[Essential cryoglobulinemia with glomerulonephritis as a variant of the purpura-arthralgia-nephritis syndrome].

The syndrome of mixed cryoglobulinemia is clinically characterized by the findings of purpura, arthralgia and glomerulonephritis, the latter developing in up to 50% of the cases. The cryoglobulins have rheumatoid factor activity and serum levels of complement factor C4 are significantly reduced. A report is presented on seven patients with a typical purpura-arthralgia-nephritis syndrome and two patients with essential cryoglobulinemia, rheumatoid factor activity and glomerulonephritis without extrarenal manifestations of vasculitis. Based on these observations, measurement of rheumatoid factor activity is recommended in serum of patients with unclassified glomerulonephritis.