Clinical Comparison of Retinopathy-Positive and Retinopathy-Negative Cerebral Malaria

AbstractCerebral malaria (CM) is a severe and often lethal complication of falciparum malaria. A classic malaria retinopathy is seen in some (retinopathy-positive [RP]) children but not others (retinopathy-negative [RN]), and is associated with increased parasite sequestration. It is unclear whether RN CM is a severe nonmalarial illness with incidental parasitemia or a less severe form of the same malarial illness as RP CM. Understanding the clinical differences between RP and RN CM may help shed light on the pathophysiology of malarial retinopathy. We compared clinical history, physical examination, laboratory findings, and outcomes of RP (N = 167) and RN (N = 87) children admitted to Mulago Hospital, Kampala, Uganda. Compared with RN children, RP children presented with a longer history of illness, as well as physical examination and laboratory findings indicative of more severe disease and organ damage. The hospital course of RP children was complicated by longer coma duration and a greater transfusion burden than RN children. Mortality did not differ significantly between RP and RN children (14.4% versus 8.0%, P = 0.14). Further, severity of retinal hemorrhage correlated with the majority of variables that differed between RP and RN children. The data suggest that RP and RN CM may reflect the spectrum of illness in CM, and that RN CM could be an earlier, less severe form of disease

Lack of mortality in 22 children with sickle cell anemia and severe malarial anemia

Retrospective studies suggest that there is high mortality in children with sickle cell anemia (SCA) and severe malaria. We assessed mortality in Ugandan children with severe malarial anemia (SMA, n = 232) or cerebral malaria (CM, n = 267) by sickle cell hemoglobin genotype. Admission and 2‐year follow‐up mortality did not differ among children with SMA who had homozygous form of sickle cell hemoglobin (HbSS) versus normal form of adult hemoglobin (admission, 0/22, 0%, vs. 1/208, 0.5%; follow‐up, 1/22, 4.5%; 7/207, 3.4%, respectively; all P > 0.6). The single child with CM and HbSS survived. The study findings highlight the need for large prospective studies of malaria‐related mortality in children with SCA

The Ugandan sickle Pan-African research consortium registry: design, development, and lessons

Background Sub-Saharan Africa bears the highest burden of sickle cell disease (SCD) globally with Nigeria, Democratic Republic of Congo, Tanzania, Uganda being the most affected countries. Uganda reports approximately 20,000 SCD births annually, constituting 6.67% of reported global SCD births. Despite this, there is a paucity of comprehensive data on SCD from the African continent. SCD registries offer a promising avenue for conducting prospective studies, elucidating disease severity patterns, and evaluating the intricate interplay of social, environmental, and genetic factors. This paper describes the establishment of the Sickle Pan Africa Research Consortium (SPARCo) Uganda registry, encompassing its design, development, data collection, and key insights learned, aligning with collaborative efforts in Nigeria, Tanzania, and Ghana SPARCo registries. Methods The registry was created using pre-existing case report forms harmonized from the SPARCo data dictionary and ontology to fit Uganda clinical needs. The case report forms were developed with SCD data elements of interest including demographics, consent, baseline, clinical, laboratory and others. That data was then parsed into a customized REDCap database, configured to suit the optimized ontologies and support retrieval aggregations and analyses. Patients were enrolled from one national referral and three regional referral hospitals in Uganda. Results A nationwide electronic patient-consented registry for SCD was established from four regional hospitals. A total of 5,655 patients were enrolled from Mulago National Referral Hospital (58%), Jinja Regional Referral (14.4%), Mbale Regional Referral (16.9%), and Lira Regional Referral (10.7%) hospitals between June 2022 and October 2023. Conclusion Uganda has been able to develop a SCD registry consistent with data from Tanzania, Nigeria and Ghana. Our findings demonstrate that it’s feasible to develop longitudinal SCD registries in sub-Saharan Africa. These registries will be crucial for facilitating a range of studies, including the analysis of SCD clinical phenotypes and patient outcomes, newborn screening, and evaluation of hydroxyurea use, among others. This initiative underscores the potential for developing comprehensive disease registries in resource-limited settings, fostering collaborative, data-driven research efforts aimed at addressing the multifaceted challenges of SCD in Africa

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

Autoantibody levels are associated with acute kidney injury, anemia and post-discharge morbidity and mortality in Ugandan children with severe malaria

Autoantibodies targeting host antigens contribute to autoimmune disorders, frequently occur during and after infections and have been proposed to contribute to malaria-induced anemia. We measured anti-phosphatidylserine (PS) and anti-DNA antibody levels in 382 Ugandan children prospectively recruited in a study of severe malaria (SM). High antibody levels were defined as antibody levels greater than the mean plus 3 standard deviations of community children (CC). We observed increases in median levels of anti-PS and anti-DNA antibodies in children with SM compared to CC (p < 0.0001 for both). Children with severe malarial anemia were more likely to have high anti-PS antibodies than children with cerebral malaria (16.4% vs. 7.4%), p = 0.02. Increases in anti-PS and anti-DNA antibodies were associated with decreased hemoglobin (p < 0.05). A one-unit increase in anti-DNA antibodies was associated with a 2.99 (95% CI, 1.68, 5.31) increase odds of acute kidney injury (AKI) (p < 0.0001). Elevated anti-PS and anti-DNA antibodies were associated with post-discharge mortality (p = 0.031 and p = 0.042, respectively). Children with high anti-PS antibodies were more likely to have multiple hospital readmissions compared to children with normal anti-PS antibody levels (p < 0.05). SM is associated with increased autoantibodies against PS and DNA. Autoantibodies were associated with anemia, AKI, post-discharge mortality, and hospital readmission

Dynamic modulation of spleen germinal center reactions by gut bacteria during Plasmodium infection

Gut microbiota educate the local and distal immune system in early life to imprint long-term immunological outcomes while maintaining the capacity to dynamically modulate the local mucosal immune system throughout life. It is unknown whether gut microbiota provide signals that dynamically regulate distal immune responses following an extra-gastrointestinal infection. We show here that gut bacteria composition correlated with the severity of malaria in children. Using the murine model of malaria, we demonstrate that parasite burden and spleen germinal center reactions are malleable to dynamic cues provided by gut bacteria. Whereas antibiotic-induced changes in gut bacteria have been associated with immunopathology or impairment of immunity, the data demonstrate that antibiotic-induced changes in gut bacteria can enhance immunity to Plasmodium. This effect is not universal but depends on baseline gut bacteria composition. These data demonstrate the dynamic communications that exist among gut bacteria, the gut-distal immune system, and control of Plasmodium infection

Evaluating kidney function using a point-of-care creatinine test in Ugandan children with severe malaria: a prospective cohort study

Background: Acute kidney injury (AKI) disproportionately affects individuals in low-and middle-income countries (LMIC). However, LMIC-particularly countries in sub-Saharan Africa- are under-represented in global AKI research. A critical barrier in diagnosing AKI is access to reliable serum creatinine results. We evaluated the utility of a point-of-care test to measure creatinine and diagnose AKI in Ugandan children with malaria. Methods: Paired admission creatinine was assessed in 539 Ugandan children 6 months to 4 years of age hospitalized with severe malaria based on blood smear or rapid diagnostic test. Creatinine levels were measured using isotope dilution mass spectrometry (IDMS)-traceable methods. The reference creatinine was measured using the modified Jaffe method by a certified laboratory and the point-of-care testing was conducted using an i-STAT blood analyzer (i-STAT1, with and without adjustment for the partial pressure of carbon dioxide). AKI was defined and staged using the Kidney Disease: Improving Global Outcomes criteria. Results: The mean age of children was 2.1 years, and 21.6% of children were stunted. Mortality was 7.6% in-hospital. Over the entire range of measured creatinine values (<0.20mg/dL-8.4mg/dL), the correlation between the reference creatinine and adjusted and unadjusted point-of-care creatinine was high with R2 values of 0.95 and 0.93 respectively; however, the correlation was significantly lower in children with creatinine values <1mg/dL (R2 of 0.44 between the reference and adjusted and unadjusted i-STAT creatinine). The prevalence of AKI was 45.5% using the reference creatinine, and 27.1 and 32.3% using the unadjusted and adjusted point-of-care creatinine values, respectively. There was a step-wise increase in mortality across AKI stages, and all methods were strongly associated with mortality (p<0.0001 for all). AKI defined using the reference creatinine measure was the most sensitive to predict mortality with a sensitivity of 85.4% compared to 70.7 and 63.4% with the adjusted and unadjusted point-of-care creatinine values, respectively. Conclusions: Point-of-care assessment of creatinine in lean Ugandan children <4 years of age underestimated creatinine and AKI compared to the clinical reference. Additional studies are needed to evaluate other biomarkers of AKI in LMIC to ensure equitable access to AKI diagnostics globally

Methods to estimate baseline creatinine and define acute kidney injury in lean Ugandan children with severe malaria: a prospective cohort study

Background Acute kidney injury (AKI) is increasingly recognized as a consequential clinical complication in children with severe malaria. However, approaches to estimate baseline creatinine (bSCr) are not standardized in this unique patient population. Prior to wide-spread utilization, bSCr estimation methods need to be evaluated in many populations, particularly in children from low-income countries. Methods We evaluated six methods to estimate bSCr in Ugandan children aged 6 months to 12 years of age in two cohorts of children with severe malaria (n = 1078) and healthy community children (n = 289). Using isotope dilution mass spectrometry (IDMS)-traceable creatinine measures from community children, we evaluated the bias, accuracy and precision of estimating bSCr using height-dependent and height-independent estimated glomerular filtration (eGFR) equations to back-calculate bSCr or estimating bSCr directly using published or population-specific norms. Results We compared methods to estimate bSCr in healthy community children against the IDMS-traceable SCr measure. The Pottel-age based equation, assuming a normal GFR of 120 mL/min per 1.73m2, was the more accurate method with minimal bias when compared to the Schwartz height-based equation. Using the different bSCr estimates, we demonstrated the prevalence of KDIGO-defined AKI in children with severe malaria ranged from 15.6–43.4%. The lowest estimate was derived using population upper levels of normal and the highest estimate was derived using the mean GFR of the community children (137 mL/min per 1.73m2) to back-calculate the bSCr. Irrespective of approach, AKI was strongly associated with mortality with a step-wise increase in mortality across AKI stages (p < 0.0001 for all). AKI defined using the Pottel-age based equation to estimate bSCr showed the strongest relationship with mortality with a risk ratio of 5.13 (95% CI 3.03–8.68) adjusting for child age and sex. Conclusions We recommend using height-independent age-based approaches to estimate bSCr in hospitalized children in sub-Saharan Africa due to challenges in accurate height measurements and undernutrition which may impact bSCr estimates. In this population the Pottel-age based GFR estimating equation obtained comparable bSCr estimates to population-based estimates in healthy children

Parenteral artemisinins are associated with reduced mortality and neurologic deficits and improved long-term behavioral outcomes in children with severe malaria

Background: In 2011, the World Health Organization recommended injectable artesunate as the first-line therapy for severe malaria (SM) due to its superiority in reducing mortality compared to quinine. There are limited data on long-term clinical and neurobehavioral outcomes after artemisinin use for treatment of SM. Methods: From 2008 to 2013, 502 Ugandan children with two common forms of SM, cerebral malaria and severe malarial anemia, were enrolled in a prospective observational study assessing long-term neurobehavioral and cognitive outcomes following SM. Children were evaluated a week after hospital discharge, and 6, 12, and 24 months of follow-up, and returned to hospital for any illness. In this study, we evaluated the impact of artemisinin derivatives on survival, post-discharge hospital readmission or death, and neurocognitive and behavioral outcomes over 2 years of follow-up. Results: 346 children received quinine and 156 received parenteral artemisinin therapy (artemether or artesunate). After adjustment for disease severity, artemisinin derivatives were associated with a 78% reduction in in-hospital mortality (adjusted odds ratio, 0.22; 95% CI, 0.07-0.67). Among cerebral malaria survivors, children treated with artemisinin derivatives also had reduced neurologic deficits at discharge (quinine, 41.7%; artemisinin derivatives, 23.7%, p=0.007). Over a 2-year follow-up, artemisinin derivatives as compared to quinine were associated with better adjusted scores (negative scores better) in internalizing behavior and executive function in children irrespective of the age at severe malaria episode. After adjusting for multiple comparisons, artemisinin derivatives were associated with better adjusted scores in behavior and executive function in children <6 years of age at severe malaria exposure following adjustment for child age, sex, socioeconomic status, enrichment in the home environment, and the incidence of hospitalizations over follow-up. Children receiving artesunate had the greatest reduction in mortality and benefit in behavioral outcomes and had reduced inflammation at 1-month follow-up compared to children treated with quinine. Conclusions: Treatment of severe malaria with artemisinin derivatives, particularly artesunate, results in reduced in-hospital mortality and neurologic deficits in children of all ages, reduced inflammation following recovery, and better long-term behavioral outcomes. These findings suggest artesunate has long-term beneficial effects in children surviving severe malaria

Rapid gene fusion testing using the NanoString nCounter platform to improve pediatric leukemia diagnoses in Sub-Saharan Africa

Risk stratification and molecular targeting have been key to increasing cure rates for pediatric cancers in high-income countries. In contrast, precise diagnosis in low-resource settings is hindered by insufficient pathology infrastructure. The Global HOPE program aims to improve outcomes for pediatric cancer in Sub-Saharan Africa (SSA) by building local clinical care and diagnostic capacity. This study aimed to assess the feasibility of implementing molecular assays to improve leukemia diagnoses in SSA. Custom NanoString nCounter gene fusion assays, previously validated in the US, were used to test samples from suspected leukemia patients. The NanoString platform was chosen due to relatively low cost, minimal technical and bioinformatics expertise required, ability to test sub-optimal RNA, and rapid turnaround time. Fusion results were analyzed blindly, then compared to morphology and flow cytometry results. Of 117 leukemia samples, 74 were fusion-positive, 30 were negative, 7 were not interpretable, and 6 failed RNA quality. Nine additional samples were negative for leukemia by flow cytometry and negative for gene fusions. All 74 gene fusions aligned with the immunophenotype determined by flow cytometry. Fourteen samples had additional information available to further confirm the accuracy of the gene fusion results. The testing provided a more precise diagnosis in &gt;60% of cases, and 9 cases were identified that could be treated with an available tyrosine kinase inhibitor, if detected at diagnosis. As risk-stratified and targeted therapies become more available in SSA, implementing this testing in real-time will enable the treatment of pediatric cancer to move toward incorporating risk stratification for optimized therapy