Correction to: Efficacy, tolerability and safety of darbepoetin alfa injection for the treatment of anemia associated with chronic kidney disease (CKD) undergoing dialysis: a randomized, phase-III trial.

Following publication of the original article [1], the authors reported errors in the presentation of Tables 2, 4 and 5.

Efficacy, tolerability and safety of darbepoetin alfa injection for the treatment of anemia associated with chronic kidney disease (CKD) undergoing dialysis: a randomized, phase-III trial.

BACKGROUND: Darbepoetin alfa (DA-α) is a long-acting erythropoiesis-stimulating glycoprotein which has half-life three-fold longer than that of Erythropoietin alfa (EPO). The objective of this study was to compare the efficacy and safety of DA-α injection versus EPO for treating renal anemia amongst Indian patients with end-stage renal disease (ESRD) undergoing dialysis. METHODS: Patients of either gender (aged 18-65 years) with ESRD undergoing dialysis who had hemoglobin (Hb) levels < 10 g/dL after receiving EPO were switched to DA-α (0.45 µg/kg) once weekly subcutaneously or EPO 50 IU/kg thrice weekly subcutaneously (centrally randomized 1:1) for 12-24 weeks (correction phase) followed by 12 weeks maintenance phase (for Hb levels ≥10 g/dL). The primary efficacy endpoint was mean change in Hb level from baseline to end of correction phase. RESULTS: In the intention-to-treat population (n = 126), the between group difference in mean Hb change was - 0.01 g/dL (95% CI - 0.68 to - 0.66, p = 0.97). After adjusting for covariates, the difference was - 0.2878 g/dL (95% CI -0.936 to0.360). The lower limit of the two-sided 95% CI of primary endpoint was above the pre-specified non-inferiority margin of - 1.0 g/dL. Similar trend of non-inferiority was observed for per-protocol population. Safety profile of DA-α and EPO were observed to be similar. CONCLUSION: Our study results demonstrated that for patients with ESRD undergoing dialysis, administering DA-α at lower dose frequency, is equally effective and well tolerated as EPO for treating renal anemia. TRIAL REGISTRATION: CTRI/2012/07/002835 [Registered on: 27/07/2012]; Trial Registered Prospectively.

Indian chronic kidney disease study: Design and methods.

AIM: The rate and factors that influence progression of chronic kidney disease (CKD) in developing countries like India are unknown. A pan-country prospective, observational cohort study is needed to address these knowledge gaps. METHODS: The Indian Chronic Kidney Disease (ICKD) study will be a cohort study of approximately 5000 patients with mild to moderate CKD presenting to centres that represent different geographical regions in India. Time to 50% decline in baseline estimated glomerular filtration rate, need of renal replacement therapy or any new cardiovascular disease (CVD) event or death from CVD are the primary end points. VALUE OF STUDY: This study will provide the opportunity to determine risk factors for CKD progression and development of CVD in Indian subjects and perform international comparisons to determine ethnic and geographical differences. A bio-repository will provide a chance to discover biomarkers and explore genetic risk factors.

WITHDRAWN: Efficacy and Safety of Mycophenolate Mofetil Versus Levamisole in Children and Adolescents With Idiopathic Nephrotic Syndrome: Results of a Randomized Clinical Trial.

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Efficacy of Febuxostat for Slowing the GFR Decline in Patients With CKD and Asymptomatic Hyperuricemia: A 6-Month, Double-Blind, Randomized, Placebo-Controlled Trial.

BACKGROUND: Hyperuricemia is a putative risk factor for the progression of chronic kidney disease (CKD). We hypothesized that control of asymptomatic hyperuricemia may slow disease progression in CKD. STUDY DESIGN: This was a single-center, double-blind, randomized, parallel-group, placebo-controlled study. SETTING & PARTICIPANTS: Eligible participants were adults from Eastern India aged 18 to 65 years with CKD stages 3 and 4, with asymptomatic hyperuricemia. INTERVENTION: The intervention group received febuxostat, 40mg, once daily for 6 months, while the placebo group received placebo; both groups were followed up for 6 months. OUTCOMES: The primary outcome was the proportion of patients showing a >10% decline in estimated glomerular filtration rate (eGFR) from baseline in the febuxostat and placebo groups. Secondary outcomes included changes in eGFRs in the 2 groups from baseline and at the end of the study period. RESULTS: 45 patients in the febuxostat group and 48 in the placebo group were analyzed. Mean eGFR in the febuxostat group showed a nonsignificant increase from 31.5±13.6 (SD) to 34.7±18.1mL/min/1.73m(2) at 6 months. With placebo, mean eGFR decreased from a baseline of 32.6±11.6 to 28.2±11.5mL/min/1.73m(2) (P=0.003). The difference between groups was 6.5 (95% CI, 0.08-12.81) mL/min/1.73m(2) at 6 months (P=0.05). 17 of 45 (38%) participants in the febuxostat group had a >10% decline in eGFR over baseline compared with 26 of 48 (54%) from the placebo group (P<0.004). LIMITATIONS: Limitations of this study included small numbers of patients and short follow-up, and ∼10% of the randomly assigned population dropped out prior to completion. CONCLUSIONS: Febuxostat slowed the decline in eGFR in CKD stages 3 and 4 compared to placebo.

Tip variant of focal segmental glomerulosclerosis: is it truly a benign variant?

BACKGROUND: Even though frequently described as a benign entity, the outcomes of the tip variant of focal segmental glomerulosclerosis (FSGS) have proven to be unclear. METHODS: This retrospective study includes a cohort of tip variant cases who presented to us from 2009 to 2012 and the analysis of their presenting clinical, histopathological features and treatment outcomes in comparison to the not otherwise specified (NOS) variants from our center in East India. RESULTS: Of the 224 biopsies of primary FSGS, 30 cases were the tip variant (13.39%). The mean age of presentation was around 29 years, with 57% being males. A nephrotic presentation was seen in 87% of cases, with 20% showing a presentation at <18 years of age for the first time. Global sclerosis, interstitial fibrosis, tubular atrophy and arteriolar hyalinosis were seen more commonly in the NOS variant. Twenty five patients of tip variant received steroid therapy and eight received alternative immunosuppression. Around 87% of the tip variant cases achieved some form of remission in proteinuria and 13.3% had a doubling of creatinine at a median follow-up of 2 years in comparison to NOS group in which 80% achieved some form of remission and 20% had a doubling of creatinine. CONCLUSION: Though the histopathological features and treatment responsiveness of the tip variant appear to be better than the NOS variety, the prognostic outcome does not seem to be as favorable as implicated previously with an important percentage of patients showing progressive worsening of renal function within a relatively short time span (2 years) in our cohort.

Hypopituitarism in patients with vasculotoxic snake bite envenomation related acute kidney injury: a prospective study on the prevalence and outcomes of this complication.

Acute kidney injury (AKI) is common in patients with vasculotoxic snake bite (SB) envenomation but hypopituitarism (HP) is an uncommonly reported complication. We conducted a prospective observational study on survivors of SB-AKI who were evaluated and followed up from September 2010 till September 2012. Pituitary function tests were done if they developed any symptoms of HP. MRI of the hypothalamo-pituitary axis was done in those with documented HP. Response to therapy in the form of improvement in the quality of life (QoL) was evaluated by asking patients to mark on a visual analogue scale marked over 0-100 mm which was reported as percentage improvement. 126 patients were included for this study (30 were lost to follow up and were excluded). 25 cases were clinically suspected to have pituitary dysfunction and underwent evaluation with 9 (9.37%, n = 96) found to have evidence of HP. One child had partial empty sella on MRI with anterior as well as posterior pituitary abnormality and stunting; imaging was normal in others. Higher number of patients with HP had hypotension (p = 0.005, n = 7), coagulation abnormalities (p = 0.005, n = 9), severe clinical snake bite envenomation (p = 0.024, n = 9) and progression to chronic kidney disease (CKD) (p = 0.001, n = 5) as compared to those who did not. Dialysis dependence at presentation was not significantly different (p = 0.348, n = 9). Only development of CKD on follow up predicted the development of HP. Patients had an improvement in the QoL after treatment with mean score on the visual analogue scale of 66.67 ± 14.14%. HP is not very uncommon in patients with severe vasculotoxic SB-AKI. Threshold of clinical suspicion and evaluation should be low as it causes significant morbidity.

Safety and feasibility of outpatient percutaneous native kidney biopsy in the developing world: experience in a large tertiary care centre in Eastern India.

AIM: Optimal time of observation following percutaneous biopsy has not been clearly established. Outpatient biopsy protocol was established in our centre for low risk patients and we assessed its efficacy and safety. METHODS: Patients fulfilling the low risk profile underwent a real time ultrasound-guided percutaneous native kidney biopsy. They were observed for 6 h and any complication was recorded. Ultrasound and hematocrit was done only in those patients with complications. Patients were contacted on telephone after 24 h and in case of any emergency. RESULTS: A total of 403 native kidney biopsies were performed from June 2011 to June 2012 of which 115 (28.5%) were on an outpatient basis. This was a 41.4% increase in the number of biopsies compared to the same period in the previous year. Fifteen patients (13.04%) had macroscopic haematuria within 2, 4 and 6 h in eight (53.33%), six (40%) and one (6.67%) patient, respectively. One of them had haematuria on follow-up phone call resolving without intervention. Only two (1.74%) patients developed significant bleeding with a drop in haematocrit needing overnight observation, with one requiring blood transfusion (with perinephric haematoma not requiring intervention). Complication rates were also similar in the 288 patients who had at least an overnight inpatient observation post-biopsy. There was no biopsy related mortality. CONCLUSIONS: Percutaneous native kidney biopsies can be safely performed on an outpatient basis in selected low risk patients. This approach increases the number of procedures, decreases the waiting periods and can have potential cost savings making it an attractive option in the developing world.

Unexpected origins of the enhanced pairing affinity of 2'-fluoro-modified RNA.

Various chemical modifications are currently being evaluated for improving the efficacy of short interfering RNA (siRNA) duplexes as antisense agents for gene silencing in vivo. Among the 2'-ribose modifications assessed to date, 2'deoxy-2'-fluoro-RNA (2'-F-RNA) has unique properties for RNA interference (RNAi) applications. Thus, 2'-F-modified nucleotides are well tolerated in the guide (antisense) and passenger (sense) siRNA strands and the corresponding duplexes lack immunostimulatory effects, enhance nuclease resistance and display improved efficacy in vitro and in vivo compared with unmodified siRNAs. To identify potential origins of the distinct behaviors of RNA and 2'-F-RNA we carried out thermodynamic and X-ray crystallographic analyses of fully and partially 2'-F-modified RNAs. Surprisingly, we found that the increased pairing affinity of 2'-F-RNA relative to RNA is not, as commonly assumed, the result of a favorable entropic contribution ('conformational preorganization'), but instead primarily based on enthalpy. Crystal structures at high resolution and osmotic stress demonstrate that the 2'-F-RNA duplex is less hydrated than the RNA duplex. The enthalpy-driven, higher stability of the former hints at the possibility that the 2'-substituent, in addition to its important function in sculpting RNA conformation, plays an underappreciated role in modulating Watson-Crick base pairing strength and potentially π-π stacking interactions.

Acute kidney injury with pigment nephropathy following spider bite: a rarely reported entity in India.

Acute kidney injury (AKI) can be seen in tropical regions following bites of various venomous animals and insects. Renal failure is seen most commonly following the bite of spiders of the Loxosceles spp. Dermonecrosis, systemic inflammatory response, hemolysis, rhabdomyolysis, and direct venom-related effects are postulated as causes of AKI. We report a documented case of AKI with pigment nephropathy following the bite of a brown spider from a tropical region which is known to have many venomous animals but has no previous reports of AKI following spider bite. Whether this is due to absence of toxic spider species or underreporting needs to be determined.

Spectrum of nephrotic syndrome in adults: clinicopathological study from a single center in India.

BACKGROUND: The etiology of nephrotic syndrome (NS) in adults varies depending on the geographical location and is poorly studied in the Indian subcontinent. METHODS: Patients (≥16 years old) with NS presenting to our center and undergoing a kidney biopsy from April 2010 to September 2012 were included for this study. All biopsies were subjected to light and immunofluorescence microscopy, and electron microscopy in selected cases. The histopathological spectrum was analyzed according to the various clinical parameters. RESULTS: A total of 410 kidney biopsies were included for analysis. Two hundred and thirty seven (57.8%) patients were male and 173 (42.19%) patients were female. The average age at presentation was 33.68 ± 13.88 years. Among the patients, 88.05% (n = 361) were diagnosed with primary glomerular diseases (PGD) and 11.95% (n = 49) with secondary glomerular diseases (SGD). The most common histological lesions were focal segmental glomerulosclerosis (FSGS) (24.63%) followed by minimal change disease (MCD) (23.9%) and membranous nephropathy (MN) (22.44%). The most common form of SGD was lupus nephritis (LN) (6.58% of all cases). FSGS (28.27%) and MCD (21.96%) were the most common lesions in males and females, respectively. In the age groups of 16-29 years, 30-59 years, and ≥60 years, MCD (28.96%), MN (24%), and MN (40.74%) were the most common lesions, respectively, followed by FSGS in all groups (25.68%, 24.5%, and 18.52%, respectively). Among the patients, 27.07% had serum creatinine ≥1.5 mg/dL and 28.54% had either macroscopic or microscopic hematuria. CONCLUSIONS: FSGS is increasingly becoming the most common cause of adult NS. This trend in Asia is seen predominantly in countries of the Indian subcontinent.

Growth retardation due to panhypopituitarism and central diabetes insipidus following Russell's viper bite.

Russell's viper envenomation and its related complications, especially acute kidney injury, is an important cause of morbidity and mortality in tropical developing countries of South Asia. Unusual complications, especially hypopituitarism, are rare and probably missed due to lack of clinical suspicion and diagnostic facilities. We report a rare presentation of growth retardation resulting from hypopituitarism due to Russell's viper envenomation along with central diabetes insipidus. Awareness of the fact that hypopituitarism may occur in this clinical setting is necessary for early diagnosis and treatment, especially among general care practitioners taking care of these patients.

New Oligonucleotide 2'-O-Alkyl N3'→P5' (Thio)-Phosphoramidates as Potent Antisense Agents: Physicochemical Properties and Biological Activity.

We describe here the design, synthesis, physicochemical properties, and hepatitis B antiviral activity of new 2'-O-alkyl ribonucleotide N3'→P5' phosphoramidate (2'-O-alkyl-NPO) and (thio)-phosphoramidite (2'-O-alkyl-NPS) oligonucleotide analogs. Oligonucleotides with different 2'-O-alkyl modifications such as 2'-O-methyl, -O-ethyl, -O-allyl, and -O-methoxyethyl combined with 3'-amino sugar-phosphate backbone were synthesized and evaluated. These molecules form stable duplexes with complementary DNA and RNA strands. They show an increase in duplex melting temperatures of up to 2.5°C and 4°C per linkage, respectively, compared to unmodified DNA. The results agree with predominantly C3'-endo sugar pucker conformation. Moreover, 2'-O-alkyl phosphoramidites demonstrate higher hydrolytic stability at pH 5.5 than 2'-deoxy NPOs. In addition, the relative lipophilicity of the 2'-O-alkyl-NPO and NPS oligonucleotides is higher than that of their 3'-O- counterparts. The 2'-O-alkyl-NPS oligonucleotides were evaluated as antisense (ASO) compounds in vitro and in vivo using Hepatitis B virus as a model system. Subcutaneous delivery of GalNAc conjugated 2'-O-MOE-NPS gapmers demonstrated higher activity than the 3'-O-containing 2'-O-MOE counterpart. The properties of 2'-O-alkyl-NPS constructs make them attractive candidates as ASO suitable for further evaluation and development.

Mechanistic insights into LDL nanoparticle-mediated siRNA delivery.

Although small interfering RNA (siRNA) can silence the expression of disease-related genes, delivery of these highly charged molecules is challenging. Delivery approaches for siRNAs are actively being pursued, and improved strategies are required for nontoxic and efficient delivery for gene knockdown. Low density lipoprotein (LDL) is a natural and endogenous nanoparticle that has a rich history as a delivery vehicle. Here, we examine purified LDL nanoparticles as carriers for siRNAs. When siRNA was covalently conjugated to cholesterol, over 25 chol-siRNA could be incorporated onto each LDL without changing nanoparticle morphology. The resulting LDL-chol-siRNA nanoparticles were selectively taken up into cells via LDL receptor mediated endocytosis, resulting in enhanced gene silencing compared to free chol-siRNA (38% gene knock down versus 0% knock down at 100 nM). However, silencing efficiency was limited by the receptor-mediated entrapment of the LDL-chol-siRNA nanoparticles in endolysosomes. Photochemical internalization demonstrated that endolysosome disruption strategies significantly enhance LDL-mediated gene silencing (78% at 100 nM).

Metabolism, pharmacokinetics, tissue distribution, and stability studies of the prodrug analog of an anti-hepatitis B virus dinucleoside phosphorothioate.

The alkoxycarbonyloxy dinucleotide prodrug R(p), S(p)-2 is an orally bioavailable anti-hepatitis B virus agent. The compound is efficiently metabolized to the active dinucleoside phosphorothioate R(p), S(p)-1 by human liver microsomes and S9 fraction without cytochrome P450-mediated oxidation or conjugation. The conversion of R(p), S(p)-2 to R(p), S(p)-1 appears to be mediated by liver esterases, occurs in a stereospecific manner, and is consistent with our earlier reported studies of serum-mediated hydrolytic conversion of R(p), S(p)-2 to R(p), S(p)-1. However, further metabolism of R(p), S(p)-1 does not occur. The presence of a minor metabolite, the desulfurized product 10 was noted. The prodrug R(p), S(p)-2 was quite stable in simulated gastric fluid, whereas the active R(p), S(p)-1 had a half-life of <15 min. In simulated intestinal fluid, the prodrug 2 was fully converted to 1 in approximately 3 h, whereas 1 remained stable. To ascertain the tissue distribution of the prodrug 2 in rats, the synthesis of (35)S-labeled R(p), S(p)-2 was undertaken. Tissue distribution studies of orally and intravenously administered radiolabeled [(35)S]2 demonstrated that the radioactivity concentrates in the liver, with the highest liver/plasma ratio in the intravenous group at 1 h being 3.89 (females) and in the oral group at 1 h being 2.86 (males). The preferential distribution of the dinucleotide 1 and its prodrug 2 into liver may be attributed to the presence of nucleoside phosphorothioate backbone because phosphorothioate oligonucleotides also reveal a similar tissue distribution profile upon intravenous administration.

Non-IgA mesangioproliferative glomerulonephritis: a benign entity?

BACKGROUND: Non-IgA mesangioproliferative glomerulonephritis is a well recognized but less studied entity. The clinical manifestations, treatment response and long-term outcome have not been clearly defined. METHODS: This single-centre study included patients with biopsy-proven non-IgA mesangioproliferative glomerulonephritis who had been on regular follow-up for >3 years. Their clinical features at presentation, response to therapy and long-term renal outcome are addressed in this study. RESULTS: Nephrotic syndrome developed in 51 of 57 patients (89.4%). The majority of them--34 of 51(80%)--were steroid sensitive and had either infrequent or no relapse. However, steroid-dependent nephrotic syndrome occurred in eight patients (15.6%), while steroid resistance occurred in nine patients (17.6 %). Thirteen patients developed chronic kidney disease (CKD) with three progressing to end-stage renal disease, three to CKD Stage 4 and seven to CKD Stage 3. CONCLUSIONS: Non-IgA mesangioproliferative glomerulonephritis is a disease, which is not benign, and is associated with significant treatment-related morbidity.

Modulation of thermal stability can enhance the potency of siRNA.

During RNA-induced silencing complex (RISC) assembly the guide (or antisense) strand has to separate from its complementary passenger (or sense) strand to generate the active RISC complex. Although this process was found to be facilitated through sense strand cleavage, there is evidence for an alternate mechanism, in which the strands are dissociated without prior cleavage. Here we show that the potency of siRNA can be improved by modulating the internal thermodynamic stability profile with chemical modifications. Using a model siRNA targeting the firefly luciferase gene with subnanomolar IC50, we found that placement of thermally destabilizing modifications, such as non-canonical bases like 2,4-difluorotoluene or single base pair mismatches in the central region of the sense strand (9-12 nt), significantly improve the potency. For this particular siRNA, the strongest correlation between the decrease in thermal stability and the increase in potency was found at position 10. Controls with stabilized sugar-phosphate backbone indicate that enzymatic cleavage of the sense strand prior to strand dissociation is not required for silencing activity. Similar potency-enhancing effects were observed as this approach was applied to other functional siRNAs targeting a different site on the firefly luciferase transcript or endogenously expressed PTEN.

Long-term renal outcome of snake bite and acute kidney injury: a single-center experience.

BACKGROUND: Snake bite can cause acute kidney injury (AKI) through multiple mechanisms. Many of these patients have severe kidney injury requiring renal replacement therapy. The long-term outcome of survivors of such severe AKI is not known. METHODS: We prospectively followed up 60 patients who developed dialysis-requiring severe AKI following snake bite and had survived the hospital stay. RESULTS: A total of 25 (41%) patients showed persistent renal involvement in the form of renal dysfunction, proteinuria, or hypertension at a mean period of follow-up of 45 months. Totally 5% of the patients progressed to end-stage renal disease (ESRD) while 20% had glomerular filtration rate (GFR) <45 mL/min. CONCLUSIONS: Long-term outcome of snake bite and AKI is not benign with a significant percentage of patients continuing to have features of persistent renal damage.

Clinicopathological Spectrum of Henoch-Schönlein Purpura Vasculitis: An Experience from a Tertiary Care Center.

Henoch-Schönlein purpura (HSP) is a small vessel vasculitis with multiorgan involvement. Renal involvement is the key factor predicting morbidity. We have aimed to analyze the clinicopathological spectrum of HSP vasculitis and HSP nephritis to assess the risk factors associated with kidney involvement. This retrospective study was performed in the department of pathology with collaboration of department of dermatology and department of nephrology of a tertiary care center. All clinical details along with biopsy findings were retrieved. Starting materials of the study were cases of leukocytoclastic vasculitis with only perivascular IgA deposit of more than ++ in the absence of other immunoglobulin and trace complements. To investigate the possible factors that are influential on the development of biopsy-proven HSP nephritis, we divided the whole study population in two groups -group 1: with and group 2: without biopsy-proven nephritis. One-way analysis of variance was carried out during comparative analysis between two groups using IBM SPSS statistics software, version 19 and MedCalc software, version 12.3.0.0. HSP vasculitis comprised 11.6% (n = 19) of total cutaneous vasculitis in 2 years (164 cases) with a mean age of 13.52 ± 8.10 (range: 4-33 years). Three cases developed de novo kidney disease (15.79%). A correlation analysis revealed that predictors were seasonal variation (P = 0.018), severe gastrointestinal involvement (P = 0.03), and subcutaneous edema (P = 0.005). Various clinical and laboratory parameters were associated with renal consequences. Occult nephritis was the most common presentation with crescent as a constant histopathological feature.

Targeting TLR9 agonists to secondary lymphoid organs induces potent immune responses against HBV infection.

Despite the existence of a prophylactic vaccine against hepatitis B virus (HBV), chronic hepatitis B virus (CHB) infection remains the leading cause of cirrhosis and liver cancer in developing countries. Because HBV persistence is associated with insufficient host immune responses to the infection, development of an immunomodulator as a component of therapeutic vaccination may become an important strategy for treatment CHB. In the present study, we aimed to design a novel immunomodulator with the capacity to subvert immune tolerance to HBV. We developed a lymphoid organ-targeting immunomodulator by conjugating a naturally occurring, lipophilic molecule, α-tocopherol, to a potent CpG oligonucleotide adjuvant pharmacophore. This approach resulted in preferential trafficking of the α-tocopherol-conjugated oligonucleotide to lymphoid organs where it was internalized by antigen-presenting cells (APCs). Moreover, we show that conjugation of the oligonucleotides to α-tocopherol results in micelle-like structure formation, which improved cellular internalization and enhanced immunomodulatory properties of the conjugates. In a mouse model of chronic HBV infection, targeting CpG oligonucleotide to lymphoid organs induced strong cellular and humoral immune responses that resulted in sustained control of the virus. Given the potency and tolerability of an α-tocopherol-conjugated CpG oligonucleotide, this modality could potentially be broadly applied for therapeutic vaccine development.