[Renal damage during type II cryoglobulinemia]

Abstract

THE CONTEXT: Type II cryoglobulinemia, composed of a monoclonal IgM rheumatoid factor directed against polyclonal IgG, is associated in most cases with chronic hepatitis C viral infection. THE CHARACTERISTICS OF RENAL DAMAGE: Frequent, the renal damage usually occurs after the onset of various systemic manifestations and is expressed by moderate renal failure, microscopic haematuria, proteinuria lower than 3 g/d and hypertension difficult to control. More severe aspects are possible such as acute nephrotic or nephritic syndromes, or even multi-organ failure with anuria. A renal biopsy confirms the diagnosis by revealing a membranoproliferative glomerulonephritis, characterized by the intensity of the monocyte infiltration and glomerular deposits, often arranged in curved microtubules under electronic microscopy and often associated with vasculitis lesions. Progression towards terminal renal failure is rare.

Therapeutic modalities: Treatment, unclearly defined, relies on anti-virals (interferon a and ribavirin), which are partially effective when the viral replication is inhibited, associated with corticosteroids and immunosuppressors or even plasma exchange in the severe forms. The management and treatment of the cardiovascular complications condition the vital prognosis.