Henoch-Schönlein Purpura Nephritis: Understanding the 7 Clinical Types and Managing Kidney Involvement
Henoch-Schönlein Purpura (HSP) nephritis, also known as IgA vasculitis with renal involvement, is a systemic disorder characterized by necrotizing small-vessel vasculitis. This immune-mediated condition primarily affects blood vessels throughout the body and can lead to multi-organ complications, with the kidneys being one of the most commonly impacted. When kidney damage occurs, it manifests as HSP nephritis, which typically develops within four weeks after the onset of skin purpura, although in some cases symptoms may appear simultaneously.
Common Clinical Features of HSP Nephritis
The disease often presents with a classic tetrad of symptoms: palpable purpura on the skin—usually on the lower extremities—joint pain (arthralgia), gastrointestinal disturbances such as abdominal pain and rectal bleeding, and renal abnormalities. The hallmark signs of kidney involvement include hematuria (blood in urine) and elevated proteinuria (excess protein in urine). Some patients may be asymptomatic aside from abnormal urinalysis results, while others experience more severe systemic manifestations.
Seven Clinical Subtypes of HSP Nephritis
Based on the severity and pattern of kidney injury, HSP nephritis is classified into seven distinct clinical subtypes. Accurate classification helps guide treatment decisions and predict long-term outcomes.
1. Isolated Hematuria
In this mild form, patients show microscopic or gross hematuria without significant protein excretion. Urinalysis reveals red blood cells, but daily protein loss remains below abnormal thresholds. These individuals usually have an excellent prognosis with minimal risk of progressive kidney disease.
2. Isolated Proteinuria
This subtype is defined by persistent proteinuria in the absence of visible blood in the urine. Typically, urinary protein excretion is less than 50 mg/kg per day (or below nephrotic range). While generally considered low-risk, ongoing monitoring is essential to detect any progression to more serious forms.
3. Hematuria with Mild Proteinuria
Patients exhibit both red blood cells and increased protein in their urine, though protein levels remain sub-nephrotic. This intermediate form suggests early glomerular inflammation and requires regular follow-up to assess for worsening renal function.
4. Nephrotic Syndrome Type
This more severe presentation involves heavy proteinuria (>50 mg/kg/day), hypoalbuminemia (low blood albumin), hyperlipidemia, and often generalized edema. It indicates significant glomerular damage and may require immunosuppressive therapy to prevent long-term complications.
5. Acute Nephritic Syndrome Type
Characterized by active urine sediment (hematuria, red cell casts), hypertension, reduced kidney function (elevated creatinine), and sometimes oliguria (reduced urine output). This form mimics post-infectious glomerulonephritis and may necessitate aggressive management including corticosteroids or other immunomodulatory agents.
6. Rapidly Progressive Glomerulonephritis (RPGN) Type
A rare but life-threatening variant marked by a swift decline in kidney function, rising serum creatinine and urea nitrogen, presence of crescents on biopsy, and severe urinary abnormalities. Patients often have high blood pressure, low complement levels, and systemic inflammation. Prompt intervention with pulse steroids, cyclophosphamide, or plasma exchange may be required to preserve renal function.
7. Chronic Nephritic Syndrome Type
This long-standing form features persistent hematuria, proteinuria, and gradual deterioration of kidney function over months to years. It may eventually progress to chronic kidney disease (CKD) or end-stage renal disease (ESRD), requiring long-term management strategies including blood pressure control, ACE inhibitors/ARBs, and lifestyle modifications.
Prognosis and Management Strategies
Early diagnosis and consistent medical supervision are crucial regardless of the subtype. Most children with mild HSP nephritis recover fully without lasting effects. However, those with moderate to severe forms—especially nephrotic or nephritic syndromes—require close monitoring and individualized treatment plans.
Treatment options vary widely depending on disease severity. Mild cases may only need observation and supportive care, while severe forms often involve corticosteroids, immunosuppressants like mycophenolate mofetil or azathioprine, and angiotensin-converting enzyme (ACE) inhibitors to reduce proteinuria and protect kidney function.
Regular check-ups at accredited medical facilities, routine urinalysis, blood pressure monitoring, and kidney function tests are strongly recommended. With proper care, many patients achieve remission and maintain good quality of life. Awareness, timely intervention, and adherence to medical advice significantly improve long-term renal outcomes.