Dyslipidemia in children with chronic kidney disease-findings from the Cardiovascular Comorbidity in Children with Chronic Kidney Disease (4C) study.

BACKGROUND: Dyslipidemia is an important and modifiable risk factor for CVD in children with CKD. METHODS: In a cross-sectional study of baseline serum lipid levels in a large prospective cohort study of children with stage 3-5 (predialysis) CKD, frequencies of abnormal lipid levels and types of dyslipidemia were analyzed in the entire cohort and in subpopulations defined by fasting status or by the presence of nephrotic range proteinuria. Associated clinical and laboratory characteristics were determined by multivariable linear regression analysis. RESULTS: A total of 681 patients aged 12.2 ± 3.3 years with a mean eGFR of 26.9 ± 11.6 ml/min/1.73 m2 were included. Kidney diagnosis was classified as CAKUT in 69%, glomerulopathy in 8.4%, and other disorders in 22.6% of patients. Nephrotic range proteinuria (defined by a urinary albumin/creatinine ratio > 1.1 g/g) was present in 26.9%. Dyslipidemia was found in 71.8%, and high triglyceride (TG) levels were the most common abnormality (54.7%). Fasting status (38.9%) had no effect on dyslipidemia status. Except for a significant increase in TG in more advanced CKD, lipid levels and frequencies of dyslipidemia were not significantly different between CKD stages. Hypertriglyceridemia was associated with younger age, lower eGFR, shorter duration of CKD, higher body mass index (BMI-SDS), lower serum albumin, and higher diastolic blood pressure. CONCLUSIONS: Dyslipidemia involving all lipid fractions, but mainly TG, is present in the majority of patients with CKD irrespective of CKD stage or fasting status and is significantly associated with other cardiovascular risk factors.

Pediatric kidney care experience after the 2023 Türkiye earthquake.

BACKGROUND: Two earthquakes on 6 February 2023 destroyed 10 cities in Türkiye. We report our experience with pediatric victims during these catastrophes, with a focus on crush syndrome related-acute kidney injury (Crush-AKI) and death. METHOD: Web-based software was prepared. Patient demographics, time under rubble (TUR), admission laboratory data, dialysis, and kidney and overall outcomes were recorded. RESULTS: A total of 903 injured children (median age 11.62 years) were evaluated. Mean TUR was 13 h (interquartile range 32.5, max 240 h). Thirty-one of 32 patients with a TUR of >120 h survived. The patient who was rescued after 10 days survived. Two-thirds of the patients were given 50 mEq/L sodium bicarbonate in 0.45% sodium chloride solution on admission day. Fifty-eight percent of patients were given intravenous fluid (IVF) at a volume of 2000-3000 mL/m2 body surface area (BSA), 40% at 3000-4000 mL/m2 BSA and only 2% at >4000 mL/m2 BSA. A total of 425 patients had surgeries, and 48 suffered from major bleeding. Amputations were recorded in 96 patients. Eighty-two and 66 patients required ventilator and inotropic support, respectively. Crush-AKI developed in 314 patients (36% of all patients). In all, 189 patients were dialyzed. Age >15 years, creatine phosphokinase (CK) ≥20 950 U/L, TUR ≥10 h and the first-day IVF volume <3000-4000 mL/m2 BSA were associated with Crush-AKI development. Twenty-two deaths were recorded, 20 of 22 occurring in patients with Crush-AKI and within the first 4 days of admission. All patients admitted after 7 days survived. CONCLUSIONS: These are the most extensive pediatric kidney disaster data obtained after an earthquake. Serum CK level was significantly associated with Crush-AKI at the levels of >20 950 U/L, but not with death. Adolescent age and initial IVF of less than 3000-4000 mL/m2 BSA were also associated with Crush-AKI. Given that mildly injured victims can survive longer periods in the disaster field, we suggest uninterrupted rescue activity for at least 10 days.

Tumor-educated Gr1+CD11b+ cells drive breast cancer metastasis via OSM/IL-6/JAK-induced cancer cell plasticity.

Cancer cell plasticity contributes to therapy resistance and metastasis, which represent the main causes of cancer-related death, including in breast cancer. The tumor microenvironment drives cancer cell plasticity and metastasis, and unraveling the underlying cues may provide novel strategies for managing metastatic disease. Using breast cancer experimental models and transcriptomic analyses, we show that stem cell antigen-1 positive (SCA1+) murine breast cancer cells enriched during tumor progression and metastasis had higher in vitro cancer stem cell-like properties, enhanced in vivo metastatic ability, and generated tumors rich in Gr1hiLy6G+CD11b+ cells. In turn, tumor-educated Gr1+CD11b+ (Tu-Gr1+CD11b+) cells rapidly and transiently converted low metastatic SCA1- cells into highly metastatic SCA1+ cells via secreted oncostatin M (OSM) and IL-6. JAK inhibition prevented OSM/IL-6-induced SCA1+ population enrichment, while OSM/IL-6 depletion suppressed Tu-Gr1+CD11b+-induced SCA1+ population enrichment in vitro and metastasis in vivo. Moreover, chemotherapy-selected highly metastatic 4T1 cells maintained high SCA1+ positivity through autocrine IL-6 production, and in vitro JAK inhibition blunted SCA1 positivity and metastatic capacity. Importantly, Tu-Gr1+CD11b+ cells invoked a gene signature in tumor cells predicting shorter overall survival (OS), relapse-free survival (RFS), and lung metastasis in breast cancer patients. Collectively, our data identified OSM/IL-6/JAK as a clinically relevant paracrine/autocrine axis instigating breast cancer cell plasticity and triggering metastasis.

Spatial Distribution of Macrophage Subtypes Among Rejection Subtypes in Renal Transplant Biopsies by Dual Immunohistochemistry.

We performed dual immunohistochemistry for CD163/CD34 and CD68/CD34 in 108 renal transplant indication biopsies to investigate the presence and distribution of macrophages in various renal compartments. All Banff scores and diagnoses were revised according to the Banff 2019 classification. CD163 and CD68 positive cell counts (CD163pos and CD68pos) were evaluated in the interstitium, glomerular mesangium, and, within glomerular and peritubular capillaries. The diagnosis was antibody-mediated rejection (ABMR) in 38 (35.2%), T-cell mediated rejection (TCMR) in 24 (22.2%), mixed rejection in 30 (27.8%), and no rejection in 16 (14.8%). Banff lesion scores t , i , and ti were correlated with both CD163 and CD68 interstitial inflammation scores ( r > 0.30; P < 0.05). Glomerular total CD163pos was correlated to Banff lesion scores g and cg ( r > 0.30; P < 0.05). Glomerular total, mesangial, and intracapillary CD68pos were correlated with g ( r > 0.30; P < 0.05). Both glomerular total and peritubular capillary CD68pos were correlated with peritubular capillaritis ( r > 0.30; P < 0.05). Glomerular CD163pos were significantly higher in ABMR compared with no rejection, in mixed rejection compared with no rejection and TCMR. CD163pos in peritubular capillaries was significantly higher in mixed rejection compared with no rejection. Glomerular CD68pos was significantly higher in ABMR compared with no rejection. CD68pos per peritubular capillary was higher in mixed rejection, ABMR, and TCMR compared with no rejection. In conclusion, compared with CD68 positive macrophages, localization of CD163 positive macrophages in various renal compartments seems to be different among rejection subtypes and their glomerular infiltration seems to be more specific for the presence of ABMR component.

Advances on the roles of tenascin-C in cancer.

The roles of the extracellular matrix molecule tenascin-C (TNC) in health and disease have been extensively reviewed since its discovery over 40 years ago. Here, we will describe recent insights into the roles of TNC in tumorigenesis, angiogenesis, immunity and metastasis. In addition to high levels of expression in tumors, and during chronic inflammation, and bacterial and viral infection, TNC is also expressed in lymphoid organs. This supports potential roles for TNC in immunity control. Advances using murine models with engineered TNC levels were instrumental in the discovery of important functions of TNC as a danger-associated molecular pattern (DAMP) molecule in tissue repair and revealed multiple TNC actions in tumor progression. TNC acts through distinct mechanisms on many different cell types with immune cells coming into focus as important targets of TNC in cancer. We will describe how this knowledge could be exploited for cancer disease management, in particular for immune (checkpoint) therapies.

Urinary HSP70 can predict the indication of surgery in unilateral ureteropelvic junction obstruction.

BACKGROUND: Distinguishing hydronephrosis that requires surgical intervention is a clinical challenge. The aim of this study is to determine the level of urinary heat shock protein 70 (HSP70) in children who required surgery for ureteropelvic junction obstruction and its potential use as a biomarker for prediction of surgery in children with isolated unilateral hydronephrosis. METHODS: The data of 43 children with ureteropelvic junction obstruction who underwent pyeloplasty, 25 patients with non-obstructive dilation (NOD) and 30 healthy children (control group) were collected prospectively for this study. Preoperative and postoperative urinary HSP70/Cr levels were also analyzed in 30 children in the pyeloplasty group who had available follow-up information. HSP70 levels were assessed using ELISA. RESULTS: The median age of the pyeloplasty group was 13 months (IQR 7-36 months), NOD group was 42.5 months (IQR 16-73) and it was 36 months (IQR 24-47.5) in the control group. The mean preoperative urinary HSP70/Cr was significantly higher in the pyeloplasty group when compared to controls as well as the NOD group (150.6 pg/mgCr vs. 65.0 pg/mgCr and vs. 64.7 pg/mgCr, p < 0.001 and p < 0.001, respectively). The urinary HSP70 levels significantly decreased in the postoperative period (151.5 vs 79.5, p < 0.001). Using the cutoff value of 94.7 pg/mgCr, the sensitivity and specificity of urinary HSP70 for predicting the risk of surgical intervention were 69.7% and 68%, respectively (AUC = 0.689). CONCLUSION: Urinary HSP70 may be used as an adjunct tool to clinical parameters to identify patients that would require surgery due to ureteropelvic junction obstruction.

Early childhood height-adjusted total kidney volume as a risk marker of kidney survival in ARPKD.

Autosomal recessive polycystic kidney disease (ARPKD) is characterized by bilateral fibrocystic changes resulting in pronounced kidney enlargement. Impairment of kidney function is highly variable and widely available prognostic markers are urgently needed as a base for clinical decision-making and future clinical trials. In this observational study we analyzed the longitudinal development of sonographic kidney measurements in a cohort of 456 ARPKD patients from the international registry study ARegPKD. We furthermore evaluated correlations of sonomorphometric findings and functional kidney disease with the aim to describe the natural disease course and to identify potential prognostic markers. Kidney pole-to-pole (PTP) length and estimated total kidney volume (eTKV) increase with growth throughout childhood and adolescence despite individual variability. Height-adjusted PTP length decreases over time, but such a trend cannot be seen for height-adjusted eTKV (haeTKV) where we even observed a slight mean linear increase of 4.5 ml/m per year during childhood and adolescence for the overall cohort. Patients with two null PKHD1 variants had larger first documented haeTKV values than children with missense variants (median (IQR) haeTKV 793 (450-1098) ml/m in Null/null, 403 (260-538) ml/m in Null/mis, 230 (169-357) ml/m in Mis/mis). In the overall cohort, estimated glomerular filtration rate decreases with increasing haeTKV (median (IQR) haeTKV 210 (150-267) ml/m in CKD stage 1, 472 (266-880) ml/m in stage 5 without kidney replacement therapy). Strikingly, there is a clear correlation between haeTKV in the first eighteen months of life and kidney survival in childhood and adolescence with ten-year kidney survival rates ranging from 20% in patients of the highest to 94% in the lowest quartile. Early childhood haeTKV may become an easily obtainable prognostic marker of kidney disease in ARPKD, e.g. for the identification of patients for clinical studies.

Hemodiafiltration Is Associated With Reduced Inflammation and Increased Bone Formation Compared With Conventional Hemodialysis in Children: The HDF, Hearts and Heights (3H) Study.

BACKGROUND: Patients on dialysis have a high burden of bone-related comorbidities, including fractures. We report a post hoc analysis of the prospective cohort study HDF, Hearts and Heights (3H) to determine the prevalence and risk factors for chronic kidney disease-related bone disease in children on hemodiafiltration (HDF) and conventional hemodialysis (HD). METHODS: The baseline cross-sectional analysis included 144 children, of which 103 (61 HD, 42 HDF) completed 12-month follow-up. Circulating biomarkers of bone formation and resorption, inflammatory markers, fibroblast growth factor-23, and klotho were measured. RESULTS: Inflammatory markers interleukin-6, tumor necrosis factor-α, and high-sensitivity C-reactive protein were lower in HDF than in HD cohorts at baseline and at 12 months (P < .001). Concentrations of bone formation (bone-specific alkaline phosphatase) and resorption (tartrate-resistant acid phosphatase 5b) markers were comparable between cohorts at baseline, but after 12-months the bone-specific alkaline phosphatase/tartrate-resistant acid phosphatase 5b ratio increased in HDF (P = .004) and was unchanged in HD (P = .44). On adjusted analysis, the bone-specific alkaline phosphatase/tartrate-resistant acid phosphatase 5b ratio was 2.66-fold lower (95% confidence interval, -3.91 to -1.41; P < .0001) in HD compared with HDF. Fibroblast growth factor-23 was comparable between groups at baseline (P = .52) but increased in HD (P < .0001) and remained unchanged in HDF (P = .34) at 12 months. Klotho levels were similar between groups and unchanged during follow-up. The fibroblast growth factor-23/klotho ratio was 3.86-fold higher (95% confidence interval, 2.15-6.93; P < .0001) after 12 months of HD compared with HDF. CONCLUSION: Children on HDF have an attenuated inflammatory profile, increased bone formation, and lower fibroblast growth factor-23/klotho ratios compared with those on HD. Long-term studies are required to determine the effects of an improved bone biomarker profile on fracture risk and cardiovascular health.

Effects of stabilization exercises on disability, pain, and core stability in patients with non-specific low back pain: A randomized controlled trial.

BACKGROUND: Many studies have emphasized the importance of stabilization exercises (SE) for the management of non-specific low back pain (NSLBP), yet there is no study assessing all aspects of core stability in comparing SE and other exercises. OBJECTIVE: To investigate the effects of SE on pain and core stability by using core stability tests that focus on all aspects of core stability in patients with NSLBP. METHODS: Thirty-seven individuals with chronic NSLBP were randomly divided into two groups as SE and conventional exercises (CE). Both groups underwent the progressive exercise program three days per week for six weeks. The assessments were conducted before and after the exercise programs. The outcome measures included pain, disability, trunk strength, trunk flexor, extensor and lateral flexor endurance, function, flexibility, and motor control during eyes open/closed. RESULTS: All assessment parameters except motor control during eyes open improved after SE (p < 0.05). Also, all assessment parameters except motor control during eyes open/closed and lateral trunk endurance improved after CE (p < 0.05). When comparing groups for gain scores, there were more significant improvements in pain during activity, endurance and function after SE (p < 0.05). CONCLUSIONS: SE is more effective than CE in reducing pain during activity and improving core stability regarding functionality and endurance.

Impact of Tenascin-C on Radiotherapy in a Novel Syngeneic Oral Squamous Cell Carcinoma Model With Spontaneous Dissemination to the Lymph Nodes.

Radiotherapy, the most frequent treatment of oral squamous cell carcinomas (OSCC) besides surgery is employed to kill tumor cells but, radiotherapy may also promote tumor relapse where the immune-suppressive tumor microenvironment (TME) could be instrumental. We established a novel syngeneic grafting model from a carcinogen-induced tongue tumor, OSCC13, to address the impact of radiotherapy on OSCC. This model revealed similarities with human OSCC, recapitulating carcinogen-induced mutations found in smoking associated human tongue tumors, abundant tumor infiltrating leukocytes (TIL) and, spontaneous tumor cell dissemination to the local lymph nodes. Cultured OSCC13 cells and OSCC13-derived tongue tumors were sensitive to irradiation. At the chosen dose of 2 Gy mimicking treatment of human OSCC patients not all tumor cells were killed allowing to investigate effects on the TME. By investigating expression of the extracellular matrix molecule tenascin-C (TNC), an indicator of an immune suppressive TME, we observed high local TNC expression and TIL infiltration in the irradiated tumors. In a TNC knockout host the TME appeared less immune suppressive with a tendency towards more tumor regression than in WT conditions. Altogether, our novel syngeneic tongue OSCC grafting model, sharing important features with the human OSCC disease could be relevant for future anti-cancer targeting of OSCC by radiotherapy and other therapeutic approaches.

Tenascin-C immobilizes infiltrating T lymphocytes through CXCL12 promoting breast cancer progression.

Immune checkpoint therapy, where CD8 tumor infiltrating T lymphocytes (TIL) are reactivated, is a promising anti-cancer treatment approach, yet with low response rates. The extracellular matrix, in particular tenascin-C, may generate barriers for TIL. To investigate this possibility, we used a MMTV-NeuNT and syngeneic mammary gland grafting model derived thereof with engineered tenascin-C levels and observed accumulation of CD8 TIL in tenascin-C-rich stroma. Inhibition studies revealed that tenascin-C induced CXCL12 through TLR4. By binding CXCL12, tenascin-C retained CD8 TIL in the stroma. Blockade of CXCR4, the receptor of CXCL12, enhanced macrophage and CD8 TIL infiltration and reduced tumor growth and subsequent metastasis. Retention of CD8 TIL by tenascin-C/CXCL12 was also observed in human breast cancer by tissue staining. Moreover, whereas high CD8 TIL numbers correlated with longer metastasis-free survival, this was not the case when also tenascin-C and CXCL12 levels were high. Altogether, these results may be useful for improving tumor immunity as diagnostic tool and to formulate a future "TIL-matrix-release-and-reactivate" strategy.

Primary coenzyme Q10 Deficiency-6 (COQ10D6): Two siblings with variable expressivity of the renal phenotype.

Primary coenzyme Q10 deficiency-6 (COQ10D6) is a rare autosomal recessive disorder caused by COQ6 mutations. The main clinical manifestations are infantile progressive nephrotic syndrome (NS) leading to end-stage renal disease and sensorineural deafness. A 7-year-old girl was diagnosed with steroid-resistant NS (SRNS) and an audiological work-up revealed bilateral sensorineural deafness. A renal biopsy demonstrated focal segmental glomerulosclerosis. Despite immunosuppressive therapy, her serum levels of creatinine increased and haemodialysis was indicated within 1 year after the diagnosis. Living-donor kidney transplantation was performed in the eighth month of haemodialysis. A diagnostic custom-designed panel-gene test including 30 genes for NS revealed homozygous c.1058C > A [rs397514479] in exon nine of COQ6. Her older brother, who had sensorineural hearing loss with no renal or neurological involvement, had the same mutation in homozygous form. COQ6 mutations should be considered not only in patients with SRNS with sensorineural hearing loss but also in patients with isolated sensorineural hearing loss with a family history of NS. The reported p.His174 variant of COQ8B was suggested to be a risk factor for secondary CoQ deficiency, while p.Arg174 appeared to improve the condition in a yeast model. Family segregation and the co-occurrence of biallelic p.Arg174 of COQ8B in a brother with hearing loss implied that the interaction of the altered COQ8B with the mutant COQ6 alleviated the symptoms in this family. CoQ10 replacement therapy should be initiated for these patients, as primary CoQ10 deficiency is considered the only known treatable mitochondrial disease.

Tenascin-C increases lung metastasis by impacting blood vessel invasions.

Metastasis is a major cause of death in cancer patients. The extracellular matrix molecule tenascin-C is a known promoter of metastasis, however the underlying mechanisms are not well understood. To further analyze the impact of tenascin-C on cancer progression we generated MMTV-NeuNT mice that develop spontaneous mammary tumors, on a tenascin-C knockout background. We also developed a syngeneic orthotopic model in which tumor cells derived from a MMTV-NeuNT tumor. Tumor cells were transfected with control shRNA or with shRNA to knockdown tenascin-C expression and, were grafted into the mammary gland of immune competent, wildtype or tenascin-C knockout mice. We show that stromal-derived tenascin-C increases metastasis by reducing apoptosis and inducing the cellular plasticity of cancer cells located in pulmonary blood vessels invasions (BVI), before extravasation. We characterized BVI as organized structures of tightly packed aggregates of proliferating tumor cells with epithelial characteristics, surrounded by Fsp1+ cells, internally located platelets and, a luminal monolayer of endothelial cells. We found extracellular matrix, in particular, tenascin-C, between the stromal cells and the tumor cell cluster. In mice lacking stromal-derived tenascin-C, the organization of pulmonary BVI was significantly affected, revealing novel functions of host-derived tenascin-C in supporting the integrity of the endothelial cell coat, increasing platelet abundance, tumor cell survival, epithelial plasticity, thereby promoting overall lung metastasis. Many effects of tenascin-C observed in BVI including enhancement of cellular plasticity, survival and migration, could be explained by activation of TGF-ß signaling. Finally, in several human cancers, we also observed BVI to be surrounded by an endothelial monolayer and to express tenascin-C. Expression of tenascin-C is specific to BVI and is not observed in lymphatic vascular invasions frequent in breast cancer, which lack an endothelial lining. Given that BVI have prognostic significance for many tumor types, such as shorter cancer patient survival, increased metastasis, vessel occlusion, and organ failure, our data revealing a novel mechanism by which stromal tenascin-C promotes metastasis in human cancer, may have potential for diagnosis and therapy.

Risk Factors for Early Dialysis Dependency in Autosomal Recessive Polycystic Kidney Disease.

OBJECTIVE: To identify prenatal, perinatal, and postnatal risk factors for dialysis within the first year of life in children with autosomal recessive polycystic kidney disease (ARPKD) as a basis for parental counseling after prenatal and perinatal diagnosis. STUDY DESIGN: A dataset comprising 385 patients from the ARegPKD international registry study was analyzed for potential risk markers for dialysis during the first year of life. RESULTS: Thirty-six out of 385 children (9.4%) commenced dialysis in the first year of life. According to multivariable Cox regression analysis, the presence of oligohydramnios or anhydramnios, prenatal kidney enlargement, a low Apgar score, and the need for postnatal breathing support were independently associated with an increased hazard ratio for requiring dialysis within the first year of life. The increased risk associated with Apgar score and perinatal assisted breathing was time-dependent and vanished after 5 and 8 months of life, respectively. The predicted probabilities for early dialysis varied from 1.5% (95% CI, 0.5%-4.1%) for patients with ARPKD with no prenatal sonographic abnormalities to 32.3% (95% CI, 22.2%-44.5%) in cases of documented oligohydramnios or anhydramnios, renal cysts, and enlarged kidneys. CONCLUSIONS: This study, which identified risk factors associated with onset of dialysis in ARPKD in the first year of life, may be helpful in prenatal parental counseling in cases of suspected ARPKD.

Glomerular and Tubular Functions in Children and Adults with Transfusion-Dependent Thalassemia.

This study aimed at assessing renal functions in patients with transfusion-dependent thalassemia (TDT). Fifty patients and 30 controls were enrolled in this prospective study. Serum levels of electrolytes and albumin were measured by a spectrophotometer. Serum levels of cystatin-C and urinary levels of ß2-microglobulin were measured by nephelometric method. Thirty-eight patients were receiving deferasirox and 8 were on deferiprone. Serum electrolytes and albumin levels of the patients were found to be within normal ranges. Urinary ß2-microglobulin and serum cystatin-C levels were significantly higher in patients than controls. They did not significantly differ between the subgroup of patients on deferiprone and the control group, whereas they were found to be higher in patients using deferasirox compared to controls. Urinary ß2-microglobulin levels significantly increased in patients who were receiving high-dose deferasirox compared to those who were receiving a daily dose of 15-20 mg/kg or controls. Subclinical renal injury may be present in TDT patients.

Association of Serum Soluble Urokinase Receptor Levels With Progression of Kidney Disease in Children.

Importance: Conventional methods to diagnose and monitor chronic kidney disease (CKD) in children, such as creatinine level and cystatin C-derived estimated glomerular filtration rate (eGFR) and assessment of proteinuria in spot or timed urine samples, are of limited value in identifying patients at risk of progressive kidney function loss. Serum soluble urokinase receptor (suPAR) levels strongly predict incident CKD stage 3 in adults. Objective: To determine whether elevated suPAR levels are associated with renal disease progression in children with CKD. Design, Setting, and Participants: Post hoc analysis of 2 prospectively followed up pediatric CKD cohorts, ie, the ESCAPE Trial (1999-2007) and the 4C Study (2010-2016), with serum suPAR level measured at enrollment and longitudinal eGFR measured prospectively. In the 2 trials, a total of 898 children were observed at 30 (ESCAPE Trial; n = 256) and 55 (4C Study; n = 642) tertiary care hospitals in 13 European countries. Renal diagnoses included congenital anomalies of the kidneys and urinary tract (n = 637 [70.9%]), tubulointerstitial nephropathies (n = 92 [10.2%]), glomerulopathies (n = 69 [7.7%]), postischemic CKD (n = 42 [4.7%]), and other CKD (n = 58 [6.5%]). Total follow-up duration was up to 7.9 years, and median follow-up was 3.1 years. Analyses were conducted from October 2016 to December 2016. Exposures: Serum suPAR level was measured at enrollment, and eGFR was measured every 2 months in the ESCAPE Trial and every 6 months in the 4C Study. The primary end point of CKD progression was a composite of 50% eGFR loss, eGFR less than 10 mL/min/1.73 m2, or initiation of renal replacement therapy. Main Outcomes and Measures: The primary end point in this study was renal survival, defined as a composite of 50% loss of GFR that persisted for at least 1 month, the start of renal replacement therapy, or an eGFR less than 10 mL/min/1.73 m2. Results: Of the 898 included children, 560 (62.4%) were male, and the mean (SD) patient age at enrollment was 11.9 (3.5) years. The mean (SD) eGFR was 34 (16) mL/min/1.73 m2. The 5-year end point-free renal survival was 64.5% (95% CI, 57.4-71.7) in children with suPAR levels in the lowest quartile compared with 35.9% (95% CI, 28.7-43.0) in those in the highest quartile (P < .001). By multivariable analysis, the risk of attaining the end point was higher in children with glomerulopathies and increased with age, blood pressure, proteinuria, and lower eGFR at baseline. In patients with baseline eGFR greater than 40 mL/min/1.73 m2, higher log-transformed suPAR levels were associated with a higher risk of CKD progression after adjustment for traditional risk factors (hazard ratio, 5.12; 95% CI, 1.56-16.7; P = .007). Conclusions and Relevance: Patients with high suPAR levels were more likely to have progression of their kidney disease. Further studies should determine whether suPAR levels can identify children at risk for future CKD.

The Clinical and Mutational Spectrum of Turkish Patients with Cystinosis.

BACKGROUND AND OBJECTIVES: Infantile nephropathic cystinosis is a severe disease that occurs due to mutations in the cystinosis gene, and it is characterized by progressive dysfunction of multiple organs; >100 cystinosis gene mutations have been identified in multiple populations. Our study aimed to identify the clinical characteristics and spectrum of cystinosis gene mutations in Turkish pediatric patients with cystinosis. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We identified the clinical characteristics and spectrum of cystinosis gene mutations in Turkish patients with cystinosis in a multicenter registry that was established for data collection. The data were extracted from this registry and analyzed. RESULTS: In total, 136 patients (75 men and 61 women) were enrolled in the study. The most common clinical findings were growth retardation, polyuria, and loss of appetite. None of the patients had the 57-kb deletion, but seven novel mutations were identified. The most common mutations identified were c.681G>A (p.Glu227Glu; 31%), c.1015G>A (p.Gly339Arg; 22%), and c.18_21 del (p.Thr7Phefs*7; 14%). These mutations were associated with earlier age of disease onset than the other mutations. To understand the effects of these allelic variants on clinical progression, the mutations were categorized into two major groups (missense versus deletion/duplication/splice site). Although patients with missense mutations had a better eGFR at the last follow-up visit, the difference was not significant. Patients in whom treatment began at age <2 years old had later onset of ESRD (P=0.02). Time to ESRD did not differ between the patients with group 1 and group 2 mutations. CONCLUSIONS: The most common cystinosis gene mutations identified in Turkey were c.681G>A (p.Glu227Glu), c.1015G>A (p.Gly339Arg), and c.18_21 del (p.Thr7Phefs*7). Patients with less severe cystinosis gene mutations tend to have better kidney outcome.

Metabolic acidosis is common and associates with disease progression in children with chronic kidney disease.

Recent studies in adult chronic kidney disease (CKD) suggest that metabolic acidosis is associated with faster decline in estimated glomerular filtration rate (eGFR). Alkali therapies improve the course of kidney disease. Here we investigated the prevalence and determinants of abnormal serum bicarbonate values and whether metabolic acidosis may be deleterious to children with CKD. Associations between follow-up serum bicarbonate levels categorized as under 18, 18 to under 22, and 22 or more mmol/l and CKD outcomes in 704 children in the Cardiovascular Comorbidity in Children with CKD Study, a prospective cohort of pediatric patients with CKD stages 3-5, were studied. The eGFR and serum bicarbonate were measured every six months. At baseline, the median eGFR was 27 ml/min/1.73m2 and median serum bicarbonate level 21 mmol/l. During a median follow-up of 3.3 years, the prevalence of metabolic acidosis (serum bicarbonate under 22 mmol/l) was 43%, 60%, and 45% in CKD stages 3, 4, and 5, respectively. In multivariable analysis, the presence of metabolic acidosis as a time-varying covariate was significantly associated with log serum parathyroid hormone through the entire follow-up, but no association with longitudinal growth was found. A total of 211 patients reached the composite endpoint (ESRD or 50% decline in eGFR). In a multivariable Cox model, children with time-varying serum bicarbonate under 18 mmol/l had a significantly higher risk of CKD progression compared to those with a serum bicarbonate of 22 or more mmol/l (adjusted hazard ratio 2.44; 95% confidence interval 1.43-4.15). Thus, metabolic acidosis is a common complication in pediatric patients with CKD and may be a risk factor for secondary hyperparathyroidism and kidney disease progression.

Long-Term Outcome of Steroid-Resistant Nephrotic Syndrome in Children.

We investigated the value of genetic, histopathologic, and early treatment response information in prognosing long-term renal outcome in children with primary steroid-resistant nephrotic syndrome. From the PodoNet Registry, we obtained longitudinal clinical information for 1354 patients (disease onset at >3 months and <20 years of age): 612 had documented responsiveness to intensified immunosuppression (IIS), 1155 had kidney biopsy results, and 212 had an established genetic diagnosis. We assessed risk factors for ESRD using multivariate Cox regression models. Complete and partial remission of proteinuria within 12 months of disease onset occurred in 24.5% and 16.5% of children, respectively, with the highest remission rates achieved with calcineurin inhibitor-based protocols. Ten-year ESRD-free survival rates were 43%, 94%, and 72% in children with IIS resistance, complete remission, and partial remission, respectively; 27% in children with a genetic diagnosis; and 79% and 52% in children with histopathologic findings of minimal change glomerulopathy and FSGS, respectively. Five-year ESRD-free survival rate was 21% for diffuse mesangial sclerosis. IIS responsiveness, presence of a genetic diagnosis, and FSGS or diffuse mesangial sclerosis on initial biopsy as well as age, serum albumin concentration, and CKD stage at onset affected ESRD risk. Our findings suggest that responsiveness to initial IIS and detection of a hereditary podocytopathy are prognostic indicators of favorable and poor long-term outcome, respectively, in children with steroid-resistant nephrotic syndrome. Children with multidrug-resistant sporadic disease show better renal survival than those with genetic disease. Furthermore, histopathologic findings may retain prognostic relevance when a genetic diagnosis is established.