The Nephrotic Syndrome Study Network (NEPTUNE) is a North American multi-center collaborative consortium established to develop a translational research infrastructure for Nephrotic Syndrome. This includes a longitudinal observational cohort study, a pilot and ancillary studies program, a training program, and a patient contact registry. NEPTUNE will enroll 450 adults and children with minimal change disease, focal segmental glomerulosclerosis and membranous nephropathy for detailed clinical, histopathologic, and molecular phenotyping at the time of clinically-indicated renal biopsy. Initial visits will include an extensive clinical history, physical examination, collection of urine, blood and renal tissue samples, and assessments of quality of life and patient-reported outcomes. Follow-up history, physical measures, urine and blood samples, and questionnaires will be obtained every 4 months in the first year and bi-annually, thereafter. Molecular profiles and gene expression data will be linked to phenotypic, genetic, and digitalized histologic data for comprehensive analyses using systems biology approaches. Analytical strategies were designed to transform descriptive information to mechanistic disease classification for Nephrotic Syndrome and to identify clinical, histological, and genomic disease predictors. Thus, understanding the complexity of the disease pathogenesis will guide further investigation for targeted therapeutic strategies.

Expression quantitative trait loci (eQTL) studies illuminate the genetics of gene expression and, in disease research, can be particularly illuminating when using the tissues directly impacted by the condition. In nephrology, there is a paucity of eQTL studies of human kidney. Here, we used whole-genome sequencing (WGS) and microdissected glomerular (GLOM) and tubulointerstitial (TI) transcriptomes from 187 individuals with nephrotic syndrome (NS) to describe the eQTL landscape in these functionally distinct kidney structures. Using MatrixEQTL, we performed cis-eQTL analysis on GLOM (n = 136) and TI (n = 166). We used the Bayesian "Deterministic Approximation of Posteriors" (DAP) to fine-map these signals, eQTLBMA to discover GLOM- or TI-specific eQTLs, and single-cell RNA-seq data of control kidney tissue to identify the cell type specificity of significant eQTLs. We integrated eQTL data with an IgA Nephropathy (IgAN) GWAS to perform a transcriptome-wide association study (TWAS). We discovered 894 GLOM eQTLs and 1,767 TI eQTLs at FDR < 0.05. 14% and 19% of GLOM and TI eQTLs, respectively, had >1 independent signal associated with its expression. 12% and 26% of eQTLs were GLOM specific and TI specific, respectively. GLOM eQTLs were most significantly enriched in podocyte transcripts and TI eQTLs in proximal tubules. The IgAN TWAS identified significant GLOM and TI genes, primarily at the HLA region. In this study, we discovered GLOM and TI eQTLs, identified those that were tissue specific, deconvoluted them into cell-specific signals, and used them to characterize known GWAS alleles. These data are available for browsing and download via our eQTL browser, "nephQTL."

Non-adherence to medical regimens is a ubiquitous hindrance to quality health care among adolescent transplant recipients. Identification of potentially modifiable barriers to adherence when patients are listed for organ transplant would help with early intervention efforts to prepare adolescents for the stringent medication regimen post-transplant. Fifty-six adolescents listed for a kidney transplant, mean age 14.27 (s.d. = 2.2; range 11-18 yr), 73.2% male, 62.5% Caucasian participated in a semi-structured interview, the Medical Adherence Measure, to assesses the patient's knowledge of the prescribed regimen, reported adherence (missed and late doses), the system used to organized medications, and who holds the primary responsibility over medication management. Better knowledge of the medication regimen was associated with fewer missed doses (r = -0.48, p < 0.001). Patients who perceived more barriers had more missed (r = 0.38, p = 0.004) and late (r = 0.47, p < 0.001) doses. Patients who endorsed "just forget," the most common barrier (56.4%), reported significantly more missed (z = -4.25, p < 0.001) and late (z = -2.2, p = 0.02) doses. Only one-third of the transplant candidates used a pillbox to organize medications but these patients had significantly better adherence, z = -2.2, p = 0.03. With regard to responsibility over managing the regimens, adolescents missed fewer doses when their parents were in charge than when they were solely responsible, z = -2.1, p = 0.04. Interventions developed to prepare transplant candidates for a stringent post-transplant regimen need to focus on ensuring accurate knowledge of as simple a regimen as possible. Use of an organized system such as a pillbox to establish a routine and facilitate tracking of medications is recommended with integration of reminders that may be appealing for this age group. Although individuation is developmentally normative at this age, parent involvement seems critical until the adolescent is able to manage the responsibility more independently.