What Is Endocapillary Proliferative Glomerulonephritis?

Endocapillary proliferative glomerulonephritis (EPGN) is a specific form of kidney inflammation that primarily affects the glomeruli—the tiny filtering units within the kidneys. Often referred to in clinical settings as acute glomerulonephritis, this condition is characterized by an abnormal proliferation of cells inside the capillary walls of the glomeruli, leading to impaired kidney function and noticeable changes in urine composition.

Understanding the Causes Behind EPGN

This type of kidney disease most commonly develops following an infection with group A beta-hemolytic streptococcus, typically occurring one to three weeks after a throat or skin infection such as strep throat or impetigo. The immune system's response to the infection triggers an inflammatory cascade that mistakenly targets the glomerular structures, resulting in endocapillary hypercellularity—where endothelial and mesangial cells multiply excessively within the capillary loops.

Pathological Features and Diagnosis

Under microscopic examination, kidney biopsies from patients with EPGN show a hallmark pattern: increased cellularity confined within the glomerular capillaries. This distinguishes it from other forms of glomerulonephritis that may involve crescent formation or membranous changes. Immunofluorescence often reveals deposits of immunoglobulin G (IgG) and complement component C3 along the glomerular basement membrane, supporting the diagnosis of post-infectious origin.

Clinical Presentation and Symptoms

Patients typically present with visible signs of kidney dysfunction, including hematuria (blood in the urine), proteinuria (excess protein in the urine), swelling (especially around the face and legs), and elevated blood pressure. Some may also experience reduced urine output and general malaise. In children, the condition often follows a mild respiratory infection and can be mistaken for a simple viral illness at first.

Prognosis and Recovery Outlook

The prognosis for endocapillary proliferative glomerulonephritis is generally excellent, particularly in younger patients and those with post-streptococcal etiology. Most individuals experience full recovery within 6 to 8 weeks, with normalization of urinalysis findings—protein and red blood cells typically disappear from the urine during this period. Blood pressure usually stabilizes without long-term medication.

Treatment Approaches and Management

There is no specific cure targeting the underlying pathology; instead, management focuses on supportive and symptomatic care. This includes controlling hypertension with antihypertensive medications such as ACE inhibitors, managing fluid retention through dietary sodium restriction, and monitoring kidney function regularly. Antibiotics may be prescribed if there is evidence of ongoing streptococcal infection, although they do not alter the course of established nephritis.

In rare cases where symptoms persist beyond several months or kidney function declines significantly, further evaluation is necessary to rule out more severe or chronic forms of glomerular disease. However, the vast majority of EPGN cases resolve spontaneously without complications.

Early recognition, proper monitoring, and conservative treatment remain key to ensuring favorable outcomes. With timely medical attention and adherence to follow-up protocols, patients can expect a complete return to normal kidney health.