Neurofilament light chain: A potential biomarker for cerebrovascular disease in children with sickle cell anaemia.

Cerebrovascular injury frequently occurs in children with sickle cell anaemia (SCA). Limited access to magnetic resonance imaging and angiography (MRI-MRA) in sub-Saharan Africa impedes detection of clinically unapparent cerebrovascular injury. Blood-based brain biomarkers of cerebral infarcts have been identified in non-SCA adults. Using plasma samples from a well-characterized cross-sectional sample of Ugandan children with SCA, we explored relationships between biomarker levels and MRI-detected cerebral infarcts and transcranial Doppler (TCD) arterial velocity. Testing was performed using a 4-plex panel of brain injury biomarkers, including neurofilament light chain (NfL), a central nervous system neuron-specific protein. Mean biomarker levels from the SCA group (n = 81) were similar to those from non-SCA sibling controls (n = 54). Within the SCA group, NfL levels were significantly higher in those with MRI-detected infarcts compared to no infarcts, and higher with elevated TCD velocity versus normal velocity. Elevated NfL remained strongly associated with MRI-detected infarcts after adjusting for sex and age. All non-SCA controls and SCA participants lacking MRI-detected infarcts had low NfL levels. These data suggest potential utility of plasma-based NfL levels to identify children with SCA cerebrovascular injury. Replication and prospective studies are needed to confirm these novel findings and the clinical utility of NfL versus MRI imaging.

Brain Magnetic Resonance Imaging and Angiography in Children with Sickle Cell Anaemia in Uganda in a Cross-Sectional Sample.

OBJECTIVE: Children with sickle cell anaemia (SCA) are highly susceptible to cerebrovascular injury. We performed brain magnetic resonance imaging and angiography (MRI-MRA) in Ugandan children with SCA to identify structural cerebrovascular abnormalities and examine their relationship to standardized clinical assessments. METHODS: A sub-sample (n=81) was selected from a cross-sectional study of children attending SCA clinic, including 52 (64.2%) with and 29 (35.8%) without clinically detected abnormalities. Clinical evaluation included assessment for prior stroke, cognitive testing and cerebral arterial transcranial doppler (TCD) flow velocity. MRI-MRA scans were interpreted by at least two neuroradiologists. RESULTS: Mean age was 6.5±2.7 years, with 39 (48.1%) female. Mean haemoglobin was 7.3±0.9 g/dl. Overall, 13 (16.0%) were malnourished. Infarcts and/or stenoses were detected in 55 (67.9%) participants, with stenoses primarily in the anterior circulation. Infarcts were seen in those with normal 17/29 (58.6%) or abnormal 34/52 (65.4%) clinical testing (p=0.181). Neither abnormal MRI nor MRA was associated with age, sex, haemoglobin, or malnutrition. Abnormal MRA was highly associated with infarcts (p<0.0001). Participants with abnormal imaging had two-fold higher proportion of stroke on exam and/or impaired cognition. Stroke on exam was strongly associated with an imaging abnormality after adjusting for age, sex, malnutrition, and haemoglobin (OR 11.8, 95%CI 1.87-74.2). CONCLUSION: Over half of these SCA children had cerebrovascular infarcts and/or arterial stenoses. Cerebrovascular disease was frequently undetectable by clinical assessments. While rarely available in under-resourced settings, MRI-MRA brain imaging is an important tool for defining SCA cerebrovascular disease and for assessing impact of clinical intervention trials.

Chronic pain among children with cerebral palsy attending a Ugandan tertiary hospital: a cross-sectional study.

BACKGROUND: Children with cerebral palsy (CP) frequently experience chronic pain. The burden and severity of such pain is often underestimated in relation to their other impairments. Recognition and awareness of this chronic pain among children with CP constitute the cornerstone for caretakers and clinicians to improve the quality of life of those children. This study aimed to determine the prevalence of chronic pain among children with CP, and the factors associated. METHODS: A cross-sectional study of children with CP, aged 2-12 years, attending the CP rehabilitation clinic and Pediatric Neurology Clinic at Mulago Hospital, Uganda from November 2017 to May 2018. A detailed history and clinical examination were performed and the co-morbidities were determined. CP was classified using the Gross Motor Function Classification System (GMFCS), Manual Ability Classification System, Communication Function Classification System (CFCS), and the Eating and Drinking Ability Classification System (EDACS) and documented with the level of impairment in the different domains. Pain was assessed by using the revised Face, Legs, Activity, Consolability, Cry pain scale. RESULTS: A total of 224 children with CP were enrolled. The prevalence of chronic pain was 64.3%. The majority had spastic bilateral CP (77.8%), moderate pain lasting over 6 months, and none of them was on long-term pain management. Epilepsy (60.9%), behavioral problem (63.2%), hearing impairment (66,7%), learning problem (67,6%), dental caries (75%), gastro-esophageal reflux (75%), sleep disorders (79.5%), vision impairment (80%), and malnutrition (90%) were co- morbid conditions of chronic pain in children with CP in this study. The factors independently associated with chronic pain among children with CP were the GMFCS level IV & V, CFCS level IV & V, EDACS level IV & V, female children, and caretaker aged more than 30 years. CONCLUSIONS: Two-thirds of children with CP attending rehabilitation in this hospital had chronic pain. None was receiving pain management. Chronic pain was associated with the presence of multiple co-morbidities and more severe disability. Rehabilitation and care programs for children with CP should include assessment of pain in routine care and provide interventions for pain relief in children with CP even at an early age.

Burden of neurological and neurocognitive impairment in pediatric sickle cell anemia in Uganda (BRAIN SAFE): a cross-sectional study.

BACKGROUND: Children with sickle cell anemia (SCA) are highly susceptible to stroke and other manifestations of pediatric cerebral vasculopathy. Detailed evaluations in sub-Saharan Africa are limited. METHODS: We aimed to establish the frequency and types of pediatric brain injury in a cross-sectional study at a large SCA clinic in Kampala, Uganda in a randomly selected sample of 265 patients with HbSS ages 1-12 years. Brain injury was defined as one or more abnormality on standardized testing: neurocognitive impairment using an age-appropriate test battery, prior stroke by examination or transcranial Doppler (TCD) velocities associated with stroke risk in children with SCA (cerebral arterial time averaged mean maximum velocity ≥ 170 cm/second). RESULTS: Mean age was 5.5 ± 2.9 years; 52.3% were male. Mean hemoglobin was 7.3 ± 1.01 g/dl; 76.4% had hemoglobin < 8.0 g/dl. Using established international standards, 14.7% were malnourished, and was more common in children ages 5-12. Overall, 57 (21.5%) subjects had one to three abnormal primary testing. Neurocognitive dysfunction was found in 27, while prior stroke was detected in 15 (5.7%). The most frequent abnormality was elevated TCD velocity 43 (18.1%), of which five (2.1%) were in the highest velocity range of abnormal. Only impaired neurocognitive dysfunction increased with age (OR 1.44, 95%CI 1.23-1.68), p < 0.001). In univariate models, malnutrition defined as wasting (weight-for-height ≤ -2SD), but not sex or hemoglobin, was modestly related to elevated TCD (OR 1.37, 95%CI 1.01-1.86, p = 0.04). In adjusted models, neurocognitive dysfunction was strongly related to prior stroke (OR 6.88, 95%CI 1.95-24.3, p = .003) and to abnormal TCD (OR 4.37, 95%CI 1.30, p = 0.02). In a subset of 81 subjects who were enriched for other abnormal results, magnetic resonance imaging and angiography (MRI/MRA) detected infarcts and/or arterial stenosis in 52%. Thirteen subjects (25%) with abnormal imaging had no other abnormalities detected. CONCLUSIONS: The high frequency of neurocognitive impairment or other abnormal results describes a large burden of pediatric SCA brain disease in Uganda. Evaluation by any single modality would have underestimated the impact of SCA. Testing the impact of hydroxyurea or other available disease-modifying interventions for reducing or preventing SCA brain effects is warranted.

Paediatric immunisation and chemoprophylaxis in a Ugandan sickle cell disease clinic.

AIM: We aimed to assess the receipt of recommended care for young children with sickle cell disease (SCD) in a central SCD clinic in Kampala Uganda, focusing on standard vaccination and antibacterial and antimalarial prophylaxis. METHODS: A cross-sectional assessment of immunisation status and timeliness and prescribed antibacterial and antimalarial prophylaxis was performed in a sample with SCD aged ≤71 months in Mulago Hospital SCD Clinic. Government-issued immunisation cards and clinic-issued visit records for prescribed prophylaxis were reviewed. RESULTS: Vaccinations were documented by immunisation cards in 104 patients, mean age 31.7 months (range 3-70 months). Only 48 (46.2%) received all doses of each of the four recommended vaccine types, including pneumococcal 10-valent conjugate vaccine (pneumococcal conjugate vaccine (PCV)-10), which became available in 2014. Vaccination completion was associated with younger age and, for polio, maternal employment. PCV-10 series was completed in 54.8% of the sample and in 18.2% of those aged 48-71 months. Of children completing all vaccination types, an average 68.8% were immunised on time, defined as <60 days beyond the recommended age. Only 17 (13.5%) children were both fully and timely vaccinated. In an overlapping sample of 147 children, with a mean age of 38.4 months (4-70 months), 81.6% had ≥1 documented prescription for penicillin and/or antimalarial prophylaxis. CONCLUSIONS: Standardised vaccination and antibacterial and antimalarial protective measures for young children at this central SCD clinic were incomplete, especially PCV-10 for age ≥24 months, and often late. Child age, but not general maternal demographics, were associated with vaccination and chemoprophylaxis. Clinic-based oversight may improve timely uptake of these preventative measures.

A randomized trial of prolonged co-trimoxazole in HIV-infected children in Africa.

BACKGROUND: Co-trimoxazole (fixed-dose trimethoprim-sulfamethoxazole) prophylaxis administered before antiretroviral therapy (ART) reduces morbidity in children infected with the human immunodeficiency virus (HIV). We investigated whether children and adolescents receiving long-term ART in sub-Saharan Africa could discontinue co-trimoxazole. METHODS: We conducted a randomized, noninferiority trial of stopping versus continuing daily open-label co-trimoxazole in children and adolescents in Uganda and Zimbabwe. Eligible participants were older than 3 years of age, had been receiving ART for more than 96 weeks, were using insecticide-treated bed nets (in malaria-endemic areas), and had not had Pneumocystis jirovecii pneumonia. Coprimary end points were hospitalization or death and adverse events of grade 3 or 4. RESULTS: A total of 758 participants were randomly assigned to stop or continue co-trimoxazole (382 and 376 participants, respectively), after receiving ART for a median of 2.1 years (interquartile range, 1.8 to 2.3). The median age was 7.9 years (interquartile range, 4.6 to 11.1), and the median CD4 T-cell percentage was 33% (interquartile range, 26 to 39). Participants who stopped co-trimoxazole had higher rates of hospitalization or death than those who continued (72 participants [19%] vs. 48 [13%]; hazard ratio, 1.64; 95% confidence interval [CI], 1.14 to 2.37; P = 0.007; noninferiority not shown). There was no evidence of variation across ages (P=0.93 for interaction). A total of 2 participants in the prophylaxis-stopped group (1%) died, as did 3 in the prophylaxis-continued group (1%). Most hospitalizations in the prophylaxis-stopped group were for malaria (49 events, vs. 21 in the prophylaxis-continued group) or infections other than malaria (53 vs. 25), particularly pneumonia, sepsis, and meningitis. Rates of adverse events of grade 3 or 4 were similar in the two groups (hazard ratio, 1.20; 95% CI, 0.83 to 1.72; P=0.33), but more grade 4 adverse events occurred in the prophylaxis-stopped group (hazard ratio, 2.04; 95% CI, 0.99 to 4.22; P=0.05), with anemia accounting for the largest number of events (12, vs. 2 with continued prophylaxis). CONCLUSIONS: Continuing co-trimoxazole prophylaxis after 96 weeks of ART was beneficial, as compared with stopping prophylaxis, with fewer hospitalizations for both malaria and infection not related to malaria. (Funded by the United Kingdom Medical Research Council and others; ARROW Current Controlled Trials number, ISRCTN24791884.).

Mineral bone disorders and kidney disease in hospitalized children with sickle cell anemia.

Background: Mineral bone disorders (MBD) are common in sickle cell anemia (SCA). Frequent vaso-occlusive crises (VOC) further impact MBD in children with SCA. We evaluated the prevalence of markers of SCA-related MBD (sMBD) in hospitalized children and assessed the relationship between sMBD and individual mineral abnormalities with kidney disease. Methods: We prospectively recruited 185 children with SCA hospitalized with a VOC. Serum measures of mineral bone metabolism (calcium, phosphate, parathyroid hormone, 25-hydroxy vitamin D, FGF23, osteopontin) were measured at enrollment. The primary outcome was markers of sMBD defined as a composite of hypocalcemia, hyperphosphatemia, hyperparathyroidism, or deficiency in 25-OH vitamin D. Secondary outcomes included individual abnormalities in mineral metabolism. The Kidney Disease: Improving Global Outcomes (KDIGO) guidelines were used to define SCA-associated acute kidney injury (AKI). AKI was further assessed using urine NGAL as a marker of tubular injury. Acute kidney disease (AKD) was defined as a composite of AKI, an eGFR < 90 ml/min per 1.73 m2 using the Cystatin C GFR equation, or evidence of structural injury (positive biomarker test or albuminuria). Results: The mean age of children was 8.9 years and 41.6% were female. The prevalence of sMBD was 47.6%, with hypocalcemia the most frequent abnormality (29.9%, 55/184) followed by hyperphosphatemia (20.7%, 38/184), hyperparathyroidism (8.7%, 16/185), and vitamin D deficiency (5.4%, 10/185). There was no association between sMBD and sKDIGO-defined AKI using serial changes in creatinine or when incorporating biomarkers to define AKI. However, the presence of AKD was associated with a 2.01-fold increased odds of sMBD (95% CI 1.05 to 3.83) and was driven by a decrease in eGFR (OR, 2.90 95% CI: 1.59 to 5.29). When evaluating individual mineral abnormalities, hypocalcemia was associated with AKD and low eGFR while hyperparathyroidism was associated with low eGFR, AKI and structural injury. Vitamin D deficiency was associated with structural kidney injury. Vitamin D deficiency, hyperparathryoidism, and increases in FGF23 and osteopontin predicted mortality (p < 0.05 for all). Conclusion: MBD is common among children with SCA hospitalized with VOC. Biomarkers of kidney injury and bone health may help risk stratify children at risk of sMBD. Routine evaluation of sMBD in children with SCA may improve long-term bone health.

Stroke Prevalence in Children With Sickle Cell Disease in Sub-Saharan Africa: A Systematic Review and Meta-Analysis.

Objectives. The prevalence of stroke among children with sickle cell disease (SCD) in sub-Saharan Africa was systematically reviewed. Methods. Comprehensive searches of PubMed, Embase, and Web of Science were performed for articles published between 1980 and 2016 (English or French) reporting stroke prevalence. Using preselected inclusion criteria, titles and abstracts were screened and full-text articles were reviewed. Results. Ten full-text articles met selection criteria. Cross-sectional clinic-based data reported 2.9% to 16.9% stroke prevalence among children with SCD. Using available sickle gene frequencies by country, estimated pediatric mortality, and fixed- and random-effects model, the number of affected individuals is projected as 29 800 (95% confidence interval = 25 571-34 027) and 59 732 (37 004-82 460), respectively. Conclusion. Systematic review enabled the estimation of the number of children with SCD stroke in sub-Saharan Africa. High disease mortality, inaccurate diagnosis, and regional variability of risk hamper more precise estimates. Adopting standardized stroke assessments may provide more accurate determination of numbers affected to inform preventive interventions.

Once vs twice-daily abacavir and lamivudine in African children.

BACKGROUND: Antiretroviral therapy (ART) adherence is critical for successful HIV treatment outcomes. Once-daily dosing could improve adherence. Plasma concentrations of once-daily vs twice-daily abacavir + lamivudine are bioequivalent in children, but no randomized trial has compared virological outcomes. METHODS: Children taking abacavir + lamivudine-containing first-line regimens twice daily for more than 36 weeks in the ARROW trial (NCT02028676, ISRCTN24791884) were randomized to continue twice-daily vs move to once-daily abacavir + lamivudine (open-label). Co-primary outcomes were viral load suppression at week 48 (12% noninferiority margin, measured retrospectively) and lamivudine or abacavir-related grade 3/4 adverse events. RESULTS: Six hundred and sixty-nine children (median 5 years, range 1-16) were randomized to twice daily (n = 333) vs once daily (n = 336) after median 1.8 years on twice-daily abacavir + lamivudine-containing first-line ART. Children were followed for median 114 weeks. At week 48, 242/331 (73%) twice daily vs 236/330 (72%) once daily had viral load less than 80 copies/ml [difference -1.6% (95% confidence interval -8.4,+5.2%) P = 0.65]; 79% twice daily vs 78% once daily had viral load less than 400 copies/ml (P = 0.76) (week 96 results similar). One grade 3/4 adverse event was judged uncertainly related to abacavir + lamivudine (hepatitis; once daily). At week 48, 9% twice daily vs 10% once daily reported missing one or more ART pills in the last 4 weeks (P = 0.74) and 8 vs 8% at week 96 (P = 0.90). Carers strongly preferred once-daily dosing. There was no difference between randomized groups in postbaseline drug-resistance mutations or drug-susceptibility; WHO 3/4 events; ART-modifying, grade 3/4 or serious adverse events; CD4% or weight-for-age/height-for-age (all P > 0.15). CONCLUSION: Once-daily abacavir + lamivudine was noninferior to twice daily in viral load suppression, with similar resistance, adherence, clinical, immunological and safety outcomes. Abacavir + lamivudine provides the first once-daily nucleoside backbone across childhood that can be used to simplify ART.

Prospective long-term outcomes of a cohort of Ugandan children with laboratory monitoring during antiretroviral therapy.

BACKGROUND: Treatment of HIV-1 infected Ugandan children with antiretroviral therapy (ART) is increasing, but few prospective long-term studies evaluating the treatment process have been reported. In this study, we sought to determine prospectively how consistent monitoring of HIV-1 RNA levels affects the ART treatment process. METHODS: One hundred eight children initiating ART were enrolled into this study. These children had comprehensive laboratory monitoring, including HIV-1 RNA level determination and genotype analysis (where appropriate), CD4% plus absolute counts and safety laboratory measurements performed before starting therapy and at regular intervals after receiving ART. Kaplan-Meier statistics were used to examine predictors of survival and virologic failure. Viral genotype analysis was performed on samples obtained from children having virologic failure to determine the emergence of mutations. RESULTS: Clinically, there was no difference in the 3-year survival between our cohort receiving consistent laboratory monitoring and a matched historical clinic cohort not routinely receiving laboratory monitoring. However, 34% of children receiving ART demonstrated virologic failure. Eleven of these children received second-line ART, and all responded with an undetectable HIV-1 RNA level and an increase in CD4 count. Children remaining on a failing antiretroviral regimen accumulated resistance mutations. CONCLUSIONS: Our prospective long-term findings support the general use of monitoring HIV-1 RNA levels for the management of children on ART and the adoption of a clearer definition for virologic failure and better guidelines for managing children with unsuppressed HIV-1 RNA levels.