Monoclonal gammopathy of renal significance: An atypical presentation of Waldenström's disease.

Waldenström's disease is a rare lymphoproliferative syndrome in the bone marrow and sometimes in lymphoid organs which secretes high amounts of monoclonal immunoglobulin M into serum. It can remain indolent for years and rarely affects the kidney, with intraglomerular rather than intratubular damage being predominant, in contrast to multiple myeloma. Different studies identified AL amyloidosis as the most frequent renal lesion, followed by cryoglobulinemic glomerulonephritis. Signs and symptoms may be unspecific, as well as renal manifestations, so collaboration between nephrologists, hematologists, and pathologists is crucial to establish the role of paraprotein in the development of renal damage. We present an atypical case of Waldenström's disease that had a minimal monoclonal peak and clinically debuted with nephritic and nephrotic syndromes. The diagnosis was cryoglobulinemic glomerulonephritis. Currently, there are numerous treatment options, without enough evidence yet to establish a standardised treatment.

Correlation of X chromosome inactivation with clinical presentation of Fabry disease in a case report.

Fabry disease or also called Anderson-Fabry disease (FD) is a rare disease caused by pathogenic variants in the GLA gene, located on the X chromosome. This gene is involved in the metabolism of glycosphingolipids and its pathogenic variants cause a deficit or absence of α-galactosidase A causing the deposition of globotriaosylceramide throughout the body. Females have a variable phenotypic expression and a better prognosis than males. This is due to the X chromosome inactivation phenomenon. We present a clinical case of Fabry disease in a female with predominantly renal involvement and demonstrate how the X chromosome inactivation phenomenon is tissue dependent, showing preferential inactivation of the mutated allele at the renal level.

IgA Nephropathy Is the Most Common Underlying Disease in Patients With Anticoagulant-Related Nephropathy.

Introduction: Anticoagulant-related nephropathy (ARN) is a relatively novel recognized entity characterized by hematuria-associated acute kidney injury (AKI) in the context of overanticoagulation. Preexisting or underlying kidney disease seems to be a predisposing factor; however, few studies have described histologic findings in patients with ARN. We aimed to evaluate underlying kidney pathology in patients on oral anticoagulation who presented an episode of AKI with hematuria in whom a kidney biopsy was performed. Methods: Retrospective observational multicenter case study in patients treated with oral anticoagulants who developed macroscopic or intense hematuria followed by AKI. Only patients with available kidney biopsy specimens were included. Histologic findings and clinical data throughout follow-up were analyzed. Results: A total of 26 patients were included with a median age of 75 years (62-80) and a follow-up period of 10.1 months. Of the patients, 80% were male, and most cases (92%) were on anticoagulation with vitamin K antagonists (VKAs). At admission, median serum creatinine (SCr) level was 4.2 mg/dl (2.8-8.2), median international normalized ratio (INR) 2.4 (1.5-3.4), and 11 patients (42%) required acute dialysis during hospitalization. Kidney biopsy results revealed that all patients except 1 had an underlying nephropathy: IgA nephropathy (IgAN) in 19, probable IgAN in 1, diabetic nephropathy in 3, nephrosclerosis in 1, and idiopathic nodular glomerulosclerosis in 1. At 12 weeks after discharge, only 6 subjects (24%) attained complete kidney recovery whereas 7 (28%) remained on chronic dialysis. Conclusion: IgAN was the most common underlying kidney disease in our biopsy-proven series of ARN, in which a significant percentage of patients did not achieve kidney function recovery.