Monoclonal Gammopathy of Renal Significance with Deposits of Infrequent Morphology: Two Case Reports of Light and Heavy Chain Deposition Disease with Atypical Presentation and Literature Review.

BACKGROUND: Monoclonal immunoglobulin deposition disease (MIDD) includes three entities: light chain deposition disease (LCDD), heavy chain deposition disease (HCDD) and light and heavy chain deposition disease (LHCDD). The renal presentation can manifest with varying degrees of proteinuria and/or nephrotic syndrome, microhematuria, and often leads to end-stage renal disease. Given the rarity of LHCDD, therapeutic approaches for this condition remain inconclusive, as clinical trials are limited. CASE PRESENTATION: We report two male patients with underlying monoclonal gammopathy of renal significance (MGRS) associated with LHCDD lesions. Both cases had non-nephrotic proteinuria, moderately impaired renal function, and normal levels of C3 and C4. Light microscopy of the renal biopsies in both patients did not show lesions of nodular glomerulosclerosis. Immunofluorescence showed a staining pattern with interrupted linear IgA-κ in patient #1 and IgA-λ in patient #2 only along the glomerular basement membrane (GBM). Electron microscopy of patient #1 revealed electrodense deposits in the subendothelial and mesangial areas only along the GBM. DISCUSSION: In this case series, we discuss the clinical, analytical, and histopathological findings of two rare cases of LHCDD. Both patients exhibited IgA monoclonality and were diagnosed with monoclonal gammopathy of undetermined significance (MGUS) by the hematology department at the time of renal biopsy. Treatment with steroids and cytotoxic agents targeting the clone cells responsible for the deposition disease resulted in a favorable renal and hematologic response.

A Case Report of Tuberous Sclerosis and Autosomal Dominant Polycystic Kidney Disease in the Era of Tolvaptan.

BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) may coexist with other genetic disorders, such as tuberous sclerosis, when deletion in TSC2/PKD1 genes occurs. Recently, the effect of tolvaptan has been explored in ADPKD patients alone, but its safety and efficacy on TSC2/PKD1 contiguous gene syndrome are unknown. CASE PRESENTATION: This report describes the case of an asymptomatic patient with TSC2/PKD1 contiguous gene syndrome that fulfills the imaging criteria for initiating the treatment with tolvaptan. After twelve months, the patient did not exhibit severe adverse effects and blood pressure control improved. CONCLUSION: In this TSC2/PKD1 contiguous gene syndrome single case report, tolvaptan was safe and well-tolerated. More extensive experimental studies are needed to deeply understand the therapeutic implications of vasopressin V2-receptor inhibition in the TSC2/PKD1 contiguous gene syndrome patients.

Risk of Intradialytic Hypotension by Day of the Week in Maintenance Hemodialysis.

Intradialytic hypotension (IDH) is a common complication of hemodialysis (HD) and is associated with a higher risk of cardiovascular (CV) events and mortality. CV events are more common on the days of HD, especially following the longer interdialytic interval. We investigated the risk of IDH according to day of HD in adults undergoing in-center, thrice-weekly HD in the Hemodialysis (HEMO) Study (N = 1,837 patients; n = 64,474 sessions), and the DaVita Clinical Research biorepository [BioReG]) (N = 952 patients; n = 61,197 sessions). Random effects logistic regression models assessed the risk of IDH (defined as nadir intra-HD systolic blood pressure [SBP] <90 mm Hg if pre-HD SBP <160 mm Hg, or <100 mm Hg if pre-HD SBP ≥160 mm Hg [Nadir90/100 definition]) according to HD day (Mon/Tue [HD1]; Wed/Thu [HD2]; Fri/Sat [HD3]). Alternative definitions of IDH were explored. Nadir90/100 occurred in 14% of HEMO and 18% of BioReG sessions. A monotonic increase in the risk of IDH was observed for HD2 and HD3, compared with HD1, for all IDH definitions in both cohorts. Compared with HD1, HD2 was associated with a 10% higher risk of Nadir90/100 (adjusted odds ratio, 1.10; 95% CI, 1.03-1.17) and HD3 was associated with a 31% higher risk (adjusted odds ratio, 1.31; 95% CI, 1.19-1.45) in HEMO, with consistent results in BioReG. We observed a monotonic increased risk of IDH with later days of the dialytic week in two separate cohorts. Further research to determine the underlying mechanisms is necessary to guide strategies for IDH prevention.

Serum Magnesium, Blood Pressure, and Risk of Hypertension and Chronic Kidney Disease Progression in the CRIC Study.

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Safety and Tolerability of Tolvaptan in an Autosomal Dominant Polycystic Kidney Disease Spanish Cohort: A Real-World Experience.

INTRODUCTION: Autosomal dominant polycystic kidney disease (ADPKD) is the commonest inherited disorder of the kidneys. A vasopressin V2-receptor antagonist (tolvaptan) was recently approved for the treatment of ADPKD. This study aims to analyze the safety and tolerability of tolvaptan for the management of ADPKD patients in a real-world setting. METHODS: We conducted a descriptive retrospective study in ADPKD patients in an outpatient clinic setting in Spain from 2018 to 2019. Descriptive statistical analysis of demographics and clinical data, at baseline and one year after tolvaptan initiation, was assessed. Data are presented as median and interquartile range, and as frequencies for categorical variables. RESULTS: Ten patients with ADPKD were identified. At baseline median age was 49.5 (38.5-63.5) years and 60% were males. During treatment with tolvaptan, no significant aquaresis-related symptoms or hepatotoxicity were described. No serious adverse events, discontinuation, or deaths were reported during the study. CONCLUSION: Tolvaptan was well-tolerated without severe adverse events in patients with ADPKD who showed rapid disease progression criteria. Longer follow-up is required to learn about the long-term effects of this treatment.