Alpha-enolase is a renal-specific antigen associated with kidney involvement in mixed cryoglobulinemia.

OBJECTIVE

To study the specificity of antibodies reactive with renal antigens in mixed cryoglobulinemia.

METHODS

Sera from mixed cryoglobulinemia (MC) patients were tested on human kidney extracts by immunoblot. A partially purified renal antigen was subjected to N-terminal sequencing.

RESULTS

Antibodies reactive with a renal antigen of 48 kD were detected in 7 out of 11 patients with MC and renal involvement. N-terminal sequencing of this antigen showed that it was identical with alpha-enolase. This result was confirmed by the reactivity of the renal antigen with a rabbit anti-serum specific for alpha-enolase.

CONCLUSIONS

The results indicate that antibodies specific for alpha-enolase are frequently produced by mixed cryoglobulinemia patients with renal involvement.