Glomerulonephritis

Glomerulonephritis (GN) is inflammation of the glomeruli — the tiny filtering units in the kidneys. When glomeruli are inflamed or damaged, the kidneys can't filter blood properly. Waste products build up, and red blood cells and protein leak into the urine. GN can be short-term (acute) or long-standing (chronic), and can range from mild to severe.

Types

Glomerulonephritis covers many distinct conditions. Some common ones:

• Post-streptococcal GN — follows a streptococcal throat or skin infection, more common in children. Still relatively common in India.
• IgA nephropathy — the most common primary GN worldwide; causes episodes of blood in urine, often after infections
• Minimal change disease — mainly in children; causes nephrotic syndrome
• Focal segmental glomerulosclerosis (FSGS)
• Membranous nephropathy
• Rapidly progressive (crescentic) GN — an emergency; can destroy kidney function in weeks
• GN as part of systemic disease — lupus nephritis, ANCA-associated vasculitis, diabetic nephropathy, HIV-related, hepatitis-associated

Symptoms

• Blood in the urine — may make urine look cola-coloured or tea-coloured
• Foamy urine (from excess protein)
• Swelling of face, hands, feet, or abdomen
• High blood pressure
• Reduced urine output
• Tiredness, weakness, nausea
• Sometimes no symptoms, with abnormal tests found on routine check-up

Diagnosis

• Urine tests — looking for blood, protein, and casts under the microscope
• Blood tests — kidney function, electrolytes, immunological markers (ANA, anti-dsDNA, ANCA, complement levels, hepatitis, HIV)
• Blood pressure measurement
• Ultrasound of the kidneys
• Kidney biopsy — often essential to identify the specific type and guide treatment

Treatment

Treatment depends on the type and cause:

• Controlling blood pressure — usually with ACE inhibitors or ARBs, which also reduce protein leak
• Reducing protein in urine — same medicines
• Immunosuppression — steroids, and sometimes other immunosuppressant medicines, for autoimmune or aggressive types
• Treating infections — antibiotics for post-infectious GN
• Managing fluid overload — diuretics, salt restriction
• Treating underlying conditions — lupus, vasculitis, diabetes, hepatitis
• Dialysis or kidney transplant — for end-stage disease