Acute kidney injury in a tropical country: a cohort study of 253 patients in an infectious diseases intensive care unit

Acute kidney injury associated with dengue virus infection: a review

Acute kidney injury (AKI) is one of the least studied complications of dengue, but it carries high mortality rates and prolonged hospital stay. Due to the severity of this complication, the risk of developing chronic kidney disease (CKD) and the increasing number of dengue cases reported worldwide, particularly in the tropical and subtropical regions of Africa, Southeast Asia and South America, including Brazil, we embarked on this narrative review, aimed to update the epidemiology of AKI associated with dengue, elucidate the main pathophysiological mechanisms of AKI caused by the dengue virus infection, as well as discuss useful information on the prevention and management of AKI in patients with dengue.

Prevalence, Characteristics, and Factors Associated with Acute Kidney Injury among Adult Dengue Patients in Vietnam

Acute kidney injury (AKI) is a serious and potentially lethal complication of dengue disease; however, the actual incidence in dengue patients in Vietnam is unknown. This study aimed to determine the prevalence, clinical and laboratory characteristics, and risk factors for AKI in adults with dengue. This is a multicenter, cross-sectional study conducted between January and December 2017 in 2,417 adult patients with dengue. Indicators of demographic, clinical, and laboratory findings were evaluated. The prevalence of dengue disease-associated AKI was 2.7% (64/2,417), and dengue patients with AKI had a higher mortality rate than patients without AKI (12.5% versus 0.6%; P < 0.01). Characteristics of AKI were more common in male gender (male: female was 6.1:1), a history of hypertension (7.8% versus 2.3%; P < 0.02), the situations of hemoconcentration (hematocrit > 44%; P < 0.008), hypovolemic shock (21.9% versus 6.8%; P < 0.01), organ failure (42.3% versus 2.3%; P < 0.01), or manifestations of myocarditis (20.3% versus 6.6%; P < 0.01), hyperbilirubinemia (28.7 ± 7.6 versus 12.0 ± 0.9; P < 0.01), elevated enzymes such as ALT (407 ± 151 versus 113 ± 6; P < 0.01) and AST (891 ± 475 versus 172 ± 11; P < 0.01), and prolonged PT (s) (13.9 ± 4.6 versus 12.3 ± 1.5; P < 0.01). Independent risk factors for AKI by multivariate analysis were male gender (OR: 43.6; 95% CI: 2.4-810), severe dengue classification (OR: 25.7; 95% CI: 2-333), and creatine kinase > 190 U/L (OR: 11.7; 95% CI: 1.1-122.4). The study results indicate a need to continue studying the association between AKI and mortality in dengue disease and the need for improved management of AKI with dengue.

Continuous renal replacement therapy in patients with HIV/AIDS

Background

Acute kidney injury (AKI) is a common complication among human immunodeficiency virus (HIV)-infected patients resulting in increased morbidity and mortality. Continuous renal replacement therapy (CRRT) is a useful method and instrument in critically ill patients with fluid overload and metabolic disarray, especially in those who are unable to tolerate the intermittent hemodialysis. However, the epidemiology, influence factors of CRRT and mortality in patients with HIV/AIDS are still unclear in China. This study aims to study the HIV-infected patients admitted in Intensive Care Unit (ICU) and explore the influence factors correlated with CRRT and their prognosis.

Methods

We performed a retrospective case-control study in the ICU of the Beijing Ditan Hospital Capital Medical University. From June 1, 2005 to May 31, 2017, 225 cases were enrolled in this clinical study.

Results

122 (54.2%) patients were diagnosed with AKI during their stay in ICU, the number and percentage of AKI stage 1, 2 and 3 were 38 (31.1%), 21(17.2%) and 63(51.7%), respectively. 26.2% of AKI patients received CRRT during the stay of ICU. 56.25% CRRT patients died in ICU. The 28-day mortality was 62.5%, and the 90-day mortality was 75%. By univariate logistics analysis, it showed that higher likelihood of diagnosis for respiratory failure (OR = 7.333,95% CI 1.467–36.664, p = 0.015), higher likelihood of diagnosis for septic shock (OR = 1.005,95% CI 1.001–1.01, p = 0.018), and higher likelihood to use vasoactive agents (OR = 10.667,95% CI 1.743–65.271, p = 0.001), longer mechanical ventilation duration (OR = 1.011,95% CI 1.002–1.019, p = 0.011), higher likelihood for diagnosis for PCP (OR = 7.50,95% CI 1.288–43.687, p = 0.025), higher SOFA score at ICU admission (OR = 1.183,95% CI 1.012–1.383, p = 0.035), longer duration of CRRT (OR = 1.014,95% CI 1.001–1.028, p = 0.034) contributed to a higher mortality at ICU. The Cox Analysis for the cumulative survival of AKI 3 patients between the CRRT and non-CRRT groups shows no significant differences (p = 0.595).

Conclusions

There is a high incidence of AKI in HIV-infected patients admitted in our ICU. Patients with severe AKI were more prone to be admitted for CRRT and have a consequent poor prognosis.

A systematic review and meta-analysis of acute kidney injury in the intensive care units of developed and developing countries

Objectives

Although the majority of the global population lives in developing countries, most of the epidemiological data related to intensive care unit (ICU) acute kidney injury (AKI) comes from developed countries. This systematic review aims to ascertain the methodology of studies on ICU AKI patients in developing and developed countries, to determine whether epidemiological comparisons between these two settings are possible, and to present a summary estimate of AKI incidence.

Methods

A systematic review of published studies reporting AKI in intensive care units (2005–2015) identified in PubMed, LILACS, and IBECs databases was conducted. We compared developed and developing countries by evaluating study methodology, AKI reference serum creatinine definitions, population characteristics, AKI incidence and mortality. AKI incidence was calculated with a random-effects model.

Results

Ninety-two studies were included, one of which reported data from both country categories: 60 from developed countries (1,057,332 patients) and 33 from developing countries (34,539 patients). In 78% of the studies, AKI was defined by the RIFLE, AKIN or KDIGO criteria. Oliguria had 11 different definitions and reference creatinine 23 different values. For the meta-analysis, 38 studies from developed and 18 from developing countries were selected, with similar AKI incidence: 39.3% and 35.1%, respectively. The need for dialysis, length of ICU stay and mortality were higher in developing countries.

Conclusion

Although patient characteristics and AKI incidence were similar in developed and developing countries, main outcomes were worse in developing country studies. There are significant caveats when comparing AKI epidemiology in developed and developing countries, including lack of standardization of reference serum creatinine, oliguria and the timeframe for AKI assessment. Larger, prospective, multicenter studies from developing countries are urgently needed to capture AKI data from the overall population without ICU access.

Renal Involvement in Children with Dengue Fever: A Study in Tertiary Care Hospital of Bangladesh

Background and Objective: Dengue has emerged globally as the most relevant viral infection transmitted by a mosquito bite and represents a major threat to public health. Dengue-related renal manifestations such as proteinuria, hematuria, acute kidney injury (AKI), and rhabdomyolysis are not uncommon, and acute kidney injury (AKI) is a serious complication of dengue fever. There is relatively few data on the renal manifestations of dengue fever in children. Hence, this study was conducted to evaluate the incidence, characteristics, and clinical outcome of dengue fever with renal manifestations. Method. This prospective cross sectional study was conducted in Dr. M R Khan Children Hospital and Institute of Child Health, Dhaka, over a period of 1 year from January 2018 to December 2018. The study was approved by the ethical committee of the institute. A total number of 316 patients were admitted with the diagnosis of dengue fever either NS1 positive or antibody IgM positive or both IgM and IgG positive. Data were collected in a structured questionnaire form and were analyzed by SPSS version 20.0. The disease severity was classified according to the World Health Organization criteria. Renal manifestations were divided into AKI groups using pRIFLE criteria. Proteinuria was defined as urinary protein >1+ (30 mg/dL) by dipstick test. Hematuria was defined as red blood cell (RBC) >5/μL in a fresh uncentrifuged urine specimen. Result. Among 316 dengue patients, thirty-one patients (9.8%) had renal involvement. Most of the patients (54.83%) with renal manifestations were aged between 1 and 5 years. A total of 14 patients were found to have proteinuria (4.4%). Nephrotic-range proteinuria was seen in only one patient (0.3%). AKI was defined by pRIFLE criteria and was seen in 13 patients (4.1%); among AKI 6 (46.15%) had risk, three patients (23.07%) had injury and 4 (30.7%) had failure and needed peritoneal dialysis. Death occurred in 3 patients (9.6%) in dengue with AKI who had failure. The incidence of renal manifestations (proteinuria, hematuria, and AKI) is as high as 9.8% among patients with dengue, and those with AKI had significant morbidity and mortality. Conclusion. Renal involvement in children with dengue is not uncommon. Dengue associated with AKI had significant mortality and morbidity.

An epidemiologic overview of acute kidney injury in intensive care units

SUMMARY INTRODUCTION Acute kidney injury (AKI) is a frequent event among critically ill patients hospitalized in intensive care units (ICU) and represents a global public health problem, being imperative an interdisciplinary approach. OBJECTIV To investigate, through literature review, the AKI epidemiology in ICUs. METHODS: Online research in Medline, Scientific Electronic Library Online, and Latin American and Caribbean Literature in Health Sciences databases, with analysis of the most relevant 47 studies published between 2010 and 2017. RESULTS Data of the 67,033 patients from more than 300 ICUs from different regions of the world were analyzed. The overall incidence of AKI ranged from 2.5% to 92.2%, and the mortality from 5% to 80%. The length of ICU stay ranged from five to twenty-one days, and the need for renal replacement therapy from 0.8% to 59.2%. AKI patients had substantially higher mortality rates and longer hospital stays than patients without AKI. CONCLUSION AKI incidence presented high variability among the studies. One of the reasons for that were the different criteria used to define the cases. Availability of local resources, renal replacement therapy needs, serum creatinine at ICU admission, volume overload, and sepsis, among others, influence mortality rates in AKI patients.

Infections and the kidney: a tale from the tropics

Tropical infections are caused by a variety of bacteria, viruses and parasitic organisms across varying geographical regions and are more often reported in adults than in children. Most of the infections are acute, presenting as a febrile illness with involvement of multiple organ systems, including the kidney. The gamut of renal manifestations extends from asymptomatic urinary abnormalities to acute kidney injury and-albeit rarely-chronic kidney disease. Tropical infections can involve the glomerular, tubulointerstitial and vascular compartments of the kidney. Leptospirosis, malaria, dengue, rickettsial fever and schistosomiasis are the most prevalent tropical infections which affect the kidneys of children living in the tropics. In this review we discuss renal involvement in these most prevalent tropical infections.

Tropical diseases in the ICU: A syndromic approach to diagnosis and treatment

Tropical infections form 20-30% of ICU admissions in tropical countries. Diarrheal diseases, malaria, dengue, typhoid, rickettsial diseases and leptospirosis are common causes of critical illness. Overlapping clinical features makes initial diagnosis challenging. A systematic approach involving (1) history of specific continent or country of travel, (2) exposure to specific environments (forests or farms, water sports, consumption of exotic foods), (3) incubation period, and (4) pattern of organ involvement and subtle differences in manifestations help in differential diagnosis and choice of initial empiric therapy. Fever, rash, hypotension, thrombocytopenia and mild derangement of liver function tests is seen in a majority of patients. Organ failure may lead to shock, respiratory distress, renal failure, hepatitis, coma, seizures, cardiac arrhythmias or hemorrhage. Diagnosis in some conditions is made by peripheral blood smear examination, antigen detection or detection of microbial nucleic acid by PCR. Tests that detect specific IgM antibody become positive only in the second week of illness. Initial therapy is often empiric; a combination of intravenous artesunate, ceftriaxone and either doxycycline or azithromycin would cover a majority of the treatable syndromes. Additional antiviral or antiprotozoal medications are required for some specific syndromes. Involving a physician specializing in tropical or travel medicine is helpful.

Acute Kidney Injury of Infectious Etiology in Monsoon Season: A Prospective Study Using Acute Kidney Injury Network Criteria

The epidemiological pattern of acute kidney injury (AKI) in tropical countries during monsoon reflects infectious disease as the most important cause. AKI is a confounding factor and may be overlooked by primary health-care providers and underreported in health statistics. The present study prospectively helps estimate the burden of disease and analyze etiology, clinical profile, and outcome in a tertiary care hospital of a metropolitan city in a tropical country. The study period included monsoon season of 2012 and 2013, a total of 8 months. AKI staging was done as per the AKI Network (AKIN) criteria. Patients were treated for primary disease. Renal replacement therapy (RRT) was given as required. Patients were followed up during hospitalization till recovery/death. Out of a total of 9930 admissions during this period, 1740 (17.52%) were for infections and 230 (2.31%) had AKI secondary to infectious diseases during monsoon. The incidence of AKI (230/1740) in infectious diseases during monsoon was 13.21%. The study population (n = 230) comprised 79.5% of males and the mean age was 40.95 ± 16.55 years. Severe AKI: AKIN Stage III was seen in 48.26% of patients and AKIN Stage I in 41.74%. The most common etiology of AKI was malaria (28.3%) followed by acute gastroenteritis (23%), dengue (16.5%), leptospirosis (13%), undifferentiated fever (10.4%), more than one etiology (5.4%), and enteric fever (3.5%). RRT was required in 44.78% of patients. Requirement for RRT was maximum in patients with more than one etiology followed by leptospirosis, malaria, dengue, and least in typhoid. The overall mortality was 12.17%. In multivariate analysis, vasopressor support and assisted ventilation were risk factors for mortality.

Acute Kidney Injury in the Tropics: Epidemiology, Presentation, Etiology, Specific Diseases, and Treatment

The characteristics of AKI are significantly influenced by the setting in which it develops. The unique characteristics in the tropical ecosystem along with the prevailing socioeconomic circumstances in the region make AKI in the tropics different regarding etiology, clinical characteristics, and outcomes. Community-acquired AKI caused by infections; animal, plant, or chemical toxins; and obstetric complications are common in the tropics, compared to predominantly hospital-acquired AKI from sepsis and diagnostic and therapeutic interventions elsewhere. It is possible to discern certain distinct “AKI syndromes” in the tropics, like febrile illness with AKI, envenomation-related AKI, and obstetric AKI, where the patients develop AKI along with a typical constellation of clinical features, allowing more specific and quick diagnostic and therapeutic approach. Changes in disease epidemiology and ongoing socioeconomic transitions in the tropics are reflected in changing epidemiology of tropical AKI. While the incidence of obstetric AKI has shown a steady decline, HIV-associated AKI emerged as a significant entity in regions where HIV was endemic in the past few decades. There is better recognition of scrub typhus as a significant contributor to AKI with availability of better diagnostic techniques, and it is well recognized that the epidemiology of AKI associated with post-infectious glomerulonephritis is different in the tropics. Rapid urbanization has made large swaths of population susceptible to emerging infections like dengue fever, with increased incidence of AKI. Climate change and scarcity of potable water are expected to pose significant challenges to kidney health in the tropics in the future. However, community-acquired AKI in the tropics also presents a unique opportunity for prevention of AKI, and attendant morbidity and mortality as most of the contributing factors can be addressed by public health interventions and innovative strategies to deliver healthcare.

The impact of transient and persistent acute kidney injury on short-term outcomes in very elderly patients

Objectives

Acute kidney injury (AKI) is a common complication in elderly patients and is associated with poor outcomes. However, the effect of transient and persistent geriatric AKI on short-term mortality is unclear. We aimed to study the incidence, clinical characteristics, and prognostic impact of transient and persistent AKI in such patients.

Methods

We retrospectively enrolled very elderly patients (≥75 years) from the geriatric department of the Chinese PLA General Hospital between 2007 and 2015. AKI was defined according to the 2012 Kidney Disease: Improving Global Outcomes criteria. AKI patients were divided into transient or persistent AKI groups based on their renal function at 3 days post-AKI. Renal function recovery was defined as a return to the baseline serum creatinine (SCr) levels.

Results

In total, 668 geriatric patients (39.0%) experienced AKI, and 652 satisfied the inclusion criteria. Of these 652 patients, 270 (41.4%) had transient AKI, and 382 (58.6%) had persistent AKI. The 90-day mortality was 5.9% in patients with transient AKI and 53.1% in patients with persistent AKI. Multivariate analysis revealed that low hemoglobin levels (odds ratio [OR] =0.989; 95% CI: 0.980–0.999; P=0.025), low mean aortic pressure (OR =0.985; 95% CI: 0.971–1.000; P=0.043), peak SCr (OR =1.020; 95% CI: 1.015–1.026; P<0.001) levels, high uric acid (OR =1.002; 95% CI: 1.000–1.003; P=0.040) levels, high blood urea nitrogen (OR =1.028; 95% CI: 1.000–1.056; P=0.047) levels, and mechanical ventilation requirements (OR =1.610; 95% CI: 1.012–2.562; P=0.044) were associated with persistent AKI. Persistent AKI (hazard ratio [HR] =5.741; 95% CI: 3.356–9.822; P<0.001) and more severe AKI stages (stage 2: HR =3.363; 95% CI: 1.973–5.732; P<0.001 and stage 3: HR =4.741; 95% CI: 2.807–8.008; P<0.001) were associated with 90-day mortality.

Conclusion

AKI is common in very elderly patients, with transient renal injury representing close to 42% of all cases of geriatric AKI. More frequent SCr measurements may be helpful for the early diagnosis of transient geriatric AKI. Persistent geriatric AKI is independently associated with a significantly higher risk of 90-day mortality.

Acute Kidney Injury Risk Assessment: Differences and Similarities Between Resource-Limited and Resource-Rich Countries

The incidence of acute kidney injury (AKI) among acutely ill patients is reportedly very high and has vexing consequences on patient outcomes and health care systems. The risks and impact of AKI differ between developed and developing countries. Among developing countries, AKI occurs in young individuals with no or limited comorbidities, and is usually due to environmental causes, including infectious diseases. Although several risk factors have been identified for AKI in different settings, there is limited information on how risk assessment can be used at population and patient levels to improve care in patients with AKI, particularly in developing countries where significant health disparities may exist. The Acute Disease Quality Initiative consensus conference work group addressed the issue of identifying risk factors for AKI and provided recommendations for developing individualized risk stratification strategies to improve care. We proposed a 5-dimension, evidence-based categorization of AKI risk that allows clinicians and investigators to study, define, and implement individualized risk assessment tools for the region or country where they practice. These dimensions include environmental, socioeconomic and cultural factors, processes of care, exposures, and the inherent risks of AKI. We provide examples of these risks and describe approaches for risk assessments in the developing world. We anticipate that these recommendations will be useful for health care providers to plan and execute interventions to limit the impact of AKI on society and each individual patient. Using a modified Delphi process, this group reached consensus regarding several aspects of AKI risk stratification.

[Comparative study of community acute kidney injury in HIV infected versus non-infected persons: Experience of an internal medicine department in Abidjan (Côte d'Ivoire)]

BACKGROUND

Acute kidney injury (AKI) is commonly associated with HIV infection.

OBJECTIVES

To describe the profile of AKI in HIV infected versus non-infected persons.

PATIENTS AND METHODS

This is a prospective study that was carried out during the study period from January 2010 to December 2015 in the department of nephrology-internal medicine D of Treichville University Hospital (Côte d'Ivoire).

RESULTS

The prevalence of HIV infection was 35.2% in the population of AKI. The average age of patients was 42±18 years in the HIV positive group against 51±18 years in the HIV negative group (P=0.0001). Etiologies were infections in 65.1% in the HIV positive group against 38.8% in the HIV negative group (P=0.0001) and water loss in 24.7% in the HIV positive group against 7.8% in the HIV negative group (P=0.0001). Factors such as the AIDS stage (P=0.002), severe sepsis (P=0.002) and acute pyelonephritis (P=0.001) were associated with mortality in HIV positive patients against severe anemia (P=0.0001) and severe sepsis (P=0.0001) in the HIV-negative group.

CONCLUSION

HIV positive patients are younger with a female predominance. The mortality rate is identical in both groups.

CLINICAL CHARACTERISTICS, OUTCOMES AND RISK FACTORS FOR DEATH AMONG CRITICALLY ILL PATIENTS WITH HIV-RELATED ACUTE KIDNEY INJURY

Background:

The aim of this study is to describe clinical characteristics, outcomes and risk factors for death among patients with HIV-related acute kidney injury (AKI) admitted to an intensive care unit (ICU).

Methods:

A retrospective study was conducted with HIV-infected AKI patients admitted to the ICU of an infectious diseases hospital in Fortaleza, Brazil. All the patients with confirmed diagnosis of HIV and AKI admitted from January 2004 to December 2011 were included. A comparison between survivors and non-survivors was performed. Risk factors for death were investigated.

Results:

Among 256 AKI patients admitted to the ICU in the study period, 73 were identified as HIV-infected, with a predominance of male patients (83.6%), and the mean age was 41.2 ± 10.4 years. Non-survivor patients presented higher APACHE II scores (61.4 ± 19 vs. 38.6 ± 18, p = 0.004), used more vasoconstrictors (70.9 vs. 37.5%, p = 0.02) and needed more mechanical ventilation - MV (81.1 vs. 35.3%, p = 0.001). There were 55 deaths (75.3%), most of them (53.4%) due to septic shock. Independent risk factors for mortality were septic shock (OR = 14.2, 95% CI = 2.0-96.9, p = 0.007) and respiratory insufficiency with need of MV (OR = 27.6, 95% CI = 5.0-153.0, p < 0.001).

Conclusion:

Non-survivor HIV-infected patients with AKI admitted to the ICU presented higher severity APACHE II scores, more respiratory damage and hemodynamic impairment than survivors. Septic shock and respiratory insufficiency were independently associated to death.

A Clinical Study of Acute Kidney Injury in Tropical Acute Febrile Illness

INTRODUCTION

Tropical Acute Febrile Illness (TAFI) is one of the most common causes of morbidity within the community. Acute Kidney Injury (AKI) due to infective and non infective causes is a major complication. Presence of AKI is a major cause of mortality among patients with TAFI.

AIM

To study the spectrum of tropical acute febrile illness; the proportion, spectrum and staging of acute kidney injury; Renal Replacement Therapy (RRT) initiation and in-hospital mortality.

MATERIALS AND METHODS

A total of 600 TAFI patients were prospectively studied at a tertiary care centre in coastal Karnataka between September 2012 and September 2014 for the aetiology of TAFI; the development and staging of AKI based on Kidney disease: Improving global outcomes (KDIGO) guidelines; the initiation of RRT and in-hospital mortality.

STATISTICAL ANALYSIS

Data analysis was done using SPSS version 17.0 with statistical significance calculated using chi-square and Fisher's exact t-test for which p-value <0.05 was considered significant.

RESULTS

The spectrum of TAFI, in decreasing order, was vivax malaria, leptospirosis, dengue fever, falciparum malaria, mixed malaria, enteric fever, scrub typhus and the most common aetiology was malaria. The proportion of AKI was 54%. The most common cause of AKI, its stages 2 and 3, RRT initiation and in-hospital mortality was leptospirosis; and AKI stage 1 was dengue fever. KDIGO AKI stage 1, 2 and 3 was seen in 46.9%, 31.2% and 21.9% of AKI patients, respectively. RRT initiation was required in 10.2% of AKI patients and in-hospital mortality was 3% among all patients. AKI, RRT initiationand in-hospital mortality were significantly associated with older age, fever duration and other presenting complaints, examination findings, renal function and other parameters, leptospirosis, dengue fever, falciparum malaria.

CONCLUSION

The aetiology in about half of TAFI patients in coastal Karnataka was malaria. More than 50% develop AKI with greater than one-fifth of them progressing to AKI stage 3 and one-tenth requiring RRT. The most common cause of AKI, AKI stage 2, 3, RRT initiation and in-hospital mortality was leptospirosis. AKI was present in almost all patients with leptospirosis. Therefore leptospirosis was the most nephrotoxic acute febrile illness in the present study population. Dengue fever was the most common cause of AKI stage 1. Vivax malaria was the third most common cause of AKI. The factors like age, presenting complaints, examination findings, renal function and other parameters, aetiology and RRT initiation may be used to predict AKI and in-hospital mortality.

Acute Kidney Injury in Western Countries

BACKGROUND

Acute kidney injury (AKI) is frequent and is associated with poor outcomes, including increased mortality, higher risk of chronic kidney disease, and prolonged hospital lengths of stay. The epidemiology of AKI mainly derives from studies performed in Western high-income countries. More limited data are available from Western low-income and middle-income countries (LMICs) located in Central and South America.

SUMMARY

In this review, we summarize the most recent data on the epidemiology of AKI in Western countries, aiming to contrast results from industrialized high-income countries with LMICs. The global picture of AKI in LMICs is not as well characterized as in the USA and Europe. In addition, in some LMICs, the epidemiology of AKI may vary depending on the region and socioeconomic status, which contributes to the difficulty of getting a better portrait of the clinical condition. In low-income regions and tropical countries, AKI is frequently attributed to diarrhea, infections, nephrotoxins, as well as obstetric complications. As opposed to the situation in high-income countries, access to basic care in LMICs is limited by economic constraints, and treatment is often delayed due to late presentation and recognition of the condition, which contribute to worse outcomes. In addition, dialysis is often not available or must be paid by patients, which further restricts its use.

KEY MESSAGES

There are great disparities in the epidemiology of AKI between Western high-income countries and Western LMICs. In LMICs, education and training programs should increase the public awareness of AKI and improve preventive and basic treatments to improve AKI outcomes.

FACTS FROM EAST AND WEST

(1) More than 90% of the patients recruited in AKI studies using KDIGO-equivalent criteria originate from North America, Europe, or Oceania, although these regions represent less than a fifth of the global population. However, the pooled incidence of AKI in hospitalized patients reaches 20% globally with moderate variance between regions. (2) The lower incidence rates observed in Asian countries (except Japan) may be due to a poorer recognition rate, for instance because of less systematically performed serum creatinine tests. (3) AKI patients in South and Southeastern Asia are younger than in East Asia and Western countries and present with fewer comorbidities. (4) Asian countries (and to a certain extent Latin America) face specific challenges that lead to AKI: nephrotoxicity of traditional herbal and less strictly regulated nonprescription medicines, environmental toxins (snake, bee, and wasp venoms), and tropical infectious diseases (malaria and leptospirosis). A higher incidence and less efficient management of natural disasters (particularly earthquakes) are also causes of AKI that Western countries are less likely to encounter. (5) The incidence of obstetric AKI decreased globally together with an improvement in socioeconomic levels particularly in China and India in the last decades. However, antenatal care and abortion management must be improved to reduce AKI in women, particularly in rural areas. (6) Earlier nephrology referral and better access to peritoneal dialysis should improve the outcome of AKI patients.

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.

Dengue-associated acute kidney injury

Dengue is presently the most relevant viral infection transmitted by a mosquito bite that represents a major threat to public health worldwide. Acute kidney injury (AKI) is a serious and potentially lethal complication of this disease, and the actual incidence is unknown. In this review, we will assess the most relevant epidemiological and clinical data regarding dengue and the available evidence on the frequency, etiopathogenesis, outcomes and treatment of dengue-associated AKI.

Proteomic analysis of urine exosomes reveals renal tubule response to leptospiral colonization in experimentally infected rats

Background

Infectious Leptospira colonize the kidneys of reservoir (e.g. rats) and accidental hosts such as humans. The renal response to persistent leptospiral colonization, as measured by urinary protein biosignatures, has not been systematically studied. Urinary exosomes--bioactive membrane-bound nanovesicles--contain cell-state specific cargo that additively reflect formation all along the nephron. We hypothesized that Leptospira-infection will alter the content of urine exosomes, and further, that these Leptospira-induced alterations will hold clues to unravel novel pathways related to bacterial-host interactions.

Methodology/Principal findings

Exosome protein content from 24 hour urine samples of Leptospira-infected rats was compared with that of uninfected rats using SDS-PAGE and liquid chromatography/tandem mass spectrometry (LC-MS/MS). Statistical models were used to identify significantly dysregulated proteins in Leptospira-infected and uninfected rat urine exosomes. In all, 842 proteins were identified by LC-MS/MS proteomics of total rat urine and 204 proteins associated specifically with exosomes. Multivariate analysis showed that 25 proteins significantly discriminated between uninfected control and infected rats. Alanyl (membrane) aminopeptidase, also known as CD13 topped this list with the highest score, a finding we validated by Western immunoblotting. Whole urine analysis showed Tamm-Horsfall protein level reduction in the infected rat urine. Total urine and exosome proteins were significantly different in male vs. female infected rats.

Conclusions

We identified exosome-associated renal tubule-specific responses to Leptospira infection in a rat chronic colonization model. Quantitative differences in infected male and female rat urine exosome proteins vs. uninfected controls suggest that urine exosome analysis identifies important differences in kidney function that may be of clinical and pathological significance.

Leptospirosis is a bacterial disease commonly transmitted from animals to humans. Though this disease affects more than three quarters of a million people every year and takes a disproportionate toll on the poor in in tropical regions, few virulence factors have been identified and very little is known regarding the pathogenesis of leptospirosis. Symptoms vary from fever and fatigue to severe pulmonary hemorrhage and death. Approximately 5–10% of Leptospira infections in humans are chronic (>1 year) and asymptomatic (no overt signs of disease). Nonetheless, very little is known about the clinical significance of these infections. In this report, we show that non-invasive tools namely proteomic analysis of urinary exosomes can be used to identify differences between healthy and Leptospira-infected rat kidney and between Leptospira-infected male and female rat kidney. In future studies, these analyses will be extended to determine clinical significance and extent of renal dysfunction in the asymptomatic human.