Magnesium and Fracture Risk in the General Population and Patients Receiving Dialysis: A Narrative Review

Purpose of Review

Magnesium is an essential mineral for bone metabolism, but little is known about how magnesium intake alters fracture risk. We conducted a narrative review to better understand how magnesium intake, through supplementation, diet, or altering the concentration of dialysate magnesium, affects mineral bone disease and the risk of fracture in individuals across the spectrum of kidney disease.

Sources of Information

Peer-reviewed clinical trials and observational studies.

Methods

We searched for relevant articles in MEDLINE and EMBASE databases. The methodologic quality of clinical trials was assessed using a modified version of the Downs and Black criteria checklist.

Key Findings

The role of magnesium intake in fracture prevention is unclear in both the general population and in patients receiving maintenance dialysis. In those with normal kidney function, 2 meta-analyses showed higher bone mineral density in those with higher dietary magnesium, whereas 1 systematic review showed no effect on fracture risk. In patients receiving maintenance hemodialysis or peritoneal dialysis, a higher concentration of dialysate magnesium is associated with a lower concentration of parathyroid hormone, but little is known about other bone-related outcomes. In 2 observational studies of patients receiving hemodialysis, a higher concentration of serum magnesium was associated with a lower risk of hip fracture.

Limitations

This narrative review included only articles written in English. Observed effects of magnesium intake in the general population may not be applicable to those with chronic kidney disease particularly in those receiving dialysis.

Personalised cooler dialysate for patients receiving maintenance haemodialysis (MyTEMP): a pragmatic, cluster-randomised trial

BACKGROUND

Haemodialysis centres have conventionally provided maintenance haemodialysis using a standard dialysate temperature (eg, 36·5°C) for all patients. Many centres now use cooler dialysate (eg, 36·0°C or lower) for potential cardiovascular benefits. We aimed to assess whether personalised cooler dialysate, implemented as centre-wide policy, reduced the risk of cardiovascular-related death or hospital admission compared with standard temperature dialysate.

METHODS

MyTEMP was a pragmatic, two-arm, parallel-group, registry-based, open-label, cluster-randomised, superiority trial done at haemodialysis centres in Ontario, Canada. Eligible centres provided maintenance haemodialysis to at least 15 patients a week, and the medical director of each centre had to confirm that their centre would deliver the assigned intervention. Using covariate-constrained randomisation, we allocated 84 centres (1:1) to use either personalised cooler dialysate (nurses set the dialysate temperature 0·5-0·9°C below each patient's measured pre-dialysis body temperature, with a lowest recommended dialysate temperature of 35·5°C), or standard temperature dialysate (36·5°C for all patients and treatments). Patients and health-care providers were not masked to the group assignment; however, the primary outcome was recorded in provincial databases by medical coders who were unaware of the trial or the centres' group assignment. The primary composite outcome was cardiovascular-related death or hospital admission with myocardial infarction, ischaemic stroke, or congestive heart failure during the 4-year trial period. Analysis was by intention to treat. The study is registered at ClinicalTrials.gov, NCT02628366.

FINDINGS

We assessed all of Ontario's 97 centres for inclusion into the study. Nine centres had less than 15 patients and one director requested that four of their seven centres not participate. 84 centres were recruited and on Feb 1, 2017, these centres were randomly assigned to administer personalised cooler dialysate (42 centres) or standard temperature dialysate (42 centres). The intervention period was from April 3, 2017, to March 31, 2021, and during this time the trial centres provided outpatient maintenance haemodialysis to 15 413 patients (about 4·3 million haemodialysis treatments). The mean dialysate temperature was 35·8°C in the cooler dialysate group and 36·4°C in the standard temperature group. The primary outcome occurred in 1711 (21·4%) of 8000 patients in the cooler dialysate group versus 1658 (22·4%) of 7413 patients in the standard temperature group (adjusted hazard ratio 1·00, 96% CI 0·89 to 1·11; p=0·93). The mean drop in intradialytic systolic blood pressure was 26·6 mm Hg in the cooler dialysate group and 27·1 mm Hg in the standard temperature group (mean difference -0·5 mm Hg, 99% CI -1·4 to 0·4; p=0·14).

INTERPRETATION

Centre-wide delivery of personalised cooler dialysate did not significantly reduce the risk of major cardiovascular events compared with standard temperature dialysate. The rising popularity of cooler dialysate is called into question by this study, and the risks and benefits of cooler dialysate in some patient populations should be clarified in future trials.

FUNDING

Canadian Institutes of Health Research, Heart and Stroke Foundation of Canada, Ontario Renal Network, Ontario Strategy for Patient-Oriented Research Support Unit, Dialysis Clinic, Inc., ICES (formerly known as the Institute for Clinical Evaluative Sciences), Lawson Health Research Institute, and Western University.

MyTEMP: Statistical Analysis Plan of a Registry-Based, Cluster-Randomized Clinical Trial

Background:

Major Outcomes with Personalized Dialysate TEMPerature (MyTEMP) is a 4-year cluster-randomized clinical trial comparing the effect of using a personalized, temperature-reduced dialysate protocol versus a dialysate temperature of 36.5°C on cardiovascular-related death and hospitalization. Randomization was performed at the level of the dialysis center (“the cluster”).

Objective:

The objective is to outline the statistical analysis plan for the MyTEMP trial.

Design:

MyTEMP is a pragmatic, 2-arm, parallel-group, registry-based, open-label, cluster-randomized trial.

Setting:

A total of 84 dialysis centers in Ontario, Canada.

Patients:

Approximately 13 500 patients will have received in-center hemodialysis at the 84 participating dialysis centers during the trial period (April 3, 2017, to March 1, 2021, with a maximum follow-up to March 31, 2021).

Methods:

Patient identification, baseline characteristics, and study outcomes will be obtained primarily through Ontario administrative health care databases held at ICES. Covariate-constrained randomization was used to allocate the 84 dialysis centers (1:1) to the intervention group or the control group. Centers in the intervention group used a personalized, temperature-reduced dialysate protocol, and centers in the control group used a fixed dialysate temperature of 36.5°C.

Outcomes:

The primary outcome is a composite of cardiovascular-related death or major cardiovascular-related hospitalization (defined as a hospital admission with myocardial infarction, congestive heart failure, or ischemic stroke) recorded in administrative health care databases. The key secondary outcome is the mean drop in intradialytic systolic blood pressure, defined as the patients’ predialysis systolic blood pressure minus their nadir systolic blood pressure during the dialysis treatment. Anonymized data on patients’ predialysis and intradialytic systolic blood pressure were collected at monthly intervals from each dialysis center.

Analysis plan:

The primary analysis will follow an intent-to-treat approach. The primary outcome will be analyzed at the patient level as the hazard ratio of time-to-first event, estimated from a subdistribution hazards model. Within-center correlation will be accounted for using a robust sandwich estimator. In the primary analysis, patients’ observation time will end if they experience the primary outcome, emigrate from Ontario, or die of a noncardiovascular cause (which will be treated as a competing risk event). The between-group difference in the mean drop in intradialytic systolic blood pressure obtained during the dialysis sessions throughout the trial period will be analyzed at the center level using an unadjusted random-effects linear mixed model.

Trial status:

The MyTEMP trial period is April 3, 2017, to March 31, 2021. We expect to analyze and report results by 2023 once the updated data are available at ICES.

Trial registration:

MyTEMP is registered with the US National Institutes of Health at clincaltrials.gov (NCT02628366).

Statistical analytic plan:

Version 1.1 June 15, 2021.

Rhabdomyolysis and Acute Kidney Injury Associated With Terbinafine Use: A Case Report

Rationale:

Terbinafine is an antimicrobial agent commonly prescribed for fungal infections. Its side effect profile is generally benign, but there is limited evidence that it has the potential to cause rhabdomyolysis. Rhabdomyolysis is a potentially life-threatening condition caused by profound muscle injury. It has characteristic findings of muscle pain, weakness, and dark urine. When recognized early, patients with rhabdomyolysis can be managed conservatively with hydration and watchful monitoring. However, if treatments are delayed, or in severe cases of rhabdomyolysis, complications such as electrolyte abnormalities, acute kidney injury, and disseminated intravascular coagulation can develop.

Presenting concerns of the patient:

A previously healthy 22-year-old male presented with nausea, vomiting, and dark urine after taking terbinafine 250 mg daily for a tinea infection for 9 days. He developed severe rhabdomyolysis with a serum creatine kinase (CK) of >100 000 U/L as well as anuric acute kidney injury.

Diagnosis:

The clinical history combined with the diagnostic findings suggest acute kidney injury and rhabdomyolysis associated with terbinafine use.

Interventions:

Terbinafine use was stopped immediately. The patient was started on intravenous fluids and bicarbonate drip. Hemodialysis was initiated to prevent further complications. After his CK level decreased and his clinical status stabilized, he was discharged home and continued to receive outpatient hemodialysis treatments.

Outcome:

The patient’s kidney function returned to baseline after 1 month of outpatient hemodialysis treatments.

Novel finding:

In this report, we present a case of rhabdomyolysis associated with terbinafine use that progressed to acute kidney injury requiring dialysis. Our case highlights a less known and severe side effect of this medication and emphasizes the importance of early recognition and treatment of rhabdomyolysis.

A Higher Concentration of Dialysate Magnesium to Reduce the Frequency of Muscle Cramps: A Narrative Review

Purpose of review:

Strategies to mitigate muscle cramps are a top research priority for patients receiving hemodialysis. As hypomagnesemia is a possible risk factor for cramping, we reviewed the literature to better understand the physiology of cramping as well as the epidemiology of hypomagnesemia and muscle cramps. We also sought to review the evidence from interventional studies on the effect of oral and dialysate magnesium-based therapies on muscle cramps.

Sources of information:

Peer-reviewed articles.

Methods:

We searched for relevant articles in major bibliographic databases including MEDLINE and EMBASE. The methodological quality of interventional studies was assessed using a modified version of the Downs and Blacks criteria checklist.

Key findings:

The etiology of muscle cramps in patients receiving hemodialysis is poorly understood and there are no clear evidence-based prevention or treatment strategies. Several factors may play a role including a low concentration of serum magnesium. The prevalence of hypomagnesemia (concentration of <0.7 mmol/L) in patients receiving hemodialysis ranges from 10% to 20%. Causes of hypomagnesemia include a low dietary intake of magnesium, use of medications that inhibit magnesium absorption (eg, proton pump inhibitors), increased magnesium excretion (eg, high-dose loop diuretics), and a low concentration of dialysate magnesium. Dialysate magnesium concentrations of ≤0.5 mmol/L may be associated with a decrease in serum magnesium concentration over time. Preliminary evidence from observational and interventional studies suggests a higher dialysate magnesium concentration will raise serum magnesium concentrations and may reduce the frequency and severity of muscle cramps. However, the quality of evidence supporting this benefit is limited, and larger, multicenter clinical trials are needed to further determine if magnesium-based therapy can reduce muscle cramps in patients receiving hemodialysis. In studies conducted to date, increasing the concentration of dialysate magnesium appears to be well-tolerated and is associated with a low risk of symptomatic hypermagnesemia.

Limitations:

Few interventional studies have examined the effect of magnesium-based therapy on muscle cramps in patients receiving hemodialysis and most were nonrandomized, pre-post study designs.

Major Outcomes With Personalized Dialysate TEMPerature (MyTEMP): Rationale and Design of a Pragmatic, Registry-Based, Cluster Randomized Controlled Trial

BACKGROUND

Small randomized trials demonstrated that a lower compared with higher dialysate temperature reduced the average drop in intradialytic blood pressure. Some observational studies demonstrated that a lower compared with higher dialysate temperature was associated with a lower risk of all-cause mortality and cardiovascular mortality. There is now the need for a large randomized trial that compares the effect of a low vs high dialysate temperature on major cardiovascular outcomes.

OBJECTIVE

The purpose of this study is to test the effect of outpatient hemodialysis centers randomized to (1) a personalized temperature-reduced dialysate protocol or (2) a standard-temperature dialysate protocol for 4 years on cardiovascular-related death and hospitalizations.

DESIGN

The design of the study is a pragmatic, registry-based, open-label, cluster randomized controlled trial.

SETTING

Hemodialysis centers in Ontario, Canada, were randomized on February 1, 2017, for a trial start date of April 3, 2017, and end date of March 31, 2021.

PARTICIPANTS

In total, 84 hemodialysis centers will care for approximately 15 500 patients and provide over 4 million dialysis sessions over a 4-year follow-up.

INTERVENTION

Hemodialysis centers were randomized (1:1) to provide (1) a personalized temperature-reduced dialysate protocol or (2) a standard-temperature dialysate protocol of 36.5°C. For the personalized protocol, nurses set the dialysate temperature between 0.5°C and 0.9°C below the patient's predialysis body temperature for each dialysis session, to a minimum dialysate temperature of 35.5°C.

PRIMARY OUTCOME

A composite of cardiovascular-related death or major cardiovascular-related hospitalization (a hospital admission with myocardial infarction, congestive heart failure, or ischemic stroke) captured in Ontario health care administrative databases.

PLANNED PRIMARY ANALYSIS

The primary analysis will follow an intent-to-treat approach. The hazard ratio of time-to-first event will be estimated from a Cox model. Within-center correlation will be considered using a robust sandwich estimator. Observation time will be censored on the trial end date or when patients die from a noncardiovascular event.

TRIAL REGISTRATION

www.clinicaltrials.gov; identifier: NCT02628366.

Posttransplant Lymphoproliferative Disorder: Experience from a Pediatric Nephrology Unit in North India

Posttransplant lymphoproliferative disorder (PTLD) is reported in 1%–3% among pediatric renal allograft recipients. We report the experience of PTLD among pediatric renal allograft recipients at a pediatric nephrology center in North India. Four cases of PTLD were identified from among records of 95 pediatric renal allograft recipients over a period of 21 years. Constitutional and localizing symptoms were present in three patients each. The diagnosis was suggested on positron emission tomography in three patients and confirmed by histopathology in all. Sites affected included tonsils, cervical lymph nodes, duodenum, and para-aortic lymph nodes in one patient each. The lymphocytic infiltrate was polymorphic in three patients and monomorphic in one. Immunostaining suggested B-cell origin in all patients. There was evidence of Epstein–Barr virus infection in only one patient. The patients were successfully managed with reduction of immunosuppression (in all), rituximab (in 3), and excision of affected tissue (in 1). Over a follow-up period of 30–88 months, there were no episodes of disease recurrence or allograft rejection, and renal function was preserved.

Effect of Coaching to Increase Water Intake on Kidney Function Decline in Adults With Chronic Kidney Disease: The CKD WIT Randomized Clinical Trial

IMPORTANCE

In observational studies, increased water intake is associated with better kidney function.

OBJECTIVE

To determine the effect of coaching to increase water intake on kidney function in adults with chronic kidney disease.

DESIGN, SETTING, AND PARTICIPANTS

The CKD WIT (Chronic Kidney Disease Water Intake Trial) randomized clinical trial was conducted in 9 centers in Ontario, Canada, from 2013 until 2017 (last day of follow-up, May 25, 2017). Patients had stage 3 chronic kidney disease (estimated glomerular filtration rate [eGFR] 30-60 mL/min/1.73 m2 and microalbuminuria or macroalbuminuria) and a 24-hour urine volume of less than 3.0 L.

INTERVENTIONS

Patients in the hydration group (n = 316) were coached to drink more water, and those in the control group (n = 315) were coached to maintain usual intake.

MAIN OUTCOMES AND MEASURES

The primary outcome was change in kidney function (eGFR from baseline to 12 months). Secondary outcomes included 1-year change in plasma copeptin concentration, creatinine clearance, 24-hour urine albumin, and patient-reported overall quality of health (0 [worst possible] to 10 [best possible]).

RESULTS

Of 631 randomized patients (mean age, 65.0 years; men, 63.4%; mean eGFR, 43 mL/min/1.73 m2; median urine albumin, 123 mg/d), 12 died (hydration group [n = 5]; control group [n = 7]). Among 590 survivors with 1-year follow-up measurements (95% of 619), the mean change in 24-hour urine volume was 0.6 L per day higher in the hydration group (95% CI, 0.5 to 0.7; P < .001). The mean change in eGFR was -2.2 mL/min/1.73 m2 in the hydration group and -1.9 mL/min/1.73 m2 in the control group (adjusted between-group difference, -0.3 mL/min/1.73 m2 [95% CI, -1.8 to 1.2; P = .74]). The mean between-group differences (hydration vs control) in secondary outcomes were as follows: plasma copeptin, -2.2 pmol/L (95% CI, -3.9 to -0.5; P = .01); creatinine clearance, 3.6 mL/min/1.73 m2 (95% CI, 0.8 to 6.4; P = .01); urine albumin, 7 mg per day (95% CI, -4 to 51; P = .11); and quality of health, 0.2 points (95% CI, -0.3 to 0.3; P = .22).

CONCLUSIONS AND RELEVANCE

Among adults with chronic kidney disease, coaching to increase water intake compared with coaching to maintain the same water intake did not significantly slow the decline in kidney function after 1 year. However, the study may have been underpowered to detect a clinically important difference.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01766687.

Cardiovascular outcomes of Nephrotic syndrome in childhood (CVONS) study: a protocol for prospective cohort study

BACKGROUND

Nephrotic syndrome (NS) is characterized by dyslipidemia which is a well-known risk factor for atherogenesis. Atherosclerosis in childhood is mostly subclinical and endothelial dysfunction is known to precede this. Evidence for screening for endothelial dysfunction and cardiovascular risk factors and early identification of premature onset of atherosclerosis in childhood NS remains tenuous in the absence of well-designed prospective studies addressing cardiovascular comorbidity in NS. The objective of our study is to examine endothelial dysfunction and short-term cardiovascular outcomes in a carefully phenotyped cohort of patients with Nephrotic syndrome as compared to healthy controls.

METHODS

In a multi-centric prospective cohort study, 70 Steroid Resistant NS (SRNS), 70 Steroid Sensitive (SSNS) patients along with 70 Healthy Controls are being recruited. After a baseline assessment of functional and structural status of heart (2D Echocardiography), arteries (Carotid Doppler and Intima Media Thickness measurements) and microcirculation [a combination of 2D Echocardiography, Laser Doppler Flowmetry (LDF) and Brachial Artery Flow mediated dilation (FMD) and Nail Fold Capillaroscopy (NFC)], the patients are being investigated for endothelial dysfunction. Venous blood sample (15 ml) is being collected for routine investigations and assay of biochemical endothelial markers through Flow Cytometry. The patients will be followed up at 12 months and 24 months after the recruitment to look for any change from baseline period.

DISCUSSION

This study will able to provide a better understanding of the epidemiology of endothelial dysfunction and associated subclinical cardiovascular co-morbidity in childhood NS. Findings on characterization of prevalence of endothelial dysfunction and subclinical markers may be used to design future randomized controlled trials for evaluating the efficacy of preventive and therapeutic interventions in reducing the incidence of cardiovascular disease.

Fluoride-associated ultrastructural changes and apoptosis in human renal tubule: a pilot study

The susceptibility of the kidneys to fluoride toxicity can largely be attributed to its anatomy and function. As the filtrate moves along the complex tubular structure of each nephron, it is concentrated in the proximal and distal tubules and collecting duct. It has been frequently observed that the children suffering from renal impairments also have some symptoms of dental and skeletal fluorosis. The findings suggest that fluoride somehow interferes with renal anatomy and physiology, which may lead to renal pathogenesis. The aim of this study was to evaluate the fluoride-associated nephrotoxicity. A total of 156 patients with childhood nephrotic syndrome were screened and it was observed that 32 of them had significantly high levels ( p ≤ 0.05) of fluoride in urine (4.01 ± 1.83 ppm) and serum (0.1 ± 0.013 ppm). On the basis of urinary fluoride concentration, patients were divided into two groups, namely group 1 (G-1) ( n = 32) containing normal urine fluoride (0.61 ± 0.17 ppm) and group 2 (G-2) ( n = 32) having high urine fluoride concentration (4.01 ± 1.83 ppm). Age-matched healthy subjects ( n = 33) having normal levels of urinary fluoride (0.56 ± 0.15 ppm) were included in the study as control (group 0 (G-0)). Kidney biopsies were taken from G-1 and G-2 only, who were subjected to ultrastructural (transmission electron microscopy) and apoptotic (terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick end labeling) analysis. Various subcellular ultrastructural changes including nuclear disintegration, chromosome condensation, cytoplasmic ground substance lysis, and endoplasmic reticulum blebbing were observed. Increased levels of apoptosis were observed in high fluoride group (G-2) compared to normal fluoride group (G-1). Various degrees of fluoride-associated damages to the architecture of tubular epithelia, such as cell swelling and lysis, cytoplasmic vacuolation, nuclear condensation, apoptosis, and necrosis, were observed.

Acute phase response in lame crossbred dairy cattle

AIM

The study was undertaken to study acute phase response based on acute phase proteins (APPs) such as C-reactive protein (CRP), haptoglobin (Hp), serum amyloid A (SAA), and fibrinogen in lame crossbred dairy cattle.

MATERIALS AND METHODS

Lame animals (n=30) were selected within 3-7 days of being noticed as lame by the farm veterinarian, from a local dairy farm in southeast Ludhiana over a period of 6 months, stratified proportionately with respect to stage of lactation with non-lame healthy cows (n=10). All the cows were otherwise healthy and did not have any other inflammatory problems such as pneumonia, enteritis, mastitis, or any kind of acute uterine inflammation. Blood samples were collected from all the animals; serum and plasma samples were separated and stored at -20°C. The levels of CRP, Hp, and SAA were estimated using Sandwich ELISA, whereas fibrinogen was estimated by heat precipitation method.

RESULTS

SAA levels in lame cows were significantly higher (22.19±0.85 µg/ml), approximately 3 times as compared to non-lame cows (8.89±0.72 µg/ml), whereas serum Hp concentration was approximately 20 times higher in the lame cattle (21.71±3.32 mg/dl) as compared to non-lame cows (1.17±0.07 mg/dl). Fibrinogen also increased in the lame cattle (3.97±0.22 g/L) as compared to non-lame group (1.40±0.17 g/L). Serum CRP levels analyzed in the lame cattle for the first time in the present study, and significant high concentration was appreciated in lame cattle (4.41±0.33 mg/L) as compared to non-lame cattle (0.61±0.14 mg/L). Lame cattle were having more of sole hemorrhages, sole ulcers, and white line lesions as compared to non-lame cattle.

CONCLUSION

It can be concluded that lame cattle exhibit high levels of APPs including CRP, Hp, SAA, and fibrinogen as compared to non-lame cattle.

Idiopathic collapsing glomerulopathy: A clinicopathologic analysis of 30 cases

Collapsing glomerulopathy (CG) is a distinct clinicopathologic entity associated with various infections, medications and acute ischemia. There have been few scattered reports of CG from India. This study aimed at evaluating the clinicopathologic features of idiopathic CG in Indian patients with comparison between adult-onset and childhood CG. This study included all cases of idiopathic CG diagnosed over a period of 4 years (2006-2009). Appropriate clinical details and laboratory findings were retrieved. Renal biopsies were reviewed and detailed pathologic features assessed. Statistical analysis was performed to compare various features between adult-onset and childhood CG. Over these 4 years, 30 cases of idiopathic CG were diagnosed. Of these, 11 were children. Childhood CG cases had longer duration of symptoms and lower serum urea and creatinine levels compared with adult patients. In renal histology, tubular atrophy and interstitial fibrosis was frequent in our cases. Pediatric cases of CG showed a higher proportion of segmental glomerulosclerosis. On clinical follow-up, nine of the 30 patients progressed to end-stage renal disease and these included two pediatric patients. Idiopathic CG is a significant cause of renal dysfunction in both pediatric and adult patients. Childhood and adult-onset CG differ in few clinicopathologic features. Early and accurate diagnosis of CG is imperative for appropriate management of these patients.

Calcineurin inhibitor induced nephrotoxicity in steroid resistant nephrotic syndrome

Prolonged therapy with calcineurin inhibitors (CNI) is effective in patients with difficult nephrotic syndrome. However, information on prevalence and risk factors for nephrotoxicity in children with steroid-resistant nephrotic syndrome is limited. This retrospective observational study was conducted on 40 patients with steroid-resistant nephrotic syndrome treated with cyclosporine (CyA) (n = 28) or tacrolimus (n = 12) for more than 2 years. Nephrotoxicity was defined by the presence of striped fibrosis involving ≥10% of the interstitium or nodular hyalinosis in more than one arteriole. Ten additional parameters were graded semi-quantitatively. Continuous data are presented as median and interquartile range (IQR). The median (IQR) age at onset of nephrotic syndrome and CNI therapy were 30 (21-45) and 49.5 (40-102.5) months. A second renal biopsy, following 30 (26-35) months of CNI therapy, showed histological toxicity in 10 (25%) patients. Toxicity was seen in 7 and 3 patients receiving CyA and tacrolimus, respectively, and 5 patients each with minimal change and focal segmental glomerulosclerosis. Therapy with CNI was associated with significant increases in scores for global glomerulosclerosis, tubular atrophy, interstitial fibrosis, nonnodular arteriolar hyalinosis (P < –0.001 for all), arteriolar smooth-muscle vacuolization (P = –0.02), juxtaglomerular hyperplasia (P = –0.002), and tubular microcalcinosis (P = –0.06). Risk factors for nephrotoxicity were initial resistance (OR 9; 95% CI 1.0-80.1; P = –0.049); dose of CyA (OR 9.2; 95% CI 1.1-74.6; P = –0.037); duration of heavy proteinuria (OR 1.2; 95% CI 1.0-1.4; P = –0.023); and hypertension during therapy (OR 6; 95% CI 1.3-28.3; P = –0.023). Following prolonged CNI therapy, one in four biopsies show features of toxicity. Prolonged duration of heavy proteinuria, hypertension, initial steroid resistance and high CyA dose predict the occurrence of nephrotoxicity.

Revised guidelines on management of antenatal hydronephrosis

Widespread antenatal screening has resulted in increased detection of anomalies of the kidneys and urinary tract. The present guidelines update the recommendations published in 2000. Antenatal hydronephrosis (ANH) is transient and resolves by the third trimester in almost one-half cases. The presence of oligohydramnios and additional renal or extrarenal anomalies suggests significant pathology. All patients with ANH should undergo postnatal ultrasonography; the intensity of subsequent evaluation depends on anteroposterior diameter (APD) of the renal pelvis and/or Society for Fetal Urology (SFU) grading. Patients with postnatal APD exceeding 10 mm and/or SFU grade 3-4 should be screened for upper or lower urinary tract obstruction and vesicoureteric reflux (VUR). Infants with VUR should receive antibiotic prophylaxis through the first year of life, and their parents counseled regarding the risk of urinary tract infections. The management of patients with pelviureteric junction or vesicoureteric junction obstruction depends on clinical features and results of sequential ultrasonography and radionuclide renography. Surgery is considered in patients with increasing renal pelvic APD and/or an obstructed renogram with differential renal function <35-40% or its subsequent decline. Further studies are necessary to clarify the role of prenatal intervention, frequency of follow-up investigations and indications for surgery in these patients.

Common mutation underlying primary hyperoxaluria type1 in three Indian children

Primary hyperoxaluria is an autosomal recessive disorder caused by deficiency of alanine-glyoxylate aminotransferase, which is encoded by the AGXT gene. We report three Indian children with primary hyperoxaluria type1 having a common mutation in this gene. All patients had evidence of chronic kidney disease at the time of diagnosis, with subsequent progression to end-stage renal disease. The detection of an identical mutation in the AGXT gene suggests that specific genetic screening for this mutation may be useful when considering the diagnosis of primary hyperoxaluria type1.

Giant cell transformation of podocytes: A unique histological feature associated with cystinosis

Fanconi's syndrome is an unusual cause of renal insufficiency in pediatric patients. Infantile cystinosis is one of the identifiable and treatable etiologies of Fanconi's syndrome. Early diagnosis of cystinosis permits institution of specific therapy with cysteamine. A 3-year-old girl presented with failure to thrive, polyuria, and polydipsia. She was found to have renal tubular defect with renal dysfunction and bilateral small contracted kidneys. A renal biopsy revealed extensive giant cell transformation of podocytes in the glomeruli with focal tubular atrophy and dilatation. However, no crystals were identified. Subsequent ophthalmoscopic examination revealed fine cystine crystals in the cornea and a diagnosis of cystinosis causing Fanconi's syndrome was made. Polykaryocytic transformation of visceral epithelial cells is an important diagnostic clue of nephropathic cystinosis and should be carefully looked for in renal biopsy from a child with Fanconi's syndrome and renal insufficiency.

Outcome of lupus nephritis in Indian children

We report the clinicopathological features, treatment and outcome of 54 Indian children (14 boys) with biopsy-proven lupus nephritis followed over a 10-year period. The mean age (SD) at onset of disease was 9.6 ± 2.6 (range 2.5–14.4) years. Twenty-six (48.1%) patients had class IV nephritis, 7 (13.0%) had class V, whereas class I, II and III nephritis were present in 3 (5.6%), 10 (18.5%) and 6 (11.1%) patients, respectively. Hypertension, haematuria and nephrotic range proteinuria were present in 30 (55.6%), 31 (57.4%) and 28 (51.8%) patients, respectively. Compared with all the other classes combined, there were more boys among patients with class IV nephritis, and hypertension, haematuria, nephrotic syndrome and decreased glomerular filtration rate at presentation were more common. The mean duration of follow-up was 3.1 ± 2.9 years (median 2.5, range 0.2–10.3 years). Of the 39 patients who were followed-up for at least 1 year, 33 (84.6%) were in complete or partial remission, whereas six (15.4%) had no response to therapy. The incidence of serious infection was 1.5 episodes per 10 patient-years. Nine patients died, of whom four had serious infections or septicaemia, and three developed end-stage renal failure (ESRF). The patient survival rate at 3 years and at last follow-up visit was 88% and 83.3%, respectively, whereas the renal survival rates (without ESRF) were 92% and 94.4% respectively. Cox regression analysis showed no relation of gender, age of onset, presence of hypertension, haematuria and proteinuria, estimated glomerular filtration rate, renal histology and response to therapy to the outcome of death or ESRF. We found lower patient survival rate as compared with data from the developed countries but similar to that seen in developing countries. Serious infections were an important cause of mortality besides renal failure.

Are therapeutic stem cells justified in bilateral multicystic kidney disease? A review of literature with insights into the embryology

Aim was to describe the challenges faced in the management of bilateral multicystic kidney disease (MCKD). A case of antenatally detected bilateral polycystic disease was referred at 28 weeks of gestation. The patient was advised to continue pregnancy till term and be in regular follow-up. Postnatally, the male baby passed urine in normal stream and was diagnosed as bilateral multicystic kidney disease on ultrasonography. He developed symptoms of renal failure. The baby was operated with right pyeloplasty and left pyelostomy, as the left ureter was atretic. The histopathology was consistent with bilateral multicystic kidney disease. Postoperatively, the baby was stable with intermittent episodes of metabolic acidosis that were managed medically and with peritoneal dialysis. Autologous stem cells were injected at the age of 1 year into the aorta at the level of the renal arteries clamping the aorta below. Repeat biopsy at time of stem cell injection showed 5/10 glomeruli showing global sclerosis on right side and 5/15 glomeruli showing global sclerosis on left side. The only improvement seen was in decreased doses of medicines to keep the child metabolically stable. The baby kept struggling but succumbed at the age of 17 months and 15 days. Post mortem bilateral renal biopsies demonstrated presence of primitive renal tubules and blastemal cells that were not demonstrated earlier. Survival for few months in bilateral multicystic kidney disease is thus possible with adequate treatment, the novel use of stem cells in these cases may prove beneficial in future though it is too early to comment further.

EULAR/PReS endorsed consensus criteria for the classification of childhood vasculitides

BACKGROUND

There has been a lack of appropriate classification criteria for vasculitis in children.

OBJECTIVE

To develop a widely accepted general classification for the vasculitides observed in children and specific and realistic classification criteria for common childhood vasculitides (Henoch-Schönlein purpura (HSP), Kawasaki disease (KD), childhood polyarteritis nodosa (PAN), Wegener's granulomatosis (WG), and Takayasu arteritis (TA)).

METHODS

The project was divided into two phases: (1) the Delphi technique was used to gather opinions from a wide spectrum of paediatric rheumatologists and nephrologists; (2) a consensus conference using nominal group technique was held. Ten international experts, all paediatricians, met for the consensus conference. Agreement of at least 80% of the participants was defined as consensus.

RESULTS

Consensus was reached to base the general working classification for childhood vasculitides on vessel size. The small vessel disease was further subcategorised into "granulomatous" and "non-granulomatous." Final criteria were developed to classify a child as HSP, KD, childhood PAN, WG, or TA, with changes introduced based on paediatric experience. Mandatory criteria were suggested for all diseases except WG.

CONCLUSIONS

It is hoped that the suggested criteria will be widely accepted around the world because of the reliable techniques used and the international and multispecialist composition of the expert group involved.

T cell Vbeta repertoires in childhood vasculitides

Superantigens (SAgs) are potent stimulators of T cells bearing specific Vbeta T cell receptors (TCR) and may play a role in the aetiopathogenesis of systemic vasculitis, although this remains contentious. To investigate the possible aetiological role of SAgs, this study examined peripheral blood T cell Vbeta repertoires in children with systemic vasculitis. FACS analysis of 17 different peripheral blood T cell Vbeta families was performed in 20 healthy control children, 27 disease control children with nonvasculitic inflammatory disease, 25 children with primary systemic vasculitis, six patients with Kawasaki disease (KD) and six patients with Henoch-Schönlein purpura (HSP). There was a significantly increased variance of CD4 Vbeta12 and Vbeta17, and CD8 Vbeta1 in the primary systemic vasculitis group compared to control and disease controls. Moreover, 80% of the primary systemic vasculitis children had one or more CD4 Vbeta expansions or deletions, compared with 30% of controls (P < 0.002), and 37% of the disease controls (P < 0.002). In the KD group, the mean percentage of CD4 Vbeta2 T cells was higher than in controls or disease controls. In the HSP group, there was no consistent skewing of the T cell Vbeta repertoire. We have observed changes in the T cell Vbeta repertoire in children with vasculitis over and above those observed in disease controls. While these data provide impetus for further research into this contentious field, they do not resolve unequivocally the question of the role of SAgs in childhood vasculitic syndromes.

Treatment of focal glomerulosclerosis with pulse steroids and oral cyclophosphamide

Patients with steroid-resistant nephrotic syndrome often have an unsatisfactory long-term outcome and are at risk of developing chronic renal failure. We prospectively treated 65 children with idiopathic steroid-resistant nephrotic syndrome and focal segmental glomerulosclerosis (FSGS) with intravenous pulses of corticosteroids and oral cyclophosphamide. Dexamethasone (5 mg/kg) or methylprednisolone (30 mg/kg) was administered intravenously, initially 6 pulses on alternate days, followed by 4 fortnightly and 8 monthly pulses. Oral cyclophosphamide therapy was given for 12 weeks and tapering doses of prednisolone were administered for 52 weeks. The mean age at treatment was 85.7+/- 44.9 months. Five patients developed serious infections during administration of initial alternate-day pulses and were excluded. Of 59 patients who completed initial alternate-day therapy, 17 had complete and 8 partial remission; 34 (57.6%) patients did not respond to treatment. The median urine protein to creatinine ratio decreased from 10.0 to 0.75 (P<0.005) and serum albumin increased from 1.9 g/dl to 2.4 g/dl (P<0.01). The median duration of follow-up after stopping pulse therapy was 25.6 months. Thirty-four patients were followed for more than 3 years (median 4.5 years). Of these, 22 (64.7%) patients had a favorable outcome; persistent complete remission was seen in 15 patients and steroid-responsive relapses in 7. Seven patients had non- nephrotic-range proteinuria, 2 had nephrotic-range proteinuria, and 3 (8.8%) were in chronic renal failure. There was no significant difference in the short- and long-term outcome of patients with initial (n=28) and late resistance (n=31). The outcome in patients receiving intravenous dexamethasone (n=48) or methylprednisolone (n=11) was also similar. The chief side effects included worsening of height standard deviation score (47.4%), transient hypertension (42.5%), and serious infections (18.5%). We conclude that prolonged treatment with intravenous corticosteroids and oral cyclophosphamide is beneficial in patients with steroid-resistant FSGS. Expensive protocols can be successfully modified and used, depending upon the availability of health resources.

Urinary tract infections: evaluation and treatment

Urinary tract infections (UTI) are the second most common bacterial infection in children after those of the respiratory tract. These infections are important in view of their acute morbidity and the long-term risk of renal scarring. Occurrence of UTI below two years of age, delay in starting treatment and presence of vesicoureteric reflux or obstruction are the chief risk factors associated with renal scarring. The classical features of UTI are absent in young children, who often present with few signs or symptoms other than fever. Since the diagnosis of UTI warrants a thorough evaluation subsequently, empiric treatment based on symptoms or urinalysis alone should be avoided. Therapy with appropriate antibiotics is started only after obtaining a urine culture. The distinction between upper and lower urinary tract infections is difficult and the choice of therapy guided by the patient's age and severity of clinical manifestations. All children with UTI should be investigated to identify those with an underlying urinary tract anomaly.

Association of parvovirus B19 infection with idiopathic collapsing glomerulopathy

BACKGROUND

Collapsing glomerulopathy (CG), a disorder with severe glomerular and tubular involvement, occurs either as an idiopathic lesion or in some patients with human immunodeficiency virus (HIV) infection known as HIV-associated nephropathy (HIVAN). We previously reported a renal transplant recipient with de novo CG and red cell aplasia in association with persistent parvovirus B19 (PVB19) infection. This prompted us to look for an association between PVB19 infection and CG.

METHODS

DNA from archived biopsies of patients with CG was analyzed for PVB19 by polymerase chain reaction (PCR). Results were compared with HIVAN, idiopathic focal segmental glomerulosclerosis (FSGS), and controls. In situ hybridization (ISH) was done to localize PVB19 in renal biopsies. Peripheral blood specimens of patients with CG, HIV infection, healthy controls, and randomly selected hospitalized patients (sick controls) were also analyzed for PVB19.

RESULTS

PVB19 DNA was detected in renal biopsies of 18 out of 23 (78.3%) patients with CG, 3 out of 19 (15.8%) with HIVAN, 6 out of 27 (22.2%) with FSGS, and 7 out of 27 (25.9%) controls (P < 0.01, CG vs. HIVAN, FSGS, and controls). PVB19 was detected in peripheral blood of 7 out of 8 (87.5%) CG patients, 3 out of 22 (13.6%) with HIV infection, 4 out of 133 (3%) healthy controls, and 2 out of 50 (4%) sick controls (P < 0.001, CG vs. HIV infected, healthy, and sick controls). PVB19 was identified in glomerular parietal and visceral epithelial and tubular cells by ISH.

CONCLUSIONS

The significantly higher prevalence of PVB19 DNA in renal biopsies and peripheral blood of CG patients suggests a specific association between PVB19 infection and CG. In susceptible individuals, renal epithelial cell infection with PVB19 may induce CG.

Hypocalcemic heart failure masquerading as dilated cardiomyopathy

Hypocalcemia is a rare, but reversible, cause of congestive heart failure. We report a 4-month-old boy diagnosed as dilated cardiomyopathy who had prolonged QoTc with low blood levels of calcium, normal phosphate, elevated alkaline phosphatase and findings suggestive of rickets. In view of non response to calcium and vitamin D3, a possible diagnosis of VDDR I (Vitamin D-dependent rickets) was made and he was treated with calcium and calcitriol. The serum calcium levels normalised within 10 days, along with resolution of the signs and symptoms of heart failure, near normal left ventricular function and normalisation of QoTc. Pediatricians should be aware of the association of hypocalcemia with cardiac dysfunction and should keep it as a possible reversible cause of heart failure in children.

Role of supravital staining of urine sediment and bright field microscopy in diagnosis of acute renal failure in bedside medicine

BACKGROUND

An early accurate etiological categorization of acute renal failure (ARF) into acute glomerulonephritis (AGN), acute tubular necrosis (ATN) and acute interstitial nephritis (AIN) is very important in clinical medicine.

METHODS

To evaluate the efficacy of a simple, cheap supravital staining method developed in our laboratory, we examined urine of 32 cases of ARF at their initial presentation in oliguric phase, which were later biopsied. The stain consisted of 1% crystal violet and 0.5% safranin in normal saline. The coverslip preparations of coded and stained urine sediments were examined under ordinary bright field microscope (BFM) by two independent observers.

RESULTS

The renal biopsy showed 12 cases of AGN, 12 ATN and 8 AIN. The diagnosis could be predicted by supravital staining method in 75% cases with 95% uniformity among two observers with a sensitivity of 85.7% for AGN followed by AIN (80%) and ATN (75%).

CONCLUSION

Thus this simple supravital staining technique can be used with ordinary BFM for accurate urine sediment analysis in cases of ARF in bedside medicine.

Sustained hypertension in children

OBJECTIVE

To study the etiology and clinical profile of children with sustained hypertension.

DESIGN

Retrospective hospital-based study.

SETTING

Tertiary care, referral center.

SUBJECTS

246 children with sustained hypertension presenting between January 1983 and December 1996.

RESULTS

The mean age at presentation was 8.2+/-3.9 yr; range 2 months-16 yr. There were 180 boys. An underlying cause for hypertension was identified in 242 (98.4%); 4 patients were considered to have essential hypertension. The chief causes included chronic glomerulonephritis (GN) in 121 (49.2%), obstructive uropathy in 39 (15.8%), reflux nephropathy in 30 (12.2%), thrombotic microangiopathy in 15 (6.1%) and renovascular disease in 14 (5.7%). Takayasu's disease was the most common cause of renovascular hypertension. Coarctation of aorta was the commonest cause of hypertension in infancy, being present in 53.3% of cases. In 198 subjects (80.5%) hypertension was detected as a feature of a known underlying disease. Thirty-five patients however, presented for the first time with complications of severe hypertension, including congestive cardiac failure in 21 and encephalopathy in 23. Thirteen patients presented with nonspecific symptoms and hypertension was detected on clinical examination.

CONCLUSIONS

Most patients with sustained hypertension have an underlying etiology. A significant proportion of patients with renovascular and endocrine conditions may present, for the first time, with complications of hypertension.

Phrenic nerve palsy: a rare complication of indwelling subclavian vein catheter

The use of central venous catheters as access for hemodialysis has become common in children with end-stage renal disease. Phrenic nerve palsy is an unusual complication of this procedure. We report a case of delayed right diaphragmatic palsy due to phrenic nerve damage resulting from an indwelling right subclavian catheter in a 3-year-old child.

Traditional Indian systems of medicine

INTRODUCTION

A number of traditional systems of medicine exist in India of which Ayurveda is the most popular. Despite being in use for more than 3000 years, few properly designed trials have scientifically examined the clinical potential of Ayurvedic and other medications.

METHODS

We reviewed the MEDLINE database to identify clinical trials conducted using traditional Indian medicines. Single case reports were excluded.

RESULTS

Ayurvedic preparations have been successfully used for the treatment of bronchial asthma, ischaemic heart disease and hyperlipidaemia. Formulations containing curcumin were reported to reduce inflammation and disability in double-blind clinical trials on patients with rheumatoid arthritis. A number of products are reported to be useful in patients with acute viral hepatitis. A multicentric study by the Indian Council of Medical Research showed that a preparation from Pterocarpus marsupium was effective in reducing levels of blood glucose and glycosylated haemoglobin in patients with non-insulin-dependent diabetes mellitus. In another multicentric trial, patients with fistula-in-ano were randomised to surgery or application of medicated seton (Ksharsootra). Surgical treatment led to a faster cure but recurrence rates were lower with medicated seton. Administration of extract from Bacopa monnieri, to children with mental retardation, was reported to significantly improve short-term and long-term memory.

CONCLUSIONS

Evidence-based studies on the efficacy and safety of traditional Indian medicines are limited. The essential ingredient in most formulations is not precisely defined. High quality studies are necessary to evaluate and compare the value of traditional Indian drugs to modern medicine.

Prolonged versus standard prednisolone therapy for initial episode of nephrotic syndrome

We have examined, in a prospective randomized controlled trial, the effect of 8- and 16-week initial steroid treatment on the course of idiopathic nephrotic syndrome (INS). Patients with a first episode of INS were randomized to receive standard 8-week prednisolone (2 mg/kg daily for 4 weeks, then 1.5 mg/kg on alternate days for 4 weeks) or prolonged 16-week prednisolone treatment (2 and 1.5 mg/kg daily each for 4 weeks, then 1.5 and 1 mg/kg on alternate days each for 4 weeks). Relapses were treated with prednisolone, 2 mg/kg daily for 2 weeks, then 1.5 mg/kg on alternate days for 4 weeks. Of 45 patients, 23 received standard therapy and 22 prolonged therapy. The mean duration of follow-up was 29.2 and 27.3 months in the standard and prolonged treatment groups, respectively. The time to first relapse was longer in the prolonged treatment (mean 222.2 days, median 120.0 days) than the standard group (mean 134.3 days, median 96.5 days). The percentage of patients with no relapse at 6 and 12 months after prednisolone withdrawal was 40.9% and 27.3% in the prolonged treatment and 21.7% and 8.7% in the standard groups, respectively. The inability to show statistically significant differences between the two groups was probably related to the small number of patients studied. Prolonged therapy did not affect the subsequent relapse rates and proportion of patients with frequent relapses and steroid dependence. The mean dose of prednisolone received, for the initial episode and relapses during the next year, was higher and associated with significant steroid toxicity in the prolonged treatment group. Our findings suggest that 16-week prednisolone treatment for the initial episode of INS may delay occurrence of the first relapse, but results in significant side effects. Prolongation of initial therapy may be useful in developing countries where frequent infections often induce early relapses.

An indigenously developed nitrite kit to aid in the diagnosis of urinary tract infection

OBJECTIVE

To evaluate the utility of an indigenously developed nitrite kit for the rapid diagnosis of urinary tract infection (UTI) METHODS: 1018 urine specimens were collected from all cases where there was clinical suspicion of UTI. Samples were cultured as per standard microbiological protocol. Presence of nitrites was indicated by the development of purple color on addition of color developing solution and compared with the set of graded positive and negative controls also provided in the Kit.

RESULTS

The results of the nitrite kit were compared with the semi-quantitative urine culture as the gold standard. The sensitivity, specificity, positive predictive and negative predictive values were 47%, 87%, 31% and 93%, respectively.

CONCLUSION

Nitrite kit as a screening test can decrease the work load in the clinical bacteriology laboratory. More importantly in a field set up that is devoid of culture facilities, it can be used to correctly predict the absence of UTI.

McCune Albright syndrome and hypophosphatemic rickets

A 4 year-old girl had coxa vara, tibial bowing and hyperpigmented macules. The x-ray showed polyostotic fibrous dysplasia and evidence of rickets. Biochemical investigations confirmed hyperphosphaturic hypophosphatemic rickets. The literature has been reviewed.