Hyperviscosity syndrome in rheumatoid arthritis

Area of Science:

• Rheumatology
• Hematology
• Internal Medicine

Background:

• Rheumatoid hyperviscosity syndrome is a rare complication of rheumatoid arthritis.
• It is characterized by increased blood viscosity due to immune complex deposition.

Observation:

• The patient presented with somnolence, circulatory overload, bleeding diathesis, and dilated retinal veins.
• Laboratory findings included marked hypergammaglobulinemia, elevated IgM and IgG, and high rheumatoid factor titers.
• Unusual findings were spurious hyponatremia and a negative anion gap.

Findings:

• High molecular weight IgG-IgM immune complexes in serum were identified as the cause of hyperviscosity.
• Plasmapheresis rapidly resolved acute hyperviscosity symptoms, including normalization of serum sodium and anion gap.
• Elevated gamma globulin concentrations decreased following plasmapheresis.

Implications:

• This case highlights the clinical manifestations and laboratory features of rheumatoid hyperviscosity syndrome.
• Effective management involves plasmapheresis for acute symptoms and corticosteroids for long-term control.
• Understanding immune complex dynamics is crucial for managing this rare condition.