Epstein-Barr virus-induced systemic lupus erythematosus

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Primary nephrotic syndrome in the new millennium in KwaZulu-Natal, South Africa

Background. The outcome and response of idiopathic nephrotic syndrome (NS) to steroids have been linked to race.Objectives. To determine the age of presentation, sex, race, histopathology, kidney function and disease status at the last hospital visit and correlate these with steroid response in Indian and black African children with idiopathic NS.Methods. This is a retrospective review of 231 children aged 1 - 14 years, who were seen at Inkosi Albert Luthuli Central Hospital, Durban, South Africa (SA) from 2003 to 2018.Results. The mean (standard deviation (SD)) age of presentation was 6.2 (3.4) years, with the majority of children (n=107; 46.3%) presenting at an early age (1 - 3 years) with a mean (SD) follow-up of 3.0 (2.4) years. One-hundred and twenty-one (52.4%) were males and 110 (47.6%) were females, with a male/female ratio of 1.1:1. There were 166 (71.9%) black African and 65 (28.1%) Indian children. The latter presented at a younger age than black African children (p<0.001). Seventy-six (32.9%) children were steroid sensitive (SS) and 155 (67.1%) were steroid resistant (SR). Black African children were more likely to be SR (odds ratio (OR) 2.0; p=0.02; 95% confidence interval (CI) 1.1 - 3.7). A kidney biopsy was performed in 209 (90.5%) children. Minimal change disease (MCD) was observed in 32 (13.9%) children and 162 (70.1%) had focal segmental glomerulosclerosis (FSGS). Black African children were slightly more likely to have FSGS; this, however, did not reach statistical significance (122/166 (73.5%) v. 40/65 (61.5%); OR 1.73; p=0.08; 95% CI 0.94 - 3.18). On comparing disease status at last hospital visit by race, 49/65 (75.4%) Indian and 94/166 (56.6%) black African children were in remission. At last hospital visit, black African children were less likely to be in remission than Indian children (OR 0.47; p=0.02; 95% CI 0.2 - 0.9), while 15/65 (23.1%) Indian and 47/166 (28.3%) black African children had relapsed, with no significant difference between the two groups. One (1.5%) Indian child and 25 (15.1%) black African children had end-stage kidney disease (ESKD) (OR 9.27; p=0.03; 95% CI 1.2 - 70.4) ‒ the majority had FSGS. Sixteen (61.5%) received renal replacement therapy.Conclusions. Our study shows a rising incidence of FSGS, with the majority of patients having SRNS, particularly black African children. This highlights the need for alternative efficacious therapy in the management of this disease. Also, a higher percentage of black African children with both MCD and FSGS were SS on histopathological examination, which was in keeping with reports from other regions in SA. There are still major challenges for the inclusion of all children into a chronic dialysis and transplant programme

HBV and proteinuria in relatives and contacts of children with hepatitis B virus-associated membranous nephropathy

HBV and proteinuria in relatives and contacts of children with hepatitis B virus-associated membranous nephropathy.BackgroundHepatitis B virus (HBV)-associated membranous nephropathy (HBVMN) is an important cause of childhood nephrotic syndrome in regions endemic for the virus, but little is understood of the biosocial context in which the disease develops. We evaluated HBV status and proteinuria in family members and household contacts of index children with HBVMN to test the hypothesis that HBV carriage and asymptomatic proteinuria are closely linked and may be causally associated.MethodsThirty-one black children with biopsy-proven HBVMN were the index cases. One hundred and fifty-two family members and 43 black household contacts were the subjects of the study. We assessed HBV carrier status by testing for HBV antigens and antibodies using enzyme-linked immunosorbent assays (ELISA) and for HBV DNA by using slot-blot hybridization and the polymerase chain reaction. Sequencing of the precore region of HBV was done in a subset of both index cases and subjects. Proteinuria was assessed by measuring the urinary protein/creatinine ratio.ResultsSeventy-two (37%) of the 195 family members and household contacts were HBV carriers, and 53 (27%) had a protein/creatinine ratio greater than the physiological limit. The frequency of abnormal proteinuria was not significantly different in those with [22 out of 72 (30.5%)] or without [33 out of 104 (32%)] HBV carriage. This lack of association remained when carriers were classified into those who were HBsAg positive only and those with active viral replication (HBsAg and/or HBeAg and/or HBV DNA; P = 0.01). Family members were more predisposed to HBV carriage than household contacts, but abnormal proteinuria was present with equal frequency (P = 0.48). Age had a significant impact on proteinuria, with children less than five years being more likely to have abnormal proteinuria (P = 0.008). The prevalence of abnormal proteinuria in family members and household contacts of the index cases was more than that in community-based controls. The 10 index HBVMN cases and the 14 family members and household contacts who were tested all had HBV of genotype A.ConclusionThese results suggest that the family members and household contacts of children with HBVMN are at very high risk of HBV carriage; they also have asymptomatic proteinuria at a significantly higher rate than community-based controls. The HBV carrier status was not associated with proteinuria, a finding supported by peak prevalences of proteinuria in those under five years but no corresponding peak for HBV carriage. Proteinuria may indicate glomerular basement membrane dysfunction. Environmental and social factors may underpin development of these two covert disorders, but are insufficient to account for the index cases of HBVMN. The emergence of children with HBVMN from such households additionally depends on unidentified and possibly genetic factors

Trends in the nephrologist workforce in South Africa (2002–2017) and forecasting for 2030

Background: The growing global health burden of kidney disease is substantial and the nephrology workforce is critical to managing it. There are concerns that the nephrology workforce appears to be shrinking in many countries. This study analyses trends in South Africa for the period 2002–2017, describes current training capacity and uses this as a basis for forecasting the nephrology workforce for 2030. Methods: Data on registered nephrologists for the period 2002 to 2017 was obtained from the Health Professions Council of South Africa and the Colleges of Medicine of South Africa. Training capacity was assessed using data on government-funded posts for nephrologists and nephrology trainees, as well as training post numbers (the latter reflecting potential training capacity). Based on the trends, the gap in the supply of nephrologists was forecast for 2030 based on three targets: reducing the inequalities in provincial nephrologist densities, reducing the gap between public and private sector nephrologist densities, and international benchmarking using the Global Kidney Health Atlas and British Renal Society recommendations. Results: The number of nephrologists increased from 53 to 141 (paediatric nephrologists increased from 9 to 22) over the period 2002–2017. The density in 2017 was 2.5 nephrologists per million population (pmp). In 2002, the median age of nephrologists was 46 years (interquartile range (IQR) 39–56 years) and in 2017 the median age was 48 years (IQR 41–56 years). The number of female nephrologists increased from 4 to 3 and the number of Black nephrologists increased from 3 to 24. There have been no nephrologists practising in the North West and Mpumalanga provinces and only one each in Limpopo and the Northern Cape. The current rate of production of nephrologists is eight per year. At this rate, and considering estimates of nephrologists exiting the workforce, there will be 2.6 nephrologists pmp in 2030. There are 17 government-funded nephrology trainee posts while the potential number based on the prescribed trainer-trainee ratio is 72. To increase the nephrologist density of all provinces to at least the level of KwaZulu-Natal (2.8 pmp), which has a density closest to the country average, a projected 72 additional nephrologists (six per year) would be needed by 2030. Benchmarking against the 25th centile (5.1 pmp) of upper-middle income countries (UMICs) reported in the Global Kidney Health Atlas would require the training of an additional eight nephrologists per year. Conclusions South Africa has insufficient nephrologists, especially in the public sector and in certain provinces. A substantial increase in the production of new nephrologists is required. This requires an increase in funded training posts and posts for qualified nephrologists in the public sector. This study has estimated the numbers and distribution of nephrologists needed to address provincial inequalities and achieve realistic nephrologist density targets

Effect of renal Doppler ultrasound on the detection of nutcracker syndrome in children with hematuria

To assess the detection rate of nutcracker syndrome in children with isolated hematuria, renal Doppler ultrasound examinations were routinely performed on 216 consecutive children (176 microscopic hematuria and 40 gross hematuria). Renal Doppler ultrasound was also performed on 32 healthy normal children. The peak velocity (PV) was measured at the hilar portion of the left renal vein (LRV) and at the LRV between the aorta and the superior mesenteric artery. The PV at the aortomesenteric portion (P=0.003) and the PV ratios of the LRV (P=0.003) were significantly higher in children with hematuria than in normal children, while the PV at the hilar portion was not different. If a PV ratio of the LRV of at least 4.1 (the cut-off level set at the mean ±2 SD of the value for the normal children) was defined as abnormal, 72 cases (33.3%) in children with hematuria and no cases in normal children were diagnosed as having nutcracker syndrome. The prevalence of nutcracker syndrome is relatively high in children with isolated hematuria, and the inclusion of renal Doppler ultrasound as a screening examination has a substantial effect on the detection of nutcracker syndrome

Mapping an epitope in EBNA-1 that is recognized by monoclonal antibodies to EBNA-1 that cross-react with dsDNA

Introduction: The Epstein Barr Virus (EBV) has been associated with the autoimmune disease, Systemic Lupus Erythematosus (SLE). EBV nuclear antigen-I (EBNA-1) is the major nuclear protein of EBV. We previously generated an IgG monoclonal antibody (MAb) to EBNA-1, 3D4, and demonstrated that it crossreacts with double stranded DNA (dsDNA) and binds the 148 amino acid viral binding site (VBS) in the carboxyl region of EBNA-1. The aim of the present study was to characterize another antibody to EBNA-1 that cross-reacts with dsDNA, compare its immunoglobulin genes to 3D4, and finely map the epitope in EBNA-1 that is recognized by these cross-reactive antibodies. Methods: We generated an IgM MAb to EBNA-1, 16D2, from EBNA-1 injected mice and demonstrated by ELISA that it cross-reacts with dsDNA and binds the 148 amino acid VBS. We sequenced the variable heavy and light chain genes of 3D4 and 16D2 and compared V gene usage. To more finely map the epitope in EBNA-1 recognized by these MAbs, we examined their binding by ELISA to 15 overlapping peptides spanning the 148 amino acid domain. Results: Sequence analysis revealed that 3D4 and 16D2 utilize different VH and VL genes but identical JH and Jk regions with minimal junctional diversity. This accounts for similarities in their CDR3 regions and may explain their similar dual binding specificity. Epitope mapping revealed 3D4 and 16D2 bind the same peptide in the VBS. Based on the crystal structure of EBNA-1, we observed that this peptide resides at the base of an exposed proline rich loop in EBNA-1. Conclusion: We have demonstrated that two MAbs that bind EBNA-1 and crossreact with dsDNA, recognize the same peptide in the VBS. This peptide may serve as a mimetope for dsDNA and may be of diagnostic and therapeutic value in SLE

Experience with tacrolimus in children with steroid-resistant nephrotic syndrome

Children with steroid-resistant nephrotic syndrome (SRNS) are at risk of developing renal failure. We report here the results of a single-center retrospective observational study of the remission rate in pediatric patients with SNRS receiving tacrolimus. Serial renal biopsies from children on tacrolimus therapy were evaluated for tubulointerstitial fibrosis and transforming growth factor-β immunostaining. Of the 16 children with SRNS, 15 went into complete remission after a median of 120 days of therapy. Nine children were able to stop steroids, while the others were on tapering doses. Forty-seven percent had relapses, most of which were steroid-responsive. Serial renal biopsies were obtained from seven children after a median treatment duration of 24 months; two of these children had increased tubulointerstitial fibrosis and four showed increased transforming growth factor-β tissue staining. Children with worsening histological findings were younger. There was no significant association between tacrolimus exposure and biopsy changes, although the average trough level was higher in those children with worsening histological findings. In conclusion, tacrolimus may be a safe and effective alternative agent for inducing remission in children with SRNS. However, caution needs to be taken when prescribing this agent due to its narrow therapeutic index. Serial renal biopsies are necessary to check for subclinical nephrotoxicity, especially in younger children and those with higher trough levels

Hepatitis B and Renal Disease

Glomerulonephritis is an important extrahepatic manifestation of chronic hepatitis B virus (HBV) infection. The uncommon occurrence, variability in renal histopathology, and heterogeneity in clinical course present challenges in clinical studies and have resulted in a relative paucity of data and uncertainty with regard to the optimal management of HBV-related glomerular diseases. The advent of nucleos(t)ide analogue medications that effectively suppress HBV replication has markedly altered the clinical outcomes of kidney transplant recipients with HBV infection, but the emergence of drug resistance is an escalating problem. This article reviews the recent knowledge of the pathogenesis and treatment of HBV-related membranous nephropathy, and discusses the management of hepatitis B in kidney transplant recipients, which is continuously evolving

Enterohaemorrhagic Escherichia coli and Shigella dysenteriae type 1-induced haemolytic uraemic syndrome

Haemolytic uraemic syndrome (HUS) can be classified according to the aetiology of the different disorders from which it is composed. The most prevalent form is that induced by shigatoxin producing Escherichia coli (STEC) and, in some tropical regions, by Shigella dysenteriae type 1. STEC cause a zoonosis, are widely distributed in nature, enter the food chain in different ways, and show regional differences. Not all STEC are human pathogens. Enterohaemorrhagic E. coli usually cause attachment and effacing lesions in the intestine. This is not essential, but production of a shigatoxin (Stx) is. Because Stx are encoded by a bacteriophage, this property is transferable to naïve strains. Laboratory methods have improved by identifying STEC either via the toxin or its bacteriophage. Shigella dysenteriae type 1 produces shigatoxin, identical to Stx-1, but also has entero-invasive properties that enterohaemorrhagic Escherichia coli (EHEC) do not. Shigella patients risk bacteremia and benefit from early antibiotic treatment, unlike those with EHEC