Role of antiribosomal P protein antibodies in the diagnosis of lupus isolated to the central nervous system.

BACKGROUND

When lupus presents with isolated central nervous system findings, the usual serologic markers are often absent and diagnostic difficulty with a delay in treatment is common.

OBJECTIVE

To report the usefulness of antiribosomal P protein antibodies in the diagnosis of lupus isolated to the central nervous system when results of tests for anti-double-stranded DNA antibodies are negative.

DESIGN

Case report.

SETTING

University medical center.

PATIENT

The patient was evaluated and treated on referral and follow up for 1 year.

RESULTS

We describe a patient with acute onset of psychosis followed by coma and focal clonic movements with undetectable DNA antibodies. Serum antiribosomal P protein antibody levels were elevated. Steroid therapy was followed by marked clinical improvement and a decrease in antibody titer.

CONCLUSION

Antiribosomal P protein antibodies provide an important confirmatory test for the diagnosis of lupus isolated to the central nervous system when results of tests for anti-double-stranded DNA antibodies are negative.