Sex bias in response to hepatitis B vaccination in end-stage renal disease patients: Meta-analysis

AIM: To systematically review the literature for studies investigating the potential effect of gender of dialysis patients on the immunogenicity of hepatitis B virus vaccines.

METHODS: Literature searches were conducted by the MEDLINE and Google Scholar. The key words used included “hepatitis B (HB)”, “vaccine”, “dialysis”, “hemodialysis”, “sex”, “male” and “female”. Data of seroresponse to HB vaccine in clinical trials regarding sex of the recipients have been achieved and analyzed. Finally data from 19 clinical trials have been pooled and analyzed.

RESULTS: Analysis of response to HB vaccination in our dialysis population showed males significantly respond less to hepatitis B vaccination (P = 0.002, Z = 3.08) with no significant heterogeneity detected [P = 0.766; heterogeneity χ² = 14.30 (df = 19); I² = 0%]. A reanalysis of the pooled data was conducted regarding the dialysis mode to evaluate potential differential impact of sex on HB vaccine response. Hemodialysis was the only subgroup that showed a significant difference regarding dialysis mode in response to HB vaccination regarding sex (P = 0.042, Z = 2.03).

CONCLUSION: This Meta-analysis showed significant effect for the sex of chronic kidney disease and dialysis patients on the immunogenicity of HB vaccine. This sex discrimination was most prominent among hemodialysis patients.

Complement activation and long-term graft function in ABO-incompatible kidney transplantation

BACKGROUND

ABO-incompatible and ABO-compatible kidney transplantation are equivalent in terms of short-term graft and patient survival. This is thought to be the result of ABO-incompatible graft accommodation, which occurs when anti-blood group antibodies re-occur after transplantation but somehow do not yield their detrimental effect. The underlying mechanism is unclear, but one of the hypotheses is that this is the result of complement inhibition. Since virtually all ABO-incompatible graft biopsies are C4d positive, this complement inhibition must occur somewhere in the complement cascade after the formation of C4d has already taken place, but where exactly is unclear. It is also unclear whether complement inhibition is complete. Incomplete accommodation could explain why recent studies have shown that long-term graft function in ABO-incompatible transplantation is somewhat inferior to ABO-compatible kidney transplantation.

AIM

To unravel the relationship between pre-transplant anti-ABO antibodies, complement activation, and long-term graft function.

METHODS

We included all 27 ABO-incompatible transplantations that were performed between 2008 and 2013 at the Academic Medical Center Amsterdam and the University Medical Center Groningen. For each ABO-incompatible transplantation, we included four ABO-compatible controls matched by age, sex, and transplantation date.

RESULTS

Graft and patient survival were not significantly different. The slope of kidney function during five-year follow-up was also not significantly different, but ABO-incompatible recipients did have a lower kidney function at three months (creatinine clearance 58 vs 69 mL/min, P = 0.02, Modification of Diet in Renal Disease 46 vs 52 mL/min/1.73 m², P = 0.08), due to a high rate of early rejection (33% vs 15%, P = 0.03), mostly T-cell mediated. Pre-transplant anti-ABO IgG titers were positively correlated with C5b-9 staining, which itself was positively correlated with the occurrence of T-cell mediated rejection. This may be the result of concurrent C5a formation, which could function as a costimulatory signal for T-cell activation.

CONCLUSION

Co-stimulation of T-cell activation by ongoing complement activation by anti-ABO antibodies may be responsible for an impaired long-term graft function in ABO-incompatible kidney transplantation.

Preemptive living donor kidney transplantation: Access, fate, and review of the status in Egypt

BACKGROUND

Preemptive living donor kidney transplantation (PLDKT) is recommended as the optimal treatment for end-stage renal disease.

AIM

To assess the rate of PLDKT among patients who accessed KT in our center and review the status of PLDKT in Egypt.

METHODS

We performed a retrospective review of the patients who accessed KT in our center from November 2015 to November 2022. In addition, the PLDKT status in Egypt was reviewed relative to the literature.

RESULTS

Of the 304 patients who accessed KT, 32 patients (10.5%) had preemptive access to KT (PAKT). The means of age and estimated glomerular filtration rate were 31.7 ± 13 years and 12.8 ± 3.5 mL/min/1.73 m2, respectively. Fifty-nine patients had KT, including 3 PLDKTs only (5.1% of total KTs and 9.4% of PAKT). Twenty-nine patients (90.6%) failed to receive PLDKT due to donor unavailability (25%), exclusion (28.6%), regression from donation (3.6%), and patient regression on starting dialysis (39.3%). In multivariate analysis, known primary kidney disease (P = 0.002), patient age (P = 0.031) and sex (P = 0.001) were independent predictors of achievement of KT in our center. However, PAKT was not significantly (P = 0.065) associated with the achievement of KT. Review of the literature revealed lower rates of PLDKT in Egypt than those in the literature.

CONCLUSION

Patient age, sex, and primary kidney disease are independent predictors of achieving living donor KT. Despite its non-significant effect, PAKT may enhance the low rates of PLDKT. The main causes of non-achievement of PLDKT were patient regression on starting regular dialysis and donor unavailability or exclusion.

Epigenetics of epithelial Na+ channel-dependent sodium uptake and blood pressure regulation

The epithelial Na⁺ channel (ENaC) consists of α, β, γ subunits. Its expression and function are regulated by aldosterone at multiple levels including transcription. ENaC plays a key role in Na⁺ homeostasis and blood pressure. Mutations in ENaC subunit genes result in hypertension or hypotension, depending on the nature of the mutations. Transcription of αENaC is considered as the rate-limiting step in the formation of functional ENaC. As an aldosterone target gene, αENaC is activated upon aldosterone- mineralocorticoid receptor binding to the cis-elements in the αENaC promoter, which is packed into chromatin. However, how aldosterone alters chromatin structure to induce changes in transcription is poorly understood. Studies by others and us suggest that Dot1a-Af9 complex represses αENaC by directly binding and regulating targeted histone H3 K79 hypermethylation at the specific subregions of αENaC promoter. Aldosterone decreases Dot1a-Af9 formation by impairing expression of Dot1a and Af9 and by inducing Sgk1, which, in turn, phosphorylates Af9 at S435 to weaken Dot1a-Af9 interaction. MR attenuates Dot1a-Af9 effect by competing with Dot1a for binding Af9. Af17 relieves repression by interfering with Dot1a-Af9 interaction and promoting Dot1a nuclear export. Af17^-/- mice exhibit defects in ENaC expression, renal Na⁺ retention, and blood pressure control. This review gives a brief summary of these novel findings.

Sentinel lymph node biopsy in renal malignancy: The past, present and future

Sentinel lymph node biopsy (SLNB) is now an established technique in penile and pelvic cancers, resulting in a lower mortality and morbidity when compared with the traditional lymph node dissection. In renal cancer however, despite some early successes for the SLNB technique, paucity of data remains a problem, thus lymph node dissection and extended lymph node dissection remain the management of choice in clinically node positive patients, with surveillance of lymph nodes in those who are clinically node negative. SLNB is a rapidly evolving technique and the introduction of new techniques such as near infra-red fluorescence optical imaging agents and positron emission tomography/computed tomography scans, may improve sensitivity. Evidence in support of this has already been recorded in bladder and prostate cancer. Although the lack of large multi-centre studies and issues around false negativity currently prevent its widespread use, with evolving techniques improving accuracy and the support of large-scale studies, SLNB does have the potential to become an integral part of staging in renal malignancy.

Species differences in regulation of renal proximal tubule transport by certain molecules

Renal proximal tubules (PTs) play important roles in the regulation of acid/base, plasma volume and blood pressure. Recent studies suggest that there are substantial species differences in the regulation of PT transport. For example, thiazolidinediones (TZDs) are widely used for the treatment of type 2 diabetes mellitus, but the use of TZDs is associated with fluid overload. In addition to the transcriptional enhancement of sodium transport in distal nephrons, TZDs rapidly stimulate PT sodium transport via a non-genomic mechanism depending on peroxisome proliferator activated receptor γ/Src/epidermal growth factor receptor (EGFR)/MEK/ERK. In mouse PTs, however, TZDs fail to stimulate PT transport probably due to constitutive activation of Src/EGFR/ERK pathway. This unique activation of Src/ERK may also affect the effect of high concentrations of insulin on mouse PT transport. On the other hand, the effect of angiotensin II (Ang II) on PT transport is known to be biphasic in rabbits, rats, and mice. However, Ang II induces a concentration-dependent, monophasic transport stimulation in human PTs. The contrasting responses to nitric oxide/guanosine 3’,5’-cyclic monophosphate pathway may largely explain these different effects of Ang II on PT transport. In this review, we focus on the recent findings on the species differences in the regulation of PT transport, which may help understand the species-specific mechanisms underlying edema formation and/or hypertension occurrence.

Any link of gout disease control among hypertensive patients and onset of end-stage renal disease? Results from a population-based study

AIM

To determine the impact of allopurinol non-adherence as a proxy for uncontrolled disease on primary prevention of end-stage renal disease (ESRD).

METHODS

A cohort of 2752 patients with gout diagnosis was reconstructed using the Québec Régie de l’assurance maladie du Québec and MedEcho administrative databases. Eligible patients were new users of allopurinol, aged 45-85, with a diagnosis of hypertension, and treated with an antihypertensive drug between 1997 and 2007.

RESULTS

Major risk factor for ESRD onset was chronic kidney disease at stages 1 to 3 [rate ratio (RR) = 8.00; 95% confidence interval (CI): 3.16-22.3 and the severity of hypertension (≥ 3 vs < 3 antihypertensives)] was a trending risk factor as a crude estimate (RR = 1.94; 95%CI: 0.68-5.51). Of 341 patients, cases (n = 22) and controls (n = 319), high adherence level (≥ 80%) to allopurinol therapy, compared with lower adherence level (< 80%), was associated with a lower rate of ESRD onset (RR = 0.35; 95%CI: 0.13-0.91).

CONCLUSION

Gout control seem to be associated with a significant decreased risk of ESRD onset in hypertensive populations, further research should be conducted confirming this potential associated risk.

Carbon dioxide: Global warning for nephrologists

The large prevalence of respiratory acid-base disorders overlapping metabolic acidosis in hemodialysis population should prompt nephrologists to deal with the partial pressure of carbon dioxide (pCO2) complying with the reduced bicarbonate concentration. What the most suitable formula to compute pCO2 is reviewed. Then, the neglected issue of CO2 content in the dialysis fluid is under the spotlight. In fact, a considerable amount of CO2 comes to patients' bloodstream every hemodialysis treatment and "acidosis by dialysate" may occur if lungs do not properly clear away this burden of CO2. Moreover, vascular access recirculation may be easy diagnosed by detecting CO2 in the arterial line of extracorporeal circuit if CO2-enriched blood from the filter reenters arterial needle.

Review on renal recovery after anatrophic nephrolithotomy: Are we really healing our patients?

The main goals for urinary stone treatment are to preserve renal function, reduce or avoid complications related to calculi, and to render the patient free of calculi as soon as possible. Anatrophic nephrolithotomy (ANL) is a valid and useful alternative for conventional staghorn calculi excision. Although excellent stone free rates can be achieved with ANL there are some drawbacks that may be of concern. Morbidity related to intraoperative and postoperative complications is one of them. Another, great concern is the possibility of reduction on renal function related to the procedure itself. This may be related to nephron injury during nephrotomy and parenchymal closure or to ischemic injury. In this review we assess functional results after anatrophic nephrolithotomy.

Liposoluble vitamins A and E in kidney disease

Kidney disease (KD) is characterized by the presence of elevated oxidative stress, and this is postulated as contributing to the high cardiovascular morbidity and mortality in these individuals. Chronic KD (CKD) is related to high grade inflammatory condition and pro-oxidative state that aggravates the progression of the disease by damaging primary podocytes. Liposoluble vitamins (vitamin A and E) are potent dietary antioxidants that have also anti-inflammatory and antiapoptotic functions. Vitamin deficits in CKD patients are a common issue, and multiple causes are related to them: Anorexia, dietary restrictions, food cooking methods, dialysis losses, gastrointestinal malabsorption, etc. The potential benefit of retinoic acid (RA) and α-tocopherol have been described in animal models and in some human clinical trials. This review provides an overview of RA and α tocopherol in KD.

Urgent call for reconsideration of chronic kidney disease

Circulating toxins namely: free radicals, cytokines and metabolic products induce glomerular endothelial dysfunction, hemodynamic maladjustment and chronic ischemic state;this leads to tubulointerstitial fibrosis in chronic kidney disease (CKD). Altered vascular homeostasis observed in late stage CKD revealed defective angiogenesis and impaired nitric oxide production explaining therapeutic resistance to vasodilator treatment in late stage CKD. Under current practice, CKD patients are diagnosed and treated at a rather late stage due to the lack of sensitivity of the diagnostic markers available. This suggests the need for an alternative therapeutic strategy implementing the therapeutic approach at an early stage. This view is supported by the normal or mildly impaired vascular homeostasis observed in early stage CKD. Treatment at this early stage can potentially enhance renal perfusion, correct the renal ischemic state and restore renal function. Thus, this alternative therapeutic approach would effectively prevent end-stage renal disease.

Acute kidney injury from different poisonous substances

AIM

To report our experience of acute kidney injury (AKI) developed after exposure to poisonous substance.

METHODS

Retrospective study where data was collected from case records of patients coming to this institute during January 1990 to May 2016. This institution is a tertiary care center for renal care in the metropolitan city of Karachi, Pakistan. History of ingested substance, symptoms on presentation, basic laboratory tests on arrival, mode of treatment and outcome were recorded from all patients and are presented here. Patients developing AKI after snake envenomation or scorpion stings are not included in this study.

RESULTS

During studied period 184 cases of AKI developing after poisoning were seen at our institution. The largest group was from paraphenyline diamine poisoning comprising 135 patients, followed by methanol in 8, organophosphorus compounds in 5, paraquat in 5, copper sulphate in 5, tartaric acid in 4, phenobarbitone in 3 and benzodiazipines, datura, rat killer, fish gall bladder, arsenic, boiler water, ammonium dichromate, acetic acid and herbs with lesser frequency. In 8 patients multiple substances were ingested in combination. Renal replacement therapy was required in 96% of patients. Complete recovery was seen in 72.28% patients, 20% died during acute phase of illness.

CONCLUSION

It is important to report poisonous substances causing vital organ failure to increase awareness among general population as well as health care providers.

Unilateral hypoplastic kidney in adults: An experience of a tertiary-level urology center

BACKGROUND

Unilateral small-sized kidney is a radiological term referring to both the congenital and acquired causes of reduced kidney volume. However, the hypoplastic kidney may have peculiar clinical and radiological characterizations.

AIM

To evaluate the clinical presentations, complications, and management approaches of the radiologically diagnosed unilateral hypoplastic kidney.

METHODS

A retrospective review of the records of patients with a radiological diagnosis of unilateral hypoplastic kidney between July 2015 and June 2020 was done at Assiut Urology and Nephrology Hospital, Assiut University, Egypt.

RESULTS

A total of 33 cases were diagnosed to have unilateral hypoplastic kidney with a mean (range) age of 39.5 ± 11.2 (19-73) years. The main clinical presentation was loin pain (51.5%), stone passer (9.1%), anuria (12.1%), accidental discovery (15.2%), or manifestations of urinary tract infections (12.1%). Computed tomography was the most useful tool for radiological diagnosis. However, radioisotope scanning could be requested for verification of surgical interventions and nephrectomy decisions. Urolithiasis occurred in 23 (69.7%) cases and pyuria was detected in 22 (66.7%) cases where the infection was documented by culture and sensitivity test in 19 cases. While the non-complicated cases were managed by assurance only (12.1%), nephrectomy (15.2%) was performed for persistent complications. However, symptomatic (27.3%) and endoscopic (45.6%) approaches were used for the management of correctable complications.

CONCLUSION

Unilateral hypoplastic kidney in adults has various complications that range from urinary tract infections to death from septicemia. Diagnosis is mainly radiological and management is usually conservative or minimally invasive.

Biomarkers in kidney transplantation: From bench to bedside

Immunosuppressive drug level monitoring and serum creatinine are widely used for kidney transplantation (KT) monitoring. Monitoring of drug level is not the direct measurement of the immune response while the rising of creatinine is too late for detection of allograft injury. Kidney biopsy, the gold standard for KT monitoring, is invasive and may lead to complications. Many biomarkers have been discovered for direct monitoring of the immune system in KT and the benefit of some biomarkers has reached clinical level. In order to use biomarkers for KT monitoring, physicians have to understand the biology including kinetics of each marker. This can guide biomarker selection for specific condition. Herein, we summarize the recent findings of donor specific anti-human leukocyte antigen antibody, B lymphocyte stimulator, interferon-gamma induced protein of 10 kDa, and intracellular adenosine triphosphate monitoring, all of which have very strong evidence support for the clinical use in KT.

Update on kidney transplantation in human immunodeficiency virus infected recipients

Improved survival of human immunodeficiency virus (HIV) infected patients with chronic kidney disease following the introduction of antiretroviral therapy resulted in the need to revisit the topic of kidney transplantation in these patients. Large cohort studies have demonstrated favorable outcomes and proved that transplantation is a viable therapeutic option. However, HIV-infected recipients had higher rates of rejection. Immunosuppressive therapy did not negatively impact the course of HIV infection. Some of the immunosuppressive drugs used following transplantation exhibit antiretroviral effects. A close collaboration between infectious disease specialists and transplant professionals is mandatory in order to optimize transplantation outcomes in these patients. Transplantation from HIV⁺ donors to HIV⁺ recipients has been a subject of intense debate. The HIV Organ Policy Equity act provided a platform to research this area further and to develop guidelines. The first HIV⁺ to HIV⁺ kidney transplant in the United States and the first HIV⁺ to HIV⁺ liver transplant in the world were recently performed at the Johns Hopkins University Medical Center.

Comamonas testosteroni-associated peritonitis in a pediatric peritoneal dialysis patient

Comamonas testosteroni (C. testosteroni) has been rarely observed as an infectious agent in clinical practice. Few reports described its potential pathogenicity in bloodstream and abdominal infections. Here, we report our experience in the treatment of a C. testosteroni-associated peritonitis in a four-year-old girl receiving chronic peritoneal dialysis (PD). The organism was shown to be highly susceptible to appropriate antibiotic therapy. Infection responded promptly and the patient was managed conservatively without withdrawal from PD.

Atypical hemolytic-uremic syndrome due to complement factor I mutation

Atypical hemolytic-uremic syndrome (aHUS) is a rare disease of complement dysregulation leading to thrombotic microangiopathy (TMA). Renal involvement and progression to end-stage renal disease are common in untreated patients. We report a 52-year-old female patient who presented with severe acute kidney injury, microangiopathic hemolytic anemia, and thrombocytopenia. She was managed with steroid, plasma exchange, and dialysis. Kidney biopsy shows TMA and renal cortical necrosis. Genetic analysis reveals heterozygous complement factor I (CFI) mutation. Eculizumab was initiated after 3 mo of presentation, continued for 9 mo, and stopped because of sustained hematologic remission, steady renal function, and cost issues. Despite this, the patient continued to be in hematologic remission and showed signs of renal recovery, and peritoneal dialysis was stopped 32 mo after initiation. We report a case of aHUS due to CFI mutation, which, to the best of our knowledge, has not been reported before in Saudi Arabia. Our case illustrates the challenges related to the diagnosis and management of this condition, in which a high index of suspicion and prompt treatment are usually necessary.

Silent diabetic nephropathy

AIM: To examine the risk of renal events in patients with biopsy-proven diabetic nephropathy (DN) and its possible associated factors.

METHODS: Clinical and histological data of 60 patients diagnosed with diabetic nephropathy were retrospectively collected. Patients with evidence or suspicion of other nephropathies were excluded from the study. The final event was defined as renal replacement therapy (RRT) initiation or progression of chronic kidney disease (CKD), according to the KDIGO 2012 definition of a decrease in CKD category and a decrease in GFR of 25% or more.

RESULTS: A total of 45 patients with a follow-up of at least 3 mo were included. Most of the patients presented type 2 DM, with a mean age of 58.3 years old. The time of evolution of DM was 9.6 ± 7.8 years, although in 13 patients, it was less than 5 years. A total of 62% of patients reached the final event in a median period of 3.4 years (95%CI: 2.1-4.7), with 21 of them requiring dialysis. The factors that were independently associated with renal survival were estimated glomerular filtration rate (eGFR) at the time of biopsy, cardiovascular disease (CVD) history and HbA1c less than 7%. Therefore, for each 10 mL/min per 1.73 m² reduction in eGFR, we obtained a DN progression risk of HR = 2 (1.3-3.0) (P = 0.001); patients with CVD were at greater risk for DN progression (HR = 2.8, 1.1-7.1, P = 0.032), and CKD patients with HbA1c < 7% demonstrated greater renal risk than patients with HbA1c ≥ 7%, with an HR of 2.9 (1.0-8.4) (P = 0.054).

CONCLUSION: A past history of CVD is a risk factor for DN progression. Levels of HbA1c less than 7% could favor an eGFR decrease in these patients.

Chronic kidney disease in children and adolescents in Brunei Darussalam

AIM

To determine epidemiology of Bruneian paediatric chronic kidney disease (CKD) patients and factors that affect growth and progression of disease.

METHODS

A cross-sectional study conducted on all children below 18 years old who were diagnosed with CKD over a ten year period (2004 to 2013). The reference population was all children (< 18 years old) suffering from CKD and attending the tertiary paediatric nephrology clinic in Brunei Darussalam. Demographic (current age, age of diagnosis, gender, ethnicity), anthropometric (weight and height), diagnosis, laboratory data (serum creatinine and haemoglobin, urinalysis) and blood pressure were extracted from the patients' clinical case notes and recorded using a data collection form.

RESULTS

The study revealed a high national prevalence [736 per million child population (pmcp)] and incidence (91 pcmp) of CKD. If CKD was defined at Stage 1, 2, 3, 4 or 5, the associated prevalence figures were 736, 132, 83, 50 and 33 pmcp. Glomerulonephritis accounted for 69% of all prevalent cases, followed by congenital abnormalities of kidney and urinary tract (20%) and tubulointerstitial diseases (8%). Minimal change disease being the most common histological diagnosis. The median age of diagnosis was 4.5 years, with congenital disease patients experiencing an earlier onset of diagnosis. A large proportion of patients were below the 5% percentile for height and weight. Non-glomerular diseases, adolescent and female patients were significantly associated with poor growth, but not glomerular filtration rate, age of diagnosis or steroid usage.

CONCLUSION

Brunei has a high prevalence of chronic kidney disease in the paediatric population with glomerulonephritis being the most common disease.

New antigens involved in membranous nephropathy beyond phospholipase A2 receptor

When the physiopathology of membranous nephropathy was first described, almost 30% of cases were recognized to be secondary to well-known diseases such as autoimmune diseases, tumors or infections. The remaining 70% cases were called primary membranous nephropathy as the exact mechanism or pathogenic factor involved was unknown. The discovery of the M type phospholipase A2 receptor and thrombospondin type 1 domain containing 7A as causative antigens in these "so called" primary membranous nephropathies provided new insights into the effective causes of a large proportion of these cases. Novel techniques such as laser microdissection and tandem mass spectrometry as well as immunochemistry with antibodies directed against novel proteins allowed the confirmation of new involved antigens. Finally, using confocal microscopy to localize these new antigens and immunoglobulin G and Western blot analysis of serum samples, these new antigens were detected on the glomerular membrane, and the related antibodies were detected in serum samples. The same antigens have been recognized in some cases of secondary membranous disease due to autoimmune diseases, tumors and infections. This has allowed examination of the relationship between antigens in primary membranous nephropathy and their presence in some secondary nephropathies. The aim of this study is to describe the characteristics of the new antigens discovered and their association with other diseases.

Renal biopsy reports in nephritic syndrome: Update

BACKGROUND

Nephritic syndrome (NiS) is a major indicator of serious renal diseases necessitating kidney biopsies for histopathological evaluations, but due to the lack of comprehensive reviews in the literature, the current understanding of the syndrome and its significance is limited.

AIM

To collect all the evidence retrievable from the literature on the diagnoses made on the renal biopsies performed for NiS as the indication to the procedure.

METHODS

A literature search was conducted to find studies reporting final diagnoses on renal biopsies in NiS patients. Data were pooled and analyzed with stratifications on age and regions. Meta-analyzes were performed using Stata v.9.

RESULTS

Overall, 26414 NiS patients from the total number of 96738 kidney biopsy diagnoses reported by 47 studies from 23 countries from all continents (except sub-Saharan Africa) were found and analyzed. NiS was the indication for renal biopsy in 21% of the patient populations across the reviewed studies. Immunoglobulin A (IgA) nephropathy was the single most frequent diagnosis in these patients (approximately 38%) followed by lupus nephritis (approximately 8%) and Henoch Schönlein purpura (approximately 7%). IgA nephropathy was the most frequent diagnosis reported for the NiS patients from the East Asia, comprising half of all the cases, and least prevalent in South Asia. Considering the age subgroups, adult (vs pediatric or elderly) patients were by far the most likely age group to be diagnosed with the IgA nephropathy. A myriad of such regional and age disparities have been found and reported.

CONCLUSION

As the indication for renal biopsy, NiS represents a very distinctive epidemiology of final renal disease diagnoses compared to the other major syndromes.

What is the purpose of launching the World Journal of Nephrology?

The launch of the World Journal of Nephrology (WJN) has distinct purposes. Its main purpose is to incorporate the fields of diabetes, hypertension, urology, cardiology and neurology, which are related to kidney disease, and to make all of our readers, contributors and allied health professionals feel at home with the WJN. The WJN aims to rapidly report new theories, methods and techniques for prevention, diagnosis, treatment, rehabilitation and nursing skill in the field of nephrology. The WJN will cover diagnostic imaging, disorders of kidney development, renal obstruction, atrophy and regeneration, kidney tumors, renal pharmacology and therapy, renal replacement therapies including transplantation, and Chinese herbal medicine. The WJN issues will include an editorial, frontier, invited review of articles and commentaries in addition to original articles submitted. The WJN will solicit articles from investigators in areas of diabetes and hypertension, and high priority will be given to those articles with an emphasis on the prevention of dialysis. Final decision for publication will be based on the merit of the article, language and lucidity.

Innocuous-looking skin scab over an arteriovenous fistula: Case report and literature review

Little is written on the management of an innocuous-looking skin scab over an autogenous arteriovenous fistula (AVF) used for haemodialysis. The seriousness of the underlying pathology can be under-estimated, and this may lead to early loss of the AVF, and major-life-threatening haemorrhage. We describe the management of a 78-year-old patient presenting with an innocuous-looking scab over an AVF and review the pertinent literature on this subject.

Kinin B2 receptor does not exert renoprotective effects on mice with glycerol-induced rhabdomyolysis

AIM: To investigate a potential protective role of the kinin B₂ receptor in a glycerol-induced rhabdomyolysis mouse model.

METHODS: We separated 28 C57Bl/6 male mice into 4 groups: untreated WT animals, untreated B₂ knockout mice, glycerol-treated WT and glycerol-treated B₂ knockout mice. Glycerol-treated animals received one intramuscular injections of glycerol solution (50% v/v, 7 mL/kg). After 48 h, urine and blood samples were collected to measure creatinine and urea levels. Additionally, kidney samples were extracted for histological evaluation, and the mRNA expression levels of kinin B1 and B2 receptors and inflammatory mediators were measured by real-time polymerase chain reaction.

RESULTS: Serum creatinine and urea levels showed differences between untreated wild-type and glycerol-treated wild-type mice (0.66 ± 0.04 vs 2.61 ± 0.53 mg/dL, P < 0.01; and 33.51 ± 2.08 vs 330.2 ± 77.7 mg/dL, P < 0.005), and between untreated B₂ knockout mice and glycerol-treated knockout mice (0.56 ± 0.03 vs 2.23 ± 0.87 mg/dL, P < 0.05; and 42.49 ± 3.2 vs 327.2 ± 58.4 mg/dL, P < 0.01), but there was no difference between the glycerol-treated wild-type and glycerol-treated knockout mice. Glycerol was able to induce a striking increase in kinin B₂ receptor expression (> 30 times, 31.34 ± 8.9) in kidney. Animals injected with glycerol had a higher degree of tubular injury than untreated animals. Wild-type and knockout mice treated with glycerol intramuscularly present kidney injury, with impairment in renal function. However, B₂ knockout mice treated with glycerol did not show a different phenotype regarding kidney injury markers, when compared to the wild-type glycerol-treated group.

CONCLUSION: We conclude that the kinin B₂ receptor does not have a protective role in renal injury.

Epidemiology, pathophysiology, clinical characteristics and management of childhood cardiorenal syndrome

Cardiorenal syndrome (CRS) is a new term recently introduced to describe the acute or chronic comorbid state of the heart and kidney that has been long known and frequently managed in very sick individuals. The tight and delicate coordination of physiological functions among organ systems in the human body makes dysfunction in one to lead to malfunction of one or more other organ systems. CRS is a universal very common morbidity in the critically ill, with a high mortality rate that has received very little research attention in children. Simultaneous management of heart and renal failures in CRS is quite challenging; the therapeutic choice made for one organ must not jeopardize the other. This paper reviews the epidemiology, pathophysiology, clinical characteristics and management of acute and chronic CRS in children.