Differential Diagnosis for Hematuria, Proteinuria, and High Autoantibody Levels

Single Most Likely Diagnosis

• Systemic Lupus Erythematosus (SLE): This diagnosis is most likely due to the combination of hematuria, proteinuria, and high levels of anti-dsDNA antibodies, which are highly specific for SLE. The presence of high anti-dsDNA antibodies is a key criterion for diagnosing SLE.

Other Likely Diagnoses

• Mixed Connective Tissue Disease (MCTD): This condition overlaps with SLE, scleroderma, and polymyositis, and the presence of high levels of anti-U1 RNP (not explicitly mentioned but often associated with MCTD), anti-SSB, and Jo-1 antibodies could suggest MCTD, although the high anti-dsDNA levels point more towards SLE.
• Sjögren's Syndrome: While primarily known for causing dry eyes and mouth, Sjögren's can also present with renal involvement (leading to hematuria and proteinuria) and positive anti-SSB antibodies. However, the high levels of anti-dsDNA and other antibodies make SLE more likely.
• Rheumatoid Arthritis (RA) with Secondary Sjögren's: The presence of anti-SSB and Jo-1 antibodies could also suggest RA with secondary Sjögren's syndrome, but the renal findings and high anti-dsDNA levels are less typical for RA.

Do Not Miss Diagnoses

• Goodpasture Syndrome: Although less likely given the autoantibody profile, Goodpasture syndrome can cause hematuria and renal failure due to anti-GBM antibodies. It's crucial to rule out this condition due to its potential for severe renal and pulmonary complications.
• ANCA-Associated Vasculitis: Conditions like granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), and eosinophilic granulomatosis with polyangiitis (EGPA) can present with renal involvement and various autoantibodies. While the specific antibodies mentioned do not directly point to ANCA-associated vasculitis, the renal symptoms warrant consideration.

Rare Diagnoses

• Scleroderma (Systemic Sclerosis): While scleroderma can involve the kidneys (scleroderma renal crisis) and present with various autoantibodies, the combination of high anti-dsDNA, anti-SSB, Jo-1, and SM antibodies is less typical. Scleroderma is more commonly associated with anti-Scl-70 or anti-centromere antibodies.
• Overlap Syndrome with Polymyositis/Dermatomyositis: The presence of Jo-1 antibodies suggests myositis, but the combination with high anti-dsDNA and other antibodies makes this a less likely primary diagnosis. However, overlap syndromes can occur, presenting with features of multiple autoimmune diseases.