Glomerulopathies

Glomerulopathies are a diverse group of diseases that primarily affect the glomeruli, the microscopic filters of the kidneys. They can be primary, confined to the kidneys, or secondary to systemic conditions such as autoimmune diseases, infections, or diabetes. Clinically they often present with proteinuria, hematuria, edema, hypertension, and varying degrees of reduced kidney function.

Classification commonly distinguishes nephritic syndromes, nephrotic syndromes, and mixed or asymptomatic presentations. Primary glomerulopathies include minimal change disease, focal segmental glomerulosclerosis, membranous nephropathy, IgA nephropathy, post-infectious glomerulonephritis, and anti-GBM disease. Secondary forms include lupus nephritis, diabetic nephropathy, and ANCA-associated vasculitis. Across these categories, the underlying mechanisms frequently involve immune-mediated injury, immune complex deposition, complement activation, and podocyte or mesangial cell damage, leading to inflammation and scarring.

Diagnosis relies on clinical assessment and laboratory testing: urinalysis for protein and blood, quantitative proteinuria by urine protein-to-creatinine ratio, serum creatinine and eGFR, albumin levels, lipid profile, and often serologies and complement levels. Kidney biopsy with light microscopy, immunofluorescence, and electron microscopy provides definitive classification and guides treatment.

Management aims to reduce kidney damage, control symptoms, and treat the underlying cause. Key strategies include blood pressure control with renin–angiotensin system blockers, management of edema and hyperlipidemia, and disease-specific therapies such as immunosuppression for immune-mediated glomerulopathies. Therapies range from corticosteroids to targeted agents, depending on the diagnosis. Prognosis varies widely, from spontaneous resolution to progression to chronic kidney disease or end-stage renal disease.