prognostic applications as well as designing novel immunotherapeutic strategies in future.
Collapse
Affiliation(s)
- Chin Vk
- Department of Medical Microbiology & Parasitology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400, UPM, Serdang, Selangor, Malaysia.
| | - Lee Ty
- Department of Pathology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400, UPM Serdang, Selangor, Malaysia; School of Foundation Studies, Perdana University, 43400, Serdang, Malaysia.
| | - Lim Wf
- Department of Pathology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400, UPM Serdang, Selangor, Malaysia; Integrative Pharmacogenomics Institute (iPROMISE), Universiti Teknologi MARA Selangor, Puncak Alam Campus, 42300 Bandar Puncak Alam, Selangor, Malaysia.
| | - Wan Shahriman Ywy
- Department of Medical Microbiology & Parasitology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400, UPM, Serdang, Selangor, Malaysia; Department of Medical Laboratory Technology, Faculty of Health Sciences, Universiti Teknologi MARA, Cawangan Selangor Kampus Puncak Alam, 42300 Bandar Puncak Alam, Selangor, Malaysia.
| | - Syafinaz An
- Department of Medical Microbiology & Parasitology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400, UPM, Serdang, Selangor, Malaysia.
| | - Zamberi S
- Department of Medical Microbiology & Parasitology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400, UPM, Serdang, Selangor, Malaysia.
| | - Maha A
- Department of Pathology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400, UPM Serdang, Selangor, Malaysia.
| |
Collapse
|
8
|
Rajapakse S, Weeratunga P, Niloofa MJR, Fernando N, Rodrigo C, Maduranga S, de Silva NL, Fernando NL, de Silva HJ, Karunanayake L, Handunnetti S. Clinical and laboratory associations of severity in a Sri Lankan cohort of patients with serologically confirmed leptospirosis: a prospective study. Trans R Soc Trop Med Hyg 2016; 109:710-6. [PMID: 26464233 DOI: 10.1093/trstmh/trv079] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Leptospirosis results in significant morbidity and mortality. This study elucidates markers of severity in a cohort of Sri Lankan patients. METHODS Patients presenting to three healthcare institutions in the Western province of Sri Lanka with leptospirosis serological confirmed by the microscopic agglutination test (MAT) were included. Prospective data regarding demographic, clinical and laboratory parameters was extracted. Univariate associations and subsequent multivariate logistic regression models were constructed. RESULTS The study included 232 patients, with 68.5% (159) demonstrating severe disease. Significant associations of severe disease at a significance level of p<0.05 were fever >38.8°C on presentation, age >40 years, muscle tenderness, tachycardia on admission, highest white cell count >12 350/mm(3) and <7900/mm(3), highest neutrophil percentage >84%, haemoglobin >11.2 g/dL and <10.2 g/dL, packed cell volume (PCV) >33.8% and <29.8%, lowest platelet count <63 500/mm(3), highest alanine transaminase (ALT) >70 IU/L and hyponatremia with sodium <131 mEq/L. On multivariate analysis, PCV <29.8% (p=0.011; OR 3.750; CI: 1.394-10.423), ALT >70 IU/L (p=0.044; OR 2.639; CI: 1.028-6.774) and hyponatremia <131 mEq/L (p=0.019; OR 6.413; CI: 1.353-30.388) were independent associations of severe disease. CONCLUSIONS Severity associations were demonstrated with both clinical and laboratory parameters. There is a need for novel biomarkers for prediction of severity in leptospirosis.
Collapse
Affiliation(s)
- Senaka Rajapakse
- Tropical Medicine Research Unit, Department of Clinical Medicine, Faculty of Medicine, University of Colombo, Colombo 08, Sri Lanka
| | - Praveen Weeratunga
- Tropical Medicine Research Unit, Department of Clinical Medicine, Faculty of Medicine, University of Colombo, Colombo 08, Sri Lanka
| | - M J Roshan Niloofa
- Institute of Biochemistry, Molecular Biology and Biotechnology, University of Colombo, Colombo 03, Sri Lanka
| | - Narmada Fernando
- Institute of Biochemistry, Molecular Biology and Biotechnology, University of Colombo, Colombo 03, Sri Lanka
| | - Chathuraka Rodrigo
- Tropical Medicine Research Unit, Department of Clinical Medicine, Faculty of Medicine, University of Colombo, Colombo 08, Sri Lanka
| | - Sachith Maduranga
- Tropical Medicine Research Unit, Department of Clinical Medicine, Faculty of Medicine, University of Colombo, Colombo 08, Sri Lanka
| | - Nipun Lakshitha de Silva
- Tropical Medicine Research Unit, Department of Clinical Medicine, Faculty of Medicine, University of Colombo, Colombo 08, Sri Lanka
| | - Nipun Lakshitha Fernando
- Tropical Medicine Research Unit, Department of Clinical Medicine, Faculty of Medicine, University of Colombo, Colombo 08, Sri Lanka
| | - H Janaka de Silva
- Department of Medicine, Faculty of Medicine, University of Kelaniya, Ragama, Sri Lanka
| | - Lilani Karunanayake
- Department of Bacteriology, Medical Research Institute, Colombo 08, Sri Lanka
| | - Shiroma Handunnetti
- Institute of Biochemistry, Molecular Biology and Biotechnology, University of Colombo, Colombo 03, Sri Lanka
| |
Collapse
|
9
|
Protein Carbonyl as a Biomarker of Oxidative Stress in Severe Leptospirosis, and Its Usefulness in Differentiating Leptospirosis from Dengue Infections. PLoS One 2016; 11:e0156085. [PMID: 27280281 PMCID: PMC4900524 DOI: 10.1371/journal.pone.0156085] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2016] [Accepted: 05/09/2016] [Indexed: 01/29/2023] Open
Abstract
Pathogenesis of disease severity in leptospirosis is not clearly understood whether it is due to direct damage by pathogen or by adverse immune responses. Knowledge on biomarkers of oxidative stress which could be used in identifying patients with severe illness has shown to be of great value in disease management. Thus, the main aim of this study was to assess the damage to serum proteins and lipids, and their significance as biomarkers of oxidative stress in severe leptospirosis. In regions endemic for both leptospirosis and dengue, leptospirosis cases are often misdiagnosed as dengue during dengue epidemics. Therefore, the second aim was to assess the potential of the oxidative stress markers in differentiating severe leptospirosis from critical phase dengue. We measured serum antioxidants (uric acid and bilirubin), total antioxidant capacity (AOC), protein carbonyl (PC) and lipid hydroperoxide (LP) in patients with severe leptospirosis (n = 60), mild leptospirosis (n = 50), dengue during the critical phase (n = 30) and in healthy subjects (n = 30). All patient groups had similar total antioxidant capacity levels. However, the presence of significantly high uric acid and total bilirubin levels may reflect the degree of renal and hepatic involvement seen in severe leptospirosis patients (p<0.02). Serum PC and LP levels were significantly higher in leptospirosis patients compared to critical phase dengue infections (p<0.005). Moreover, high serum PC levels appear to differentiate SL from DC [area under the curve (AUC) = 0.96; p<0.001]. Serum PC may be a reliable biomarker of oxidative damage to serum proteins to identify severe leptospirosis patients (AUC = 0.99) and also to differentiate severe leptospirosis from mild cases (AUC = 0.78; p<0.005) indicating its contribution to pathogenesis. Use of serum PC as an indicator of leptospirosis severity and as an oxidative stress biomarker in differentiating leptospirosis from dengue would provide the opportunity to save lives via prompt patient management.
Collapse
|
10
|
Rajapakse S, Rodrigo C, Handunnetti SM, Fernando SD. Current immunological and molecular tools for leptospirosis: diagnostics, vaccine design, and biomarkers for predicting severity. Ann Clin Microbiol Antimicrob 2015; 14:2. [PMID: 25591623 PMCID: PMC4299796 DOI: 10.1186/s12941-014-0060-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Accepted: 12/22/2014] [Indexed: 12/18/2022] Open
Abstract
Leptospirosis is a zoonotic spirochaetal illness that is endemic in many tropical countries. The research base on leptospirosis is not as strong as other tropical infections such as malaria. However, it is a lethal infection that can attack many vital organs in its severe form, leading to multi-organ dysfunction syndrome and death. There are many gaps in knowledge regarding the pathophysiology of leptospirosis and the role of host immunity in causing symptoms. This hinders essential steps in combating disease, such as developing a potential vaccine. Another major problem with leptospirosis is the lack of an easy to perform, accurate diagnostic tests. Many clinicians in resource limited settings resort to clinical judgment in diagnosing leptospirosis. This is unfortunate, as many other diseases such as dengue, hanta virus, rickettsial infections, and even severe bacterial sepsis, can mimic leptospirosis. Another interesting problem is the prediction of disease severity at the onset of the illness. The majority of patients recover from leptospirosis with only a mild febrile illness, while a few others have severe illness with multi-organ failure. Clinical features are poor predictors of potential severity of infection, and therefore the search is on for potential biomarkers that can serve as early warnings for severe disease. This review concentrates on these three important aspects of this neglected tropical disease: diagnostics, developing a vaccine, and potential biomarkers to predict disease severity.
Collapse
Affiliation(s)
- Senaka Rajapakse
- Department of Clinical Medicine, Faculty of Medicine, University of Colombo, 25, Kynsey Road, Colombo, 08, Sri Lanka.
| | - Chaturaka Rodrigo
- Department of Clinical Medicine, Faculty of Medicine, University of Colombo, 25, Kynsey Road, Colombo, 08, Sri Lanka.
| | - Shiroma M Handunnetti
- Institute of Biochemistry, Molecular Biology and Biotechnology, University of Colombo, Colombo, Sri Lanka.
| | | |
Collapse
|
11
|
Fluidic automation of nitrate and nitrite bioassays in whole blood by dissolvable-film based centrifugo-pneumatic actuation. SENSORS 2013; 13:11336-49. [PMID: 24064595 PMCID: PMC3821360 DOI: 10.3390/s130911336] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Revised: 08/07/2013] [Accepted: 08/14/2013] [Indexed: 11/17/2022]
Abstract
This paper demonstrates the full centrifugal microfluidic integration and automation of all liquid handling steps of a 7-step fluorescence-linked immunosorbent assay (FLISA) for quantifying nitrate and nitrite levels in whole blood within about 15 min. The assay protocol encompasses the extraction of metered plasma, the controlled release of sample and reagents (enzymes, co-factors and fluorescent labels), and incubation and detection steps. Flow control is implemented by a rotationally actuated dissolvable film (DF) valving scheme. In the valves, the burst pressure is primarily determined by the radial position, geometry and volume of the valve chamber and its inlet channel and can thus be individually tuned over an extraordinarily wide range of equivalent spin rates between 1,000 RPM and 5,500 RPM. Furthermore, the vapour barrier properties of the DF valves are investigated in this paper in order to further show the potential for commercially relevant on-board storage of liquid reagents during shelf-life of bioanalytical, ready-to-use discs.
Collapse
|