Consensus regarding diagnosis and management of atypical hemolytic uremic syndrome

Thrombotic microangiopathy (TMA) is defined by specific clinical characteristics, including microangiopathic hemolytic anemia, thrombocytopenia, and pathologic evidence of endothelial cell damage, as well as the resulting ischemic end-organ injuries. A variety of clinical scenarios have features of TMA, including infection, pregnancy, malignancy, autoimmune disease, and medications. These overlapping manifestations hamper differential diagnosis of the underlying pathogenesis, despite recent advances in understanding the mechanisms of several types of TMA syndrome. Atypical hemolytic uremic syndrome (aHUS) is caused by a genetic or acquired defect in regulation of the alternative complement pathway. It is important to consider the possibility of aHUS in all patients who exhibit TMA with triggering conditions because of the incomplete genetic penetrance of aHUS. Therapeutic strategies for aHUS are based on functional restoration of the complement system. Eculizumab, a monoclonal antibody against the terminal complement component 5 inhibitor, yields good outcomes that include prevention of organ damage and premature death. However, there remain unresolved challenges in terms of treatment duration, cost, and infectious complications. A consensus regarding diagnosis and management of TMA syndrome would enhance understanding of the disease and enable treatment decision-making.

Clinical manifestations of BK virus infection in pediatric kidney transplant patients

Background

Polyomavirus BK (BKV) infection is an important cause of graft loss in kidney transplant patients.

Purpose

The purpose of this study was to evaluate clinical findings and risk factors for BKV in pediatric patients after kidney transplantation.

Methods

This retrospective single-center study included 31 pediatric kidney transplant recipients from January 2002 to December 2017. Two patients received 2 transplantations during the study period, and each transplant was analyzed independently. Total number of cases is 33 cases with 31 patients. BKV infection was confirmed from blood samples via periodic quantitative polymerase chain reaction.

Results

The mean age at kidney transplantation was 11.0±4.7 years, and the male-to-female ratio was 2.7:1. Three patients had a past medical history of high-dose chemotherapy and autologous stem-cell transplantation for solid tumors. Nine patients (27.3%) developed BKV infection. The median period from kidney transplantation to BKV detection in blood was 5.6 months. There was no statistically significant difference in estimated glomerular filtration rate between patients with and those without BKV infection. Among 9 patients with BKV viremia, 7 were treated by reducing their immunosuppressant dose, and BKV was cleared in 6 of these 7 patients. In the other 2 BKV-positive patients, viremia improved without immunosuppressant reduction.

Conclusion

BKV infection is common in children with kidney transplantation and might not have affected short-term renal function in our patient sample due to early immunosuppressant reduction at the time of BKV detection.

Mental health and psychosocial adjustment in pediatric chronic kidney disease derived from the KNOW-Ped CKD study

BACKGROUND

Psychosocial development of pediatric chronic kidney disease (CKD) patients is substantially affected due to growth retardation, frequent school absences, and difficulties engaging in normal peer relationship activities. While many studies focus on specific issues such as depression, anxiety, or neurocognitive function, few evaluate prevalence of various types of mental health and psychosocial adjustment problems among children with CKD. This study aimed to investigate these within the KoreaN cohort study for Outcomes in patients With Pediatric Chronic Kidney Disease (KNOW-Ped CKD).

METHODS

One hundred sixty-six subjects who completed the Korean-Child Behavioral Checklist (K-CBCL) were included. The clinical group comprised subjects with scores indicating psychosocial adjustment or mental health problems using the T scores for the 14 subscales of the K-CBCL. We analyzed associations between mental health or adjustment problems in pediatric CKD and each variable.

RESULTS

Mean age was 11.1 (± 3.9) years, number of males was 117 (70.5%), and 20.5% and 22.3% of children had significant mental health problems and psychosocial adjustment problems, respectively. Overall, 33.1% were assigned to the clinical group, and exhibited short stature and higher rates of preterm birth history compared to the non-clinical group. Subjects with adjustment problems had higher comorbidities such as CNS disease, developmental delay, cardiovascular disease, and multi-organ involvement. Logistic regression analysis revealed preterm birth and developmental delay correlated highly with clinical group.

CONCLUSIONS

A significant proportion of children and adolescents with CKD experience mental health and adjustment problems. In particular, patients with developmental delay or preterm birth history require screening and targeted follow-up.

Structural and molecular modelling studies of antimelanogenic piper-amide TRPM1 antagonists

Piper-amides exhibit diverse biological activities, including antimelanogenic effects. In our previous studies, we identified a potent piper-amide derivative that inhibited melanogenesis via the TRPM1 calcium channel. Despite its potential as a therapeutic target, the three-dimensional structure of TRPM1 is still not available. Thus, structure-guided compound design and the discovery of novel inhibitors of melanogenesis have been limited. In the present study, a series of computational methods, including homology modelling, docking, molecular dynamics simulation and field-based pharmacophore modelling, were integrated to explore the structural features of natural piper-amide-like compounds related to the TRPM1 target. These studies suggested the binding mode and provided a 3D pharmacophore model of the ligands, which can be helpful in understanding the TRPM1-ligand interactions at the molecular level and in designing potent antagonists of TRPM1.

Safety and efficacy of nivolumab in combination with S-1/capecitabine plus oxaliplatin in patients with previously untreated, unresectable, advanced, or recurrent gastric/gastroesophageal junction cancer: interim results of a randomized, phase II trial (ATTRACTION-4)

BACKGROUND

Nivolumab is approved as an option for third- or later-line treatment of advanced gastric/gastroesophageal junction (G/GEJ) cancer in several countries after ATTRACTION-2. To further improve the therapeutic efficacy of first-line therapy, exploration of a nivolumab-chemotherapy combination is warranted. In part 1 (phase II) of ATTRACTION-4, the safety and efficacy of nivolumab combined with S-1 plus oxaliplatin (SOX) or capecitabine plus oxaliplatin (CapeOX) as first-line therapy for unresectable advanced or recurrent human epidermal growth factor receptor 2 (HER2)-negative G/GEJ cancer were evaluated.

PATIENTS AND METHODS

Patients were randomized (1 : 1) to receive nivolumab (360 mg intravenously every 3 weeks) plus SOX (S-1, 40 mg/m2 orally twice daily for 14 days followed by 7 days off; oxaliplatin, 130 mg/m2 intravenously on day 1 every 3 weeks) or CapeOX (capecitabine, 1000 mg/m2 orally twice daily for 14 days followed by 7 days off; oxaliplatin, 130 mg/m2 intravenously on day 1 every 3 weeks) until disease progression, unacceptable toxicity, or consent withdrawal.

RESULTS

Of 40 randomized patients, 39 (nivolumab plus SOX, 21; nivolumab plus CapeOX, 18) and 38 (21 and 17, respectively) comprised the safety and efficacy populations, respectively. Most frequent (>10%) grade 3/4 treatment-related adverse events were neutropenia (14.3%) in the nivolumab plus SOX group, and neutropenia (16.7%), anemia, peripheral sensory neuropathy, decreased appetite, type 1 diabetes mellitus, and nausea (11.1% each) in the nivolumab plus CapeOX group. No treatment-related death occurred. Objective response rate was 57.1% (95% confidence interval 34.0-78.2) with nivolumab plus SOX and 76.5% (50.1-93.2) with nivolumab plus CapeOX. Median overall survival was not reached (NR) in both groups. Median progression-free survival was 9.7 months (5.8-NR) and 10.6 months (5.6-12.5), respectively.

CONCLUSION

Nivolumab combined with SOX/CapeOX was well tolerated and demonstrated encouraging efficacy for unresectable advanced or recurrent HER2-negative G/GEJ cancer. ATTRACTION-4 has proceeded to part 2 (phase III) to compare nivolumab plus SOX/CapeOX versus placebo plus SOX/CapeOX.

CLINICALTRIALS.GOV ID

NCT02746796.

Anemia and Iron Deficiency in Children with Chronic Kidney Disease (CKD): Data from the Know-Ped CKD Study

Children with chronic kidney disease (CKD) are at high risk of anemia, an important risk factor for cardiovascular disease and poor quality of life. The present study used baseline data from the Korean cohort study for Outcome in patients With Pediatric Chronic Kidney Disease (KNOW-PedCKD). A Total of 437 patients was included in the analyses excluding missing data. The characteristics of patients with and without anemia and those of patients with and without iron deficiency were compared. Logistic regression analysis and Pearson correlation were conducted to evaluate associated risk factors and correlations in children with CKD. Anemia in children with CKD was associated with older age, low body weight and body mass index (BMI) z-score, birth age, preceding glomerulonephritis, decreased estimated glomerular filtration rate (eGFR), low levels of serum albumin and calcium, high levels of serum intact parathyroid hormone (iPTH), and serum phosphorus. Anemia was correlated positively with changes in the BMI z-score, body weight, and serum albumin and cholesterol levels, but correlated negatively with serum calcium, iPTH, ferritin levels, and transferrin saturation. Iron deficiency in children with CKD was associated with young age, low hemoglobin and serum ferritin levels, high BMI z-scores, and low levels of serum iPTH. This is the first nationwide cohort study of anemia in Korean children with CKD and the first prospective pediatric CKD cohort study in Asia. The study results demonstrated that anemia and iron deficiency are affected by various factors, including age, BMI, and levels of serum iPTH. To improve the retrospective outcome of affected children, it is important to understand the effect of each of these factors and to attempt an early intervention to prevent anemia and iron deficiency by regular measurement of these parameters in children at risk.

Renal replacement therapy in neonates with an inborn error of metabolism

Hyperammonemia can be caused by several genetic inborn errors of metabolism including urea cycle defects, organic acidemias, fatty acid oxidation defects, and certain disorders of amino acid metabolism. High levels of ammonia are extremely neurotoxic, leading to astrocyte swelling, brain edema, coma, severe disability, and even death. Thus, emergency treatment for hyperammonemia must be initiated before a precise diagnosis is established. In neonates with hyperammonemia caused by an inborn error of metabolism, a few studies have suggested that peritoneal dialysis, intermittent hemodialysis, and continuous renal replacement therapy (RRT) are effective modalities for decreasing the plasma level of ammonia. In this review, we discuss the current literature related to the use of RRT for treating neonates with hyperammonemia caused by an inborn error of metabolism, including optimal prescriptions, prognosis, and outcomes. We also review the literature on new technologies and instrumentation for RRT in neonates

Efficacy and safety of rituximab in childhood-onset, difficult-to-treat nephrotic syndrome: A multicenter open-label trial in Korea

BACKGROUND

The anti-CD20 monoclonal antibody rituximab (RTX) has been proposed as a rescue therapy for difficult-to-treat nephrotic syndrome (NS). We conducted a clinical trial to evaluate the efficacy and safety of RTX in children with difficult-to-treat NS dependent on or resistant to steroids and calcineurin inhibitors (CNIs).

METHODS

A multicenter open-label trial was performed at 8 major pediatric nephrology centers in Korea. The investigation consisted of a randomized controlled trial for steroid- and CNI-dependent NS (DDNS; randomization into the RTX group and the control group, at a ratio of 2:1) and a single-arm study of steroid and CNI-resistant NS (DRNS). DDNS patients in the RTX group and DRNS patients received a single dose of intravenous RTX (375 mg/m of body surface area) for B-cell depletion. A second RTX dose was administered at week 2 if the first dose failed to achieve depletion of CD19(+) cells. The primary endpoint was rate of maintaining remission at 6 months after treatment for DDNS and rate of remission achievement for DRNS.

RESULTS

Sixty-one children with DDNS were enrolled while in remission and randomized to the control group (21 patients) or the RTX group (40 patients). At 6 months after treatment, the remission rates were 74.3% in the RTX group and 31.3% in the control group (P = .003). The mean duration of remission maintenance was significantly higher in the RTX group than in the control group (9.0 vs 2.9 months, P = .004). Of the 23 patients with DRNS enrolled in the single-arm study and treated with RTX, 9 (39.1%) achieved partial or complete remission within 6 months. Depletion of B cells occurred in all patients with RTX therapy. Thirty patients (50.8% of 59 patients analyzed) experienced mild and transient infusion reaction during RTX administration, and most adverse events were mild.

CONCLUSIONS

RTX administration was safe and effective in patients with difficult-to-treat NS. One or 2 doses of RTX may be sufficient to deplete B cells and achieve better control of pediatric NS.

How Cancer Patients Reported Their Quality of Life? Findings From a Nationwide Cross-Sectional Survey in Korea

Background: Cancer treatments have negative physical and socio-emotional consequences. Understanding which problems cancer patients are suffering and their quality of life (QOL) status is therefore important. Aim: This study aimed to describe how cancer patients reported their QOL and factors associated therewith. Methods: A total of 689 cancer patients aged ≥ 19 were selected from the Korea National and Nutrition Examination Survey (KNHANES), 2007-2015. HRQOL was measured using the five dimensions and summary index (ranges from 0 to 1) of the EuroQOL-5 (EQ-5D). Higher index score and less problems reported in dimensions indicates better QOL status. Logistic regression was performed to analyze the probability of cancer patient reporting problem in QOL dimensions. Statistical analyses were adjusted for sample weights. Result: Of 689 participants, mean age was 57.7 ± 0.67, 47.9% were male, 80.4% lived in urban area. 29.3% had hypertension and 15.3% had arthritis as comorbidity. Mean EQ-5D index score was 0.898 ± 0.007; higher score was noted in 19-65 age group (0.932 ± 0.007), living in urban area (0.906 ± 0.008), living in apartment (0.926 ± 0.008), male gender (0.912 ± 0.011), higher income, higher education level and more comorbidities ( P < 0.05). Participants reported more problems in pain or discomfort (34.09%), followed by mobility (24.91%) and usual activities (19.72%). Less problems were recorded in depression (17.37%) and self-care (8.04%). Patients with two or more comorbidities experienced higher chance of reporting problems in mobility, usual activity and self-care (aOR 4.01, 3.11 and 2.82 respectively, P < 0.05). Older age group was associated with higher chance of reporting problems in all QOL dimensions. Female cancer patients experienced higher chance of reporting problems in pain/discomfort and depression/anxiety (aOR 2.11 and 2.18 respectively, P < 0.05). Conclusion: More than one third of Korean adult cancer patients reported moderate or severe level of pain and discomfort. Older age, female gender and having two or more comorbidities were factors associated with lower QOL.

Comparison of overall survival between antiviral-induced viral suppression and inactive phase chronic hepatitis B patients

Nucleot(s)ide analogues (NAs) reduce the risk of hepatocellular carcinoma (HCC) in chronic hepatitis B (CHB) patients. However, the risk of HCC is reportedly higher for NA-treated patients than for patients in the inactive CHB phase. This study aimed to compare the long-term outcomes of CHB patients with NA-induced viral suppression and those of patients with inactive CHB. This retrospective study involved 1118 consecutive CHB patients whose HBV DNA level was continuously <2000 IU/mL during follow-up with/without antiviral agents. The patients were classified into inactive CHB (n = 373) or NA groups (n = 745). The primary endpoint was overall survival. Secondary endpoints included development of HCC and other liver-related events. The median duration of follow-up was 41.0 (interquartile range = 26.5-55.0) months. The difference in overall survival between the NA group vs. the inactive CHB group was not significant (hazard ratio [HR] = 0.78; 95% confidence interval [CI] = 0.33-1.85; P = .57). The NA group showed a significantly higher risk of HCC (HR = 3.44; 95% CI = 1.82-6.52; P < .01), but comparable risk for non-HCC liver-related events (HR = 1.02; 95% CI = 0.66-1.59; P = .93), compared with the inactive CHB group. Among patients with cirrhosis, the NA group showed a significantly lower risk of death (HR = 0.31; 95% CI = 0.097-0.998; P = .05) and non-HCC liver-related events (HR = 0.51; 95% CI = 0.31-0.83; P < .01), but a slightly higher risk of HCC (HR = 2.39; 95% CI = 0.85-6.75; P = .09), compared to the inactive CHB group. The overall survival of untreated patients with inactive CHB and of CHB patients achieving viral suppression with NA was comparable. However, NA treatment of cirrhotic patients was significantly associated with longer overall survival and lower risk of liver-related events.

Antihistamine use and the risk of injurious falls or fracture in elderly patients: a systematic review and meta-analysis

Despite their anticholinergic side effects, first-generation antihistamines are widely prescribed to elderly patients. A systematic review was conducted to synthesize real-world evidence. First-generation antihistamine use is considerably associated with an increased risk of injurious falls or fracture among the elderly.

INTRODUCTION

First-generation antihistamines are considered potentially inappropriate for elderly patients owing to anticholinergic side effects. We aimed to determine whether elderly patients taking antihistamines are at increased risk of injurious falls or fracture.

METHODS

We identified studies in MEDLINE, EMBASE, and several local databases through November 2016. Observational studies on the association between antihistamine use and the risk of injurious falls or fracture were selected. Quality of the studies and the level of evidence were assessed. The random-effects model was employed for meta-analysis, and heterogeneity was examined based on I-square and Cochrane's Q test. Subgroup analyses were performed when the heterogeneity among studies could not be explained.

RESULTS

From 473 identified studies, five (three case-control studies, one cohort study, and one case-crossover study) were included in our analysis based on eligibility criteria. First-generation antihistamine use showed significantly increased risk of injurious falls or fracture (odds ratio [OR] 2.03, 95% confidence interval [CI] 1.49-2.76, heterogeneity: p = 0.41, I² = 0%). Studies including antihistamines of all generations or containing no generation information were dealing with falls during hospitalization. Among these studies, the association was statistically significant without heterogeneity (OR 2.89, 95% CI 1.71-4.89, heterogeneity: p = 0.42, I² = 0%). Due to the small number of studies included and unadjusted results, meaningful interpretation based on subgroup analysis was limited.

CONCLUSIONS

First-generation antihistamine use is considerably associated with increased risk of injurious falls or fracture among the elderly. Clinicians need to exercise caution when prescribing first-generation antihistamines to elderly patients.

A new software scheme for scatter correction based on a simple radiographic scattering model

In common radiography, image contrast is often limited due mainly to scattered x-rays and noise, decreasing the quantitative usefulness of x-ray images. Several scatter reduction methods based on software correction schemes have been extensively investigated in an attempt to overcome these difficulties, most of which are based on measurement, mathematical-physical modeling, or a combination of both. However, those methods require special equipment, system geometry, and extra manual work to measure scatter characteristics. In this study, we investigated a new software scheme for scatter correction based on a simple radiographic scattering model where the intensity of the scattered x-rays was directly estimated from a single x-ray image using a weighted l¹-norm contextual regularization framework. We implemented the proposed algorithm and performed a systematic simulation and experiment to demonstrate its viability. We also conducted some clinical image studies using patient's image data of breast and L-spine to verify the clinical effectiveness of the proposed scheme. Our results indicate that the degradation of image characteristics by scattered x-rays and noise was effectively recovered by using the proposed software scheme, thus improving radiographic visibility considerably. Graphical abstract The schematic illustrations of scatter suppression methods by using a an antiscatter grid and b a scatter estimation algorithm.

Optimal Prescriptions of Continuous Renal Replacement Therapy in Neonates with Hyperammonemia

BACKGROUND/AIMS

The aim of this study was to evaluate patients' outcomes, determine the prescriptions of continuous renal replacement therapy (CRRT) that effectively reduce serum ammonia levels, and analyze the prognostic factors in neonates with hyperammonemia.

METHODS

The medical records of 12 Korean neonates with inborn error of metabolism (IEM) who underwent CRRT for hyperammonemia were retrospectively analyzed.

RESULTS

All patients received continuous venovenous hemodiafiltration. The median ultrafiltration rate (UFR) at the initiation of CRRT was 2,288.4 mL/h/1.73 m2. The median ammonia level at CRRT initiation was 1,320 µmol/L, and the median time to reduce the initial ammonia level by at least 50% was 12.8 h. The survival rate during hospitalization was 83.3%. There were significant differences between patients with neurologic sequelae and those without poor outcomes in peak serum ammonia level before CRRT and serum ammonia level at CRRT initiation.

CONCLUSION

This study suggested that CRRT could be a therapeutic option for neonates with IEM. However, it is necessary to raise the UFR above 4,000 mL/h/1.73 m2 in patients with high initial ammonia level.

Impaired finger dexterity and nigrostriatal dopamine loss in Parkinson's disease

Impaired finger dexterity occurs in Parkinson's disease (PD) and has been considered a limb-kinetic apraxia associated with primary sensory cortical dysfunction. To study the role of nigrostriatal dopamine loss and elementary parkinsonian motor deficits in impaired finger dexterity of PD. Thirty-two right-handed untreated PD patients and 30 right-handed healthy controls were included. All patients underwent [¹⁸F] FP-CIT positron emission tomography studies. We examined the associations among unilateral coin rotation (CR) score, Unified Parkinson's Disease Rating Scale (UPDRS) subscores for bradykinesia and rigidity of the corresponding arm, and contralateral regional striatal dopamine transporter (DAT) uptake. We also measured the effect of oral levodopa dose on CR scores and UPDRS subscores. PD patients performed worse than controls on the CR task. Unilateral arm UPDRS bradykinesia scores were associated with DAT uptake in the contralateral putamen. The left CR score was associated with left arm bradykinesia and rigidity scores and DAT uptake in the right posterior putamen, whereas no such associations were found for the right CR score. There was a significant effect of handedness on the association of putamen DAT uptake with CR scores, but not with UPDRS subscores. An oral levodopa challenge improved CR scores and UPDRS subscores on both sides. Impaired finger dexterity in PD is related to elementary parkinsonian motor deficits and nigrostriatal dopamine loss. Impaired dominant hand dexterity associated with nigrostriatal dopamine loss seems to be compensated to some extent by the dominant cerebral cortex specialized for controlling precise finger movements.

Modelling acute myeloid leukaemia in a continuum of differentiation states

Here we present a mathematical model of movement in an abstract space representing states of cellular differentiation. We motivate this work with recent examples that demonstrate a continuum of cellular differentiation using single cell RNA sequencing data to characterize cellular states in a high-dimensional space, which is then mapped into ℝ 2 or ℝ 2 with dimension reduction techniques. We represent trajectories in the differentiation space as a graph, and model directed and random movement on the graph with partial differential equations. We hypothesize that flow in this space can be used to model normal and abnormal differentiation processes. We present a mathematical model of hematopoeisis parameterized with publicly available single cell RNA-Seq data and use it to simulate the pathogenesis of acute myeloid leukemia (AML). The model predicts the emergence of cells in novel intermediate states of differentiation consistent with immunophenotypic characterizations of a mouse model of AML.

Entecavir and tenofovir reduce hepatitis B virus-related hepatocellular carcinoma recurrence more effectively than other antivirals

Nucleos(t)ide analogues (NAs) have been shown to decrease the risk of hepatocellular carcinoma (HCC) recurrence. This study evaluated whether high-potency NAs (entecavir and tenofovir disoproxil fumarate [TDF]) reduce the risk of tumour recurrence more potently than low-potency NAs after curative treatment of hepatitis B virus (HBV)-related HCC. This study included 607 consecutive HBV-related HCC patients treated with surgical resection or radiofrequency ablation. The patients were categorized into three groups according to antiviral treatment: group A (no antiviral; n = 261), group B (low-potency NA; n = 90) and group C (high-potency NA; n = 256). The primary end-point was recurrence-free survival (RFS). During the duration of follow-up, the median RFS was 29.4, 25.1, and 88.2 months in groups A, B and C, respectively (P < .001, log-rank test). The multivariate Cox analysis indicated that group C had a significantly longer RFS than both group A (adjusted hazard ratio [HR] = 0.39, P < .001) and group B (adjusted HR = 0.47, P < .001). When baseline characteristics were balanced using inverse probability weighting, group C still had a significantly longer RFS than group A (adjusted HR = 0.46, P < .001) and group B (adjusted HR = 0.59, P = .007). Group C had significantly lower risk of viral breakthrough than group B (HR = 0.19, P < .001). Viral breakthrough was an independent risk factor for shorter RFS among groups B and C (adjusted HR = 2.03, P = .007, time-dependent Cox analysis). Antiviral agents with high genetic barrier to resistance (entecavir and TDF) reduced the risk of HCC recurrence compared with other antivirals and no antiviral treatment, especially in patients with high baseline viral load.

Intensity of surveillance for hepatocellular carcinoma determines survival in patients at risk in a hepatitis B-endemic area

BACKGROUND

Data are insufficient regarding the survival benefit of surveillance for hepatocellular carcinoma (HCC).

AIM

To investigate the effectiveness of HCC surveillance in a hepatitis B-endemic population.

METHODS

This retrospective cohort study included 1402 consecutive patients who were newly diagnosed with HCC between 2005 and 2012 at a single tertiary hospital in Korea. The primary endpoint was overall survival. Lead-time and length-time biases were adjusted (sojourn time = 140 days) and sensitivity analyses were performed.

RESULTS

The most common aetiology was hepatitis B (80.4%). Cirrhosis was present in 78.2%. HCC was diagnosed during regular surveillance (defined as mean interval of ultrasonography <8 months, n = 834), irregular surveillance (n = 104) or nonsurveillance (n = 464). Patients in the regular surveillance group were diagnosed at earlier stages ([very] early stage, 64.4%) than the irregular surveillance (40.4%) or nonsurveillance (26.9%) groups and had more chance for curative treatments (52.4%) than the irregular surveillance (39.4%) or nonsurveillance (23.3%) groups (all P < 0.001). Mortality risk was significantly lower in the regular surveillance group (adjusted hazard ratio [aHR], 0.69; 95% [CI], 0.57-0.83) but not in the irregular surveillance group (aHR, 0.94; 95% CI, 0.69-1.28) compared with the nonsurveillance group after adjusting for confounding factors and lead-time. When the subjects were restricted to cirrhotic patients or Child-Pugh class A/B patients, similar results were obtained for mortality risk reduction between groups.

CONCLUSIONS

HCC surveillance was associated with longer survival owing to earlier diagnosis and curative treatment. Survival advantage was significant with regular surveillance but not with irregular surveillance.

Delayed viral suppression during antiviral therapy is associated with increased hepatocellular carcinoma rates in HBeAg-positive high viral load chronic hepatitis B

The treatment option in chronic hepatitis B (CHB) patients with persistent low-level viremia despite entecavir or tenofovir monotherapy is unclear. This study investigated the development of hepatocellular carcinoma (HCC) or cirrhosis in hepatitis B e antigen (HBeAg)-positive high viral load CHB patients, according to the time needed to achieve complete viral suppression. A total of 325 HBeAg-positive CHB patients with high viral load who were recently started on antiviral therapy with entecavir or tenofovir were included. The enrolled patients were divided into 2 groups with 4 separate criteria based on the time needed to achieve complete viral suppression: within 1, 2, 3 or 4 years of therapy initiation. The outcomes were development of HCC and cirrhosis. The cumulative incidence of HCC was significantly higher in patients failing complete viral suppression within 1 year (hazard ratio (HR), 4.54; 95% confidence interval (CI), 1.03-19.93; P = .045) or 2 years (HR, 3.38; 95% CI, 1.24-9.23; P = .018), than patients who achieved complete viral suppression within 1 or 2 years, respectively. Cumulative incidence of cirrhosis was also significantly higher in patients failing suppression within 1 year (HR, 1.95; 95% CI, 1.04-3.66; P = .037) or 2 years (HR, 2.44; 95% CI, 1.41-4.22; P = .001). When the time for achieving viral suppression exceeded 2 years, the cumulative incidence of HCC or cirrhosis was not different regardless of viral suppression. Complete hepatitis B virus suppression within 2 years of antiviral therapy initiation is associated with risk reduction in HCC or cirrhosis development.

The robustness of T2 value as a trabecular structural index at multiple spatial resolutions of 7 Tesla MRI

PURPOSE

To evaluate the robustness of MR transverse relaxation times of trabecular bone from spin-echo and gradient-echo acquisitions at multiple spatial resolutions of 7 T.

METHODS

The effects of MRI resolutions to T₂ and T2* of trabecular bone were numerically evaluated by Monte Carlo simulations. T₂ , T2*, and trabecular structural indices from multislice multi-echo and UTE acquisitions were measured in defatted human distal femoral condyles on a 7 T scanner. Reference structural indices were extracted from high-resolution microcomputed tomography images. For bovine knee trabecular samples with intact bone marrow, T₂ and T2* were measured by degrading spatial resolutions on a 7 T system.

RESULTS

In the defatted trabecular experiment, both T₂ and T2* values showed strong ( |r| > 0.80) correlations with trabecular spacing and number, at a high spatial resolution of 125 µm³ . The correlations for MR image-segmentation-derived structural indices were significantly degraded ( |r| < 0.50) at spatial resolutions of 250 and 500 µm³ . The correlations for T2* rapidly dropped ( |r| < 0.50) at a spatial resolution of 500 µm³ , whereas those for T₂ remained consistently high ( |r| > 0.85). In the bovine trabecular experiments with intact marrow, low-resolution (approximately 1 mm³ , 2 minutes) T₂ values did not shorten ( |r| > 0.95 with respect to approximately 0.4 mm³ , 11 minutes) and maintained consistent correlations ( |r| > 0.70) with respect to trabecular spacing (turbo spin echo, 22.5 minutes).

CONCLUSION

T₂ measurements of trabeculae at 7 T are robust with degrading spatial resolution and may be preferable in assessing trabecular spacing index with reduced scan time, when high-resolution 3D micro-MRI is difficult to obtain.

Acute kidney injury in pediatric patients with rhabdomyolysis

Purpose

This study aimed to evaluate the clinical findings in pediatric rhabdomyolysis and the predictive factors for acute kidney injury (AKI) in Korean children.

Methods

Medical records of 39 Korean children, who were newly diagnosed with rhabdomyolysis from January 2008 to December 2015, were retrospectively analyzed. The diagnosis was made from the medical history, elevated serum creatinine kinase level >1,000 IU/L, and plasma myoglobin level >150 ng/mL. Patients with muscular dystrophy and myocardial infarction were excluded.

Results

The median patient age at diagnosis was 14.0 years (range, 3–18 years), and the male to female ratio was 2.5. The most common presenting symptom was myalgia (n=25, 64.1%), and 14 patients (35.9%) had rhabdomyolysis-induced AKI. Eighteen patients (46.2%) had underlying diseases, such as epilepsy and psychotic disorders. Ten of these patients showed rhabdomyolysis-induced AKI. The common causes of rhabdomyolysis were infection (n=12, 30.7%), exercise (n=9, 23.1%), and trauma (n=8, 20.5%). There was no difference in the distribution of etiology between AKI and non-AKI groups. Five patients in the AKI group showed complete recovery of renal function after stopping renal replacement therapy. The median length of hospitalization was 7.0 days, and no mortality was reported. Compared with the non-AKI group, the AKI group showed higher levels of peak creatinine kinase and myoglobin, without statistical significance.

Conclusion

The clinical characteristics of pediatric rhabdomyolysis differ from those observed in adult patients. Children with underlying diseases are more vulnerable to rhabdomyolysis-induced AKI. AKI more likely develops in the presence of a high degree of albuminuria.

Pediatric renovascular hypertension: Treatment outcome according to underlying disease

BACKGROUND

Renovascular hypertension (RVH) accounts for 5-10% of pediatric hypertension, and can be associated with underlying disease involving other organs. The purpose of this study was to evaluate the clinical characteristics and assess the treatment outcomes of Korean pediatric patients with RVH.

METHODS

The medical records of 25 Korean pediatric patients with RVH were retrospectively reviewed.

RESULTS

Twenty-four patients had underlying disease, and the most common cause was moyamoya disease (MMD; n = 10; 40%). Of 10 patients with MMD, seven had RVH prior to MMD. All patients required antihypertensive medication as the initial treatment and 22 patients subsequently underwent percutaneous transluminal angioplasty (PTA). The majority of patients with MMD had ostial lesions on angiography. Eight patients had favorable outcomes after the first PTA. One patient received nephrectomy, and two patients received bypass surgery because of restenosis after PTA and technical failure of PTA, respectively. During follow up, blood pressure was well-controlled in nine patients, but only four patients were able to discontinue medication. Eight patients had target-organ damage of the brain, heart, and retina at the time of initial diagnosis, and five patients developed chronic kidney disease during follow up.

CONCLUSION

The most common cause of RVH in Korean children is MMD, and RVH caused by MMD with an ostial lesion is associated with poor PTA outcomes. Angioplasty alone does not appear to control blood pressure effectively in MMD patients, and combined treatment is necessary to prevent target organ damage.

Risk of diabetes in viral hepatitis B or C patients compared to that in noninfected individuals in Korea, 2002-2013: A population-based cohort study

While the association between hepatitis C virus (HCV) infection and diabetes has been established, the relationship between hepatitis B virus (HBV) infection and diabetes remains unclear. Therefore, we compared the association between diabetes development in HBV, HCV and co-infected (HBV/HCV) patients to that in noninfected participants using population-based cohort data. We used the National Health Insurance Service-National Sample Cohort, which consists of 514 791 randomly selected persons among those who underwent health check-ups from 2002 to 2003 aged 40-79 years. Adults found to have HBV or HCV infection from 2002 to 2003, without a prior history of diabetes, were selected as subjects. Competing risk regression models were used to estimate cumulative incidence and hazards ratios (HRs) of diabetes development. The cumulative incidences, incidence densities and HRs of diabetes were highest in the co-infected group, followed by those in the HCV-, HBV- and noninfected groups. The 12-year cumulative incidences were as follows: 42.0% in HBV/HCV-, 32.9% in HCV-, 23.9% in HBV- and 18.3% in the noninfected groups. The incidence density per 1000 person-years was 55.0, 51.5, 38.2 and 28.2 for the HBV/HCV-, HCV-, HBV- and noninfected groups, respectively. The adjusted HRs for diabetes were 1.90, 1.68 and 1.41 for the HBV/HCV-, HCV- and HBV-infected groups, respectively. Our findings suggest that both HCV and HBV infections are associated with the development of diabetes; therefore, prevention of, screening for, and treatment of both may reduce the risk of diabetes in these patients.

Scoring and Staging Systems Using Cox Linear Regression Modeling and Recursive Partitioning

Objectives: Scoring and staging systems are used to determine the order and class of data according to predictors. Systems used for medical data, such as the Child-Turcotte-Pugh scoring and staging systems for ordering and classifying patients with liver disease, are often derived strictly from physicians’ experience and intuition. We construct objective and data-based scoring/staging systems using statistical methods.

Methods: We consider Cox linear regression modeling and recursive partitioning techniques for censored survival data. In particular, to obtain a target number of stages we propose cross-validation and amalgamation algorithms. We also propose an algorithm for constructing scoring and staging systems by integrating local Cox linear regression models into recursive partitioning, so that we can retain the merits of both methods such as superior predictive accuracy, ease of use, and detection of interactions between predictors. The staging system construction algorithms are compared by cross-validation evaluation of real data.

Results: The data-based cross-validation comparison shows that Cox linear regression modeling is somewhat better than recursive partitioning when there are only continuous predictors, while recursive partitioning is better when there are significant categorical predictors. The proposed local Cox linear recursive partitioning has better predictive accuracy than Cox linear modeling and simple recursive partitioning.

Conclusions: This study indicates that integrating local linear modeling into recursive partitioning can significantly improve prediction accuracy in constructing scoring and staging systems.

Effectiveness of irrigation with chlorhexidine after removal of mandibular third molars: a randomised controlled trial

To evaluate the effect of postoperative irrigation with chlorhexidine on inflammatory complications after the extraction of lower third molars under local anaesthesia, we recruited 100 patients to participate in a controlled, single-blind, randomised clinical trial. They were assigned to one of two groups: the intervention group (postoperative irrigation of the surgical site with chlorhexidine for seven days) or the control group (postoperative chlorhexidine mouth rinse for seven days). The primary outcome variables were pain, swelling, trismus, infection, and alveolar osteitis. The secondary outcome variables were wound dehiscence and food impaction. A total of 95 participants completed the study (47 in the irrigation group and 48 in the rinse group). In the irrigation group, alveolar osteitis and facial swelling had reduced significantly at seven days postoperatively (both p<0.01). Pain scores had also reduced significantly at seven days (p<0.01), but not at 48hours, and patients had lower levels of food impaction (p<0.01) and less severe symptoms (p=0.02). Routine irrigation with chlorhexidine after the extraction of third molars helps to reduce pain and lowers the incidence of alveolar osteitis.

Rifaximin treatment is associated with reduced risk of cirrhotic complications and prolonged overall survival in patients experiencing hepatic encephalopathy

BACKGROUND

Rifaximin might decrease the risk of portal hypertension-related complications by controlling small intestinal bacterial overgrowth.

AIM

To evaluate whether rifaximin was associated with the risk of death and cirrhotic complications.

METHODS

We conducted a retrospective study that included 1042 patients experiencing hepatic encephalopathy (HE): 421 patients without hepatocellular carcinoma (HCC; the non-HCC cohort) and 621 patients with HCC (the HCC cohort). The primary endpoint was overall survival and secondary endpoints were recurrence of HE and the development of spontaneous bacterial peritonitis (SBP), hepatorenal syndrome (HRS) and variceal bleeding.

RESULTS

In the non-HCC cohort, 145 patients received rifaximin plus lactulose (the rifaximin group) and 276 patients received lactulose alone (the control group). The multivariate analysis revealed that rifaximin was significantly associated with lower risk of death (adjusted hazard ratio [aHR], 0.697; P = .024) and reduced the risk of recurrent HE (aHR, 0.452; P < .001), SBP (aHR, 0.210; P < .001) and variceal bleeding (aHR, 0.425; P = .011) but not HRS (aHR, 0.598; P = .08). In the HCC cohort, 173 patients received rifaximin plus lactulose and 448 patients received lactulose. Rifaximin was not associated with the risk of death (aHR, 1.177; P = .121). Rifaximin was associated with lower risk of SBP (aHR, 0.323; P < .001) but not with variceal bleeding (aHR, 0.660; P = .104) or recurrent HE (aHR, 0.689; P = .057). The risk of Clostridium difficile-associated diarrhoea was not different between the groups (aHR, 0.028; P = .338).

CONCLUSIONS

In patients without HCC, rifaximin treatment was significantly associated with prolonged overall survival and reduced risks of spontaneous bacterial peritonitis, variceal bleeding and recurrent hepatic encephalopathy.

Accuracy and reliability of landmark-based, surface-based and voxel-based 3D cone-beam computed tomography superimposition methods

OBJECTIVES

To evaluate and compare the accuracy and reliability of 3 different methods of three-dimensional cone-beam computed tomography scans (3D CBCTs) superimpositions: landmark-based, surface-based and voxel-based.

MATERIALS AND METHODS

Pre- and post-orthodontic treatment CBCTs (T1 and T2) of 20 subjects with a mean age of 11 years were obtained. Seven points on the zygomatic arch and supraorbital region were selected to perform landmark-based superimposition. Surface-based and voxel-based superimpositions were performed using the anterior cranial base as a reference. Each superimposition method of T1 and T2 scans was repeated twice to assess the reliability. Accuracy of each technique was tested by superimposing duplicated sets of T1 scans. A total of 11 landmarks on the anterior cranial base, maxilla and mandible were located, and deviations of these landmarks on superimposed data were quantified to assess reliability and accuracy of all superimpositions.

RESULTS

There were no significant differences from zero when duplicated sets of T1 scans were superimposed using surface-based and voxel-based methods. Statistical significant differences were detected in several parameters when evaluating the accuracy of the landmark superimposition. Superimposition of T1 and T2 scans for testing the reliability revealed intraclass correlation coefficients greater than 0.90 for all measurements except for ACP-x and PNS-y of landmark-based method as well as ANS-x of voxel-based method.

CONCLUSIONS

Surface-based and voxel-based superimposition methods using the anterior cranial base as a reference structure were accurate and reliable in detecting changes in landmark positions when superimposing. Landmark-based superimposition method was reliable but less accurate than the other methods.