Lupus glomerulonephritis with thrombotic microangiopathy

Area of Science:

• Nephrology
• Rheumatology
• Pathology

Background:

• Systemic lupus erythematosus (SLE) is an autoimmune disease with diverse clinical manifestations.
• Thrombotic microangiopathy (TMA) is a rare but serious complication characterized by microangiopathic hemolytic anemia, thrombocytopenia, and organ damage.
• Co-occurrence of SLE and TMA is infrequently documented, posing diagnostic and therapeutic challenges.

Observation:

• A 25-year-old female patient with SLE presented with acute renal failure.
• Renal biopsy showed proliferative lupus glomerulonephritis.
• Distinct arteriolar thrombosis and arterial intimal changes consistent with TMA were observed.

Findings:

• Direct immunofluorescence of vessels was negative for immunoglobulins and complement.
• Electron microscopy revealed fibrillar and flocculent deposits in the subendothelial space of a small artery and glomeruli.
• These ultrastructural findings in the vascular lesions were characteristic of TMA and differentiated them from immune complex vasculopathy typical of SLE.

Implications:

• This case highlights the importance of considering TMA in SLE patients with renal failure, even with overlapping features.
• The distinct vascular pathology suggests potential alternative mechanisms driving TMA in this context.
• Further research into the pathogenesis of TMA in SLE may lead to improved diagnostic criteria and targeted therapies.