RIFLE and Acute Kidney Injury Network classifications predict mortality in leptospirosis-associated acute kidney injury

Identifying risk factors and disease severity in leptospirosis: A meta-analysis of clinical predictors

Leptospirosis is a bacterial zoonosis with a wide spectrum of clinical presentations. In order to identify potential risk factors and predictors of disease severity, a meta-analysis of the clinical features of severe and non-severe leptospirosis patients was conducted. PubMed was searched to collect studies on the difference in clinical characteristics of severe and nonsevere patients, and data were analyzed using Comprehensive Meta-Analysis V3 software. Results showed that patients with severe outcomes were more likely to have dyspnoea, oliguria, and hemorrhagic symptoms than nonsevere patients. Determining these predictors in the early stages of the disease could thus significantly reduce the development of severe cases and related mortality.

Leptospirosis: Prognostic Model for Patient Mortality in the Transcarpathian Region, Ukraine

Background: Leptospirosis is a bacterial zoonosis of worldwide distribution with a wide spectrum of clinical presentations that range from subclinical or mild to severe and fatal outcomes. Identifying clinical predictors for the severe form of the disease is critical to reduce disease complications and death. As a result, we conducted a retrospective case-control study to identify clinical markers of mortality in leptospirosis patients from the Transcarpathian region. Materials and Methods: The study used 102 medical records of patients with leptospirosis in the period from 2009 to 2019. There were 26 fatal cases and 76 survivors. Predictors were examined using univariate and bivariate statistics. Results: Fatal and nonfatal groups did not differ in age or gender composition (p > 0.5), nor did they differ in signs or symptoms, except that oliguria occurred significantly more often in fatal cases (p < 0.001). Laboratory diagnostic tests, however, differed between outcomes in 7/9 recorded variables; primarily associated with liver and kidney function as well thrombocytopenia and elevated white blood cell counts for fatal cases (p < 0.01 for all variables). Conclusions: Logistic regression analysis indicated that a combination of creatinine levels and direct bilirubin levels were the best predictors of patient outcome. The specificity of the model was 90.9% and the area under the receiver operator characteristic function as 93.6%. This model can be used when a patient is admitted to a hospital to better characterize patient risk.

Determinants of prolonged hospitalization and mortality among leptospirosis patients attending tertiary care hospitals in northeastern state in peninsular Malaysia: A cross sectional retrospective analysis

Background

Leptospirosis is the most common anthropozoonosis worldwide and imposes a major public health problem in many tropical countries. It is a leading cause of disease burden in form of mortality, morbidity and hospital admission. Identifying patients at high risk for mortality or for prolonged hospitalization may save lives and preserve economy. The aim of the current study is to identify significant factors associated with disease mortality and prolonged hospitalization.

Design

Cress-sectional retrospective study.

Settings

Tertiary care teaching hospitals in Kelantan, Peninsular Malaysia.

Participants

Adult patients proven to have leptospirosis depending on IgM ELISA were classified into two classes depending on prolonged hospitalization (&gt;7 days or ≤ 7 days) and mortality (fatal cases or non-fatal cases). Patients' clinico-laboratory data were compared according to these two outcomes using the appropriate statistical test.

Results

Of the 525 patients enrolled, 136 (25.9%) had prolonged hospitalization. The mean length of stay was 6.77 ± 5.68 days. Logistic regression analysis identified acute kidney injury (AKI) (OR 2.3), Jaundice (OR 2.7), elevated alanine aminotransferase (ALT) (OR 2), and prolonged prothrombin time (PT) (OR 1.9) independently associated with prolonged hospitalization. Case fatality rate was 6.48% and around one third of fatal cases had prolonged hospitalization of more than seven days. Factors associated with leptospirosis mortality included age &gt;40 years (p &lt; 0.001), patients presented with tachypnea (p = 0.002), pulmonary infiltrate (p &lt; 0.001), T-wave changes (p &lt; 0.001), atrial fibrillation (p = 0.013), conducting abnormality (p &lt; 0.001), chronic kidney diseases (p &lt; 0.001), multiple organ dysfunctions (p &lt; 0.0010), respiratory failure (p &lt; 0.001), pneumonia (p &lt; 0.001), sepsis (p = 0.004), low venous PH (p = 0.042), AKI (P &lt; 0.001), elevated AST (p &lt; 0.001) or ALT (p = 0.004), hypoalbuminemia (p &lt; 0.001), rhabdomyolysis (p &lt; 0.001), severe thrombocytopenia (p = 0.042), prolonged PT (p &lt; 0.001) or prolonged aPTT (p &lt; 0.017).

Conclusions

Significant proportion of leptospirosis patients (25.9%) had prolonged hospital stay and less proportion died (6.48%). Early identifying patients with factors associated with prolonged hospitalization and death will positively impact practitioners' decisions regarding the proper and fast course of management including ICU admission.

Plasma Osteopontin Levels is Associated with Biochemical Markers of Kidney Injury in Patients with Leptospirosis

Leptospirosis becomes severe, with a fatality rate of >10%, and manifests as severe lung injury accompanied by acute kidney injury. Using urine and blood samples of 112 patients with leptospirosis, osteopontin (OPN), galectin-9 (Gal-9) and other kidney-related biomarkers were measured to understand the pathological and diagnostic roles of OPN and Gal-9 in leptospirosis. Plasma levels of full-length (FL)-OPN (pFL-OPN) (p < 0.0001), pFL-Gal-9(p < 0.0001) and thrombin-cleaved OPN (p < 0.01) were significantly higher in patients with leptospirosis than in healthy controls (n = 30), as were levels of several indicators of renal toxicity: serum cystatin C (p < 0.0001), urine N-acetyl-β-glucosaminidase (NAG)/creatinine (p < 0.05), and urine clusterin/creatinine (p < 0.05). pFL-Gal-9 levels were negatively correlated with pFL-OPN levels (r = −0.24, p < 0.05). pFL-OPN levels were positively correlated with serum cystatin C (r = 0.41, p < 0.0001), urine NAG/creatinine (r = 0.35, p < 0.001), urine clusterin/creatinine (r = 0.33, p < 0.01), and urine cystatin C/creatinine (r = 0.33, p < 0.05) levels. In a group of patients with abnormally high creatinine levels, significantly higher levels of serum cystatin C (p < 0.0001) and pFL-OPN (p < 0.001) were observed. Our results demonstrate that pFL-OPN reflect kidney injury among patients with leptospirosis.

Mortality of leptospirosis associated acute kidney injury (LAKI) & predictors for its development in adults: A systematic review

Leptospirosis is the most widely spread zoonosis and Leptospirosis Associated Acute Kidney Injury (LAKI) is common and fatal if not properly and swiftly treated. The aim of this review is to evaluate the mortality of LAKI and to identify the risk factors for its development. An electronic search was performed to identify the studies included LAKI patients series. Only studies which investigated mortality or risk factors for LAKI development in adults were included. Twenty-three studies with 24 patients series were included in the final analysis and included 1698 patients. The median series mortality was 10.05% (range 0-33.3%) with a total of 223 death. Only four studies identified the independent risk factors for LAKI development which were oliguria, jaundice, arrhythmia, crackles, elevated direct bilirubin level, elevated activated prothrombin time, hyperbilirubinemia and leukocytosis. Although the mortality of LAKI is high, its predictors are not studied enough in literature.

Lp25 membrane protein from pathogenic Leptospira spp. is associated with rhabdomyolysis and oliguric acute kidney injury in a guinea pig model of leptospirosis

Acute kidney injury (AKI) from leptospirosis is frequently nonoliguric with hypo- or normokalemia. Higher serum potassium levels are observed in non-survivor patients and may have been caused by more severe AKI, metabolic disarrangement, or rhabdomyolysis. An association between the creatine phosphokinase (CPK) level and maximum serum creatinine level has been observed in these patients, which suggests that rhabdomyolysis contributes to severe AKI and hyperkalemia. LipL32 and Lp25 are conserved proteins in pathogenic strains of Leptospira spp., but these proteins have no known function. This study evaluated the effect of these proteins on renal function in guinea pigs. Lp25 is an outer membrane protein that appears responsible for the development of oliguric AKI associated with hyperkalemia induced by rhabdomyolysis (e.g., elevated CPK, uric acid and serum phosphate). This study is the first characterization of a leptospiral outer membrane protein that is associated with severe manifestations of leptospirosis. Therapeutic methods to attenuate this protein and inhibit rhabdomyolysis-induced AKI could protect animals and patients from severe forms of this disease and decrease mortality.

Changing patterns in leptospirosis: a three-decade study in Brazil

BACKGROUND

This study was conducted to investigate changes in the clinical pattern of leptospirosis over time, analyzing its clinical and laboratory presentations in a metropolitan city of Brazil.

METHOD

This was a retrospective study including all patients with leptospirosis admitted to tertiary care hospitals in Fortaleza in the northeast of Brazil, between 1985 and 2015. Patients were divided into three groups according to the year of hospital admission: group I for the years 1985-1995, group II for 1996-2005, and group III for 2006-2015. Demographic, clinical, and laboratory data were compared between the groups.

RESULTS

A total of 507 patients were included. Their mean age was 37.3±15.9years and 82.4% were male. The mean time between symptom onset and admission was 7±4 days. There was a linear decrease in the levels of serum urea (190.1±92.7, 135±79.5, and 95.6±73.3mg/dl, respectively, p <0.0001) and creatinine (5.8±2.9, 3.8±2.6, and 3.0±2.5mg/dl, respectively, p <0.0001) in each decade, while levels of hemoglobin (10.31±1.9, 10.8±2.0, and 11.5±2.1g/dl, respectively, p <0.0001) and platelets (57.900±52.650, 80.130±68.836, and 107.101±99.699×10⁹/l, respectively, p<0.0001) increased. There was a tendency towards a linear decrease in mortality (22%, 14%, and 11.6%, respectively, p=0.060).

CONCLUSIONS

Leptospirosis showed significant changes over time in this region. The main changes point to a decrease in disease severity and complications, such as acute kidney injury. Mortality has decreased, being close to 11%.

Acute kidney injury due to tropical infectious diseases and animal venoms: a tale of 2 continents

South and Southeast Asia and Latin American together comprise 46 countries and are home to approximately 40% of the world population. The sociopolitical and economic heterogeneity, tropical climate, and malady transitions characteristic of the region strongly influence disease behavior and health care delivery. Acute kidney injury epidemiology mirrors these inequalities. In addition to hospital-acquired acute kidney injury in tertiary care centers, these countries face a large preventable burden of community-acquired acute kidney injury secondary to tropical infectious diseases or animal venoms, affecting previously healthy young individuals. This article reviews the epidemiology, clinical picture, prevention, risk factors, and pathophysiology of acute kidney injury associated with tropical diseases (malaria, dengue, leptospirosis, scrub typhus, and yellow fever) and animal venom (snakes, bees, caterpillars, spiders, and scorpions) in tropical regions of Asia and Latin America, and discusses the potential future challenges due to emerging issues.

Determinants of mortality and impact of therapy in patients with leptospirosis admitted for intensive care in a Sri Lankan hospital--a three year retrospective study

INTRODUCTION

Leptospirosis is a disease of epidemic proportions in Sri Lanka. There is paucity of data on the determinants of mortality and impact of therapy in patients with leptospirosis admitted to critical care settings in endemic territories.

METHODOLOGY

This retrospective cross-sectional study was performed in patients with serologically confirmed leptospirosis admitted to the intensive care unit of the General Hospital, Kalutara from January 2011 to April 2014. Associations between socio-epidemiological, clinical and laboratory parameters and patient mortality were examined.

RESULTS

Forty-five patients were included. The mean age was 49.11(SD = 16.95) and majority (92%) were male. Percentage mortality was 44.4%. Patient mortality was associated with age > 40 (p = 0.012), symptoms of uremia (p = 0.017), evidence of CNS involvement (p = 0.039), presence of oliguria (p = 0.002) and anuria (p = 0.014), presence of multi-organ dysfunction syndrome (MODS) (p < 0.001), CRP > 96 (p = 0.036), platelet count < 20,000 (p = 0.045), Potassium > 5.0 (p = 0.05), metabolic acidosis with pH < 7.2 (p = 0.03), INR > 2 (p = 0.037) and requirement of mechanical ventilation (p < 0.001). Cox regression analysis revealed MODS and potassium > 5 to be independently associated with mortality.

CONCLUSIONS

A high mortality rate is noted. The presence of MODS and serum potassium concentration > 5.0 was independently associated with mortality in this retrospective study of patients with confirmed leptospirosis in a critical care setting.

Risk factors for intensive care unit admission in patients with severe leptospirosis: a comparative study according to patients' severity

BACKGROUND

The aim of this study is to investigate predictive factors for intensive care unit (ICU) admission among patients with severe leptospirosis.

METHODS

This is a retrospective study with all patients with severe leptospirosis admitted to a tertiary hospital. Patients were divided in ICU and ward groups. Demographical, clinical and laboratory data of the groups were compared as well as acute kidney injury (AKI) severity, according to the RIFLE criteria (R = Risk, I = Injury, F = Failure, L = Loss, E = End-stage kidney disease).

RESULTS

A total of 206 patients were included, 83 admitted to ICU and 123 to ward. Mean age was 36 ± 15.8 years, with 85.9% males. Patients in ICU group were older (38.8 ± 15.7 vs. 34.16 ± 15.9 years, p = 0.037), had a shorter hospital stay (4.13 ± 3.1 vs. 9.5 ± 5.2 days, p = 0.0001), lower levels of hematocrit (29.6 ± 6.4 vs. 33.1 ± 8.6%, p = 0.003), hemoglobin (10.2 ± 2.4 vs. 11.6 ± 1.9 g/dL, p < 0.0001), and platelets (94,427 ± 86,743 vs. 128,896 ± 137,017/mm(3), p = 0.035), as well as higher levels of bilirubin (15.0 ± 12.2 vs. 8.6 ± 9.5 mg/dL, p = 0.001). ICU group also had a higher frequency of severe AKI (RIFLE-"Failure": 73.2% vs. 54.2%, p < 0.0001) and a higher prevalence of dialysis requirement (57.3% vs. 27.6%, p < 0.0001). Mortality was higher among ICU patients (23.5% vs. 5.7%, p < 0.0001). Independent predictors for ICU admission were tachypnea (p = 0.027, OR = 13, CI = 1.3-132), hypotension (p = 0.009, OR = 5.27, CI = 1.5-18) and AKI (p = 0.029, OR = 14, CI = 1.3-150). Ceftriaxone use was a protective factor (p = 0.001, OR = 0.13, CI = 0.04-0.4).

CONCLUSIONS

Independent risk factors for ICU admission in leptospirosis include tachypnea, hypotension and AKI. Ceftriaxone was a protective factor for ICU admission, suggesting that its use may prevent severe forms of the disease.

Neutrophil Gelatinase Associated Lipocalin (NGAL) in Leptospirosis Acute Kidney Injury: A Multicenter Study in Thailand

AKI is one of the most serious complications of leptospirosis, an important zoonosis in the tropics. Recently, NGAL, one of the novel AKI biomarkers, is extensively studied in various specific settings such as sepsis, cardiac surgery, and radiocontrast nephropathy. In this multicenter study, we aimed to study the role of NGAL as an early marker and an outcome predictor of leptospirosis associated AKI. Patients who presented with clinical suspiciousness of leptospirosis were prospectively enrolled in 9 centers from August 2012 to November 2014. The first day of enrollment was the first day of clinical suspicious leptospirosis. Blood and urine samples were serially collected on the first three days and day 7 after enrollment. We used three standard techniques (microscopic agglutination test, direct culture, and PCR technique) to confirm the diagnosis of leptospirosis. KDIGO criteria were used for AKI diagnosis. Recovery was defined as alive and not requiring dialysis during hospitalization or maintaining maximum KDIGO stage at hospital discharge. Of the 221 recruited cases, 113 cases were leptospirosis confirmed cases. Thirty seven percent developed AKI. Median uNGAL and pNGAL levels in those developing AKI were significantly higher than in patients not developing AKI [253.8 (631.4) vs 24.1 (49.6) ng/ml, p < 0.001] and [1,030 (802.5) vs 192.0 (209.0) ng/ml, p < 0.001], respectively. uNGAL and pNGAL levels associated with AKI had AUC-ROC of 0.91, and 0.92, respectively. Both of urine NGAL and pNGAL level between AKI-recovery group and AKI-non recovery were comparable. From this multicenter study, uNGAL and pNGAL provided the promising result to be a marker for leptospirosis associated AKI. However, both of them did not show the potential role to be the predictor of renal recovery in this specific setting.

A Systematic Review of Mortality from Untreated Scrub Typhus (Orientia tsutsugamushi)

BACKGROUND

Scrub typhus, a bacterial infection caused by Orientia tsutsugamushi, is increasingly recognized as an important cause of fever in Asia, with an estimated one million infections occurring each year. Limited access to health care and the disease's non-specific symptoms mean that many patients are undiagnosed and untreated, but the mortality from untreated scrub typhus is unknown. This review systematically summarizes the literature on the untreated mortality from scrub typhus and disease outcomes.

METHODOLOGY/PRINCIPAL FINDINGS

A literature search was performed to identify patient series containing untreated patients. Patients were included if they were symptomatic and had a clinical or laboratory diagnosis of scrub typhus and excluded if they were treated with antibiotics. The primary outcome was mortality from untreated scrub typhus and secondary outcomes were total days of fever, clinical symptoms, and laboratory results. A total of 76 studies containing 89 patient series and 19,644 patients were included in the final analysis. The median mortality of all patient series was 6.0% with a wide range (min-max) of 0-70%. Many studies used clinical diagnosis alone and had incomplete data on secondary outcomes. Mortality varied by location and increased with age and in patients with myocarditis, delirium, pneumonitis, or signs of hemorrhage, but not according to sex or the presence of an eschar or meningitis. Duration of fever was shown to be long (median 14.4 days Range (9-19)).

CONCLUSIONS

Results show that the untreated mortality from scrub typhus appears lower than previously reported estimates. More data are required to clarify mortality according to location and host factors, clinical syndromes including myocarditis and central nervous system disease, and in vulnerable mother-child populations. Increased surveillance and improved access to diagnostic tests are required to accurately estimate the untreated mortality of scrub typhus. This information would facilitate reliable quantification of DALYs and guide empirical treatment strategies.

A Systematic Review of the Mortality from Untreated Leptospirosis

BACKGROUND

Leptospirosis occurs worldwide, but the global incidence of human disease and its mortality are not well understood. Many patients are undiagnosed and untreated due to its non-specific symptoms and a lack of access to diagnostics. This study systematically reviews the literature to clarify the mortality from untreated leptospirosis. Results will help quantify the global burden of disease and guide health policies.

METHODOLOGY/PRINCIPAL FINDINGS

A comprehensive literature search was performed to identify untreated patient series. Included patients were symptomatic, but asymptomatic patients and those who had received antibiotics, dialysis or who were treated on Intensive Care Units were excluded. Included patients had a confirmed laboratory diagnosis by culture, PCR, or serological tests. Data was extracted and individual patient series were assessed for bias. Thirty-five studies, comprising 41 patient series and 3,390 patients, were included in the study. A high degree of bias within studies was shown due to limitations in study design, diagnostic tests and missing data. Median series mortality was 2.2% (Range 0.0-39.7%), but mortality was high in jaundiced patients (19.1%) (Range 0.0-39.7%), those with renal failure 12.1% (Range 0-25.0%) and in patients aged over 60 (60%) (Range 33.3-60%), but low in anicteric patients (0%) (Range 0-1.7%).

CONCLUSIONS

This systematic review contributes to our understanding of the mortality of untreated leptospirosis and provides data for the estimation of DALYs attributable to this disease. We show that mortality is significantly higher in older patients with icteric disease or renal failure but is lower in younger, anicteric patients. Increased surveillance and accurate point-of-care diagnostics are required to better understand the incidence and improve diagnosis of disease. Empirical treatment strategies should prioritize early treatment to improve outcomes from leptospirosis.

Endothelial glycocalyx damage is associated with leptospirosis acute kidney injury

Leptospirosis is a common disease in tropical countries, and the kidney is one of the main target organs. Membrane proteins of Leptospira are capable of causing endothelial damage in vitro, but there have been no studies in humans evaluating endothelial glycocalyx damage and its correlation with acute kidney injury (AKI). We performed a cohort study in an outbreak of leptospirosis among military personnel. AKI was diagnosed in 14 of 46 (30.4%) patients. Leptospirosis was associated with higher levels of intercellular adhesion molecule-1 (ICAM-1; 483.1 ± 31.7 versus 234.9 ± 24.4 mg/L, P < 0.001) and syndecan-1 (73.7 ± 15.9 versus 21.2 ± 7.9 ng/mL, P < 0.001) compared with exposed controls. Patients with leptospirosis-associated AKI had increased level of syndecan-1 (112.1 ± 45.4 versus 41.5 ± 11.7 ng/mL, P = 0.021) and ICAM-1 (576.9 ± 70.4 versus 434.9 ± 35.3, P = 0.034) compared with leptospirosis patients with no AKI. Association was verified between syndecan-1 and ICAM-1 with serum creatinine elevation and neutrophil gelatinase-associated lipocalin (NGAL) levels. This association remained even after multivariate analysis including other AKI-associated characteristics. Endothelial injury biomarkers are associated with leptospirosis-associated renal damage.