Surgical intervention and long-term renal outcomes of congenital ureteropelvic junction obstruction in a young adult cohort.

PURPOSE: To evaluate the impact of surgical intervention on long-term renal outcomes for adult patients with congenital ureteropelvic junction obstruction (UPJO). METHODS: We queried service members diagnosed with UPJO from the United States Military Health System electronic health records from 2005 to 2020. We assessed demographic, laboratory, radiology, surgical intervention, and outcome data. We evaluated the impact of surgical intervention on renal function based on the estimated glomerular filtration rate (eGFR), hypertension (HTN, defined as any prescription for blood pressure [BP] medication and/or average of two BP readings ≥ 130/80 mmHg more than 2 weeks apart), and changes in renal excretory function on radionuclide scans. RESULTS: We identified 108 individuals diagnosed with congenital UPJO; mean follow-up of 7 years. Mean age at diagnosis was 25 years; 95% male; 69% White, 15% Black. At diagnosis, median BP was 130/78 mmHg and mean eGFR 93 ml/min/1.73m2. Subsequently, 85% had pyeloplasty and 23% had stent placement. There were no significant differences in mean eGFR pre- and post-intervention (94 vs. 93 ml/min/1.73m2, respectively; p = 0.15) and prevalence of defined HTN (59% vs. 61%, respectively; p = 0.20). Surgical intervention for right-sided UPJO significantly reduced the proportion of patients with delayed cortical excretion (54% pre vs. 35% post, p = 0.01) and T½ emptying time (35 min vs. 19 min, p = 0.009). Similar trends occurred with left-sided UPJO but were not significant. CONCLUSION: Surgical intervention was not associated with significant differences in the long-term outcomes of kidney function and HTN prevalence in our young adult cohort. However, renal excretory function improved on radionuclide scans.

Urine Single-Cell RNA Sequencing in Focal Segmental Glomerulosclerosis Reveals Inflammatory Signatures.

INTRODUCTION: Individuals with focal segmental glomerular sclerosis (FSGS) typically undergo kidney biopsy only once, which limits the ability to characterize kidney cell gene expression over time. METHODS: We used single-cell RNA sequencing (scRNA-seq) to explore disease-related molecular signatures in urine cells from subjects with FSGS. We collected 17 urine samples from 12 FSGS subjects and captured these as 23 urine cell samples. The inflammatory signatures from renal epithelial and immune cells were evaluated in bulk gene expression data sets of FSGS and minimal change disease (MCD) (The Nephrotic Syndrome Study Network [NEPTUNE] study) and an immune single-cell data set from lupus nephritis (Accelerating Medicines Partnership). RESULTS: We identified immune cells, predominantly monocytes, and renal epithelial cells in the urine. Further analysis revealed 2 monocyte subtypes consistent with M1 and M2 monocytes. Shed podocytes in the urine had high expression of marker genes for epithelial-to-mesenchymal transition (EMT). We selected the 16 most highly expressed genes from urine immune cells and 10 most highly expressed EMT genes from urine podocytes as immune signatures and EMT signatures, respectively. Using kidney biopsy transcriptomic data from NEPTUNE, we found that urine cell immune signature and EMT signature genes were more highly expressed in FSGS biopsies compared with MCD biopsies. CONCLUSION: The identification of monocyte subsets and podocyte expression signatures in the urine samples of subjects with FSGS suggests that urine cell profiling might serve as a diagnostic and prognostic tool in nephrotic syndrome. Furthermore, this approach may aid in the development of novel biomarkers and identifying personalized therapies targeting particular molecular pathways in immune cells and podocytes.

Primary renal magnesium wasting: an unusual clinical picture of exercise-induced symptoms.

Magnesium is one of the most abundant cations in the human body and plays a key role as a metabolic enzyme cofactor and regulatory ion for neurons and cardiomyocytes. Hypomagnesemia due to isolated primary renal magnesium wasting is a rare clinical condition typically associated with neurological hyperexcitability. Exercise-related gastrointestinal symptoms are caused by ischemic, mechanical, or neurohormonal changes. The role of hypomagnesemia in gastrointestinal symptoms is not well understood. We present a case of a 15-year-old male who presented with exercise-induced abdominal pain, nausea, and vomiting, who was found to have profound hypomagnesemia and inappropriately elevated fractional excretion of magnesium (FEMg). Testing for multiple intrinsic and extrinsic etiologies of renal magnesium wasting was inconclusive. He was diagnosed with primary renal magnesium wasting and his symptoms resolved acutely with intravenous magnesium sulfate and with long-term oral magnesium chloride. Primary renal magnesium wasting is a rare clinical entity that can cause extreme hypomagnesemia. It has not been associated previously with exercise-induced gastrointestinal symptoms. The effects of hypomagnesemia on the human gastrointestinal tract are not well established. This case offers unique insights into the importance of magnesium homeostasis in the gastrointestinal tract. Exercise-induced splanchnic hypoperfusion may contribute to gastrointestinal symptoms observed in this chronically hypomagnesemic patient.

Incidence, predictors and associated outcomes of renal cell carcinoma in long-term dialysis patients.

We carried out an analysis of the United States Renal Data System to determine the incidence, risk factors and prognosis of renal cell carcinoma (RCC) in a national population of patients receiving incident long-term dialysis. In Cox regression, male gender, older age, end-stage renal disease caused by obstruction, tuberous sclerosis, focal segmental glomerulosclerosis, as well as acquired renal cysts, were independently associated with RCC. Most cases of RCC in incident long-term dialysis patients occurred in patients without acquired renal cysts. A diagnosis of RCC was associated with increased risk of subsequent mortality overall and in all high-risk groups.

Failure of fenoldopam to control severe hypertension secondary to renal graft rejection in a pediatric patient.

We report the first case of the failure of fenoldopam for a pediatric patient with severe hypertension and renal failure. Our patient was a 3-year-old child with severe hypertension secondary to renal graft rejection and high-dose steroid treatment. The patient's hypertension was controlled with nitroprusside but not with fenoldopam.

The risk of cardiovascular disease in adults who have had childhood nephrotic syndrome.

While increased risk of cardiovascular disease (CVD) in patients with hyperlipidemia, chronic kidney disease (CKD), or end-stage renal disease (ESRD) is well documented, transient hyperlipidemia or intermittent renal disease as a consequence of relapsing nephrotic syndrome (NS) has not been studied. To investigate this enigma, 62 patients, between 25 and 53 years of age, who had steroid-responsive/dependent NS during childhood, were identified from the records of the Division of Pediatric Nephrology at Yale School of Medicine. Forty patients were located and contacted to ascertain symptoms or occurrences of CVD via a telephone interview. At the time of follow-up, 23-46 years after cessation of NS, none of these patients had ESRD or CKD. Three patients had experienced a myocardial infarction (MI): a 32-year-old male with a family history of CVD; a 41-year-old male with a history of heavy smoking, hypertension, diabetes mellitus, and elevated cholesterol; a 31-year-old male after a cocaine overdose. The occurrence of events (8%) and mortality from CVD (none) in this cohort of patients is comparable to patients of a similar age in the general population and is lower than that of patients of the same age who are on dialysis. The data suggest that relapsing NS during childhood does not place patients at increased risk for CVD mortality or morbidity compared with the general population. Consequently, it would appear that factors related to persistent proteinuria or renal insufficiency, rather than transient proteinuria and renal disease, contribute to the CVD documented in patients with CKD or ESRD.

The prevalence of asymptomatic Chlamydia trachomatis in military dependent adolescents.

Chlamydia trachomatis infection is common among sexually active populations and often asymptomatic. Infection is associated with complications, including pelvic inflammatory disease and infertility. Using a noninvasive urine ligase chain reaction assay, we determined the prevalence of asymptomatic C. trachomatis infection among sexually active military dependent adolescents and young adults attending clinics at military facilities in San Antonio. The overall prevalence rate was 14%, higher than that reported in many high-risk settings, including sexually transmitted disease clinics. Gender-specific rates were 15% for females and 11% for males. Given a clear cost benefit to screening and treating at-risk populations, we conclude that screening of all sexually active military dependents, both male and female, using this noninvasive test should be performed routinely.