Malaria-Associated Acute Kidney Injury in African Children: Prevalence, Pathophysiology, Impact, and Management Challenges

Admission Point-of-Care Testing for the Clinical Care of Children with Cerebral Malaria

Point-of-care testing (PoCT), an alternative to laboratory-based testing, may be useful in the clinical care of critically ill children in resource-limited settings. We evaluated the clinical utility of PoCT in the care of 193 Malawian children treated for World Health Organization-defined cerebral malaria (CM) between March 2019 and May 2023. We assessed the frequency of abnormal PoCT results and the clinical interventions performed in response to these abnormalities. We determined the association between abnormal PoCT results and patient outcomes. Overall, 52.1% of all PoCT results were abnormal. Of the children with abnormal results, clinical interventions occurred in 16.9%. Interventions most commonly followed abnormal results for PoCT glucose (100.0% of the patients had treatment for hypoglycemia), potassium (32.1%), lactate (22.0%), and creatinine (16.3%). Patients with hypoglycemia, hyperlactatemia, and hypocalcemia had a higher mortality risk than children with normal values. Future studies are needed to determine whether obtaining laboratory values using PoCT and the clinical response to these interventions modify outcomes in critically ill African children with CM.

Longitudinal associations of plasma amino acid levels with recovery from malarial coma

BACKGROUND

Disordered amino acid metabolism is observed in cerebral malaria (CM). This study sought to determine whether abnormal amino acid concentrations were associated with level of consciousness in children recovering from coma. Twenty-one amino acids and coma scores were quantified longitudinally and the data were analysed for associations.

METHODS

In a prospective observational study, 42 children with CM were enrolled. Amino acid levels were measured at entry and at frequent intervals thereafter and consciousness was assessed by Blantyre Coma Scores (BCS). Thirty-six healthy children served as controls for in-country normal amino acid ranges. Logistic regression was employed using a generalized linear mixed-effects model to assess associations between out-of-range amino acid levels and BCS.

RESULTS

At entry 16/21 amino acid levels were out-of-range. Longitudinal analysis revealed 10/21 out-of-range amino acids were significantly associated with BCS. Elevated phenylalanine levels showed the highest association with low BCS. This finding held when out-of-normal-range data were analysed at each sampling time.

CONCLUSION

Longitudinal data is provided for associations between abnormal amino acid levels and recovery from CM. Of 10 amino acids significantly associated with BCS, elevated phenylalanine may be a surrogate for impaired clearance of ether lipid mediators of inflammation and may contribute to CM pathogenesis.

Acute Kidney Injury in Children: A Focus for the General Pediatrician

Acute kidney injury (AKI) presents significant challenges in pediatric care, often remaining underrecognized. This paper provides an overview of pediatric AKI, highlighting its epidemiology, pathophysiology, diagnosis, predisposing conditions, and treatment. AKI in children stems from diverse causes, including renal tubular damage, vasoconstriction, and inflammation. Diagnosis relies on traditional markers such as serum creatinine and urine output, alongside emerging biomarkers such as Cystatin C, NGAL, KIM-1, IL-18, TIMP-2 and IGFBP7, urinary calprotectin, URBP4, L-FABP, and clusterin. Various pediatric conditions predispose to AKI, including type 1 diabetes, pneumonia, bronchiolitis, appendicitis, gastroenteritis, COVID-19, multisystem inflammatory syndrome, sickle cell disease, and malignancies. Treatment entails supportive care with fluid management and, in severe cases, renal replacement therapy. Timely recognition and management are essential to mitigating adverse outcomes. Enhanced awareness and integration of novel biomarkers could improve pediatric AKI care, warranting further research for better diagnosis and management.

Longitudinal associations of plasma amino acid levels with recovery from malarial coma

Background

Disordered amino acid metabolism is observed in cerebral malaria (CM). We sought to determine whether abnormal amino acid concentrations were associated with level of consciousness in children recovering from coma. We quantified 21 amino acids and coma scores longitudinally and analyzed data for associations.

Methods

In a prospective observational study, we enrolled 42 children with CM. We measured amino acid levels at entry and at frequent intervals thereafter and assessed consciousness by Blantyre Coma Scores (BCS). Thirty-six healthy children served as controls for in-country normal amino acid ranges. We employed logistic regression using a generalized linear mixed-effects model to assess associations between out-of-range amino acid levels and BCS.

Results

At entry 16/21 amino acid levels were out-of-range. Longitudinal analysis revealed 10/21 out-of-range amino acids were significantly associated with BCS. Elevated phenylalanine levels showed the highest association with low BCS. This finding held when out-of-normal-range data were analyzed at each sampling time.

Discussion

We provide longitudinal data for associations between abnormal amino acid levels and recovery from CM. Of 10 amino acids significantly associated with BCS, we propose that elevated phenylalanine may be a surrogate for impaired clearance of ether lipid mediators of inflammation contributing to CM pathogenesis.

sTREM-1: A Biomarker of Mortality in Severe Malaria Impacted by Acute Kidney Injury

BACKGROUND

Malaria is an important cause of mortality in African children. Identification of biomarkers to identify children at risk of mortality has the potential to improve outcomes.

METHODS

We evaluated 11 biomarkers of host response in 592 children with severe malaria. The primary outcome was biomarker performance for predicting mortality. Biomarkers were evaluated using receiver operating characteristic (ROC) curve analysis comparing the area under the ROC curve (AUROC).

RESULTS

Mortality was 7.3% among children in the study with 72% of deaths occurring within 24 hours of admission. Among the candidate biomarkers, soluble triggering receptor expressed on myeloid cells 1 (sTREM-1) had the highest AUROC (0.78 [95% confidence interval, .70-.86]), outperforming several other biomarkers including C-reactive protein and procalcitonin. sTREM-1 was the top-performing biomarker across prespecified subgroups (malaria definition, site, sex, nutritional status, age). Using established cutoffs, we evaluated mortality across sTREM-1 risk zones. Among children with acute kidney injury, 39.9% of children with a critical-risk sTREM-1 result had an indication for dialysis. When evaluated relative to a disease severity score, sTREM-1 improved mortality prediction (difference in AUROC, P = .016).

CONCLUSIONS

sTREM-1 is a promising biomarker to guide rational allocation of clinical resources and should be integrated into clinical decision support algorithms, particularly when acute kidney injury is suspected.

Association of haemato-biochemical indices and blood composite ratios with microfilaridermia in Onchocerciasis patients

BACKGROUND

Onchocerciasis causes chronic systemic inflammation. Several studies have used markers such as haemato-biochemical indices to predict the occurrence of systemic inflammation. This study assessed the variability and predictability of haemato-biochemical indices and blood composite ratios (BCRs) in microfilariae positive (MF+) and microfilariae negative (MF-) subgroups of onchocercomata participants.

METHODS

One hundred and five (105) MF + and 34 MF- participants were retrospectively recruited into the study. Screening for the presence of O. volvulus microfilariae was done from skin snips taken from the left and right iliac crests of participants using established and approved protocols. Haematological and biochemical indices were measured using standard laboratory automated analyzers. Blood composite ratios (BCRs) were calculated as ratios of the absolute parameters involved.

RESULTS

A significantly increased total WBC, absolute eosinophil, eosinophil percent and absolute basophil were observed in the MF + participants compared to MF- participants. Reduced gamma-glutamyl transferase (GGT) with increased estimated glomerular filtration rate (eGFR) was significantly associated with MF + participants compared to MF- participants. BCRs were significantly higher for eosinophil-to-neutrophil ratio (ENR), eosinophil-to-monocyte ratio (EMR), eosinophil-to-basophil ratio (EBR) and eosinophil-to-lymphocyte ratio (ELR) in MF + participants compared to MF- participants. After multivariate adjustment, onchocercomata participants with increased eosinophil counts (aOR = 13.86, 95% CI [2.07-92.90], p = 0.007), ENR x10 (aOR = 1.42, 95% CI [1.05-1.93], p = 0.025), EMR (aOR = 2.64, 95% CI [1.25-5.60], p = 0.011), EBR (aOR = 1.07, 95% CI [1.01-1.10], p = 0.020) and ELR x10 (aOR = 1.69, 95% CI [1.14-2.51], p = 0.009) were more likely to have microfilaridermia.

CONCLUSIONS

Elevated eosinophil counts with higher ENR, EMR, EBR and ELR levels are significantly associated with microfilaridermia in onchocercomata participants. Combining BCRs with eosinophil count significantly led to an improvement in the conventional model for predicting microfilaridermia.

Decreased renal function among children born to women with obstructed labour in Eastern Uganda: a cohort study

BACKGROUND

Over two million children and adolescents suffer from chronic kidney disease globally. Early childhood insults such as birth asphyxia could be risk factors for chronic kidney disease in later life. Our study aimed to assess renal function among children aged two to four years, born to women with obstructed labour.

METHODS

We followed up 144 children aged two to four years, born to women with obstructed labor at Mbale regional referral hospital in Eastern Uganda. We used serum creatinine to calculate estimated glomerular filtration rate (eGFR) using the Schwartz formula. We defined decreased renal function as eGFR less than 90 ml/min/1.73m2.

RESULTS

The mean age of the children was 2.8 years, standard deviation (SD) of 0.4 years. Majority of the children were male (96/144: 66.7%). The mean umbilical lactate level at birth among the study participants was 8.9 mmol/L with a standard deviation (SD) of 5.0. eGFR of the children ranged from 55 to 163 ml/min/1.73m2, mean 85.8 ± SD 15.9. Nearly one third of the children (45/144) had normal eGFR (> 90 ml/Min/1.73m2), two thirds (97/144) had a mild decrease of eGFR (60-89 ml/Min/1.73m2), and only two children had a moderate decrease of eGFR (< 60 ml/Min/1.73m2). Overall incidence of reduced eGFR was 68.8% [(99/144): 95% CI (60.6 to 75.9)].

CONCLUSION

We observed a high incidence of reduced renal function among children born to women with obstructed labour. We recommend routine follow up of children born to women with obstructed labour and add our voices to those calling for improved intra-partum and peripartum care.

Total daily energy expenditure and elevated water turnover in a small-scale semi-nomadic pastoralist society from Northern Kenya

BACKGROUND

Pastoralists live in challenging environments, which may be accompanied by unique activity, energy, and water requirements.

AIM

Few studies have examined whether the demands of pastoralism contribute to differences in total energy expenditure (TEE) and water turnover (WT) compared to other lifestyles.

SUBJECTS AND METHODS

Accelerometer-derived physical activity, doubly labelled water-derived TEE and WT, and anthropometric data were collected for 34 semi-nomadic Daasanach adults from three northern Kenyan communities with different levels of pastoralist activity. Daasanach TEEs and WTs were compared to those of other small-scale and industrialised populations.

RESULTS

When modelled as a function of fat-free-mass, fat-mass, age, and sex, TEE did not differ between Daasanach communities. Daasanach TEE (1564-4172 kcal/day) was not significantly correlated with activity and 91% of TEEs were within the range expected for individuals from comparison populations. Mean WT did not differ between Daasanach communities; Daasanach absolute (7.54 litres/day men; 7.46 litres/day women), mass-adjusted, and TEE-adjusted WT was higher than most populations worldwide.

CONCLUSIONS

The similar mass-adjusted TEE of Daasanach and industrialised populations supports the hypothesis that habitual TEE is constrained, with physically demanding lifestyles necessitating trade-offs in energy allocation. Elevated WT in the absence of elevated TEE likely reflects a demanding active lifestyle in a hot, arid climate.

Malaria is the leading cause of acute kidney injury among a Zambian paediatric renal service cohort retrospectively evaluated for aetiologies, predictors of the need for dialysis, and outcomes

BACKGROUND

Whilst malaria is a prominent aetiology associated with acute kidney injury (AKI) in many parts of Africa, a shift in the traditional AKI aetiologies has been witnessed in sections of the continent. Additionally, limited access to dialysis worsens patient outcomes in these low-resource settings. This retrospective cross-sectional study aimed to determine the associated aetiologies, predictors of need for dialysis and malaria-associated AKI (MAKI), and outcomes of AKI and dialysis among children evaluated by the renal service in Lusaka, Zambia.

METHODS

The study sampled all children aged 16 years or below, diagnosed with AKI between 2017 and 2021, by the renal unit at the University Teaching Hospitals- Children's Hospital (UTH-CH), and retrospectively abstracted their records for exposures and outcomes. AKI was defined using the Kidney Disease Improving Global Outcomes (KDIGO) 2012 criteria. Frequency and percentage distributions were used to describe the occurrence of AKI aetiologies and treatment outcomes. Predictors of the need for dialysis, MAKI, and poor treatment outcome were identified by using multivariable logistic regression models.

RESULTS

A total of 126 children diagnosed with AKI were included in this study. Malaria was the most frequent aetiology of AKI(61.1% (77/126, 95% Confidence Interval (CI): 52.0%-69.7%)). Of the 126 children with AKI, 74.6% (94) underwent dialysis. Predictors of the need for dialysis were oliguria (p = 0.0024; Odds ratio (OR) = 7.5, 95% CI: 2.1-27.7) and anuria (p = 0.0211; OR = 6.4, 95% CI = 1.3, 30.7). A fifth (18.3%, 23/126) of the children developed chronic kidney disease (CKD), 5.6% (7/126) died and, a year later, 77% (97/126) were lost to follow-up.

CONCLUSION

At UTH-CH, malaria is the most frequent aetiology among children with AKI undergoing dialysis and children from low-medium malaria incidence areas are at risk; a considerable proportion of children with AKI need dialysis and Tenchoff catheter use in AKI is advocated.

Point-of-care Ultrasound to Assess Hemodynamic Contributors to Acute Kidney Injury in Pediatric Patients With Cerebral Malaria: A Pilot Study

BACKGROUND

Acute kidney injury is common in severe malaria and is independently associated with mortality. The pathogenesis of acute kidney injury (AKI) in severe malaria remains incompletely understood. Ultrasound-based tools such as point-of-care ultrasound (POCUS), ultrasound cardiac output monitors (USCOMs) and renal arterial resistive index (RRI) can be used to detect hemodynamic and renal blood flow abnormalities contributing to AKI in malaria.

METHODS

We conducted a prospective study of Malawian children with cerebral malaria to determine the feasibility of using POCUS and USCOM to characterize hemodynamic contributors to severe AKI (Kidney Disease: Improving Global Outcomes stage 2 or 3). The primary outcome was feasibility (completion rate of study procedures). We also assessed for differences in POCUS and hemodynamic variables for patients with or without severe AKI.

RESULTS

We enrolled 27 patients who had admission cardiac and renal ultrasounds and USCOM. Completion rates were high for cardiac (96%), renal (100%) and USCOM studies (96%). Severe AKI occurred in 13 of 27 patients (48%). No patients had ventricular dysfunction. Only 1 patient in the severe AKI group was determined to be hypovolemic ( P = 0.64). No significant differences in USCOM, RRI or venous congestion parameters were detected among patients with and without severe AKI. Mortality was 11% (3/27) with the 3 deaths occurring in the severe AKI group ( P = 0.056).

CONCLUSIONS

Ultrasound-based cardiac, hemodynamic and renal blood flow measurements appear to be feasible in pediatric patients with cerebral malaria. We were unable to detect hemodynamic or renal blood flow abnormalities contributing to severe AKI in cerebral malaria. Larger studies are needed to corroborate these findings.

Xanthine oxidase levels and immune dysregulation are independently associated with anemia in Plasmodium falciparum malaria

Severe anemia is an important contributor to mortality in children with severe malaria. Anemia in malaria is a multi-factorial complication, since dyserythropoiesis, hemolysis and phagocytic clearance of uninfected red blood cells (RBCs) can contribute to this syndrome. High levels of oxidative stress and immune dysregulation have been proposed to contribute to severe malarial anemia, facilitating the clearance of uninfected RBCs. In a cohort of 552 Ugandan children with severe malaria, we measured the levels of xanthine oxidase (XO), an oxidative enzyme that is elevated in the plasma of malaria patients. The levels of XO in children with severe anemia were significantly higher compared to children with severe malaria not suffering from severe anemia. Levels of XO were inversely associated with RBC hemoglobin (ρ =  - 0.25, p < 0.0001), indicating a relation between this enzyme and severe anemia. When compared with the levels of immune complexes and of autoimmune antibodies to phosphatidylserine, factors previously associated with severe anemia in malaria patients, we observed that XO is not associated with them, suggesting that XO is associated with severe anemia through an independent mechanism. XO was associated with prostration, acidosis, jaundice, respiratory distress, and kidney injury, which may reflect a broader relation of this enzyme with severe malaria pathology. Since inhibitors of XO are inexpensive and well-tolerated drugs already approved for use in humans, the validation of XO as a contributor to severe malarial anemia and other malaria complications may open new possibilities for much needed adjunctive therapy in malaria.

Infections and Acute Kidney Injury: A Global Perspective

Globally, there are an estimated 13.3 million cases of acute kidney injury (AKI) annually. Although infections are a common cause of AKI globally, most infection-associated AKI occurs in low- and lower-middle-income countries. There are marked differences in the etiology of infection-associated AKI across age groups, populations at risk, and geographic location. This article provides a global overview of different infections that are associated commonly with AKI, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), human immunodeficiency virus, malaria, dengue, leptospirosis, tick-borne illnesses, and viral hemorrhagic fevers. Further discussion focuses on infectious conditions associated with AKI including sepsis, diarrheal diseases and pregnancy, peripartum and neonatal AKI. This article also discusses the future of infection-associated AKI in the framework of climate change. It explores how increased investment in achieving the sustainable development goals may contribute to the International Society of Nephrology's 0 by 25 objective to curtail avoidable AKI-related fatalities by 2025.

Renin as a Biomarker of Acute Kidney Injury and Mortality in Children With Severe Malaria or Sickle Cell Disease

BACKGROUND

Globally, a very high percentage of acute kidney injury (AKI) occurs in low- and middle-income countries (LMICs) where late recognition contributes to increased mortality. There are challenges with using existing biomarkers of AKI in LMICs. Emerging evidence suggests renin may serve as a biomarker of kidney injury that can overcome limitations in creatinine-based diagnostics.

METHODS

Two study populations in Uganda were assessed. Cohort #1 was a two-site, prospective cohort study enrolling 600 children with severe malaria (SM). Cohort #2 was a prospective cohort study enrolling 185 children with sickle cell disease (SCD) hospitalized with a vaso-occlusive crisis. Plasma or serum renin concentrations were measured in both cohorts of children at the time of hospital admission using Luminex® (Luminex Corporation, Austin, Texas, United States) or enzyme-linked immunosorbent assay (ELISA), respectively. We assessed the ability of renin to discriminate between children with or without AKI and between children who survived and children who died using receiver operating characteristic curves.

RESULTS

In both cohorts, renin concentrations were strongly associated with AKI and mortality. Renin was able to discriminate between children with or without AKI with an area under the curve (AUC) of 0.70 (95%CI, 0.65-0.74) in children with SM and 0.72 (95%CI, 0.6co3-0.81) in children with SCD. Renin was able to discriminate between children who survived and children who died with an AUC of 0.73 (95%CI, 0.63-0.83) in children with SM and 0.94 (95%CI, 0.89-0.99) in children with SCD. In Cohort #2, we compared renin against urine neutrophil gelatinase-associated lipocalin (NGAL) as the leading biomarker of AKI, and it had comparable performance in discriminating AKI and predicting mortality.

CONCLUSIONS

In two independent populations of children at risk of AKI with key differences in the etiology of kidney injury, renin was strongly associated with AKI and mortality and had moderate to good diagnostic performance to predict mortality.

PARIST study protocol: a phase I/II randomised, controlled clinical trial to assess the feasibility, safety and effectiveness of paracetamol in resolving acute kidney injury in children with severe malaria

BACKGROUND

Acute kidney injury (AKI) has in the past been considered a rare complication of malaria in children living in high-transmission settings. More recently, however, a growing number of paediatric case series of AKI in severe malaria studies in African children have been published (Artesunate vs Quinine in the Treatment of Severe P. falciparum Malaria in African children and Fluids Expansion as Supportive Therapy trials). The Paracetamol for Acute Renal Injury in Severe Malaria Trial (PARIST) therefore, aims to assess feasibility, safety and determine the effective dose of paracetamol, which attenuates nephrotoxicity of haemoproteins, red-cell free haemoglobin and myoglobin in children with haemoglobinuric severe malaria.

METHODS

PARIST is a phase I/II unblinded randomised controlled trial of 40 children aged >6 months and <12 years admitted with confirmed haemoglobinuric severe malaria (blackwater fever), a positive blood smear for P. falciparum malaria and either serum creatinine (Cr) increase by ≥0.3 mg/dL within 48 hours or to ≥1.5 times baseline and elevated blood urea nitrogen (BUN) >20 mg/dL. Children will be randomly allocated on a 1:1 basis to paracetamol intervention dose arm (20 mg/kg orally 6-hourly for 48 hours) or to a control arm to receive standard of care for temperature control (ie, tepid sponging for 30 min if fever persists give rescue treatment). Primary outcome is renal recovery at 48 hours as indicated by stoppage of progression and decrease of Cr level below baseline, BUN (<20 mg/dL). Data analysis will be on the intention-to-treat principle and a per-protocol basis.Results from this phase I/II clinical trial will provide preliminary effectiveness data of this highly potential treatment for AKI in paediatric malaria (in particular for haemoglobinuric severe malaria) for a larger phase III trial.

ETHICS AND DISSEMINATION

Ethical and regulatory approvals have been granted by the Mbale Hospital Institutional Ethics Review Committee (MRRH-REC OUT 002/2019), Uganda National Council of Science and Technology (UNCST-HS965ES) and the National drug Authority (NDA-CTC 0166/2021). We will be disseminating results through journals, conferences and policy briefs to policy makers and primary care providers.

TRIAL REGISTRATION NUMBER

ISRCTN84974248.

Factors Associated with Acute Kidney Injury among Children with Severe Malaria at Kiryandongo General Hospital, Uganda

Background

Malaria remains one of the leading health problems of the developing world, and acute kidney injury (AKI) is a well-recognized complication of severe malaria in adults; but the clinical importance of AKI in paediatric severe malaria is not well documented. Knowledge of the prevalence and factors associated with AKI among children with severe malaria is among the key strategies, which can help to reduce the burden of AKI among this vulnerable group. Methodology. A hospital-based prospective cross-sectional descriptive and analytic study of children with severe malaria was carried out at Kiryandongo General Hospital. The study involved 350 children with severe malaria attending the study site from August to October 2021. Questionnaires were administered to caretakers to obtain sociodemographic characteristics. Medical data were obtained through physical examination followed by laboratory tests. Blood samples were tested for creatinine and blood smear for malaria. Data were analyzed using binary logistic regression (bivariate and multivariate) to assess for the factors associated with AKI. A p value < 0.05 was considered statistically significant.

Results

The mean age of children with severe malaria was 7.0 ± 3.8 years, and 54.3% of them were male. Of the 350 children enrolled, 167 had AKI, giving an overall AKI prevalence of 47.7% (95% CI: 42.5-53.0). The factors that were significantly associated with AKI among children with severe malaria included caretaker with no formal education (aOR = 21.0, 95% CI: 1.68-261.18, p = 0.018), caretaker with primary education level (aOR = 4.5, 95% CI: 1.41-14.12, p = 0.011), age of child < 5 years (aOR = 1.8, 95% CI: 1.07-2.88, p = 0.025), history of receiving NSAIDs (aOR = 5.6, 95% CI: 2.34-13.22, p < 0.001), moderate anemia (aOR = 3.1, 95% CI: 1.39-6.94, p = 0.006), and severe anemia (aOR = 3.8, 95% CI: 1.66-8.55, p = 0.002).

Conclusion

The prevalence of AKI was high among children with severe malaria in Kiryandongo General Hospital. Acute kidney injury among children with severe malaria was associated with low level of education of caretakers, age of children less than 5 years, history of receiving NSAIDs, and anemia. The management of severe malaria should include screening for AKI especially in children under five years of age, anemic, and those who have received NSAIDs.

Pediatric Malaria with Respiratory Distress: Prognostic Significance of Point-of-Care Lactate

Respiratory distress (RD) in pediatric malaria portends a grave prognosis. Lactic acidosis is a biomarker of severe disease. We investigated whether lactate, measured at admission using a handheld device among children hospitalized with malaria and RD, was predictive of subsequent mortality. We performed a pooled analysis of Ugandan children under five years of age hospitalized with malaria and RD from three past studies. In total, 1324 children with malaria and RD (median age 1.4 years, 46% female) from 21 health facilities were included. Median lactate level at admission was 4.6 mmol/L (IQR 2.6–8.5) and 586 patients (44%) had hyperlactatemia (lactate > 5 mmol/L). The mortality was 84/1324 (6.3%). In a mixed-effects Cox proportional hazard model adjusting for age, sex, clinical severity score (fixed effects), study, and site (random effects), hyperlactatemia was associated with a 3-fold increased hazard of death (aHR 3.0, 95%CI 1.8–5.3, p < 0.0001). Delayed capillary refill time (τ = 0.14, p < 0.0001), hypotension (τ = −0.10, p = 0.00049), anemia (τ = −0.25, p < 0.0001), low tissue oxygen delivery (τ = −0.19, p < 0.0001), high parasite density (τ = 0.10, p < 0.0001), and acute kidney injury (p = 0.00047) were associated with higher lactate levels. In children with malaria and RD, bedside lactate may be a useful triage tool, predictive of mortality.

Novel Experimental Mouse Model to Study Malaria-Associated Acute Kidney Injury

The impact of malaria-associated acute kidney injury (MAKI), one of the strongest predictors of death in children with severe malaria (SM), has been largely underestimated and research in this area has been neglected. Consequently, a standard experimental mouse model to research this pathology is still lacking. The purpose of this study was to develop an in vivo model that resembles the pathology in MAKI patients. In this study, unilateral nephrectomies were performed on wild-type mice prior to infection with Plasmodium berghei NK65. The removal of one kidney has shown to be an effective approach to replicating the most common findings in humans with MAKI. Infection of nephrectomized mice, compared to their non-nephrectomized counterparts, resulted in the development of kidney injury, evident by histopathological analysis and elevated levels of acute kidney injury (AKI) biomarkers, including urinary neutrophil gelatinase-associated lipocalin, serum Cystatin C, and blood urea nitrogen. Establishment of this in vivo model of MAKI is critical to the scientific community, as it can be used to elucidate the molecular pathways implicated in MAKI, delineate the development of the disease, identify biomarkers for early diagnosis and prognosis, and test potential adjunctive therapies.

Long-term outcomes of acute kidney injury in children

PURPOSE OF REVIEW

Acute kidney injury (AKI) affects up to 35% of all critically ill children and is associated with substantial short-term morbidity and mortality. However, the link between paediatric AKI and long-term adverse outcomes remains incompletely understood. This review highlights the most recent clinical data supporting the role of paediatric AKI as a risk factor for long-term kidney and cardiovascular consequences. In addition, it stresses the need for long-term surveillance of paediatric AKI survivors.

RECENT FINDINGS

Recent large-scale studies have led to an increasing understanding that paediatric AKI is a significant risk factor for adverse outcomes such as hypertension, cardiovascular disease and chronic kidney disease (CKD) over time. These long-term sequelae of paediatric AKI are most often observed in vulnerable populations, such as critically ill children, paediatric cardiac surgery patients, children who suffer from severe infections and paediatric cancer patients.

SUMMARY

A growing body of research has shown that paediatric AKI is associated with long-term adverse outcomes such as CKD, hypertension and cardiovascular disease. Although therapeutic pathways tailored to individual paediatric AKI patients are yet to be validated, we provide a framework to guide monitoring and prevention in children at the highest risk for developing long-term kidney dysfunction.

The kidney-brain pathogenic axis in severe falciparum malaria

Severe falciparum malaria is a medical emergency and a leading cause of death and neurodisability in endemic areas. Common complications include acute kidney injury (AKI) and cerebral malaria, and recent studies have suggested links between kidney and brain dysfunction in Plasmodium falciparum infection. Here, we review these new findings and present the hypothesis of a pivotal pathogenic crosstalk between the kidneys and the brain in severe falciparum malaria. We highlight the evidence of a role for distant organ involvement in the development of cerebral malaria and subsequent neurocognitive impairment post-recovery, describe the challenges associated with current diagnostic shortcomings for both AKI and brain involvement in severe falciparum malaria, and explore novel potential therapeutic strategies.

Plasma Amino Acid Concentrations in Children With Severe Malaria Are Associated With Mortality and Worse Long-term Kidney and Cognitive Outcomes

BACKGROUND

Global changes in amino acid levels have been described in severe malaria (SM), but the relationship between amino acids and long-term outcomes in SM has not been evaluated.

METHODS

We measured enrollment plasma concentrations of 20 amino acids using high-performance liquid chromatography in 500 Ugandan children aged 18 months to 12 years, including 122 community children and 378 children with SM. The Kidney Disease: Improving Global Outcomes criteria were used to define acute kidney injury (AKI) at enrollment and chronic kidney disease (CKD) at 1-year follow-up. Cognition was assessed over 2 years of follow-up.

RESULTS

Compared to laboratory-defined, age-specific reference ranges, there were deficiencies in sulfur-containing amino acids (methionine, cysteine) in both community children and children with SM. Among children with SM, global changes in amino acid concentrations were observed in the context of metabolic complications including acidosis and AKI. Increases in threonine, leucine, and valine were associated with in-hospital mortality, while increases in methionine, tyrosine, lysine, and phenylalanine were associated with postdischarge mortality and CKD. Increases in glycine and asparagine were associated with worse attention in children <5 years of age.

CONCLUSIONS

Among children with SM, unique amino acid profiles are associated with mortality, CKD, and worse attention.

Metabolic Syndrome and Cardiometabolic Risk Factors in the Mixed Hypercholesterolemic Populations with Respect to Gender, Age, and Obesity in Asir, Saudi Arabia

This record study aimed to investigate the prevalence of metabolic syndrome (MetS) profiles regarding sex, age, and obesity for the riskier factor of cardiovascular diseases in a general population in Saudi Arabia. Laboratory and anthropometric measurements were performed on non-specific participants with variant ages and BMI in either sex. Serobiochemical changes were measured for metabolic profiles, i.e., A1C/FSG, TC, TGC, HDLC/LDLC, Vit.D, TSH/T4, Hb, and Cr. The study was applied in a Polyclinic, Abha, Saudi Arabia in 2020 G. The general population showed variable incidences of MetS profiles, such as 69.4% diabetes, 85.5% hypothyroidism, and 92.2% obesity. Hypothyroidism showed a higher incidence in women rather than in men, but men were more dyslipidemic, with higher TGC and LDLC but low HDLC, compared to women. Men <40 Y. showed diabetes and hypothyroidism, but elders were dyslipidemic. Women <40 Y. showed anemia and hypovitaminosis-D but were suffering from hypothyroidism at all ages. Diabetes, hypothyroidism, hypovitaminosis-D, and dyslipidemia were the main MetS components in both overweight and obese participants, and an incidence of more than 50% in each profile was recorded. Diabetes with hypertension was characteristic of obese participants rather than those overweight. About 66.1% of the mixed-hypercholesterolemic cases were diabetic, but 18.9% of the mixed-diabetic participants were hypercholesterolemic. Castelli's risk factors, CRI-I and CRI-II, and atherogenic indices, AIP and AC, were measured for evaluating the cardiac risk in different populations based on the AUC-ROC and cut-off values. Insulin-resistance marker (TyG) was also measured, showing considerable cut-off values for diabetic susceptibility in the lipidemic participants with higher TGC and TC rather than HDLC or LDLC. In conclusion, MetS showed higher susceptibility to sex and age with increased incidence in women rather than men. However, the cardiac risk was more susceptible to men of higher TGC and low HDLC than women. Type 2 Diabetes mellitus (T2DM) was more prominent in both elders (≥40 Y.) than younger ages of either sex. Anemia and deficiency of Vit. D was characteristic of young women (<40 Y.). Hypothyroidism affects young men <40 Y. but was recorded in women of all ages. Both dyslipidemia and diabetes could trigger CVD, showing higher cardiac risk in mixed-hypercholesterolemic men rather than women. Our study strongly suggests that the consumption of unhealthy junk food, tobacco smoking, lack of exercise, and physical inactivity could be conclusive evidence of MetS in the Saudi population.

Risk factors for acute kidney injury at presentation among children with CNS malaria: a case control study

BACKGROUND

Recent research has established that acute kidney injury (AKI) is a common problem in severe paediatric malaria. Limited access to kidney diagnostic studies in the low resources settings where malaria is common has constrained research on this important problem.

METHODS

Enrolment data from an ongoing clinical trial of antipyretics in children with central nervous system (CNS) malaria, CNS malaria being malaria with seizures or coma, was used to identify risk factors for AKI at presentation. Children 2-11 years old with CNS malaria underwent screening and enrollment assessments which included demographic and anthropomorphic data, clinical details regarding the acute illness, and laboratory studies including creatinine (Cr), quantitative parasite count (qPC), quantitative histidine rich protein 2 (HRP2), lactate, and bilirubin levels. Children with a screening Cr > 106 µmol/l were excluded from the study due to the potential nephrotoxic effects of the study drug. To identify risk factors for AKI at the time of admission, children who were enrolled in the study were categorized as having AKI using estimates of their baseline (i.e. before this acute illness) kidney function and creatinine at enrollment applying the Kidney Disease: Improving Global Outcome (KDIGO) 2012 guidelines. Logistic regressions and a multivariate model were used to identify clinical and demographic risk factors for AKI at presentation among those children enrolled in the study.

RESULTS

465 children were screened, 377 were age-appropriate with CNS malaria, 22 (5.8%) were excluded due to Cr > 106 µmol/l, and 209 were enrolled. Among the 209, AKI using KDIGO criteria was observed in 134 (64.1%). One child required dialysis during recovery. Risk factors for AKI in both the logistic regression and multivariate models included: hyperpyrexia (OR 3.36; 95% CI 1.39-8.12) and age with older children being less likely to have AKI (OR 0.72; 95% CI 0.62-0.84).

CONCLUSION

AKI is extremely common among children presenting with CNS malaria. Hyperpyrexia with associated dehydration may contribute to the AKI or may simply be a marker for a more inflammatory systemic response that is also affecting the kidney. Appropriate fluid management in children with CNS malaria and AKI may be challenging since generous hydration to support kidney recovery could worsen malaria-induced cerebral oedema in this critically ill population. Trial registration https://clinicaltrials.gov/ct2/show/NCT03399318.

Intestinal Injury Biomarkers Predict Mortality in Pediatric Severe Malaria

Severe malaria (SM) increases the risk of invasive bacterial infection, and there is evidence to suggest increased gastrointestinal permeability. Studies have shown sequestration of infected erythrocytes in intestinal microvasculature, and in vivo studies of rectal mucosa have demonstrated disruption of microvascular blood flow. However, the extent of intestinal injury in pediatric malaria is not well characterized. In this study, two serum biomarkers of intestinal injury, trefoil factor 3 (TFF3) and intestinal fatty acid binding protein (I-FABP), were analyzed in 598 children with SM and 120 healthy community children (CC), 6 months to 4 years of age. Serum was collected at enrollment and 1 month for laboratory studies, and participants were monitored for 12 months. Intestinal injury biomarkers were significantly elevated in children with SM, with 18.1% having levels of TFF3 and/or I-FABP greater than the 99th percentile of CC levels. TFF3 levels continued to be elevated at 1 month, while I-FABP levels were comparable to CC levels. Both markers predicted in-hospital mortality {odds ratio (OR) (95% confidence interval [CI]), 4.4 (2.7, 7.3) and 2.3 (1.7, 3.1)} for a natural log increase in TFF3 and I-FABP, respectively. TFF3 was also associated with postdischarge mortality (OR, 2.43 [95% CI, 1.1, 4.8]). Intestinal injury was associated with acute kidney injury (AKI), acidosis (P < 0.001 for both), and angiopoietin 2, a maker of endothelial activation. In conclusion, intestinal injury is common in pediatric severe malaria and is associated with an increased mortality. It is strongly associated with AKI, acidosis, and endothelial activation. IMPORTANCE In children with severe malaria, intestinal injury is a common complication associated with increased mortality. Intestinal injury is associated with acute kidney injury, acidosis, and endothelial activation. Interventions promoting intestinal regeneration and repair represent novel approaches to improve outcomes.

Blackwater fever and acute kidney injury in children hospitalized with an acute febrile illness: pathophysiology and prognostic significance

BACKGROUND

Acute kidney injury (AKI) and blackwater fever (BWF) are related but distinct renal complications of acute febrile illness in East Africa. The pathogenesis and prognostic significance of BWF and AKI are not well understood.

METHODS

A prospective observational cohort study was conducted to evaluate the association between BWF and AKI in children hospitalized with an acute febrile illness. Secondary objectives were to examine the association of AKI and BWF with (i) host response biomarkers and (ii) mortality. AKI was defined using the Kidney Disease: Improving Global Outcomes criteria and BWF was based on parental report of tea-colored urine. Host markers of immune and endothelial activation were quantified on admission plasma samples. The relationships between BWF and AKI and clinical and biologic factors were evaluated using multivariable regression.

RESULTS

We evaluated BWF and AKI in 999 children with acute febrile illness (mean age 1.7 years (standard deviation 1.06), 55.7% male). At enrollment, 8.2% of children had a history of BWF, 49.5% had AKI, and 11.1% had severe AKI. A history of BWF was independently associated with 2.18-fold increased odds of AKI (95% CI 1.15 to 4.16). When examining host response, severe AKI was associated with increased immune and endothelial activation (increased CHI3L1, sTNFR1, sTREM-1, IL-8, Angpt-2, sFlt-1) while BWF was predominantly associated with endothelial activation (increased Angpt-2 and sFlt-1, decreased Angpt-1). The presence of severe AKI, not BWF, was associated with increased risk of in-hospital death (RR, 2.17 95% CI 1.01 to 4.64) adjusting for age, sex, and disease severity.

CONCLUSIONS

BWF is associated with severe AKI in children hospitalized with a severe febrile illness. Increased awareness of AKI in the setting of BWF, and improved access to AKI diagnostics, is needed to reduce disease progression and in-hospital mortality in this high-risk group of children through early implementation of kidney-protective measures.

Neuroimmunology of Common Parasitic Infections in Africa

Parasitic infections of the central nervous system are an important cause of morbidity and mortality in Africa. The neurological, cognitive, and psychiatric sequelae of these infections result from a complex interplay between the parasites and the host inflammatory response. Here we review some of the diseases caused by selected parasitic organisms known to infect the nervous system including Plasmodium falciparum, Toxoplasma gondii, Trypanosoma brucei spp., and Taenia solium species. For each parasite, we describe the geographical distribution, prevalence, life cycle, and typical clinical symptoms of infection and pathogenesis. We pay particular attention to how the parasites infect the brain and the interaction between each organism and the host immune system. We describe how an understanding of these processes may guide optimal diagnostic and therapeutic strategies to treat these disorders. Finally, we highlight current gaps in our understanding of disease pathophysiology and call for increased interrogation of these often-neglected disorders of the nervous system.

Pathophysiology of Acute Kidney Injury in Malaria and Non-Malarial Febrile Illness: A Prospective Cohort Study

Acute kidney injury (AKI) is a life-threatening complication. Malaria and sepsis are leading causes of AKI in low-and-middle-income countries, but its etiology and pathogenesis are poorly understood. A prospective observational cohort study was conducted to evaluate pathways of immune and endothelial activation in children hospitalized with an acute febrile illness in Uganda. The relationship between clinical outcome and AKI, defined using the Kidney Disease: Improving Global Outcomes criteria, was investigated. The study included 967 participants (mean age 1.67 years, 44.7% female) with 687 (71.0%) positive for malaria by rapid diagnostic test and 280 (29.1%) children had a non-malarial febrile illness (NMFI). The frequency of AKI was higher in children with NMFI compared to malaria (AKI, 55.0% vs. 46.7%, p = 0.02). However, the frequency of severe AKI (stage 2 or 3 AKI) was comparable (12.1% vs. 10.5%, p = 0.45). Circulating markers of both immune and endothelial activation were associated with severe AKI. Children who had malaria and AKI had increased mortality (no AKI, 0.8% vs. AKI, 4.1%, p = 0.005), while there was no difference in mortality among children with NMFI (no AKI, 4.0% vs. AKI, 4.6%, p = 0.81). AKI is a common complication in children hospitalized with acute infections. Immune and endothelial activation appear to play central roles in the pathogenesis of AKI.

Acute Kidney Injury Interacts With Coma, Acidosis, and Impaired Perfusion to Significantly Increase Risk of Death in Children With Severe Malaria

BACKGROUND

Mortality in severe malaria remains high in children treated with intravenous artesunate. Acute kidney injury (AKI) is a common complication of severe malaria, but the interactions between AKI and other complications on the risk of mortality in severe malaria are not well characterized.

METHODS

Between 2014 and 2017, 600 children aged 6-48 months to 4 years hospitalized with severe malaria were enrolled in a prospective clinical cohort study evaluating clinical predictors of mortality in children with severe malaria.

RESULTS

The mean age of children in this cohort was 2.1 years (standard deviation, 0.9 years) and 338 children (56.3%) were male. Mortality was 7.3%, and 52.3% of deaths occurred within 12 hours of admission. Coma, acidosis, impaired perfusion, AKI, elevated blood urea nitrogen (BUN), and hyperkalemia were associated with increased mortality (all P < .001). AKI interacted with each risk factor to increase mortality (P < .001 for interaction). Children with clinical indications for dialysis (14.4% of all children) had an increased risk of death compared with those with no indications for dialysis (odds ratio, 6.56; 95% confidence interval, 3.41-12.59).

CONCLUSIONS

AKI interacts with coma, acidosis, or impaired perfusion to significantly increase the risk of death in severe malaria. Among children with AKI, those who have hyperkalemia or elevated BUN have a higher risk of death. A better understanding of the causes of these complications of severe malaria, and development and implementation of measures to prevent and treat them, such as dialysis, are needed to reduce mortality in severe malaria.

Kidney complications of parasitic diseases

Parasitic agents have been known to cause human disease since ancient times and are endemic in tropical and subtropical regions. Complications of parasitic diseases, including kidney involvement, are associated with worse outcomes. Chagas disease, filariasis, leishmaniasis, malaria and schistosomiasis are important parasitic diseases that can damage the kidney. These diseases affect millions of people worldwide, primarily in Africa, Asia and Latin America, and kidney involvement is associated with increased mortality. The most common kidney complications of parasitic diseases are acute kidney injury, glomerulonephritis and tubular dysfunction. The mechanisms that underlie parasitic disease-associated kidney injury include direct parasite damage; immunological phenomena, including immune complex deposition and inflammation; and systemic manifestations such as haemolysis, haemorrhage and rhabdomyolysis. In addition, use of nephrotoxic drugs to treat parasitic infections is associated with acute kidney injury. Early diagnosis of kidney involvement and adequate management is crucial to prevent progression of kidney disease and optimize patient recovery.

Acute kidney injury, persistent kidney disease, and post-discharge morbidity and mortality in severe malaria in children: A prospective cohort study

BACKGROUND

Globally, 85% of acute kidney injury (AKI) cases occur in low-and-middle-income countries. There is limited information on persistent kidney disease (acute kidney disease [AKD]) following severe malaria-associated AKI.

METHODS

Between March 28, 2014, and April 18, 2017, 598 children with severe malaria and 118 community children were enrolled in a two-site prospective cohort study in Uganda and followed up for 12 months. The Kidney Disease: Improving Global Outcomes (KDIGO) criteria were used to define AKI (primary exposure) and AKD at 1-month follow-up (primary outcome). Plasma neutrophil gelatinase-associated lipocalin (NGAL) was assessed as a structural biomarker of AKI.

FINDINGS

The prevalence of AKI was 45·3% with 21·5% of children having unresolved AKI at 24 h. AKI was more common in Eastern Uganda. In-hospital mortality increased across AKI stages from 1·8% in children without AKI to 26·5% with Stage 3 AKI (p < 0·0001). Children with a high-risk plasma NGAL test were more likely to have unresolved AKI (OR, 7·00 95% CI 4·16 to 11·76) and die in hospital (OR, 6·02 95% CI 2·83 to 12·81). AKD prevalence was 15·6% at 1-month follow-up with most AKD occurring in Eastern Uganda. Risk factors for AKD included severe/unresolved AKI, blackwater fever, and a high-risk NGAL test (adjusted p < 0·05). Paracetamol use during hospitalization was associated with reduced AKD (p < 0·0001). Survivors with AKD post-AKI had higher post-discharge mortality (17·5%) compared with children without AKD (3·7%).

INTERPRETATION

Children with severe malaria-associated AKI are at risk of AKD and post-discharge mortality.

FUNDING

This work was supported by the National Institutes of Health National Institute of Neurological Disorders and Stroke (R01NS055349 to CCJ) and the Fogarty International Center (D43 TW010928 to CCJ), and a Ralph W. and Grace M. Showalter Young Investigator Award to ALC.

Plasmodium falciparum Parasite Lines Expressing DC8 and Group A PfEMP1 Bind to Brain, Intestinal, and Kidney Endothelial Cells

Cytoadhesion of Plasmodium falciparum-infected red blood cells is a virulence determinant associated with microvascular obstruction and organ complications. The gastrointestinal tract is a major site of sequestration in fatal cerebral malaria cases and kidney complications are common in severe malaria, but parasite interactions with these microvascular sites are poorly characterized. To study parasite tropism for different microvascular sites, we investigated binding of parasite lines to primary human microvascular endothelial cells from intestine (HIMEC) and peritubular kidney (HKMEC) sites. Of the three major host receptors for P. falciparum, CD36 had low or negligible expression; endothelial protein C receptor (EPCR) had the broadest constitutive expression; and intercellular adhesion molecule 1 (ICAM-1) was weakly expressed on resting cells and was strongly upregulated by TNF-α on primary endothelial cells from the brain, intestine, and peritubular kidney sites. By studying parasite lines expressing var genes linked to severe malaria, we provide evidence that both the DC8 and Group A EPCR-binding subsets of the P. falciparum erythrocyte membrane protein 1 (PfEMP1) family encodes binding affinity for brain, intestinal, and peritubular kidney endothelial cells, and that DC8 parasite adhesion was partially dependent on EPCR. Collectively, these findings raise the possibility of a brain-gut-kidney binding axis contributing to multi-organ complications in severe malaria.

Molecular mechanisms of hematological and biochemical alterations in malaria: A review

Malaria is a dangerous disease that contributes to millions of hospital visits and hundreds of thousands of deaths, especially in children residing in sub-Saharan Africa. Although several interventions such as vector control, case detection, and treatment are already in place, there is no substantive reduction in the disease burden. Several studies in the past have reported the emergence of resistant strains of malaria parasites (MPs) and mosquitoes, and poor adherence and inaccessibility to effective antimalarial drugs as the major factors for this persistent menace of malaria infections. Moreover, victory against MP infections for many years has been hampered by an incomplete understanding of the complex nature of malaria pathogenesis. Very recent studies have identified different complex interactions and hematological alterations induced by malaria parasites. However, no studies have hybridized these alterations for a better understanding of Malaria pathogenesis. Hence, this review thoroughly discusses the molecular mechanisms of all reported hematological and biochemical alterations induced by MPs infections. Specifically, the mechanisms in which MP-infection induces anemia, thrombocytopenia, leukopenia, dyslipidemia, hypoglycemia, oxidative stress, and liver and kidney malfunctions were presented. The study also discussed how MPs evade the host's immune response and suggested strategies to limit evasion of the host's immune response to combat malaria and its complications.