Kareshma Asharam

Management of Steroid-Resistant Focal Segmental Glomerulosclerosis in Children Using Tacrolimus

Background: The use of tacrolimus in steroid-resistant (SR) focal segmental glomerulosclerosis (FSGS) has been reported in single and small series case reports. Aim: To determine the efficacy of tacrolimus in the management of SR FSGS in children. Study Design: This was a prospective study of 20 children with SR FSGS treated with tacrolimus (0.2–0.4 mg/kg/day in two divided doses over 12 h adjusted to a trough level between 7 and 15 ng/ml) for 12 months in combination with low-dose steroids. Other therapies included angiotensin-converting enzyme inhibitors, folic acid, multivitamins and lipid-lowering agents. Results: The mean age at study entry was 11.1 years (range 5.6–16.8). The mean duration of nephrotic syndrome before initiation of tacrolimus therapy was 4.7 years (range 2.1–7.6). At the end of the treatment period, 8 (40%) children were in complete remission, 9 (45%) were in partial remission, and 3 (15%) failed to respond. The average follow-up period following cessation of tacrolimus treatment was 27.5 months (range 13.7–43.7). At last hospital follow-up, 5 (25%) children were in complete remission, 10 (50%) in partial remission, and 2 (10%) in relapse. Three children died from dialysis-related complications following cessation of tacrolimus treatment. Adverse events included sepsis (2), nausea (2), diarrhea (2), anemia (4) and worsening of hypertension (4). Conclusion: Tacrolimus is a safe and effective treatment for SR FSGS. However, like cyclosporine, some children tend to relapse following cessation of treatment.

Controversy about COOPERATE ABPM Trial Data

mm Hg, 63% between 120 and 150 mm Hg, and the remaining 19% more than 150 mm Hg. A similar incidence was observed among treatment groups. Interestingly, the high variability of the systolic BP values was more characteristic among patients who were able to effectively restrict their salt intake. As compared with the systolic values, the nighttime values were constant throughout the measurements, partly because the drugs were taken at night or bedtime. Naoyuki Nakao, MD, PhD Division of Nephrology Rokko Island Hospital Koh-Yoh Cho Naka 2-11 Higashinada, Kobe, Japan

Prenatal exposures and DNA methylation in newborns: a pilot study in Durban, South Africa

The in utero environment has the potential to influence epigenetic programming and subsequently the health of offspring. Even though pregnant women living in urban Africa are exposed to multiple chemicals and infectious agents that may impact their developing children, the neonatal epigenome has not been studied in these regions. We assessed whether prenatal exposures to air pollution and maternal human immunodeficiency virus (HIV) are associated with changes to DNA methylation throughout the epigenome using a pilot sample from the Mother and Child Environmental (MACE) birth cohort, of which 36% of the mothers are HIV positive. Families living in a high air pollution region (south Durban, n = 11) and a low air pollution region (north Durban, n = 11) with comparable socioeconomic characteristics were selected for analysis. DNA methylation was quantified in cord blood plasma DNA at >430 000 CpG sites using the Infinium HumanMethylation450 BeadChip. Sites associated with living in south Durban or maternal HIV infection (p < 0.001) were more likely to be hypomethylated and located in CpG islands. Top differentially methylated sites by region of Durban were enriched in pathways related to xenobiotic metabolism, oxygen and gas transport, and sensory perception of chemical stimuli when performing gene set enrichment testing with LRpath. Differentially methylated sites by maternal HIV status were enriched in cytochrome P450s, pathways involved in detection of chemical stimuli, metabolic processes, and viral regulation and processing. Given the small sample size of the study, future work examining the impact of prenatal exposures to air pollution, maternal infection, and antiviral treatment on the epigenome and downstream health implications is merited in Sub-Saharan African populations.

OGG1 Ser326Cys polymorphism, HIV, obesity and air pollution exposure influences adverse birth outcome susceptibility, within South African Women

The global HIV and obesity epidemics are major public health concerns; particularly as both are associated with increased risk of adverse birth outcomes. Despite extensive research, their combined effect, in terms of birth outcomes, has not been investigated. A single-nucleotide polymorphism (SNP) within 8-oxoguanine glycosylase 1 (OGG1) (Ser326Cys) has been suggested to affect body mass indices and therefore could predispose South African (SA) women to adverse effects of obesity. This study investigated the associations of OGG1 Ser326Cys SNP in relation to HIV and obesity on the susceptibility of low-birthweight (LBW) and pre-term birth (PTB) in SA women exposed to ambient air-pollution living in Durban. In our study population, the OGG1 SNP was associated with HIV and obesity. Wild-type (CC)-carrying patients had increased susceptibility for HIV-associated LBW and PTB. Co-morbid HIV and obese patients delivered neonates with decreased birthweights. Living within the heavily-polluted south-Durban and carrying the CC-genotype increased the risk for PTB within our study population.

NPHS2 V260E Is a Frequent Cause of Steroid-Resistant Nephrotic Syndrome in Black South African Children

Introduction In South Africa (SA), steroid-resistant nephrotic syndrome (SRNS) is more frequent in black than in Indian children. Methods Seeking a genetic basis for this disparity, we enrolled 33 Indian and 31 black children with steroid-sensitive nephrotic syndrome (SSNS) and SRNS from KwaZulu-Natal, SA; SRNS children underwent kidney biopsy. We sequenced NPHS2 and genotyped APOL1 in 15 SSNS and 64 SRNS unrelated patients and 104 controls and replicated results in 18 black patients with steroid-resistant focal segmental glomerulosclerosis (SR-FSGS). Known FSGS genes (n = 21) were sequenced in a subset of patients. Results Homozygosity for NPHS2 V260E was found in 8 of 30 black children with SRNS (27%); all 260E/E carriers had SR-FSGS. Combining SR-FSGS patients from the 2 groups, 14 of 42 (33%) were homozygous for V260E. One black control was heterozygous for V260E; no Indian patients or controls were carriers. Haplotype analysis indicated that homozygosity for V260E was not explained by cryptic consanguinity. Children with NPHS2 260E/E developed SRNS at earlier age than noncarriers (34 vs. 78 months, P = 0.01), and none achieved partial or complete remission (0% vs. 47%, P = 0.002). APOL1 variants did not associate with NS. Sequencing FSGS genes identified a CD2AP predicted pathogenic variant in the heterozygous state in 1 Indian case with SR-FSGS. Conclusion NPHS2 260E/E was present in one-third of black FSGS patients, was absent in black controls and Indian patients, and affected patients were unresponsive to therapy. Genotyping V260E in black children from South Africa with NS will identify a substantial group with SR-FSGS, potentially sparing these children biopsy and ineffective steroid treatment.

Maternal miRNA-146a G/C rs2910164 variation, HIV/AIDS and nitrogen oxide pollution exposure collectively affects foetal growth

Objective: Nitrogen oxide (NOx) pollution and human immunodeficiency virus (HIV)/AIDS intensify inflammation during pregnancy and linked with adverse birth outcomes (ABOs). MicroRNA (miRNA)-146a plays a crucial role in regulating inflammation in the NF-κB pathway. The G/C rs2910164 dampens miRNA-146a activity and linked with inflammatory diseases. The present study investigated whether HIV/AIDS and NOx exposure throughout pregnancy further intensifies ABO in Black South African women genotyped for the rs2910164. Methods: Pregnant women (n = 300) were subdivided into low, medium and high NOx exposure groups, genotyped for the miRNA-146a G/C rs2910164 using polymerase chain reaction-restriction fragment length polymorphism, and further stratified based on HIV status. Results: Unstratified data (HIV+ and HIV− mothers combined): Mothers from the high NOx group with the variant C-allele had low blood iron levels (p = 0.0238), and had babies with reduced birthweights (p = 0.0283). As NOx increased, the prevalence of preterm birth and low birth weight also increased in mothers with the variant C-allele versus wildtype G-allele. HIV-infected mothers: In all NOx exposure groups, mothers with the variant C-allele had higher systolic blood pressure (low: p = 0.0386, medium: p = 0.0367 and high: p = 0.0109) and had babies with lower Appearance, Pulse, Grimace, Activity and Respiration scores at 1 min (low: p = 0.0190, medium: p = 0.0301 and high: p = 0.0361). Conclusion: Maternal rs2910164 variant C-allele, NOx pollution and HIV/AIDS might collectively play a role in intensifying gestational hypertension and ABO.

IL-1β haplotype influences the effect of NOx exposure on gestational age in the South African MACE birth cohort:

Objective: Cytokines, molecules within the immune system that affect either a pro- or anti-inflammatory response, have previously been shown to influence birth outcomes. The maternal cytokine gene–environment interactions are thought to alter their expression, potentially influencing susceptibility to adverse birth outcomes. The aim of this study was to determine the association between the maternal interleukin-1β (IL-1β) haplotype and expression variation with oxides of nitrogen (NOx) levels, and thereafter investigate the IL-1β haplotype-specific effects of NOx exposure levels, IL-1β mRNA expression and other variables on gestational age. Material and methods: Using the prospective Mother and Child in the Environment (MACE) birth cohort in Durban, South Africa, 335 participants were genotyped for the IL-1β haplotype. Previous studies showed that three single nucleotide polymorphisms (SNPs), IL-1β-1464G/C, -511C/T and -31C/T, constitute the IL-1β functional haplotype. These SNPs were genotyped using a restriction fragment length polymorphism assay, while IL-1β mRNA expression was measured using a quantitative real-time polymerase chain reaction assay. Individual estimates of NOx exposure were obtained by land use regression modelling. A multivariate linear regression analysis was employed to test for significant effects on gestational age. Results: IL-1β mRNA expression was found to possess a haplotype-dependent effect (p = 0.0001) and its expression levels positively correlated with NOx levels (r = 0.34; p = 0.006). In the high haplotype model, a unit increase in NOx exposure level was associated with a decrease in gestational age by 1 week (p = 0.02). Furthermore, gestational age decreased by 0.9 weeks for every unit increase of IL-1β mRNA expression level (p = 0.025). HIV-1 positivity was associated with a 0.2-week decrease in gestational age (p = 0.035) in the intermediate haplotype model and a 0.4-week decrease in the high haplotype model (p = 0.044). Conclusion: These data have implications for better understanding the effect of prenatal NOx exposure on gestational age and demonstrate the role of the IL-1β haplotype in modulating the effects of NOx exposure.

HIV induced nitric oxide and lipid peroxidation, influences neonatal birthweight in a South African population

HIV has been implicated in adverse birth outcomes, due to increased oxidative stress and inflammation. In addition, HIV has been reported to increase nitric oxide levels. Therefore the combined exposures to HIV and traffic-related air pollution, within South Durban, South Africa (SA), may lead to adverse birth outcomes. However, the exact mechanism is still unknown; this study aimed to identify a potential mechanism. First, the influence of HIV on oxidative and nitrosative stress markers in pregnant women was assessed. Secondly, the effect of these stress makers and exposure to oxides of nitrogen (NOx) on neonatal birthweight (BW) was evaluated. Finally, the effect HIV and traffic-related pollution exposure has on the oxidative and endoplasmic profile and epigenetic regulation of Nrf2-Keap1 pathway by miR-144 and miR-28 in pregnant women was determined. Women, in their third trimester with singleton pregnancies, who were HIV+ and HIV-, were recruited from Durban, SA. Biomarker levels of serum nitrites/nitrates (NO) and malondialdehyde (MDA) were analysed and mRNA expression levels of oxidative and endoplasmic stress response genes were assessed. Land regression modelling was performed to determine NOx exposure levels. HIV exposure during pregnancy was associated with increased NO levels. NO was shown to reduce neonatal BW. NO and MDA was found to reciprocally increase each other, with HIV differentially influencing MDAs effect on BW. HIV down-regulated miR-144 which was negatively associated with Nrf2, suggesting a potential mechanism for HIV associated chronic oxidative stress. This study proposes that NO plays a key role in neonatal BW reduction in response to HIV and traffic-related air pollution.

The Tyr113His T/C rs1051740 and ‘very slow’ phenotype of the EPHX1 gene alters miR-26b-5p and miR-1207-5p expression in pregnancy

BACKGROUND Environmental insults and microsomal epoxide hydrolase 1 (EPHX1) single nucleotide polymorphisms (SNPs), Tyr113His T/C rs1051740 and His139Arg A/G rs2234922, aberrantly alters microRNA (miR) expression and are linked to low birthweights (LBW). OBJECTIVES To investigate the interplay between pollution, EPHX1 SNPs and miRs during pregnancy and associated LBW outcomes. METHODS South African pregnant women (n=241) were recruited in the MACE birth cohort study in Durban, a city with high levels of industry and traffic related pollutants. EPHX1 SNPs were genotyped using PCR-RFLP and grouped into their respective phenotypes, i.e. normal (N), slow (S), very slow (VS) and fast (F). EPHX1, miR-26b-5p, miR-193b-3p and miR-1207-5p expression were determined using quantitative PCR. RESULTS Mothers with the Tyr113His SNP had low iron levels [TT vs. TC+CC: mean difference (MD)=0.67g/dl; p=0.0167], LBW [TT vs. TC+CC: MD=189.30g; p=0.0067], and low EPHX1 expression; p<0.0001. miR-26b-5p and miR-1207-5p expression were significantly higher in the CC genotypes compared to TT+TC groups; p<0.0001. The opposite trend occurred for miR-193b-3p; p=0.0045. Mothers with the VS phenotype had low iron levels [N vs. VS and VS vs. F: MD=2.03 and -1.96g/dl; p=0.0021, respectively], decreased gestational age [VS vs. F: MD=-2.14weeks; p=0.0051, respectively], and LBW [N vs. VS, VS vs. F and S vs. VS: MD=1000, -940.30 and 968.80g; p<0.0001, respectively]; F phenotype had the highest EPHX1 expression [N vs. F, VS vs. F and S vs. F: MD=-1.067, -1.854 and -1.379; p=0.0002, respectively]; and N phenotype had low miR-26b-5p [N vs. VS: MD=-0.6100; p=0.0159] and miR-1207-5p [N vs. VS and VS vs. F: MD=-0.834 and 1.103; p=0.0007, respectively] expression. miR-193b-3p expression between phenotypes remained unchanged. CONCLUSION The Tyr113His T/C variant of rs1051740 and VS phenotype alters EPHX1, miR-26b-5p and miR-1207-5p expression, and contributes towards low blood iron levels and LBW.

Consultants for the American Journal of Nephrology 2006

Kevin Abbott Christina Abrass Rajiv Agarwal Farah Ali Efthyvoulos Anastassiades Gema Ariceta Akhtar Ashfaq John Asplin Phyllis August Susan Bagby Asad Bakir George Bakris Vinod Bansal Amelia Bartholomew Amy Barton Pai David Basile Enrico Benedetti Angelito Bernardo Rajendra Bhimma Peter Blake Amy Bobrowski Michael Braun Carolyn Brecklin Ursula Brewster Ellen Brooks Nigel Brunskill Vito Campese Huseyin Celiker Michael Choi Giorgio Coen Richard Cohn Jay Cohn Terezila Coimbra James Cook Scott Cotler Mario Cozzolino Stanislaw Czekalski Mohamed Daha Farhard Danesh Robert Danziger Jie Ding