Glomerular filtration rate (GFR) is the best index for kidney function; however, the applicability of GFR estimating equations in sub-Saharan African populations remains unclear. In a cross-sectional study of adults living in Kinshasa, Democratic Republic of Congo (n[210) and Abidjan, Ivory Coast (n[284), we evaluated the performance of creatinine and cystatin C-based equations using plasma clearance of iohexol as the reference standard. The race coefficient did not improve the performance of creatinine-based GFR estimates; in fact, both the Modification of Diet in Renal Disease (MDRD) and Chronic Kidney Disease Epidemiology (CKD-EPI) equations performed better without the race coefficient in participants with GFR ‡60 mL/min/1.73m 2. The CKD-EPI and Full Age Spectrum (FAS) equations were unbiased and had similar precision (SD of 17.9 versus 19 mL/min/1.73 m 2) and accuracy within 30% (P30, 86.7% versus 87.4%) in participants with GFR ‡60 mL/min/1.73m 2. Both equations performed poorly in the subgroup with measured GFR < 60 mL/min/1.73m 2 (n[80), but the FAS equation had smaller bias (L4.8 mL/min/1.73m 2 versus L7.7 mL/min/1.73m 2 for CKD-EPI) and higher P30 (56.3% versus 31.3% for CKD-EPI). The corresponding equations including cystatin C alone or in combination with creatinine had similar performance. In a sub-Saharan African population, adjustment for race did not improve the performance of GFR estimating equations. The creatinine-based FAS and CKD-EPI equations performed reasonably well and were comparable when GFR was ‡ 60 mL/min/1.73m 2. Cystatin C did not improve performance. The FAS equation may be preferable when GFR is < 60 mL/min/1.73m 2 , but this should be confirmed in larger studies.

Context and objectiveIn the estimation of glomerular filtration rate (GFR), ethnicity is an important determinant. However, all existing equations have been built solely from Caucasian and Afro-American populations and they are potentially inaccurate for estimating GFR in African populations. We therefore evaluated the performance of different estimated GFR (eGFR) equations in predicting measured GFR (mGFR).MethodsIn a cross-sectional study, 93 healthy adults were randomly selected in the general population of Kinshasa, Democratic Republic of the Congo, between June 2015 and April 2016. We compared mGFR by plasma clearance of iohexol with eGFR obtained with the Modified Diet in Renal Disease (MDRD) equation with and without ethnic factor, the Chronic Kidney Disease Epidemiology (CKD-EPI) serum creatinine (SCr)-based equation, with and without ethnic factor, the cystatin C-based CKD-EPI equation (CKD-EPI SCys) and with the combined equation (CKD-EPI SCrCys) with and without ethnic factor. The performance of the equations was studied by calculating bias, precision and accuracy within 30% (P30) of mGFR.ResultsThere were 48 women and 45 men. Their mean age was 45.0±15.7 years and the average body surface area was 1.68±0.16m2. Mean mGFR was 92.0±17.2 mL/min/1.73m2 (range of 57 to 141 mL/min/1.73m2). Mean eGFRs with the different equations were 105.5±30.1 and 87.2±24.8 mL/min/1.73m2 for MDRD with and without ethnic factor, respectively; 108.8±24.1 and 94.3x20.9 mL/min/1.73m2 for CKD-EPI SCr with and without ethnic factor, respectively, 93.5±18.6 mL/min/1.73m2 for CKD-EPI SCys; 93.5±18.0 and 101±19.6 mL/min/ 1.73m2 for CKD-EPI SCrCys with and without ethnic factor, respectively. All equations slightly overestimated mGFR except MDRD without ethnic factor which underestimated by -3.8±23.0 mL/min /1.73m2. Both CKD-EPI SCr and MDRD with ethnic factors highly overestimated mGFR with a bias of 17.9±19.2 and 14.5±27.1 mL/min/1.73m2, respectively. There was a trend for better P30 for MDRD and CKD-EPI SCr without than with the ethnic factor [86.0% versus 79.6% for MDRD (p = 0.21) and 81.7% versus 73.1% for the CKD-EPI SCr equations (p = 0.057)]. CKD-EPI SCrCys and CKD-EPI SCys were more effective than creatinine-based equations.ConclusionIn the Congolese healthy population, MDRD and CKD-EPI equations without ethnic factors had better performance than the same equations with ethnic factor. The equations using Cys C (alone or combined with SCr) performed better than the creatinine-based equations.

BackgroundDespite the growing incidence of acute kidney injury (AKI) worldwide, there is little data on the burden and outcomes of AKI in intensive care unit (ICU) in low resource settings. The present study assessed the incidence of AKI and its impact on mortality in ICU in Kinshasa (Democratic Republic of Congo).MethodsIn a prospective cohort study, 476 consecutive critically ill patients (mean age 52 years, 57 % male) were screened for the presence of AKI in seven ICU from January 1st to March 30th, 2015. Serum creatinine was measured by the enzymatic method (Cobas C111 device®). AKI and its stages (no AKI, AKI 1, AKI 2 and AKI 3) were defined according to AKIN recommendations. The primary outcome was 28 days mortality. Survival (time-to death) curves were built using the Kaplan Meier methods. Predictors of mortality were assessed by Cox proportional hazards regression models. p < 0.05 defined the level of statistical significance.ResultsThe cumulative incidence of AKI was 52.7 % with AKI stage 1, 2 and 3 in 23.7 %, 16.2 % and 12.8 % of patients, respectively. Among patients who developed AKI, 146 died (58 %) vs 62 patients (28 %) in the group without AKI. Only 6.5 % of the patients with AKI stage 3 benefited from dialysis. Median survival time was 15.0 days in patients without AKI and 3.0 days, 6.0 days and 8.0 days in patients with AKI stage 3, 2 and 1 (p < 0.001), respectively. In addition to respiratory distress-induced polypnea (HRa 1.60; 95 % CI: 1.08–2.37; p = 0.018), oxygen desaturation (HRa 1.53; 95 % CI: 1.13–2.08; p = 0.006) and multi-organic involvement (HRa 1.63; 95 % CI: 1.15–2.30), AKI emerged as an independent predictor of death (HRa 1.82; 95 % CI: 1.34–2.48; p < 0.001).ConclusionMore than half of critically ill patients in the present cohort developed AKI which contributed substantially to short-term mortality, highlighting the need for its prevention, early detection and management as well as the availability of dialysis in ICU.

Background: Although screening programs for chronic kidney disease (CKD) may be of great value, these programs are not yet implemented in the Democratic Republic of Congo. This study focused on proteinuria and examined its prevalence in terms of the number needed to screen for the different risk factors of CKD. Such knowledge would guide the utility of population screening to prevent end-stage renal disease. Methods: A cross-sectional survey was conducted in Kinshasa on the Second World Kidney Day. A sample of 3,018 subjects was interviewed and the following measurements were performed: blood pressure, body mass index, glycemia and urine protein. Logistic regression analysis was used to identify determinants of proteinuria. Results: The prevalence of proteinuria was 17.1% (95% CI 15.8–18.6). Other CKD risk factors identified were: hypertension, diabetes mellitus, obesity and metabolic syndrome. To identify 1 case of proteinuria, one would need to screen 4 persons with diabetes, 5 persons with hypertension, 4 subjects having metabolic syndrome, 5 persons aged ≥72 years and 9 persons without any of the conditions mentioned above. Age, overweight and diabetes were the strongest factors associated with proteinuria. Conclusions: This study indicates that proteinuria and traditional risk factors for CKD are very prevalent in Kinshasa. Realistic policies to stem these conditions should be a public health priority.

Background Sub-Saharan Africans exhibit a higher frequency of chronic kidney disease (CKD) than other populations. In this study, we sought to determine the frequency of apolipoprotein L1 ( APOL1 ) genotypes in hypertension-attributed CKD in Kinshasa, Democratic Republic of the Congo. Methods We performed a case–control study identifying 162 subjects: 79 with hypertension-attributed CKD and 83 controls living in Kinshasa who were genotyped for APOL1 risk variants between July 2013 and November 2016. We selected control subjects from the general population and matched them with the cases according to age. Logistic regression analysis was used to examine the relationship between APOL1 high-risk genotypes and CKD. Results The frequencies of the APOL1 G1 and G2 alleles were 19.1 and 7.1%, respectively. The number of individuals with the G1 and G2 risk alleles was significantly higher in the CKD group (12.7%) than in the control group (2.4%), particularly in individuals with end-stage kidney disease (14.3%). Subjects carrying two risk alleles was strongly and independently associated with hypertension-attributed nephropathy, with an adjusted odds ratio of 7.7 (95% confidence interval 1.5–39.7; P = 0.014). The high-risk APOL1 genotypes were G1/G1 and G1/G2, whereas G2/G2 was not found in the study population. Conclusions The results of this study demonstrate the association of high-risk APOL1 genotypes with kidney disease in Kinshasa. The absence of G2/G2 may be consistent with powerful selective sweeps induced by Trypanosoma brucei gambiense infection. In contrast, the presence of APOL1 G2/G2 among individuals of African ancestry in the USA may indicate relaxation of natural selection in a trypanosome-free environment.

Low eGFR and proteinuria are prevalent among these HIV-infected persons. Immunodeficiency emerged as one of the strongest determinants of renal impairment. This finding emphasizes the importance of highly active antiretroviral therapy in tackling the burden of chronic kidney disease in African HIV population.

Background: The number of patients on dialysis has significantly increased worldwide. However, prospective studies estimating the cost of hemodialysis (HD) in sub-Saharan Africa remain scarce. The present study aimed to evaluate the direct cost of treating end stage renal disease. Determinants of additional direct cost were also assessed.Methods: This study is an analytical, prospective study of cost performed at two HD centers in Kinshasa for a period of 3 months among HD patients enrolled consecutively. The cost analyzed includes only expenditures: consultation, HD session, drugs, comorbidities, laboratory tests, and imaging. Transportation, patient hospitalization, and indirect costs are not taken into account. The determinants of the additional direct cost of HD are identified by multivariate logistic regression analysis. P < 0.05 is the level of statistical significance. Findings:The average quarterly direct cost of chronic HD in United States Dollars (US$) is $7070 (~US$28,280 annual cost) at a rate of US$287 per patient per HD session. This cost includes the HD session (US$237) and medicine (US$33) costs, which account for 82.5% and 11.3% of the direct costs, respectively. The presence of at least 4 comorbidities (OR adjusted 4.3,], P = 0.022) and infection (adjusted OR 4.56,.85], P = 0.043) emerged as independent determinants of additional direct cost. Conclusion:The direct cost of HD is very high in Kinshasa, where more than 80% of Congolese people live on less than US$1.25 a day.

BackgroundOxidative stress is thought to be involved in the pathogenesis of microalbuminuria in Sickle cell anemia (SCA). Antioxidant enzymes such as glutathione peroxidase (GPx) and Cu-Zn superoxide dismutase (SOD) may play an important protective role. This study aimed to evaluate the association between albuminuria and these two antioxidant enzymes.MethodsWe consecutively recruited Steady state children aged between 2 and 18 years old with established diagnosis of homozygous SCA in two hospitals of Kinshasa/DR Congo. The relationship between Urinary Albumin Creatinine Ratio (UACR) and other variables of interest (age, systolic blood pressure, diastolic blood pressure, plasma GPx and Cu-Zn SOD, free plasmatic hemoglobin, LDH, indirect bilirubin, white blood cells (WBC), percentage of fetal hemoglobin, serum iron, ferritin, CRP) was analyzed by Bivariate correlation (Pearson’s correlation coefficient). Microalbuminuria was defined by urine albumin/creatinine ratio between 30 and 299 mg/g.ResultsSeventy Steady state Black African children with SCA (56% boys; average age 9.9 ± 4.3 years; 53% receiving hydroxyurea) were selected. Prevalence of microalbuminuria was 11.8%. LDH (r = 0.260; p = 0.033) and WBC count (r = 0.264; p = 0.033) were positively correlated with UACR whereas GPx (− 0.328; p = 0.007) and Cu-Zn SOD (− 0.210; p = 0.091) were negatively correlated with UACR.ConclusionsAlbuminuria is associated with decreased antioxidant capacity and increased levels of markers of hemolysis and inflammation. Therefore, strategies targeting the reduction of sickling and subsequent hemolysis, oxidative stress and inflammation could help preventing or at least delaying the progression of kidney disease in SCA children.