Performance of race-neutral eGFR equations in patients with decompensated cirrhosis.

The 2021 Chronic Kidney Disease Epidemiology Collaboration equation [CKD-EPI 2021] is a race-neutral equation recently developed and rapidly implemented as a reference standard to estimate glomerular filtration rate(GFR). However, its role in cirrhosis has not been examined especially in low GFR. We analyzed the performance of CKD-EPI 2021 compared to other equations with protocol measured GFR(mGFR) in cirrhosis. We analyzed 2090 unique adult patients with cirrhosis undergoing protocol GFR measurements using iothalamate clearance from 1985-2015 when listed for liver transplantation at Baylor University in Dallas and Fort Worth, Texas. Using mGFR as a reference standard, the CKD-EPI 2021 was compared to CKD-EPI 2012, MDRD-4, MDRD-6, RFH and GRAIL overall and in certain subgroups(ascites, mGFR≤30 mL/min/1.73 m 2 , diagnosis, MELD and gender). We examined bias(difference between eGFR and mGFR), accuracy(p30: eGFR within ±30% of mGFR) and agreement between eGFR and mGFR categories. CKD-EPI 2021 had the 2 nd lowest bias across the entire range of GFR after GRAIL (6.6 vs. 4.6 mL/min/1.73 m 2 , respectively, p <0.001). Accuracy of CKD-EPI 2021 was similar to CKD-EPI 2012 (p30=67.8% vs. 67.9%, respectively) that was higher than the other equations ( p <0.001). It had a similar performance in patients with ascites, by diagnoses, MELD subgroups, by sex and in non-Black patients. However, it had a relatively higher overestimation in mGFR≤30 mL/min/1.73 m 2 than most equations (18.5 mL/min/1.73m 2 , p <0.001). Specifically, 64% of patients with mGFR≤30 mL/min/1.73m 2 were incorrectly classified to a less severe CKD stage by CKD-EPI 2021. In Blacks, CKD-EPI 2021 underestimated eGFR by 17.9 mL/min/1.73 m 2 that was higher than the alternate equations except RFH ( p <0.001). The novel race-neutral eGFR equation, CKD-EPI 2021, improves the GFR estimation overall but may not accurately capture true kidney function in cirrhosis specifically at low GFR. There is an urgent need for a race-neutral equation in liver disease reflecting the complexity of kidney function physiology unique to cirrhosis given implications for organ allocation and dual organ transplant.

Predictors of Respiratory Failure Development in a Multicenter Cohort of Inpatients With Cirrhosis.

INTRODUCTION: Hospitalized patients with cirrhosis can develop respiratory failure (RF), which is associated with a poor prognosis, but predisposing factors are unclear. METHODS: We prospectively enrolled a multicenter North American cirrhosis inpatient cohort and collected admission and in-hospital data (grading per European Association for the Study of Liver-Chronic Liver Failure scoring system, acute kidney injury [AKI], infections [admission/nosocomial], and albumin use) in an era when terlipressin was not available in North America. Multivariable regression to predict RF was performed using only admission day and in-hospital events occurring before RF. RESULTS: A total of 511 patients from 14 sites (median age 57 years, admission model for end-stage liver disease [MELD]-Na 23) were enrolled: RF developed in 15%; AKI occurred in 24%; and 11% developed nosocomial infections (NI). At admission, patients who developed RF had higher MELD-Na, gastrointestinal (GI) bleeding/AKI-related admission, and prior infections/ascites. During hospitalization, RF developers had higher NI (especially respiratory), albumin use, and other organ failures. RF was higher in patients receiving albumin (83% vs 59%, P < 0.0001) with increasing doses (269.5 ± 210.5 vs 208.6 ± 186.1 g, P = 0.01) regardless of indication. Admission for AKI, GI bleeding, and high MELD-Na predicted RF. Using all variables, NI (odds ratio [OR] = 4.02, P = 0.0004), GI bleeding (OR = 3.1, P = 0.002), albumin use (OR = 2.93, P = 0.01), AKI (OR = 3.26, P = 0.008), and circulatory failure (OR = 3.73, P = 0.002) were associated with RF risk. DISCUSSION: In a multicenter inpatient cirrhosis study of patients not exposed to terlipressin, 15% of patients developed RF. RF risk was highest in those admitted with AKI, those who had GI bleeding on admission, and those who developed NI and other organ failures or received albumin during their hospital course. Careful volume monitoring and preventing nosocomial respiratory infections and renal or circulatory failures could reduce this risk.

Frailty as a predictor of poor outcomes among patients awaiting liver transplant: a systematic review and meta-analysis.

Aim: This review sought to evaluate the significance of a functional assessment for liver transplant candidates, i.e., frailty, in the pre-transplant setting and its association with mortality and morbidities. Background: Liver transplantation (LT) remains the treatment of choice for patients with end-stage liver disease. Due to the shortage of organs for LT, a careful selection of suitable recipients is essential. Frailty, a measure of physiologic reserve and increased vulnerability to stressors, was initially used in geriatrics and then introduced to the field of transplantation for better patient selection. Methods: PubMed, Scopus, and Web of Science databases were reviewed up until January 2023. The search terms included: "frail*", "liver", and "transplant*". A Meta-analysis was conducted for the hazard ratios (HRs) obtained from the COX regression models. Fifty-five studies were included in this review; ten were included in the meta-analysis. Results: The prevalence of frailty varied from 2.82% to 70.09% in the studies. Meta-analysis showed that overall frailty had a significant association with mortality (pooled adjusted HR [95%CI]: 2.66 [1.96-3.63]). Subgroup analyses revealed that both the Liver Frailty Index and Fried Frailty Index were significantly associated with mortality. Furthermore, these studies have demonstrated that this population's frailty is associated with ascites, hepatic encephalopathy, and esophageal varices. Conclusion: According to emerging evidence, frailty is associated with increased morbidity and mortality of the patients on the LT waiting list. Further randomized trials are required to determine the efficacy and safety of variable interventions in the frail population.

Nonselective beta-blocker use is associated with increased hepatic encephalopathy-related readmissions in cirrhosis.

BACKGROUND: Hepatic encephalopathy (HE) is a neurocognitive condition in cirrhosis leading to frequent hospitalizations. Nonselective beta-blockers (NSBBs) are the mainstay of pharmacologic treatment in cirrhotic patients. We hypothesized that since NSBBs decrease cardiac output and portal flow, the decreased metabolic filtering process of liver parenchyma may lead to increased HE-related hospitalizations. AIM: To evaluate the impact of NSBB administration on HE-related readmissions in cirrhotic patients. METHODS: In this retrospective cohort study, we included 393 patients admitted to Baylor University Medical Center for liver-related portal hypertension indications between January 2013 and July 2018. Independent predictors of the first HE-related readmissions were identified using Cox proportional hazards analysis. The cumulative incidence of the first HE-related readmissions between patients receiving NSBBs and not receiving NSBBs was examined using Fine-Gray modeling to account for the competing risk of death or liver transplantation. RESULTS: The mean age was 58.1 ± 10.2 years and most patients fell into Child class C (49.1%) or B (43.8%). The median Model for End-Stage Liver Disease-Sodium score was 22 (IQR: 11). The cumulative incidence of the first HE-related readmissions was significantly higher in patients taking NSBBs compared to patients not receiving NSBBs (71.8% vs 41.8%, P < 0.0001). In multivariate analysis, after adjusting for demographics, markers of liver disease severity, selective beta-blocker, lactulose and rifaximin use, NSBB use [Hazard ratio: 1.74 (95%CI: 1.29-2.34)] was independently associated with the first HE-related readmissions over a median follow-up of 3.8 years. CONCLUSION: NSBB use is independently associated with increased HE-related readmissions in patients with cirrhosis, regardless of liver disease severity.

Hepatic Encephalopathy: Current and Emerging Treatment Modalities.

Hepatic encephalopathy (HE) is a potentially reversible neurocognitive complication of cirrhosis. It has been reported in at least 30% of patients with cirrhosis and imposes a significant economic burden on caregivers and the healthcare system. Ammonia has been recognized as the culprit in HE development, and all the currently approved treatments mostly act on this toxin to help with HE resolution. After a brief overview of HE characteristics and pathophysiology, this review explores the current accepted treatments for this debilitating complication of cirrhosis. This is followed by an overview of the novel available therapies and a brief focus on future treatment modalities for HE.

Strongyloides stercoralis and cytomegalovirus coinfection in a patient with a transplanted kidney.

Cytomegalovirus is a major opportunistic infection after transplantation with significant morbidity and mortality for solid organ transplant recipients. Unrecognized infection with Strongyloides stercoralis may result in significant morbidity and mortality in immunocompromised patients. Coinfection with multiple pathogens is possible, leading to diagnostic delays, and may make treatment more challenging. We report a case of coinfection with S. stercoralis and cytomegalovirus in a kidney transplant patient that resulted in pneumonitis, gastritis, and cholecystitis.

Prediction of long-term morbidity and mortality after liver transplantation using two-dimensional shear wave elastography compared with liver biopsy.

The role of noninvasive liver disease assessment by two-dimensional shear wave elastography (2D-SWE) to diagnose fibrosis is well described in patients with chronic liver disease. However, its role in prognosis, especially after liver transplantation (LT) has not been adequately examined. We hypothesized that elevated liver stiffness measurement (LSM) as measured by 2D-SWE after LT predicts future morbidity and mortality independent of fibrosis by liver biopsy. In a prospective cohort study, consecutive LT recipients underwent concomitant protocol 2D-SWE and protocol liver biopsy (2012-2014), with the assessor blinded to biopsy findings. We examined the baseline correlation of LSM with fibrosis stage and the association between elevated LSM and the development of subsequent clinical outcomes and all-cause mortality. A total of 187 LT recipients (median age 58 years, 38.5% women, median body mass index 26.5 kg/m2 , 55.1% hepatitis C virus, 17.6% nonalcoholic steatohepatitis/cryptogenic) were examined. Median time between LT and biopsy/2D-SWE assessment was 4.0 years, and the median follow-up time after LSM determination was 3.5 years. Median LSM was 9 kPa (8 kPa [F0/F1], 11.5 kPa [F2], 12 kPa [F3/F4]). There was a positive correlation between LSM and fibrosis stage (rs  = 0.41; p < 0.001). LSM ≥11 kPa was associated with lower survival within 3 years (84.8 vs. 93.7%; p = 0.04). After adjusting for age, sex, and fibrosis stage, LSM ≥11 kPa was independently associated with mortality (hazard ratio, 2.45; 95% confidence interval, 1.08-5.60). Elevated LSM by 2D-SWE is associated with increased mortality after LT independent of hepatic fibrosis. Given the overall decrease in the use of liver biopsy in the current era, 2D-SWE may serve as a novel noninvasive prognostic tool to predict relevant outcomes late after LT.

Predicting clinical decompensation in patients with cirrhosis using the Hepquant-SHUNT test.

BACKGROUND: Early identification of risk for decompensation in clinically stable cirrhotic patients helps specialists target early interventions and supports effective referrals from primary care providers to specialty centres. AIMS: To examine whether the HepQuant-SHUNT test (HepQuant LLC, Greenwood Village, Colorado, USA) predicts decompensation and the need for liver transplantation, hospitalisation or liver-related death. METHODS: Thirty-five compensated and 35 subjects with a previous episode of decompensation underwent the SHUNT Test and were followed for a median of 4.2 years. The disease severity index (DSI) (range 0-50) was examined for association with decompensation in compensated patients; and liver transplantation, liver-related death, and the number and days of liver related hospitalisations in all. DSI prediction of decompensation was also evaluated in 84 subjects with compensated cirrhosis from the Hepatitis C Antiviral Long-Term Treatment against Cirrhosis Trial (HALT-C) followed for a median of 5.8 years. RESULTS: At baseline, subjects with prior decompensation had significantly higher DSI than compensated subjects (32.6 vs 20.9, P < 0.001). DSI ≥24 distinguished the decompensated from the compensated patients and independently predicted adverse clinical outcomes (hazard ratio: 4.92, 95% confidence interval: 1.42-17.06). In the HALT-C cohort, 65% with baseline DSI ≥24 vs 19% with DSI <24 experienced adverse clinical outcomes (relative risk 3.45, P < 0.0001). CONCLUSIONS: The SHUNT test is a novel, noninvasive test that predicts risk of decompensation in previously compensated patients. DSI ≥24 is independently associated with risk for clinical decompensation, liver transplantation, death and hospitalisation.

Hepatic Encephalopathy and Nutrition Influences: A Narrative Review.

Hepatic encephalopathy (HE) is a potentially reversible neurocognitive condition seen in patients with advanced liver disease. The overt form of HE has been reported in up to 45% of patients with cirrhosis. This debilitating condition is associated with increased morbidity and mortality and imposes a significant burden on the caregivers and healthcare system. After providing an overview of HE epidemiology and pathophysiology, this review focuses on the interaction of HE and frailty, nutrition requirements and recommendations in cirrhotic patients with HE, and current dietary and pharmacologic options for HE treatment.

Accuracy of exercise tolerance test in the diagnosis of coronary artery disease in patients with left dominant coronary circulation.

BACKGROUND: Exercise is a physiologic stress that helps the physicians to clarify the presence or absence of cardiovascular disease which may be obscure at rest. Although it is sensitive, its specificity is affected by several parameters, such as some metabolic conditions, some structural heart diseases, and some baseline electrocardiogram abnormalities. Currently, the relationship between coronary dominance and accuracy of EET is not examined. Therefore, this study was conducted to determine the potential impact of coronary dominance on the accuracy of EET. METHODS: In this retrospective study, data were gathered from 720 patients from four medical centers. The pattern of dominancy was determined, and the coronary dominance pattern of the patients who had normal angiograms despite abnormal EETs was compared to that from all the patients. RESULTS: Among the patients who had a normal angiogram despite an abnormal EET, 27% were left dominant while the frequency of left dominancy in the whole population of the study was only 10.9% (P=0.013). There were no significant differences in baseline characteristics, such as age and sex, between the two studied groups. CONCLUSION: The results indicated that the presence of left dominance in patients who had normal angiograms despite an abnormal EET was significantly higher than general population. Therefore, left dominance may be considered a confounding factor for EET, producing false positive results.

What do we know about pediatric renal microlithiasis?

Renal or calyceal microlithiasis is a common disorder with increasing prevalence especially in infants and younger children. The main presenting symptoms and the underlying metabolic abnormalities of renal microlithiasis are similar to renal stone. Although renal microlithiasis is considered as a main problem of the health system with diverse etiologies, our information about its natural course is very limited. Hence, further investigations to make an appropriate clinical approach to this entity is mandatory. Also, general practitioners, pediatricians, nephrologists and urologists have to be well educated regarding renal microlithiasis for early diagnosis, appropriate evaluation and proper management of this entity. In this review study, we focused on collection of the present information about different aspects of renal microlithiasis in children.

Epidemiologic Study of Opium Use in Pars Cohort Study: A Study of 9000 Adults in a Rural Southern Area of Iran.

BACKGROUND: Opium is one of the most common substances used worldwide with variable epidemiologic features in different regions. This study was performed in southern Iran, to find the epidemiology of opium use and its association with different factors and diseases. METHODS: This cross-sectional study was performed on baseline data extracted from Pars Cohort Study performed in Valashahr, a rural area in southern Iran. For any subject, information was collected about demographic factors, some common diseases including heart disease, stroke and hypertension and the state of using opium, other substances and cigarettes. RESULTS: There were 4276 males and 4988 females, with a mean age of 52.6 ± 9.7 years of whom 8.4% reported opium use (17.3% of males and 0.7% of females). In men, the history of stroke and heart disease were significantly more common in opium users (12.6% vs. 8.8%, P = 0.001 and 2.8% vs. 1.5%, P = 0.01, respectively) while the history of hypertension was significantly more common in non-opium users (7.8% vs. 10.3%, P = 0.04). Younger age, male gender, being non-married and positive history of joint pain, cigarette smoking and alcohol consumption were the factors associated with opium use. CONCLUSION: Opium use is common in non-married men who have a positive history of cigarette smoking and alcohol consumption in the rural population of southern Iran. It is associated with increased risk of heart disease and stroke and decreased risk of hypertension in males. Global interventional and preventive measures are required to control this complicated social problem.

Acetazolamide and Hydrochlorothiazide Followed by Furosemide Versus Furosemide and Hydrochlorothiazide Followed by Furosemide for the Treatment of Adults With Nephrotic Edema: A Randomized Trial.

BACKGROUND: Nephrotic edema is considered refractory if it does not respond to maximum or near-maximum doses of loop diuretics. This condition can be treated with loop diuretics and thiazides. However, animal studies show that the simultaneous downregulation of pendrin with acetazolamide and inhibition of the sodium-chloride cotransporter with hydrochlorothiazide generates significant diuresis, and furosemide administration following a pendrin inhibitor potentiates furosemide's diuretic effect. Therefore, we performed this study to compare the efficacy of acetazolamide and hydrochlorothiazide followed by furosemide versus furosemide and hydrochlorothiazide followed by furosemide for treatment of refractory nephrotic edema. STUDY DESIGN: Randomized, double-blind, 2-arm, parallel trial. SETTING & PARTICIPANTS: 20 patients with refractory nephrotic edema despite treatment with 80mg of furosemide daily and creatinine clearance > 60mL/min. INTERVENTION: Patients were randomly assigned to 2 groups: group 1 (n=10) received 250mg of acetazolamide and 50mg of hydrochlorothiazide daily and group 2 (n=10) received 40mg of furosemide and 50mg of hydrochlorothiazide daily for 1 week in phase 1. In phase 2, both groups received 40mg of furosemide daily for 2 weeks. OUTCOMES: The primary outcome was absolute change in weight before and at the end of each phase. MEASUREMENTS: Weight and 24-hour urine volume at baseline and the end of each phase. RESULTS: The mean weight decrease was of significantly larger magnitude in group 1 compared with group 2 at the end of phase 1 (-1.4±0.52 [SD] vs -0.65±0.41kg; P=0.001) and phase 2 (-1.6±0.84 vs -0.5±0.47kg; P=0.005). The increase in 24-hour urine volume was also significantly higher in group 1 at the end of phase 2. LIMITATIONS: Small sample size, short follow-up duration, and lack of serum bicarbonate and chloride measurement. CONCLUSIONS: Acetazolamide and hydrochlorothiazide followed by furosemide is more effective than furosemide and hydrochlorothiazide followed by furosemide for the treatment of refractory nephrotic edema.

Comparison of Hemoglobin Levels Before and After Hemodialysis and Their Effects on Erythropoietin Dosing and Cost.

BACKGROUND: Hemoglobin levels measured after hemodialysis, as compared to hemoglobin levels measured before hemodialysis, are suggested to be a more accurate reflection of the hemoglobin levels between hemodialysis sessions, and to be a better reference point for adjusting erythropoietin dosing. OBJECTIVES: The aim of this study was to compare the hemoglobin levels before and after hemodialysis, to calculate the required erythropoietin doses based on these levels, and to develop a model to predict effective erythropoietin dosing. PATIENTS AND METHODS: In this cross-sectional study, the hemoglobin levels of 52 patients with end-stage renal disease were measured before and after hemodialysis. The required erythropoietin doses and the differences in cost were calculated based on the hemoglobin levels before and after hemodialysis. A model to predict the adjusted erythropoietin dosages based on post-hemodialysis hemoglobin levels was proposed. RESULTS: Hemoglobin levels measured after hemodialysis were significantly higher than the hemoglobin levels before hemodialysis (11.1 ± 1.1 vs. 11.9 ± 1.2 g/dL, P < 0.001, 7% increase). The mean required erythropoietin dose based on post-hemodialysis hemoglobin levels was significantly lower than the corresponding erythropoietin dose based on pre-hemodialysis hemoglobin levels (10947 ± 6820 vs. 12047 ± 7542 U/week, P < 0.001, 9% decrease). The cost of erythropoietin was also significantly lower when post-hemodialysis levels were used (15.96 ± 9.85 vs. 17.57 ± 11.00 dollars/patient/week, P < 0.001). This translated into 83.72 dollars/patient/year in cost reduction. The developed model for predicting the required dosage is: Erythropoietin (U/week) = 43540.8 + (-2734.8) × Post-hemodialysis Hb* (g/dL). [(R2) = 0.221; *P < 0.001]. CONCLUSIONS: Using post-hemodialysis hemoglobin levels as a reference point for erythropoietin dosing can result in significant dose and cost reduction, and can protect hemodialysis patients from hemoconcentration. The prediction of the erythropoietin adjusted dosage based on post-hemodialysis Hb may also help in avoiding overdosage.

Pattern of in-hospital pediatric mortality over a 3-year period at University teaching hospitals in Iran.

INTRODUCTION: Causes of death are different and very important for policy makers in different regions. This study was designed to analyze the data for our in-patient children mortality. MATERIALS AND METHODS: In this cross-sectional study from March 2011 to March 2013, all patients from 2 months to 18 years who died in pediatric intensive care unit, emergency room or medical pediatric wards in the teaching hospitals were studied. RESULTS: From a total of 18,915 admissions during a 2-year-period, 256 deaths occurred with a mean age of 4.3 ± 5 years and mortality 1.35%. An underlying disease was present in 70.7% of the patients and in 88.5% of them the leading causes of death were related to the underlying diseases. The most common underlying diseases were congenital heart disease and cardiomyopathy in 50 (27.6%). The four main causes of deaths were sepsis (14.8%), pneumonia (14.5%), congestive heart failure (9.8%), and hepatic encephalopathy (9.8%). CONCLUSION: We may conclude that after sepsis and pneumonia, congestive heart failure, and hepatic encephalopathy are the leading causes of death. Most patients who died had underlying diseases including malignancies, heart and liver diseases as the most common causes.

Effectiveness of treadmill training on balance control in elderly people: a randomized controlled clinical trial.

UNLABELLED: Physical exercise would improve postural stability, which is an essential factor in preventing accidental fall among the elderly population. The aim of this study is to examine the effectiveness of treadmill walking on balance improvement among the elderly people. A total of 30 community dwelling older adults with a Berg Balance Scale score of 36-48 and the ability to walk without aid were considered and divided into control (n=15) and experimental (n=15) groups. Individuals in the experimental group participated in 30 minutes of forward and backward treadmill training based on three times a week interval for a period of four weeks. Individuals in the control group were instructed to continue with their daily routine activity. Before and after training, gait speed was measured by six-minute walk test and balance ability was evaluated by Fullerton Advanced Balance Scale (FABS) and Berg Balance Scale (BBS) tests. Postural sway items such as the Center of Pressure (COP), average displacement and velocity were evaluated by using a force platform system. Data were collected in quiet standing, tandem position and standing on foam pads before and after intervention. After intervention, balance variables in the experimental group indicated a significant improvement in quiet standing on firm and foam surfaces, but no considerable improvement was shown in tandem position. A between-group comparison showed a significant reduction in COP velocity in the sagittal plane (P=0.030) during quiet standing and in the frontal plane (P=0.001) during standing on foam, whereas no significant reduction in COP parameters during tandem position was found. It is recommended that twelve sessions of forward and backward treadmill walk are effective in balance improvement in elderly people. TRIAL REGISTRATION NUMBER: IRCT201209199440N2.

A case of atypical hemolytic uremic syndrome.

A 9-year-old boy presented with fever not responding to antibiotic therapy and elevated blood urea and serum creatinine levels. The patient developed microangiopathic hemolytic anemia and thrombocytopenia during the hospital stay. Kidney biopsy confirmed the diagnosis of atypical hemolytic uremic syndrome (HUS). The patient had sufficient urine output, normal blood pressure, and no evidence of peripheral edema during the whole course of his disease. Serum levels of anti-Epstein-Barr virus immunoglobulin M was elevated, indicating the possible role of Epstein-Barr virus infection in inducing atypical HUS in this patient. The patient underwent hemodialysis with dramatic response. He was discharged with normal kidney function after a few days. Kidney function and platelet count were normal 12 months after the initial presentation. This case report shows that atypical hemolytic uremic syndrome could have unusual presentations such as the absence of oliguria, hypertension, and edema, with rapid recovery and good prognosis.

Elevated serum levels of Vitamin D in infants with urolithiasis.

INTRODUCTION: The pathophysiology of urolithiasis in infancy is not well known. The aim of this study was to investigate whether infants with urolithiasis have higher serum levels of vitamin D, as a possible risk factor for urolithiasis, compared to infants without urinary calculi. MATERIALS AND METHODS: In this case-control study, 36 infants with urolithiasis (age range, 2.5 to 24 months) were enrolled as well as 36 age- and sex-matched infants without urolithiasis. Random urine samples were tested for calcium, phosphorous, oxalate, citrate, uric acid, sodium, potassium, magnesium, and creatinine levels, and also nitroprusside test was done on the samples. Serum levels of potassium, urea nitrogen, creatinine, 25-hydroxyvitamin D3, parathyroid hormone, calcium, phosphorous, and uric acid were measured in all of the infants with urolithiasis. Serum levels of 25-hydroxyvitamin D3 were also measured in the control group. RESULTS: Serum levels of 25-hydroxyvitamin D3 were significantly higher in the infants with urolithiasis than in the controls (33.85 ± 14.78 ng/mL versus 18.26 ± 7.43 ng/mL, P < .001). Nine infants in the urolithiasis group (25%) were found to have hypercalcemia; 3 of these cases also had hypervitaminosis D. Hypercalciuria was detected in 10 infants with urolithiasis (27.8%), hypocitraturia in 6 (16.7%), hypomagnesiuria in 3 (8.3%), and hyperoxaluria in 1 (2.8%). Nineteen infants with urolithiasis had at least one metabolic disorder. CONCLUSIONS: High serum levels of vitamin D may play an important role in the pathogenesis of urolithiasis in infants with hypercalcemia. We recommend evaluation of vitamin D levels in these infants.

Urinary tract infection after kidney transplantation in children and adolescents.

INTRODUCTION: Urinary tract infection (UTI) is common after pediatric kidney transplantation. The purpose of this study was to evaluate the prevalence of UTI and its risk factors in children and adolescents with kidney transplantation in Shiraz Transplant Center. MATERIALS AND METHODS: All children with kidney transplantation from 1992 to 2008 who were under regular follow-up were included in this retrospective study. Confirmed episodes of UTI after the 1st month of kidney transplantation were reviewed. RESULTS: Of the 216 patients younger than 19 years at the time of transplantation, 138 were included. The mean age at the time of kidney transplantation was 13.6 ± 3.5 years. Urinary tract infection was documented in 24 patients (15 girls and 9 boys), of whom 12 experienced 1 episode, 4 had 2 episodes, and 8 had more than 2 episodes, during a median follow-up period of 54 months. Of the patients with UTI, 14 (58%) had urinary reflux-obstruction disorders as the primary kidney disease, 6 (25%) had suffered hereditary diseases, 3 (12.5%) had glomerular disease, and 1 (4.5%) had a urinary calculus. Occurrence of UTI was not significantly different among children with different primary kidney disease (P = .22). Despite using prophylactic antibiotics after the 1st month of kidney transplantation in all 5 patients with neurogenic bladder, they all experienced recurrent UTI. CONCLUSIONS: Despite discontinuation of antibiotic therapy, UTI was uncommon in children after the first month of transplantation. Two significant risk factors for UTI were female gender and neurogenic bladder in this transplant population.