Infection-Related Glomerulonephritis Revealed as Shunt Nephritis: A Case Report.

Introduction: Shunt nephritis is a rare immune complex-mediated glomerulonephritis associated with an infected ventriculoatrial shunt (VAS) or ventriculoperitoneal shunt (VPS). Its incidence has declined to 0.7-2% due to improved infection management. Low-grade bacteremia, particularly from VAS, often involves pathogens such as Cutibacterium acnes, Staphylococcus epidermidis, and Streptococcus species. Immune complex deposition in the kidneys leads to glomerulonephritis and nephrotic syndrome. Early diagnosis and shunt removal, alongside antibiotics, are crucial for renal recovery. Case Presentation: A 35-year-old male with a history of traumatic brain injury and VAS placement presented with generalized edema, hypertension, fatigue, and neurological decline. The patient exhibited nephrotic syndrome with low complement levels. Renal biopsy revealed diffuse membranoproliferative glomerulonephritis with subendothelial deposits. Cerebrospinal fluid (CSF) analysis showed pleocytosis and an elevated albumin ratio, with C. acnes confirmed via blood and CSF cultures. Targeted antibiotic therapy, with first externalization and then removal of the VAS, was followed by a VPS re-implantation after infection resolution. The complement levels normalized, albuminuria decreased, and renal function stabilized. Discussion: This case highlights the diagnostic challenges associated with shunt nephritis, particularly in the absence of overt infection. Early recognition, targeted antibiotics, and shunt removal are essential for preventing progressive kidney damage and resolving nephrotic syndrome. This case highlights the need for multidisciplinary management in such a complex presentation.