Chronic kidney disease is common in sickle cell disease: a cross-sectional study in the Tema Metropolis, Ghana

Prevalence, Mortality, and Access to Care for Chronic Kidney Disease in Medicaid-Enrolled Adults With Sickle Cell Disease in California: Retrospective Cohort Study

BACKGROUND

Chronic kidney disease (CKD) is a significant complication in patients with sickle cell disease (SCD), leading to increased mortality.

OBJECTIVE

This study aims to investigate the burden of CKD in Medicaid-enrolled adults with SCD in California, examine differences in disease burden between male and female individuals, and assess mortality rates and access to specialized care.

METHODS

This retrospective cohort study used the California Sickle Cell Data Collection program to identify and monitor individuals with SCD. Medicaid claims, vital records, emergency department, and hospitalization data from 2011 to 2020 were analyzed. CKD prevalence was assessed based on ICD (International Classification of Diseases) codes, and mortality rates were calculated. Access to specialized care was examined through outpatient encounter rates with hematologists and nephrologists.

RESULTS

Among the 2345 adults with SCD, 24.4% (n=572) met the case definition for CKD. The SCD-CKD group was older at the beginning of this study (average age 44, SD 14 vs 34, SD 12.6 years) than the group without CKD. CKD prevalence increased with age, revealing significant disparities by sex. While the youngest (18-29 years) and oldest (>65 years) groups showed similar CKD prevalences between sexes (female: 12/111, 10.8% and male: 12/101, 11.9%; female: 74/147, 50.3% and male: 34/66, 51.5%, respectively), male individuals in the aged 30-59 years bracket exhibited significantly higher rates than female individuals (30-39 years: 49/294, 16.7%, P=.01; 40-49 years: 52/182, 28.6%, P=.02; and 50-59 years: 76/157,48.4%, P<.001). During this study, of the 2345 adults, 435 (18.5%) deaths occurred, predominantly within the SCD-CKD cohort (226/435, 39.5%). The median age at death was 53 (IQR 61-44) years for the SCD-CKD group compared to 43 (IQR 33-56) years for the SCD group, with male individuals in the SCD-CKD group showing significantly higher mortality rates (111/242, 45.9%; P=.009) than female individuals (115/330, 34.9%). Access to specialist care was notably limited: approximately half (281/572, 49.1%) of the SCD-CKD cohort had no hematologist visits, and 61.9% (354/572) did not see a nephrologist during this study's period.

CONCLUSIONS

This study provides robust estimates of CKD prevalence and mortality among Medicaid-enrolled adults with SCD in California. The findings highlight the need for improved access to specialized care for this population and increased awareness of the high mortality risk and progression associated with CKD.

Cystatin C-derived estimated glomerular filtration rate in children with sickle cell anaemia

BACKGROUND

Sickle cell disease is the most common inherited blood disorder in humans and constitutes a major public health burden. It is a multisystemic condition with long-term renal complications. Early detection of sickle cell nephropathy and initiation of appropriate interventions are associated with improved survival and quality of life. This study aimed to compare the cystatin C-derived estimated glomerular filtration rate (GFR) of the study groups and also, to correlate the clinical features of chronic kidney disease (CKD) with decreased GFR in children with sickle cell anaemia (SCA).

METHODS

This hospital-based cross-sectional analytic study recruited 86 SCA subjects in steady-state and 86 age and sex-matched healthy HbAA controls aged 1-14 years who attended the Paediatric Haematology and Outpatient clinics of Federal Medical Centre Bida over six months. Data were collected using a semi-structured questionnaire, and participants' length/height, weight, and blood pressure were measured using standard procedures. Blood samples were drawn for serum cystatin C assay via the sandwich enzyme-linked immunosorbent assay (ELISA) technique. Filler's equation was used to calculate the glomerular filtration rate.

RESULTS

There was a significant difference in the mean cystatin C-derived GFR between the two groups, i.e. 116 ± 30mL/min/1.73m2 vs. 106 ± 24mL/min/1.73m2 for the SCA and control groups, respectively (p = 0.017). The prevalence of supernormal GFR (i.e. GFR > 140mL/min/1.73m2) and decreased GFR (i.e. GFR < 90mL/min/1.73m2) was 19.8% and 22.1%, respectively, in children with SCA. There was no significant association between the age at diagnosis of SCA, blood transfusions, blood pressure, packed cell volume and presence of peripheral oedema with decreased GFR in the study subjects.

CONCLUSIONS

Supernormal GFR is common in children with SCA and there is no significant association between clinical features of CKD with decreased GFR. Regular evaluation of renal function is, however, recommended in children with SCA for early detection and treatment of renal complications in order to halt the progression to end-stage kidney disease (ESKD).

Feasibility of smartphone colorimetry of the face as an anaemia screening tool for infants and young children in Ghana

BACKGROUND

Anaemia affects approximately a quarter of the global population. When anaemia occurs during childhood, it can increase susceptibility to infectious diseases and impair cognitive development. This research uses smartphone-based colorimetry to develop a non-invasive technique for screening for anaemia in a previously understudied population of infants and young children in Ghana.

METHODS

We propose a colorimetric algorithm for screening for anaemia which uses a novel combination of three regions of interest: the lower eyelid (palpebral conjunctiva), the sclera, and the mucosal membrane adjacent to the lower lip. These regions are chosen to have minimal skin pigmentation occluding the blood chromaticity. As part of the algorithm development, different methods were compared for (1) accounting for varying ambient lighting, and (2) choosing a chromaticity metric for each region of interest. In comparison to some prior work, no specialist hardware (such as a colour reference card) is required for image acquisition.

RESULTS

Sixty-two patients under 4 years of age were recruited as a convenience clinical sample in Korle Bu Teaching Hospital, Ghana. Forty-three of these had quality images for all regions of interest. Using a naïve Bayes classifier, this method was capable of screening for anaemia (<11.0g/dL haemoglobin concentration) vs healthy blood haemoglobin concentration (≥11.0g/dL) with a sensitivity of 92.9% (95% CI 66.1% to 99.8%), a specificity of 89.7% (72.7% to 97.8%) when acting on unseen data, using only an affordable smartphone and no additional hardware.

CONCLUSION

These results add to the body of evidence suggesting that smartphone colorimetry is likely to be a useful tool for making anaemia screening more widely available. However, there remains no consensus on the optimal method for image preprocessing or feature extraction, especially across diverse patient populations.

Biomarkers of sickle cell nephropathy in Senegal

Sickle cell anemia (SCA) is caused by a single point variation in the β-globin gene (HBB): c.20A> T (p.Glu7Val), in homozygous state. SCA is characterized by sickling of red blood cells in small blood vessels which leads to a range of multiorgan complications, including kidney dysfunction. This case-control study aims at identifying sickle cell nephropathy biomarkers in a group of patients living with SCA from Senegal. A total of 163 patients living with SCA and 177 ethnic matched controls were investigated. Biological phenotyping included evaluation of glycemia, glucosuria, albuminuria, proteinuria, tubular proteinuria, serum creatinine, urine creatinine, urine specific gravity and glomerular filtration rate. Descriptive statistics of biomarkers were performed using the χ2 -test, with the significance level set at p<0.05. Patients living with SCA had a median age of 20 years (range 4 to 57) with a female sex frequency of 53.21%. The median age of the control participants was 29 years (range: 4-77) with a female sex frequency of 66.09%. The following proportions of abnormal biological indices were observed in SCA patients versus (vs.) controls, as follows: hyposthenuria: 35.3%vs.5.2% (p<0.001); glomerular hyperfiltration: 47.66%vs.19.75% (p<0.001), renal insufficiency: 5.47%vs.3.82% (p = 0.182); microalbuminuria: 42.38%vs.5.78% (p<0.001); proteinuria: 39.33%vs.4.62% (p<0.001); tubular proteinuria: 40.97%vs.4.73% (p<0.001) and microglucosuria: 22.5%vs.5.1% (p<0.001). This study shows a relatively high proportion of SCA nephropathy among patients living with SCA in Senegal. Microglucosuria, proteinuria, tubular proteinuria, microalbuminuria, hyposthenuria and glomerular hyperfiltration are the most prevalent biomarkers of nephropathy in this group of Senegalese patients with SCA.

Neutrophil gelatinase-associated lipocalin is elevated in children with acute kidney injury and sickle cell anemia, and predicts mortality

Urine neutrophil gelatinase-associated lipocalin (NGAL) is a biomarker of acute kidney injury that has been adapted to a urine dipstick test. However, there is limited data on its use in low-and-middle-income countries where diagnosis of acute kidney injury remains a challenge. To study this, we prospectively enrolled 250 children with sickle cell anemia aged two to 18 years encompassing 185 children hospitalized with a vaso-occlusive pain crisis and a reference group of 65 children attending the sickle cell clinic for routine care follow up. Kidney injury was defined using serial creatinine measures and a modified-Kidney Disease Improving Global Outcome definition for sickle cell anemia. Urine NGAL was measured using the NGAL dipstick and a laboratory reference. The mean age of children enrolled was 8.9 years and 42.8% were female. Among hospitalized children, 36.2% had kidney injury and 3.2% died. Measured urine NGAL levels by the dipstick were strongly correlated with the standard enzyme-linked immunosorbent assay for urine NGAL (hospitalized children, 0.71; routine care reference, 0.88). NGAL levels were elevated in kidney injury and significantly increased across injury stages. Hospitalized children with a high-risk dipstick test (300ng/mL and more) had a 2.47-fold relative risk of kidney injury (95% confidence interval 1.68 to 3.61) and 7.28 increased risk of death (95% confidence interval 1.10 to 26.81) adjusting for age and sex. Thus, urine NGAL levels were found to be significantly elevated in children with sickle cell anemia and acute kidney injury and may predict mortality.

The nephropathy of sickle cell trait and sickle cell disease

Sickle cell syndromes, including sickle cell disease (SCD) and sickle cell trait, are associated with multiple kidney abnormalities. Young patients with SCD have elevated effective renal plasma flow and glomerular filtration rates, which decrease to normal ranges in young adulthood and subnormal levels with advancing age. The pathophysiology of SCD-related nephropathy is multifactorial - oxidative stress, hyperfiltration and glomerular hypertension are all contributing factors. Albuminuria, which is an early clinical manifestation of glomerular damage, is common in individuals with SCD. Kidney function declines more rapidly in individuals with SCD than in those with sickle cell trait or in healthy individuals. Multiple genetic modifiers, including APOL1, HMOX1, HBA1 and HBA2 variants are also implicated in the development and progression of SCD-related nephropathy. Chronic kidney disease and rapid decline in estimated glomerular filtration rate are associated with increased mortality in adults with SCD. Renin-angiotensin-aldosterone system inhibitors are the standard of care treatment for albuminuria in SCD, despite a lack of controlled studies demonstrating their long-term efficacy. Multiple studies of novel therapeutic agents are ongoing, and patients with SCD and kidney failure should be evaluated for kidney transplantation. Given the high prevalence and severe consequences of kidney disease, additional studies are needed to elucidate the pathophysiology, natural history and treatment of SCD-related nephropathy.

Time trends, sociodemographic and health factors associated with discharge and length of stay of hospitalised patients with sickle cell disease in Ghana: a retrospective analysis of national routine health database

OBJECTIVE

Patients with sickle cell disease (SCD) are prone to multiple episodes resulting in frequent hospital visits. We determined the time trends, sociodemographic and health factors associated with length of stay (LoS) for patients with SCD in Ghana.

DESIGN, PARTICIPANTS, SETTING

We retrospectively analysed SCD hospitalisation records of 22 680 patients from a nationwide database of the Ghana Health Service from 2012 to 2017.

OUTCOME MEASURES

Factors associated with LoS were estimated using Cox regression, while the cumulative incidence of being discharged alive was estimated with in-hospital death as a competing risk.

RESULTS

Patients admitted for SCD over 6 years constituted 22 680 (0.8%) of nearly 3 million admissions. The median age and LoS for the patients were 16 years (IQR=8-24) and 3 days (IQR=2-4), representing 14 202 (62.6%) of the patients discharged alive by the third day. Patients with sickle cell anaemia (6139, 52.6%) with a crisis were more frequent than those without a crisis. Increasing age was associated with shorter LoS when comparing age groups 10-14 years (HR=1.08, 95% CI 1.01 to 1.14) and 25-29 years (HR=1.27, 95% CI 1.17 to 1.37) to patients aged 0-4 years. Patients with comorbidities had a longer LoS compared with those without (HR=0.88, 95% CI 0.86 to 0.90).

CONCLUSION

This is the largest study to date documenting factors associated with LoS for patients admitted for SCD. The association of younger age with increased LoS supports recent calls for early SCD screening, especially newborns. The emerging trends and factors accounting for SCD admission require a multisector approach as these patients already experience frequent episodes of pain and hospital visits.

[Osteoarticular infections in patients with sickle cell disease in Lubumbashi: epidemiological study focusing on etiology and management]

INTRODUCTION

infections are the leading cause of morbidity and mortality in patients with sickle cell disease, especially before age 5 years. The purpose of this study was to highlight the epidemiological features, etiologies and management of osteoarticular infections in patients with sickle cell disease in Lubumbashi.

METHODS

we conducted a descriptive, cross-sectional and retrospective study at the Research Center for Sickle Cell Disease in Lubumbashi (RCSCDL) over a three-year period from June 2014 to June 2017. It included all patients with sickle cell disease on follow up at the RCSCDL who developed osteoarticular infection. Data were obtained from a survey form. Parameters were patient's age, age at first visit, sex, reason for consultation, history, physical signs, diagnosis, paraclinical assessment and treatment.

RESULTS

we identified 35 cases of osteoarticular infections out of a total of 380 cases of sickle-cell disease, reflecting a rate of 9.2%. The most affected age group was people under 5 years of age (37.1%); the average age was 10.9±9.5 years ranging from 8 months and 37 years. There was a slight female predominance (51.4% of cases; sex ratio 1.06 in favor of women). Most patients with osteoarticular infection had a history of transfusion (16.6%) and splenectomy (8.6%). The most common reason for consulting was limb pain (84%); 20 patients (57.1%) had bulbar conjunctival icterus and 26 (74.3%) were pale. Clinical examination showed limb swelling and wound in 27 patients (77.1%) and 19 patients (54.3%), respectively. Clinical palpation of the splenomegaly was performed in 6 patients (17.1%). Three types of osteoarticular infections were detected. They were dominated by osteomyelitis (24 cases; 68.57%) followed by osteitis (7 cases; 20%) and suppurative arthritis (4 cases; 11.43%). Out of 24 cases of osteomyelitis, 18 were acute (75%) and 6 were chronic (25%), of which 4 had a hyperostosing behaviour and 2 a fistulising behaviour. Tibia was the most affected bone (18 cases), X-ray mainly showed osteolysis (27 cases; 77.1%) and then periosteolysis (15 cases; 42.9%). Homozygous sickle cell disease was found in 88.6% of cases. Hemoculture was performed in 17 out the 35 patients and salmonella was isolated in 15 out of 17 cultures (88.23%). Pyoculture was performed in 10 patients; it isolated other germs. Assessment of inflammation was performed in 21 patients: 15 had hyperleukocytosis, 13 pathological white blood cell formula , all had increased sedimentation rate (greater than 20mm in the 1st hour). With respect to immunization schedule, 62.86% of patients received EPI vaccines while patients with sickle cell disease who needed specific vaccine had an adherence rate of 17.14%. With respect to therapy, all of our patients received medical treatment; 6 patients underwent sequestrectomy (17.14%) while the majority of patients (25 cases) underwent orthopedic treatment. Conclusion: bone infection in patients with sickle cell disease is a worryng issue in our poor environment where there isn't a specific vaccine for patients with sickle cell disease.

Occult Kidney Dysfunction in Children With Transfusion-Dependent Thalassemia

Background: Thalassemia is the commonest hemoglobinopathy in Southeast Asia. Kidney dysfunction is an underreported sequelae in children with thalassemia. We conducted a retrospective study to identify the prevalence of and predisposing factors for kidney dysfunction in children with transfusion-dependent thalassemia (TDT). Method: Abnormal kidney function was defined as children with a glomerular filtration rate (GFR) of <90 ml/min/1.73 m² or a decline in GFR of >20 ml/min/1.73 m² or presence of nephrotic range proteinuria within 3 years of commencing regular (every ≤6 weeks) red cell transfusion. Data analyzed were age at diagnosis of thalassemia, number of transfusion-years, iron chelation therapy, serum ferritin, and pre-transfusion hemoglobin levels. Results: Eighty-one children were studied. Mean age was 11.72 ± 5.275 years. Thirty out of 81 (37%) demonstrated abnormal kidney function. Evidence of glomerular hyperfiltration was seen in 29/81 patients (25.85%) at their last clinic visit. This fraction was doubled [48/81 (59.3%)] when the cohort was tracked back by 3 years from the last clinic encounter. Age at diagnosis (RR, 1.157; 95% CI, 1.014-1.319; p = 0.03) and duration of receiving transfusions (RR, 0.984; 95% CI, 0.974-0.994; p = 0.001) were associated with increased risk of developing abnormal kidney function. Conclusion: Abnormal kidney function in children with TDT may be overlooked by medical personnel without active screening measures. Children receiving regular red cell transfusions require systematic surveillance to enable early detection of kidney dysfunction and timely implementation of appropriate therapeutic interventions.

Association between renal function parameters, clinical severity score and mortality risk among adult Sudanese sickle anemia patients

BACKGROUND

Sickle Cell Anemia (SCA) is an autosomal recessive haemoglobinopathy with high morbidity and mortality. Global survival of sickle patients is increased due to advances in management; and subsequently, prevalence of chronic complications including renal manifestations also increased. Therefore, early detection and management of these complications is mandatory. This study aimed to investigate the estimated Glomerular Filtration Rate (eGFR), proteinuria and serum uric acid as markers of renal involvement in Sudanese sickle adults and association between these parameters and clinical severity score of sickle cell disease.

METHODS

Cross-sectional hospital-based study included thirty-two adult Sudanese patients diagnosed with SCA and twenty-three as controls. Written informed consent was obtained from each participant. Blood and urine samples were collected. Severity score was calculated using Bios online calculator and eGFR was calculated using Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formula without adjustment for ethnicity. Associations between the severity score and renal parameters were tested using unpaired T test and Mann Whitney test for normally and non-normally distributed data and correlations between variables were tested using SPSS version 23.

RESULTS

Protein/Creatinine Ratio (PCR) was significantly higher (p-value < 0.001) in sickle cell anaemia group compared to controls. Hyper-filtration and Hyperuricemia were manifested in 75% and 6.3% of SCA group respectively. There was no association between the severity score and renal manifestations in the SCA group.

CONCLUSIONS

Hyper-filtration and proteinuria were the most prevalent renal manifestations in SCA group. Further studies are recommended to determine the predictors of renal complications and ensure early management of such complications.

Renal abnormalities among children with sickle cell conditions in highly resource-limited setting in Ghana

Sickle cell disease (SCD) is associated with progressive multi-organ failure especially, the brain and kidney and leads to high morbidity and mortality rate. The aim of this study was to determine the prevalence of renal abnormalities among children with SCD. This cross-sectional study recruited 212 sickling positive patients comprising of 96 Hb AS, 48 Hb SC, and 68 Hb SS phenotypes from the Pediatric Unit of Wassa Akropong Government Hospital, Wassa Akropong, Ghana. Early morning urine and venous blood samples were collected from each participant. Urinalysis was conducted and serum urea and creatinine levels were estimated. Estimate glomerular filtration rate (eGFR) was calculated using the Swartz equation. Classification of chronic kidney disease (CKD) was based on 'The Kidney Disease: Improving Global Outcomes (KIDIGO)' criteria. The mean age of the children were 7.90 years. Serum creatinine (p = 0.0310) and urea (p<0.0001) levels were significantly higher among Hb AS participants compared with Hb SS phenotype. The prevalent indicators of renal abnormalities were proteinuria (26.4%), urine granular cast (5.6%) and CKD (39.6%). Proteinuria, urine granular cast and CKD were most prevalent among Hb SS (47.1%, 11.8% and 73.5% respectively) compared with Hb SC (41.7%, 8.3%, and 45.8% respectively) and Hb AS (4.2%, 0.0%, and 14.5%) phenotypes, respectively. Sickle cell conditions were significantly associated with proteinuria (p<0.0001) and CKD (p = 0.0378). Children with Hb SS [aOR = 5.04, 95% CI (2.47-10.3); p<0.0001] and Hb SC [aOR = 3.14 95% CI (1.39-7.01); p = 0.0174] were at increased odds of developing CKD after adjusting for age, BMI and gender. Proteinuria and CKD are associated with sickle cell disease (Hb SC and Hb SS). Renal function should be routinely monitored for children with SCD.

Sickle cell disease nephropathy: an update on risk factors and potential biomarkers in pediatric patients

One of the major chronic complications of sickle cell disease (SCD) is sickle cell nephropathy. The aim of this review is to discuss the pathophysiology, natural history, clinical manifestations, risk factors, biomarkers and therapeutic approaches for sickle cell nephropathy, focusing on studies with pediatric patients. The earliest manifestation of renal disease is an increase in the glomerular filtration rate. A finding that may also be observed in early childhood is microalbuminuria. Nephrin, KIM-1, VGFs, chemokines and renin-angiotensin system molecules have emerged as potential early markers of renal dysfunction in SCD. In regards to a therapeutic approach, renin-angiotensin system inhibitors and angiotensin receptor blockers seem to be effective for the control of albuminuria in adults with SCD, although new studies in children are needed. The precise moment to begin renoprotection in SCD patients who should be treated remains to be determined.

[Emergency treatment of sickle cell diseases in the Blood Diseases Department at the Koutoukou Maga National Teaching Hospital, Cotonou, Benin]

Introduction

L'évolution de la drépanocytose est marquée par la survenue de complications aigues dont certaines constituent de véritables urgences pouvant mettre en jeu le pronostic vital ou fonctionnel. Notre travail avait pour objectif d'étudier la fréquence et l'évolution des urgences drépanocytaires dans le Service des Maladies du Sang (SMAS) du Centre National Hospitalier Universitaire-Hubert Koutoukou Maga (CNHU-HKM) de Cotonou.

Méthodes

Nous avons mené une étude rétrospective et descriptive de janvier 2014 à décembre 2015 et portant sur l'ensemble des patients hospitalisés pour une urgence drépanocytaire. Nous avons exclu les patients hospitalisés pour des complications drépanocytaires chroniques.

Résultats

Deux cent quatre (204) urgences drépanocytaires pour un nombre total de 813 hospitalisations ont été enregistrés (prévalence de 25%). L'âge moyen des patients était de 24,2 ans. La tranche d'âge la plus représentée était celle de 20-30 ans (45,6%). Le sexe masculin prédominait à 60,8%. Les élèves/étudiants étaient les plus représentés à 55,9%. La douleur aigue était le motif principal d'hospitalisation à 63,7%. L'homozygotie SS était majoritairement représentée à 72,1%. Les complications vaso-occlusives ostéo-articulaires prédominaient à 70,1%. Les complications infectieuses documentées étaient dominées par le paludisme (27,5%). La décompensation anémique était notée à 30,4%. Sur le plan thérapeutique, l'hydratation a été utilisée à 85,3%. La durée moyenne de séjour était de 5,4 jours. L'évolution a été favorable dans 96,5% des cas. La létalité était de 2,5%.

Conclusion

Les urgences drépanocytaires sont fréquentes. Elles nécessitent un diagnostic rapide et une prise en charge précoce et efficace. La formation continue du personnel médical à la prise en charge des urgences drépanocytaires s'avère nécessaire pour réduire leur mortalité.

Prevalence and burden of chronic kidney disease among the general population and high-risk groups in Africa: a systematic review

OBJECTIVES

While increasing attention is paid to the rising prevalence of chronic diseases in Africa, there is little focus on chronic kidney disease (CKD). This systematic review assesses CKD burden among the general population and high-risk groups on the entire African continent.

DESIGN, SETTING AND PARTICIPANTS

We searched Medline and PubMed databases for articles published between 1 January 1995 and 7 April 2017 by sensitive search strategies focusing on CKD surveys at the community level and high-risk groups. In total, 7918 references were evaluated, of which 7766 articles were excluded because they did not meet the inclusion criteria. Thus, 152 studies were included in the final analysis.

OUTCOME MEASUREMENT

The prevalence of CKD in each study group was expressed as a range and pooled prevalence rate of CKD was calculated as a point estimate and 95% CI. No meta-analysis was done. Data were presented for different populations.

RESULTS

In the community-level studies, based on available medium-quality and high-quality studies, the prevalence of CKD ranged from 2% to 41% (pooled prevalence: 10.1%; 95% CI 9.8% to 10.5%). The prevalence of CKD in the high-risk groups ranged from 1% to 46% (pooled prevalence: 5.6%; 95% CI 5.4% to 5.8%) in patients with HIV (based on available medium-quality and high-quality studies), 11%-90% (pooled prevalence: 24.7%; 95% CI 23.6% to 25.7%) in patients with diabetes (based on all available studies which are of low quality except four of medium quality) and 13%-51% (pooled prevalence: 34.5%; 95 % CI 34.04% to 36%) in patients with hypertension (based on all available studies which are of low quality except two of medium quality).

CONCLUSION

In Africa, CKD is a public health problem, mainly attributed to high-risk conditions as hypertension and diabetes. The poor data quality restricts the validity of the findings and draws the attention to the importance of designing future robust studies.

[Screening for nephropathy in major sickle cell syndromes in patients monitored at the National Reference Center for Sickle Cell Disease in Niamey, Niger]

BACKGROUND

Sickle cell anemia is the most common hereditary hemopathy in the world. It is a disease that attacks all the systems of the organism. The kidneys are among the most sensitive organs of this disease. The main objective of this study is to detect sickle cell nephropathy in patients followed at the National Reference Center for Sickle Cell Disease in Niamey.

METHODS

It is a prospective study carried out over a period of one year (January to December 2016). It included patients aged at least two years who had not had a vaso-occlusive crisis (VOC) for 2 months and not transfused for at least 3 months. A questionnaire was sent to each patient to collect demographic, clinical and biological information. Each patient provided a fresh blood and urine sample to assess biological parameters. We used Schwartz's formula in children and CKD-EPI in adults to assess glomerular filtration rate. The Pearson correlation coefficient (r) was used to assess the relationship between the different parameters under study. The threshold for statistical significance was set at 0.05.

RESULTS

Two hundred and eighty participants were included in the study. Adolescents (≤17years) were 226 (80.71%) and adults were 54 (19.29%). The mean age of the patients was 11.94±4.70years. It was lower in SS subjects and higher in SC. The SS form accounted for 87.5% of the three sickle cell disease phenotypes encountered. The age group 6-15years was the most predominant (42.86%). The mean baseline hemoglobin in the sample was 7.59±1.15g/dL ; (6.8 ±0.9d/dL) in SS patients and higher (10.5±2.1g/dL) in SC patients. The average glomerular filtration rate was 201.04mL/min/1.73m². Glomerular hyperfiltration was found in 90% of the sample, it was lower (77.6%) in Sβ thalassemia patients (P=0.000). In young subjects hyperfiltration was present in 84.95% against it was observed in only 29.63% of adults. Proteinuria was positive in 20% of patients. Positive proteinuria was found in 6.20% pediatric cases. The SC form was the most affected and in 74.6% of the patients it was positive at 1+. Chronic kidney disease (CKD) was found in 10% of the participants, of whom 75% were of the SS phenotype. Sβ thalassemia subjects had no CKD. The male sex was predominant in subjects with CKD (P=0.000). Patients over 15 years of age accounted for more than 95% of patients in both forms of the disease (P=0.0001).

CONCLUSION

The SS form of the disease, recurrent vaso-occlusive crisis, male sex and advanced age were the main precipitating factors in the development of renal function disorders.

Use of anti-inflammatory analgesics in sickle-cell disease

WHAT IS KNOWN AND OBJECTIVE

Non-steroidal anti-inflammatory drugs (NSAIDs) have been commonly used to treat pain in sickle-cell disease (SCD), but NSAID use is associated with renal, gastrointestinal and cardiovascular toxicities. Our objective was to evaluate the use of aspirin and non-aspirin NSAIDs in SCD.

COMMENT

Despite analgesic and anti-inflammatory benefits in SCD, non-aspirin NSAIDs are associated with renal, cardiovascular and gastrointestinal toxicities in this patient population. Aspirin may have less renal and cardiovascular toxicities. The different side effect profile of NSAIDs is related to the COX-1/COX-2 selectivity at their therapeutic doses. Individual risk factors and genetic biomarkers should be considered when selecting appropriate NSAIDs and their dose.

WHAT IS NEW AND CONCLUSION

NSAIDs have the potential to be an important component of pain regimens in SCD, but the use of NSAIDs should be individualized based on potential side effects and patient risk factors and the lowest effective dose should be prescribed with proper monitoring in patients with SCD.

Glomerular hyperfiltration is strongly correlated with age in Congolese children with sickle cell anaemia

AIM

Glomerular hyperfiltration is an early marker of sickle cell nephropathy and can lead to microalbuminuria and renal failure. Our aim was to identify the associated risk factors, as these could be of preventative importance.

METHODS

We recruited 150 children with sickle cell anaemia (SCA), aged two to 18 years and living in Kinshasa, the Democratic Republic of Congo. Hyperfiltration and microalbuminuria were defined as an estimated glomerular filtration rate of less than 140 mL/min/1.73 m² and an albumin creatinine ratio of between 30 and 299 mg/g, respectively. Independent determinants of hyperfiltration were assessed using logistic regression analysis.

RESULTS

Glomerular hyperfiltration was observed in 60 (40%) children, who were significantly older (10.2 ± 4.1 versus 7.9 ± 4.3 years, p = 0.001) and had a lower body mass index level (14.7 ± 2.3 versus 15.0 ± 2.3 kg/m² ) than the 60% without. A higher proportion had microalbuminuria (25.0 versus 13.3%), but the difference was not statistically significant (p>0.05). Increased age and decreased body mass index were the main independent factors associated with glomerular hyperfiltration in the multivariate analysis. A quarter (25%) of the 60 children with SCA with glomerular hyperfiltration had microalbuminuria.

CONCLUSION

Glomerular hyperfiltration was a common finding in this study and was significantly associated with age.

Assessment of the RIFLE criteria for the diagnosis of Acute Kidney Injury; a retrospective study in South-Western Ghana

BACKGROUND

Acute kidney injury (AKI) affects 3-7 % of patients admitted to the hospital and approximately 25-30 % of patients in the intensive care unit. RIFLE, a newly developed international consensus classification for AKI, defines three grades of severity-class R (risk), I (injury) and F (failure). The aim of this study was to evaluate whether the RIFLE system of classification can detect the incidence of AKI using retrospective data of in-patients at the Effia-Nkwanta Regional Hospital.

METHODS

A total of 1070 in-patients' records spanning a period of 6 months, from July 2014 to December 2014, was used. Demographic data and hospital admission serum creatinine of each participant were used for the calculation of estimated glomerular filtration rate (eGFR) using the 4-variable modification of diet in renal disease (MDRD) equation. Also, the baseline serum creatinine was estimated assuming a standard GFR of 75 ml/min/1.73 m(2) using the simplified MDRD equation.

RESULTS

Males had higher serum creatinine, eGFR, and baseline serum creatinine than females (P < 0.0001). However, the level of increase in baseline serum creatinine was higher in females than males (P = 0.0212). The percentage ratios of the various classes from the SCr/ePCr (hospital admission serum creatinine/estimated plasma creatinine) criteria (R-1.45, I-1.53 and F-3.26) were higher than that of the eGFR criteria (R-0.34, I-0.11, F-0.12). The SCr/ePCr criteria gave more risk (89.7 %) than that of the eGFR criteria (23.1 %). The number of Injury and normal patients from the eGFR criteria was higher than the SCr/ePCr criteria.

CONCLUSION

AKI was common in the ICU population with SCr/ePCr detecting more AKI than the eGFR criteria. Males had more injury and failure than females using the eGFR criteria whereas the SCr/ePCr gave females more risk and injury than males. A prospective cohort study must be employed in subsequent studies using the RIFLE criteria to assess the incidence of AKI in hospitalized patients with known diseases or medical conditions.

[Chronic renal failure in sickle cell disease: A retrospective analysis of 100 adults sickle cell patients from black Africa]

The prevalence of chronic renal failure (CRF) in sickle cell disease (SCD) patients could vary from one country to another depending on the modalities of management. The aim of the present study was to appreciate the epidemiology of CRF in SCD patients from black Africa in order to search for promoting factors. One hundred SCD adult patients have been considered for the study. The glomerular filtration rate (GFR) has been estimated according to the CKD-EPI formula. Three groups of patients have been identified according to the value of their GFR. The mean age of the patients was 30.84±8.26 years. Male gender has represented 51% of the study population. The mean GFR value was 175.4±86.2 mL/min/1.73 m(2). The prevalence of CRF was 11%. About 3% of them had severe CRF. Subjects with normal GFR were 20%. Subjects with glomerular hyperfiltration (HF) were 69%. By univariate analysis, when subjects with HF were compared with those presenting normal GFR, the following factors have appeared to be significantly associated: female gender (female 60.9% versus male 39.1%; P<0.01), weight <60 kg (weight <60 kg; 53.67±9.45 kg versus weight >60 kg; 59.9±9.41 kg; P<0.008), age <30 years (younger age 29.36±7.9 years versus older age 35.14±8.02 years; P<0.001), lower hemoglobin value (9.38±2,3 g/dL versus 10.33±2.61 g/dL; P<0.04). By logistic regression analysis, age <30 years (age >30 years; OR=0.12 [CI95% 0.03-04]; P<0.001), female gender (male gender; OR=0.17 [0.04-0.64]; P<0.01), weight <60 kg (weight >60 kg; OR=0.19 [CI95% 0.05-0.72]; P<0.01) were associated with HF. By univariate analysis, when subjects with CRF were compared with those presenting normal GFR, a lower hemoglobin value was significantly associated with CRF (7.92±2.7 g/dL versus 10.43±2.5 g/dL; P<0.009). There was a trend for subjects not being under maintenance therapy to more experience CRF (36.4% versus 70%; P<0.07). By logistic regression analysis, only a low hemoglobin value was associated to CRF (higher hemoglobin level; OR=0.55 [0.20-6.3]; P<0.01). In total, CRF and HF are frequent complications in SCD adult patients from black Africa.

Medullary Microvascular Thrombosis and Injury in Sickle Hemoglobin C Disease

Sickle cell nephropathy is a common complication in patients with sickle cell hemoglobinopathies. In these disorders, polymerization of mutated hemoglobin S results in deformation of red blood cells, which can cause endothelial cell injury in the kidney that may lead to thrombus formation when severe or manifest by multilayering of the basement membranes (glomerular and/or peritubular capillaries) in milder forms of injury. As the injury progresses, the subsequent ischemia, tubular dysfunction, and glomerular scarring can result in CKD or ESRD. Sickle cell nephropathy can occur in patients with homozygous hemoglobin SS or heterozygous hemoglobin S (hemoglobin SC, hemoglobin S/β(0)-thalassemia, and hemoglobin S/β(+)-thalassemia). Clinical manifestations resulting from hemoglobin S polymerization are often milder in patients with heterozygous hemoglobin S. These patients may not present with clinically apparent acute sickle cell crises, but these milder forms can provide a unique view of the kidney injury in sickle cell disease. Here, we report a patient with hemoglobin SC disease who showed peritubular capillary and vasa recta thrombi and capillary basement membrane alterations primarily involving the renal medulla. This patient highlights the vascular occlusion and endothelial cell injury in the medulla that contribute to sickle cell nephropathy.