What Is Henoch-Schönlein Purpura Nephritis?

Henoch-Schönlein purpura nephritis (HSPN) is a serious complication of Henoch-Schönlein purpura (HSP), an immune-mediated systemic vasculitis that primarily affects small blood vessels. It stands as one of the most common forms of secondary glomerulonephritis in children, though it can also occur in adults. Over recent years, the incidence of HSP has risen significantly, drawing increased attention from pediatric and nephrology specialists worldwide.

Understanding the Link Between HSP and Kidney Involvement

HSP itself is characterized by inflammation of the blood vessels, typically triggered by an abnormal immune response often following an upper respiratory infection. While skin rash, joint pain, and abdominal discomfort are hallmark symptoms, renal involvement marks a more severe disease course. When the kidneys are affected, the condition progresses to HSP nephritis, which can lead to long-term complications if not properly managed.

Recognizing the Signs of Kidney Damage

One of the primary indicators of kidney involvement is hematuria—blood in the urine. This can range from microscopic hematuria, detectable only through laboratory testing, to gross hematuria, where the urine appears visibly reddish or tea-colored. Alongside hematuria, patients may develop proteinuria, where excessive protein leaks into the urine due to damaged glomeruli.

Potential Progression to Serious Kidney Conditions

In more severe cases, HSPN can evolve into nephrotic syndrome, marked by heavy proteinuria, low blood albumin levels, swelling (edema), and high cholesterol. If left untreated or poorly controlled, chronic kidney damage may ensue, potentially leading to impaired renal function or even end-stage renal disease (ESRD) in rare instances. Early diagnosis and intervention are crucial to preserving kidney health and preventing irreversible damage.

Diagnosis and Clinical Evaluation

Diagnosing HSP nephritis involves a combination of clinical assessment, urinalysis, blood tests, and sometimes a kidney biopsy to determine the extent of glomerular injury. Physicians evaluate factors such as the level of proteinuria, presence of cellular casts in urine, and histological findings under microscopy to classify disease severity and guide treatment decisions.

Management and Long-Term Outlook

Treatment strategies vary based on the severity of renal involvement. Mild cases may require only supportive care and regular monitoring, while moderate to severe forms often necessitate immunosuppressive therapy, including corticosteroids or other agents like angiotensin-converting enzyme (ACE) inhibitors to control blood pressure and reduce protein loss. With timely medical care, many children recover fully, although ongoing follow-up is recommended to monitor for late-onset complications.

Henoch-Schönlein purpura nephritis is a significant renal complication of a common childhood vasculitis. Awareness of its symptoms, early detection, and appropriate management are essential in minimizing long-term kidney risks and ensuring better patient outcomes.